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A new, faster, and safe nasal provocation test method for diagnosing mite allergic rhinitis
Ann Allergy Asthma Immunol xxx (2015) 1e6
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A new, faster, and safe nasal provocation test method for diagnosing mite allergic rhinitis Frédéric de Blay, MD *; Virginie Doyen, MD y; Céline Lutz, MD *; Julien Godet, MD z; Cindy Barnig, MD, PhD *; Shanshan Qi, MD *; and Jean-Jacques Braun, MD * * Chest
Diseases Department, Strasbourg University Hospital; Federation of Translational Medicine, University of Strasbourg, Strasbourg, France Immuno-Allergology Clinic, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium z Statistics Department, Strasbourg University Hospital, Strasbourg, France y
A R T I C L E
I N F O
Article history: Received for publication April 30, 2015. Received in revised form July 20, 2015. Accepted for publication July 22, 2015.
A B S T R A C T
Background: Diagnosing house dust mite (HDM) allergic rhinitis is difficult. The nasal provocation test (NPT) has been shown to be the most pertinent, but several methods are available. According to guidelines, the NPT requires a skin end-point titration and an objective measurement of nasal patency. Hence, NPT is time consuming and its use is limited. Objective: To evaluate the sensitivity, specificity, and safety of a new, more rapid, and simple alternative NPT (NPT-R) to HDM. Methods: Eighty-eight patients with from rhinitis (49 allergic to HDM and 39 controls with and without atopy) were included. Allergic rhinitis to HDM was confirmed by a “classic” NPT based on the Lebel score and rhinomanometry. After a period of 4 weeks, NPT-R was performed and only the clinical score was measured. Results: The study population was young (mean SD, 27.7 8.5 years old), composed mostly of women (61 vs 27 men), and 24% reported asthma. The sensitivity and specificity of NPT-R were 83.7% and 100%, respectively. The correlation between the NPTs was statistically significant (0.833, P < .0001, n ¼ 88) and the 2 NPTs were completely safe. Performing NPT-R was more rapid (mean SD, 22 8 minutes) than the classic NPT (97 20 minutes). Conclusion: The NPT-R is safe and easier and faster than the classic NPT. This new method appears to be a very useful tool in the diagnosis of HDM allergic rhinitis when the diagnosis is uncertain or before initiating immunotherapy. Trial Registration: ClinicalTrials.gov, identifier NCT01485523. Ó 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Introduction In clinical practice, the diagnosis of allergic rhinitis is typically based on results from 2 tests: the allergen skin prick test (SPT) and the serum specific IgE measurement. These results confirm the clinical assessment of a patient’s reported symptoms (sneezing, rhinorrhea, nasal blockage, nasal pruritus).1,2 However, a correlation has not been consistently found between the results of these tests.3e6 This discrepancy can complicate the diagnosis, particularly in the case of an allergy to house dust mites (HDM) Dermatophagoides pteronyssinus (Dpt) and Dermatophagoides farinae (Df). Furthermore,
Reprints: Virginie Doyen, MD, Clinics of Immuno-Allergology, CHU Brugmann, Université Libre de Bruxelles, Place Van Gehuchten, 4, 1020 Brussels, Belgium; E-mail: [email protected]. Disclosures: Dr de Blay has received funding from and served on the boards of Stallergenes, ALK, GlaxoSmithKline, AstraZeneca, Boehringer, Teva, Meda, and Anergis. Funding: Funded by Stallergenes SA, France. Abstract was presented at the 2014 meeting of the American Academy of Allergy, Asthma & Immunology.
this discrepancy suggests that many patients might be misdiagnosed and potentially desensitized unnecessarily when a diagnosis is based specifically on sensitization data, such as those obtained with the SPT and/or IgE. The nasal provocation test (NPT) has been shown to be the most pertinent test for diagnosing HDM allergic rhinitis. The NPT also has been recommended for allergic rhinitis diagnoses, for conducting pathophysiology research, and for investigating novel allergen immunotherapy approaches.7e15 However, the criteria for a positive response and methods of allergen delivery have not been standardized for NPTs.11,16 Some guidelines are available; these guidelines recommend basing the initial allergen concentration on the skin endpoint titer (SET) and using objective measurements of nasal patency to assess NPT positivity.13 In consequence, performing a NPT tends to be time consuming8e11 and, despite its appropriateness for diagnosing an HDM allergy, its use in clinical practice is limited.3,11 The aim of this study was to test the performance of an alternative rapid NPT (NPT-R) and compare its sensitivity, specificity, and safety with those of the “classic” NPT (NPT-C) combining SET and rhinomanometry.
http://dx.doi.org/10.1016/j.anai.2015.07.014 1081-1206/Ó 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
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underwent the NPT-C, followed by a washout period of at least 4 weeks, and then they underwent the NPT-R.
Table 1 Inclusion and exclusion criteria Inclusion criteria Rhinitis defined by 1 of the following symptoms: sneezing, rhinorrhea, nasal blockage or nasal pruritus and confirmed by an ENT examination Informed consent 18e65 y of age Nonsmoking or smoking <5 cigarettes/d HDM allergic rhinitis group (HDMþ)
Non-HDM allergic rhinitis group (HDM)
Perennial rhinitis HDM sensitization (positive SPT and specific IgE to Dpt and/or Df) Positive classic NPT reaction
Perennial or seasonal rhinitis Sensitization or not to aeroallergens Negative classic NPT reaction
Exclusion criteria FEV1 <70% or uncontrolled asthma Medication (antihistamines, corticosteroids, NSAIDs, antihypertensive drugs) or not respecting the appropriate washout period (antihistamines, NSAIDs, anti-leukotriene, nasal vasoconstrictors and corticosteroids: 7 d, systemic corticosteroids: 14 d, antihypertensive drugs: 21 d) Chronic rhinosinusitis, nasal polyps, significant septum deviation, anatomic or nasal surgery 8 wk before study Epilepsy, current asthma attack, high blood pressure, myocardial infarction (<3 mo), aneurysm or stroke (<3 mo) Pregnancy or lactation Abbreviations: Df, Dermatophagoides farinae; Dpt, Dermatophagoides pteronyssinus; ENT, ear, nose, and throat; FEV1, forced expiration volume in 1 second; HDM, house dust mite; HDM, control group nonallergic to house dust mite; HDMþ, test group allergic to house dust mite; NPT, nasal provocation test; NSAIDs, nonsteroidal anti-inflammatory drugs.
Methods Subjects Eighty-eight subjects (27 men, median age 23 years, range 18e58) with rhinitis were recruited at the outpatient clinic of the Allergy Division of the Chest Diseases Department of Strasbourg University Hospital (Strasbourg, France). Two populations were studied. The first group was comprised of subjects with allergic rhinitis to HDM; this group (HDMþ; n ¼ 49) was defined by a clinical history of perennial rhinitis with a positive SPT reaction and a specific IgE reaction to HDM confirmed by an NPT-C. The second group was comprised of control subjects without an allergy to HDM (HDM; n ¼ 39). Inclusion and exclusion criteria are listed in Table 1. All subjects were questioned about allergic symptoms in relation to indoor exposure to dust (eg, during housework, making the bed, emptying the vacuum cleaner, cleaning the attic or the basement, handling dusty books, staying in an old dusty house). This study was approved by the local ethics committee. All subjects provided written informed consent before participating in the study. Study Design This prospective study was performed at the Allergy Division, Chest Diseases Department, Strasbourg University Hospital. One investigator performed all measurements. Allergy Tests Before SPTs and NPTs were conducted, all subjects underwent a specific washout period for certain drugs that might interfere with the test results. The washout period lasted 7 days for anti-H1, intranasal corticosteroids, nonsteroidal anti-inflammatory drugs, anti-leukotrienes, or nasal vasoconstrictors and 2 weeks for oral or intramuscular corticosteroids. Patients with a birch or grass pollen allergy were studied outside the pollen season. All eligible subjects
Skin Prick Tests The SPTs were performed with a battery of 20 common aeroallergens (Stallergenes SA, Antony, France), a positive control (10 mg/mL of histamine), and a negative control (0.9% saline). A positive reaction was defined as a wheal diameter 3 mm larger than that of the negative control observed after 20 minutes. The SET was performed with series of 10-fold dilutions of an HDM allergen (Dpt, stock concentration 100 IR/mL; Stallergenes SA) to determine the highest allergen concentration that could elicit a negative SPT reaction. For the non-HDM sensitized patients, only the 100-IR concentration was used. The same batch of Dpt allergenic extract was used for SETs and NPTs in all subjects. The Der p 1 concentration of the stock solution measured by an enzymelinked immunosorbent assay was 7.9 mg/mL (Indoor Biotechnology, Charlottesville, Virginia). Serum IgE Measurements Specific IgE was measured in serum samples obtained before the allergen exposure (Thermo Fischer, Uppsala, Sweden). The positive threshold was defined as at least 0.7 kU/L. Nasal Provocation Tests Before the NPT, and on a different day, the same physician performed an ear, nose, and throat examination to confirm the rhinitis and exclude nasal polyps or anatomic findings that might confound the NPT results. Patients were acclimated by waiting in the room for 20 to 30 minutes before the test. Nasal hyperresponsiveness was excluded before allergen exposure by performing an NPT with 0.9% saline. When the result was negative, the NPT was performed. For the NPT, 1 puff of Dpt was applied in each nostril at room temperature for each serial dilution. The spray output of the dispenser was measured with the gravimetric method (sensitivity 0.1 mg), and the same spray dispensers were used throughout the study. The mean volume of delivered solution was 101.4 mL/puff (interassay coefficient of variation 0.7%, n ¼ 3; intraassay coefficient of variation3%, n ¼ 6). Subjects were monitored for a 6-hour period after the NPT, but only the immediate nasal response was assessed. Classic NPT Subjects with a positive SPT response to an HDM allergen (Dpt and/or Df) underwent an initial NPT-C with Dpt at the highest concentration that did not induce a positive SPT reaction during the SET with the serial HDM allergen solutions (Dpt). When the NPT-C response was negative, the NPT was repeated with a 10-fold higher concentration of the Dpt solution until a positive response was obtained (up to 100 IR). For non-sensitized subjects, only 10- and 100-IR doses were administered. Nasal flow and resistance were measured with rhinomanometry (RHINOTEST 2000, Allergopharma, Reinbek, Germany) at baseline and 10 minutes after each exposure to the allergen.8,10 The NPT-C response was considered positive when the Lebel clinical score (sneezing, rhinorrhea, nasal blockage, nasal pruritus) was at least 5 and/or when nasal resistance increased by more than 100%.16,17 Rapid NPT For the NPT-R, concentrations of 1, 5, and 10 IR were tested at 10-minute intervals, and only the Lebel clinical score was determined. For safety reasons, the 100-IR concentration was not performed, and the intermediate 5-IR dose was used. For the non-HDM sensitized subjects, only the 5- and 10-IR doses were administered.
F. de Blay et al. / Ann Allergy Asthma Immunol xxx (2015) 1e6
Safety Any asthma exacerbations that occurred during the study were noted. Subjects were monitored for 6 hours after the NPTs. The forced expiration volume at 1 second (FEV1) was measured before the NPT and at 6 and 24 hours after the NPT. Total exposure to allergen also was determined. Statistical Analysis The main objective of the study was to validate the NPT-R by determining its sensitivity and specificity. The number of subjects required was based on the expected accuracy of the estimations. To simultaneously establish 2 confidence intervals (CIs), an individual a risk of 2.53% (1 exp [Ln {0.95}/2]) was selected to calculate the 95% CI; this individual value maintained an overall risk of 5%. To achieve 95% sensitivity and specificity values, it was necessary to recruit 100 subjects. This sample size yielded a 16% CI range (expected asymmetric interval 83.2e99.4%). Taking into account incomplete data and study withdrawals, it was necessary to recruit 120 subjects. However, based on the results obtained with 88 patients, the sensitivity was higher than estimated; therefore, this number was sufficient without compromising the power of the analysis. Data were described as number (percentage) for categorical variables and as mean, median, quartiles, minimum, and maximum for continuous variables. Categorical variables were compared with the c2 or Fisher exact test, and continuous variables were compared with the Wilcoxon test. The sensitivity, specificity, and positive and negative predictive values were calculated for the NPT-R. Correlations among the SET, IgE, and SPT and between the SPT and IgE results were evaluated with the Spearman rank test. Receiver operating characteristic analyses were performed between the specific IgE (against Dpt) and the NTP-C and NPT-R results. Univariate logistic regressions were performed to identify predictive factors for allergic rhinitis triggered by HDM. Factors with a P value less than .20 were included in a multivariate analysis with a stepwise selection, and factors with a P value less than .10 were retained. P values less than .05 were considered significant. Analyses were performed with SAS 9.2 (SAS Institute, Cary, North Carolina) and R Software (R Development, Vienna, Austria). Results Study Population Eighty-eight subjects were included in the study: 49 subjects were allergic to HDM (HDMþ) and 39 subjects were not allergic to HDM (HDM) according to the inclusion criteria. All subjects had rhinitis, and 24% of subjects reported asthma. Rhinitis was classified as perennial for most subjects (91%) and the severity was mostly moderate to severe (96%). The 2 groups were well balanced for demographic characteristics, symptoms, FEV1, and rhinitis history. However, there were notable differences between the 2 groups. Proportionally more subjects with HDMþ than with HDM experienced a worsening of rhinitis symptoms over time (18% vs 2.5%, P < .05). Moreover, more subjects with HDMþ than with HDM experienced rhinitis on contact with an animal (49% vs 20.5%, P < .01) or at home (31% vs 5%, P < .001). Results are presented in Table 2. In addition, rhinitis had started more recently in subjects with HDMþ (mean SD 10.3 8.2 years old) than in subjects with HDM (18.0 12.4 years old, P < .01). The triggering factor for rhinitis most often reported by subjects with HDMþ was performing housework (94%). The authors investigated whether this criterion alone could be used as a predictive factor for identifying subjects with HDM allergic rhinitis, and they found that doing
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Table 2 Subjects’ clinical characteristics HDMþ (n ¼ 49) Sex, n (%) Women Men Age (y) Mean (SD) Median (min; max) Asthma, yes, n (%) Aggravation of rhinitis over time, yes, n (%) Seasonality, n (%) Perennial only Perennial with seasonal worsening Seasonal only Allergy to animals, yes, n (%) Symptoms at home, yes, n (%)
31 (63.5) 18 (36.7) 28.4 24 14 9
(9.6) (18; 58) (28.6) (18.0)
HDM (n ¼ 39)
30 (76.9) 9 (23.1) 26.6 23 7 1
(8.9) (18; 53) (17.9) (2.5)
Total (n ¼ 88)
61 (69.3) 27 (30.7) 27.8 23 21 10
(9.3) (18; 58) (24) (11.3)
P valuea
NS
NS NS <.05
24 (49.0) 25 (51.0)
9 (23.1) 2 (5.1)
33 (37.5) 27 (30.7)
<.05 <.0001
0 (0.0) 24 (49.0)
28 (71.8) 8 (20.5)
28 (31.8) 32 (36.4)
<.0001 <.01
15 (30.6)
2 (5.1)
17 (19.3)
<.01
Abbreviations: HDM, subjects not allergic to house dust mite (including those sensitized to house dust mite and allergic or nonallergic to another allergen); HDMþ, subjects allergic to house dust mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus); max, maximum; min, minimum; NS, not significant. a P < .05 considered statistically significant.
housework was a statistically significant factor in triggering rhinitis from HDM (P < .0001). Allergy Tests The HDMþ group was comprised of subjects with monosensitization (n ¼ 9) and poly-sensitization (n ¼ 40) and HDM allergies. The control group (HDM) was comprised of subjects without (n ¼ 9) and with (n ¼ 30) atopy (Table 3). The HDMþ group was highly sensitized to HDM; the SPT wheal diameters were 6.9 2.6 mm (mean SD) to Dpt and 5.9 2.4 mm to Df. The IgE concentrations were 19.3 23.0 kU/L (mean SD) to Dpt and 23.4 25.3 kU/L to Df. There was no correlation between HDM specific IgE levels and SPT results. The highest concentrations that did not induce a positive SPT reaction during the SET were 10 IR (2.0%), 1 IR (36.7%), 101 IR (49.0%), and 102 IR (12.2%). Nasal Provocation Tests Of the 52 subjects sensitized to HDM, 49 had a positive NPT-C result. This finding confirmed the HDM allergic rhinitis diagnosis (HDMþ). The NPT-C result was considered positive when the
Table 3 Skin prick tests results SPT
HDMþ (n ¼ 49)
HDM (n ¼ 39)
HDM (Dpt and/or Df) Cat Dog Grass Birch Ash Ragweed Alternaria Cockroach None
49 25 12 28 28 20 3 3 2 0
3 6 4 20 15 2 2 1 0 9
Abbreviations: Df, Dermatophagoides farinae; Dpt, Dermatophagoides pteronyssinus; HDM, house dust mite; HDM, subjects not allergic to house dust mite (including those sensitized to house dust mite and allergic or nonallergic to another allergen); HDMþ, subjects allergic to house dust mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus) based on a clinical history of perennial rhinitis with a positive SPT reaction and a specific IgE reaction to HDM and confirmed by classic nasal provocation testing; SPT, skin prick test.
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subject had a positive Lebel score (n ¼ 42) and/or a positive rhinomanometric level (n ¼ 28). The NPT-R was performed more rapidly than the NPT-C (mean SD 22 8 vs 97 20 minutes, respectively). The NPT-R results were positive in 41 of 49 of the HDMþ group and in none of the HDM group. Results are shown in the online supplement (eFig 1). Therefore, the NPT-R was not as sensitive as the NPT-C (83.7%), but the 2 tests were equally specific (100%; Table 4). The correlation between the 2 NPTs was excellent (0.833, 95% CI 0.756e0.888, P < .0001; Table 5). The concentrations that induced a positive response in the NPT-R or NPT-C also were correlated (0.35, P < .05). The median amount of Der p 1 that induced a positive NPT result was lower in the NPT-R group (47.4 ng, range 7.9e126.4) than in the NPT-C group (87.7 ng, range 0.08e877.7; Fig 1). Eight subjects in the HDMþ group had negative NPT-R results; in those 8 cases, the eliciting concentrations during the NPT-C were 100 IR (n ¼ 4) and 10 IR (n ¼ 4). Correlation among SPT, Specific IgE, and NPT The SET was inversely correlated to the specific IgE (Dpt, r ¼ 0.56, P < .05) and to the SPT wheal diameter (Dpt, r ¼ 0.55, P < 0.0001; Df, r ¼ 0.45, P < .005). The areas under the curve obtained with the receiver operating characteristic analyses between the IgE Dpt and NPT results were high for the NPT-C and NPT-C (0.948 and 0.910, respectively); this finding showed that the IgE Dpt results were strongly linked to the NPT results (Fig 2). Safety The 2 versions of the NPT were found to be equally safe; only 1 subject experienced an asthma exacerbation during the study. That episode was a mild asthma attack, which occurred after the NPT-C and the NPT-R. It might have been associated with hyperventilation syndrome, and it resolved after 2 puffs of a short-acting b2-agonist. In addition, the FEV1 remained constant before and after the 2 NPTs for all subjects (Table 6). Discussion The main objective of this work was to evaluate the sensitivity, specificity, and the safety of a rapid version of the NPT (NPT-R) for the diagnosis of HDM allergic rhinitis. The authors studied 2 populations, one with allergic rhinitis triggered by HDM, based on a positive NPT-C result, and one with rhinitis that was not triggered by HDM (allergic to other allergens or no allergy), based on a negative NPT-C result. The NPT-R had a positive predictive value of 100%, although the control group was comprised mainly of subjects with atopy (n ¼ 30); only approximately 23% did not have atopy (n ¼ 9). This result highlighted the high specificity of the NPT-R. The results of the 2 NPT methods were strongly correlated (0.8, P < .0001) and the eliciting concentrations were significantly correlated (0.35, P < .05). However, the negative predictive value of the NPT-R was slightly low (83%). This low negative predictive value
Table 5 Correlation between NPT-C and NPT-Ra NPT-R positive NPT-C positive NPT-C negative Correlation between NPTs
NPT-R negative
41 8 0 39 0.833 (0.756e0.888, P < .0001)
Abbreviations: NPT-C, classic nasal provocation test; NPT-R, rapid nasal provocation test. a Data are presented as number of patients.
might be explained by the absence of a 100-IR exposure in the NPTR. Indeed, the amount of Der p 1 that induced a positive NPT result was lower for the NPT-R (47.4 ng, range 7.9e126.4) than for the NPT-C (87.7 ng, range 0.08e877.7); nevertheless, 4 of 8 subjects with a negative NPT-R result reacted to 100 IR with the NPT-C (corresponding to 790 ng of Der p 1). It was difficult to compare the present results with those of previous studies that documented an eliciting dose in HDM allergic rhinitis, because previous reports were scattered, and they used different allergenic extracts, NPT methods (allergen application techniques and increments), and positivity criteria. However, Kirerleri et al,5 who used the same Dpt extract as that used in the present study, found that 92% of the population responded to an eliciting concentration lower than or equal to 3.2 IR. In addition, it was estimated that 20 ng of Der p 1 was necessary to induce an immediate bronchial response, and that 12 ng of Der p 1 was necessary to induce respiratory symptoms at home.18 Therefore, those results brought into question the clinical significance of a positive nasal response obtained with a high dose of mite allergens, such as 100 IR. Another potential reason that the NPT-R showed lower sensitivity than the NPT-C might have been that rhinomanometry was not used. The use of an objective measurement of nasal patency (peak nasal inspiratory flow, rhinomanometry, acoustic rhinometry) combined with a symptom score has been recommended,9,16 but adequate standardization remains lacking.11 In the present study, the value of adding rhinomanometry was only slightly useful for the correct diagnosis, because only 7 of 49 cases had positive rhinomanometric results combined with a negative Lebel score during NPT-C. However, 14% (7 of 49 cases) cannot be considered negligible; but the practical advantages of the NPT-R could compensate for its low added value, because the NPT-R was designed to confirm HDM allergic rhinitis diagnosis.7 The second objective of this work was to propose a more rapid, safe method for the NPT. The NPT-R was performed considerably faster than the NPT-C (22 8 vs 97 20 minutes, respectively). The time saved was due to a decrease in the number of allergen nasal delivery steps, the elimination of rhinomanometry, and the
Table 4 Sensitivity, specificity, PPV, and NPV of NPT-R with HDM allergen Positive NPT-R HDMþ
HDM
41/49
0/39
Sensitivity
83.7%
Specificity
PPV
NPV
100%
100%
83%
Abbreviations: HDM, house dust mite; HDM , subjects not allergic to house dust mite (including those sensitized to house dust mite and allergic or nonallergic to another allergen); HDMþ, subjects allergic to house dust mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus) based on a clinical history of perennial rhinitis with a positive skin prick test reaction and a specific IgE reaction to HDM and confirmed by classic nasal provocation testing; NPT-R, rapid nasal provocation test; NPV, negative predictive value; PPV, positive predictive value.
Figure 1. Histogram comparing the classic (dark gray bars) with the rapid (light gray bars) nasal provocation test (NPT) in a population allergic to house dust mite. Data are expressed as the percentage of all positive NPT results at eliciting each house dust mite allergen concentration (IR). Only 1-, 5-, and 10-IR doses were tested when using the rapid NPT and 5 IR was not tested when using the classic NPT.
F. de Blay et al. / Ann Allergy Asthma Immunol xxx (2015) 1e6
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Table 6 FEV1 values before and after NPT-C and NPT-R FEV1 (L)
NTP-C Mean SD (%) Min (%); max (%) NPT-R Mean SD (%) Min (%); max (%)
P value
Before
1 h After
6 h After
3.4 0.73 (98)
3.4 0.70 (98)
3.4 0.71 (98)
1.8 (72); 5.2 (120) 1.8 (72); 5 (117)
1.6 (71.2); 5.2 (116)
3.5 0.69 (98.1)
3.4 0.64 (98)
3.5 0.87 (98)
1.9 (77); 5 (117)
1.8 (77); 4.8 (105) 2.1 (108); 7.8 (117)
NS
NS
Abbreviations: FEV1, forced expiration volume in 1 second; max, maximum; min, minimum; NPT-C, classic nasal provocation test; NPT-R, rapid nasal provocation test; NS, not significant.
Figure 2. Receiver operating characteristic (ROC) curves of specific IgE against Dermatophagoides pteronyssinus and the (A) classic and (B) rapid nasal provocation test results.
elimination of the SET. The SET has been recommended to determine the initial dose for safety purposes. However, its elimination did not increase the rate of adverse events, and no correlation was found between the SET results and the eliciting NPT-R dose. Importantly, there were no safety concerns during this study; no exacerbation of asthma was observed, although one fourth of subjects (24%) had asthma. This finding was consistent with that of Clarke19 who reported no complications among more than 1,000 NPTs. The authors also investigated the correlation between allergy tests and the NPT. Receiver operating characteristic analysis between the IgE Dpt and the NPT results confirmed a strong link between the
Dpt IgE and the NPT results. To the authors’ knowledge, this is the first study to show a link between specific IgE and NPT results in HDM allergic rhinitis. Some works have shown a link between NPT and SPT wheal size,4,6 but others have not observed that link.3,5 In the present study, nearly all patients (49 of 52, 94.2%) who had consulted for a suspected HDM allergy (perennial rhinitis and HDM sensitization) were found to have a positive NPT-C reaction (eFigure 1). Those results were unexpected, because the prevalence was higher than in other studies. In previous studies, only 70% to 80% of patients with positive SPT responses to HDM allergens had a positive NPT result.3,4,6,19,20 The high rate of positivity found in the present study might be explained by the fact that this study population consisted of relatively young adults (mean 28.4 years, range 18e59) who were highly sensitized to HDM allergens. In younger populations (6e18 years), positive NPT results were found in 92%5 and 94%21 of subjects. In an older population, King et al22 reported a positive predictive value of only 42.86% for a positive SPT reaction. In a population the same age as that in the present study, others have reported 89% to 100% of subjects with positive NPT reactions in those sensitized to HDM.23,24 In HDM allergy, the relation between symptoms and HDM exposure can be difficult to assess, unlike allergies to cat and pollen.25 In the present study, only 30% of the HDMþ group had symptoms at home, but when asked whether doing housework was a trigger for rhinitis, a positive answer was strongly linked to HDM allergy (P < .0001). Indeed, HDM allergens in house dust become airborne only after disturbance.26 These characteristics reinforced interest in using the NPT for a specific diagnosis of HDM-triggered allergic rhinitis. This study had some limitations. First, the study could not be randomized. The provocation tests were applied in the same order for all subjects, and this order effect could lead to a bias. A crossover study design might have been more appropriate to avoid this effect. However, because the 2 tests were separated by at least 4 weeks, the authors presumed that the carryover effect due to a “priming effect” would be negligible; thus, the order effect could be ignored. Second, the allergen concentrations used for the NPT were different between subjects sensitized to HDM and those not sensitized to HDM. From a methodologic viewpoint, to evaluate the effects of omitting the SET and rhinomanometry, it would be preferable to use the same Dpt concentrations in the NPT-R and the NPT-C. However, the authors also aimed to propose an easy, safe NPT method; thus, only 3 Dpt deliveries and lower concentrations were used. The 1-, 5-, and 10-IR doses were chosen for the NPT-R protocol based on experience and on a study by Kirerleri et al.5 The present results showed that the NPT-R could facilitate confirmation of a HDM allergic rhinitis diagnosis; thus, its use could identify a false-positive HDM allergic rhinitis diagnosis before initiating immunotherapy, as recommended by international
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guidelines. Indeed, clinical studies that have assessed the effect of desensitization in adults generally included subjects 18 to 70 years old and subjects potentially less sensitized than the subjects included in the present study. Therefore, there might be a higher rate of false-positive diagnoses.8,12 In conclusion, the present study demonstrated that the NPT-R is a highly specific, rapid, safe tool for confirming the clinical relevance of HDM allergy. This tool might be particularly useful for evaluating patients with perennial rhinitis who are sensitized to HDM, because diagnosing HDM allergic rhinitis with current methods remains problematic or uncertain. Thus, this test could decrease the number of unnecessary, lengthy, and costly HDM desensitization procedures. Acknowledgment The authors thank Brigitte Sbinne and Mael Bellier for technical support. Supplementary Data Supplementary data related to this article can be found online at http://dx.doi.org/10.1016/j.anai.2015.07.014. References [1] Huet S, Grimberg P, Autegarden JE, Leynadier F. Study of validation of a questionnaire by skin testing in house dust mite allergy. Rev Fr Allergol Immunol Clin. 2001;41:712e719. [2] Bousquet J, Khaltaev N, Cruz AA, et al. Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen). Allergy. 2008;63:8e160. [3] Stenius B. Skin and provocation tests with Dermatophagoides pteronyssinus in allergic rhinitis. Comparison of prick and intracutaneous skin test methods and correlation with specific IgE. Acta Allergol. 1973;28:81e100. [4] Kanthawatana S, Maturim W, Fooanan S, Trakultivakorn M. Skin prick reaction and nasal provocation response in diagnosis of nasal allergy to the house dust mite. Ann Allergy Asthma Immunol. 1997;79:427e430. [5] Kirerleri E, Guler N, Tamay Z, Ones U. Evaluation of the nasal provocation test for its necessity in the diagnosis of nasal allergy to house dust mite. Asian Pac J Allergy Immunol. 2006;24:117e121. [6] Chusakul S, Phannaso C, Sangsarsri S, Aeumjaturapat S, Snidvongs K. Housedust mite nasal provocation: a diagnostic tool in perennial rhinitis. Am J Rhinol Allergy. 2010;24:133e136. [7] Agache I, Bilò M, Braunstahl GJ, et al. In vivo diagnosis of allergic diseasesallergen provocation tests. Allergy. 2015;70:355e365. [8] Malm L, Gerth van Wijk R, Bachert C. Guidelines for nasal provocations with aspects on nasal patency, airflow, and airflow resistance. International Committee on Objective Assessment of the Nasal Airways, International Rhinologic Society. Rhinology. 2000;38:1e6. [9] Gosepath J, Amedee RG, Mann WJ. Nasal provocation testing as an international standard for evaluation of allergic and nonallergic rhinitis. Laryngoscope. 2005;115:512e516.
[10] Riechelmann H, Bachert C, Golschmidt O, et al. Application of the nasal provocation test on diseases of the upper airways. Position paper of the German Society for Allergology and Clinical Immunology (ENT Section) in cooperation with the Working Team for Clinical Immunology. Laryngorhinootologie. 2003;82:183e188. [11] Pfaar O, Demoly P, Gerth van Wijk R, et al. Recommendations for the standardization of clinical outcomes used in allergen immunotherapy trials for allergic rhinoconjunctivitis: an EAACI Position Paper. Allergy. 2014;69: 854e867. [12] European Medicines Agency. Pre-authorsation evaluation of medicines for human use. Document HMP/EWP/18504. http://www.ema.europa.eu/docs/en_GB/ document_library/Scientific_guideline/2009/09/WC500003605.pdf. Published November 20, 2008. [13] Melillo G, Bonini S, Cocco G, et al. EAACI provocation tests with allergens. Report prepared by the European Academy of Allergology and Clinical Immunology subcommittee on provocation tests with allergens. Allergy. 1997;52(suppl):1e35. [14] Scadding G, Hellings P, Alobid I, et al. Diagnostic tools in rhinology EAACI position paper. Clin Transl Allergy. 2011;1:2. [15] Hellings PW, Scadding G, Alobid I, et al. Executive summary of European Task Force document on diagnostic tools in rhinology. Rhinology. 2012;50: 339e352. [16] Dordal MT, Lluch-Bernal M, Sánchez MC, et al. Allergen-specific nasal provocation testing: review by the rhinoconjunctivitis committee of the Spanish Society of Allergy and Clinical Immunology. J Investig Allergol Clin Immunol. 2011;21:1e12. [17] Lebel B, Bousquet J, Morel A, Chanal I, Godard P, Michel FB. Correlation between symptoms and the threshold for release of mediators in nasal secretions during nasal challenge with grass-pollen grains. J Allergy Clin Immunol. 1988;82:869e877. [18] de Blay F. Provocation tests as measure of efficacy and dosage. Allergy. 2011; 66:47e49. [19] Clarke PS. The diagnosis of perennial rhinitis due to house dust mite (Dermatophagoides pteronyssinus) demonstrated by nasal provocation tests. Ann Allergy. 1987;59:25e28. [20] Riechelmann H, Mewes T, Weschta M, Gropper G. Nasal allergen provocation with Dermatophagoides pteronyssinus in patients with chronic rhinitis referred to a rhinologic surgical center. Ann Allergy Asthma Immunol. 2002;88: 624e631. [21] Anantasit N, Vilaiyuk S, Kamchaisatian W, et al. Comparison of conjunctival and nasal provocation tests in allergic rhinitis children with Dermatophagoides pteronyssinus sensitization. Asian Pac J Allergy Immunol. 2013;31: 227e232. [22] King MJ, Tamulis T, Lockey RF. Prick puncture skin tests and serum specific IgE as predictors of nasal challenge response to Dermatophagoides pteronyssinus in older adults. Ann Allergy Asthma Immunol. 2008;101:12e17. [23] Riechelmann H, Epple B, Gropper G. Comparison of conjunctival and nasal provocation test in allergic rhinitis to house dust mite. Int Arch Allergy Immunol. 2003;130:51e59. [24] Rondón C, Romero JJ, López S, et al. Local IgE production and positive nasal provocation test in patients with persistent nonallergic rhinitis. J Allergy Clin Immunol. 2007;119:899e905. [25] Droste JH, Kerhof M, de Monchy JG, Schouten JP, Rijcken B. Association of skin test reactivity, specific IgE, total IgE, and eosinophils with nasal symptoms in a community-based population study. The Dutch ECRHS Group. J Allergy Clin Immunol. 1996;97:922e932. [26] de Blay F, Heymann PW, Chapman MD, Platts-Mills TA. Airborne dust mite allergens: comparison of group II allergens with group I mite allergen and cat-allergen Fel d I. J Allergy Clin Immunol. 1991;88:919e926.
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eFigure 1. Results of the SPT, IgE, and NPT in the study group. Df, Dermatophagoides farinae; Dpt, Dermatophagoides pteronyssinus; HDM, house dust mite; IgE, immunoglobulin E; NPT-C, classic nasal provocation test with clinical score, skin end-point titration, and rhinomanometry; NPT-R, rapid nasal provocation test with clinical score; SPT, skin prick test.
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Contents lists available at ScienceDirect
A new, faster, and safe nasal provocation test method for diagnosing mite allergic rhinitis Frédéric de Blay, MD *; Virginie Doyen, MD y; Céline Lutz, MD *; Julien Godet, MD z; Cindy Barnig, MD, PhD *; Shanshan Qi, MD *; and Jean-Jacques Braun, MD * * Chest
Diseases Department, Strasbourg University Hospital; Federation of Translational Medicine, University of Strasbourg, Strasbourg, France Immuno-Allergology Clinic, CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium z Statistics Department, Strasbourg University Hospital, Strasbourg, France y
A R T I C L E
I N F O
Article history: Received for publication April 30, 2015. Received in revised form July 20, 2015. Accepted for publication July 22, 2015.
A B S T R A C T
Background: Diagnosing house dust mite (HDM) allergic rhinitis is difficult. The nasal provocation test (NPT) has been shown to be the most pertinent, but several methods are available. According to guidelines, the NPT requires a skin end-point titration and an objective measurement of nasal patency. Hence, NPT is time consuming and its use is limited. Objective: To evaluate the sensitivity, specificity, and safety of a new, more rapid, and simple alternative NPT (NPT-R) to HDM. Methods: Eighty-eight patients with from rhinitis (49 allergic to HDM and 39 controls with and without atopy) were included. Allergic rhinitis to HDM was confirmed by a “classic” NPT based on the Lebel score and rhinomanometry. After a period of 4 weeks, NPT-R was performed and only the clinical score was measured. Results: The study population was young (mean SD, 27.7 8.5 years old), composed mostly of women (61 vs 27 men), and 24% reported asthma. The sensitivity and specificity of NPT-R were 83.7% and 100%, respectively. The correlation between the NPTs was statistically significant (0.833, P < .0001, n ¼ 88) and the 2 NPTs were completely safe. Performing NPT-R was more rapid (mean SD, 22 8 minutes) than the classic NPT (97 20 minutes). Conclusion: The NPT-R is safe and easier and faster than the classic NPT. This new method appears to be a very useful tool in the diagnosis of HDM allergic rhinitis when the diagnosis is uncertain or before initiating immunotherapy. Trial Registration: ClinicalTrials.gov, identifier NCT01485523. Ó 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Introduction In clinical practice, the diagnosis of allergic rhinitis is typically based on results from 2 tests: the allergen skin prick test (SPT) and the serum specific IgE measurement. These results confirm the clinical assessment of a patient’s reported symptoms (sneezing, rhinorrhea, nasal blockage, nasal pruritus).1,2 However, a correlation has not been consistently found between the results of these tests.3e6 This discrepancy can complicate the diagnosis, particularly in the case of an allergy to house dust mites (HDM) Dermatophagoides pteronyssinus (Dpt) and Dermatophagoides farinae (Df). Furthermore,
Reprints: Virginie Doyen, MD, Clinics of Immuno-Allergology, CHU Brugmann, Université Libre de Bruxelles, Place Van Gehuchten, 4, 1020 Brussels, Belgium; E-mail: [email protected]. Disclosures: Dr de Blay has received funding from and served on the boards of Stallergenes, ALK, GlaxoSmithKline, AstraZeneca, Boehringer, Teva, Meda, and Anergis. Funding: Funded by Stallergenes SA, France. Abstract was presented at the 2014 meeting of the American Academy of Allergy, Asthma & Immunology.
this discrepancy suggests that many patients might be misdiagnosed and potentially desensitized unnecessarily when a diagnosis is based specifically on sensitization data, such as those obtained with the SPT and/or IgE. The nasal provocation test (NPT) has been shown to be the most pertinent test for diagnosing HDM allergic rhinitis. The NPT also has been recommended for allergic rhinitis diagnoses, for conducting pathophysiology research, and for investigating novel allergen immunotherapy approaches.7e15 However, the criteria for a positive response and methods of allergen delivery have not been standardized for NPTs.11,16 Some guidelines are available; these guidelines recommend basing the initial allergen concentration on the skin endpoint titer (SET) and using objective measurements of nasal patency to assess NPT positivity.13 In consequence, performing a NPT tends to be time consuming8e11 and, despite its appropriateness for diagnosing an HDM allergy, its use in clinical practice is limited.3,11 The aim of this study was to test the performance of an alternative rapid NPT (NPT-R) and compare its sensitivity, specificity, and safety with those of the “classic” NPT (NPT-C) combining SET and rhinomanometry.
http://dx.doi.org/10.1016/j.anai.2015.07.014 1081-1206/Ó 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
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underwent the NPT-C, followed by a washout period of at least 4 weeks, and then they underwent the NPT-R.
Table 1 Inclusion and exclusion criteria Inclusion criteria Rhinitis defined by 1 of the following symptoms: sneezing, rhinorrhea, nasal blockage or nasal pruritus and confirmed by an ENT examination Informed consent 18e65 y of age Nonsmoking or smoking <5 cigarettes/d HDM allergic rhinitis group (HDMþ)
Non-HDM allergic rhinitis group (HDM)
Perennial rhinitis HDM sensitization (positive SPT and specific IgE to Dpt and/or Df) Positive classic NPT reaction
Perennial or seasonal rhinitis Sensitization or not to aeroallergens Negative classic NPT reaction
Exclusion criteria FEV1 <70% or uncontrolled asthma Medication (antihistamines, corticosteroids, NSAIDs, antihypertensive drugs) or not respecting the appropriate washout period (antihistamines, NSAIDs, anti-leukotriene, nasal vasoconstrictors and corticosteroids: 7 d, systemic corticosteroids: 14 d, antihypertensive drugs: 21 d) Chronic rhinosinusitis, nasal polyps, significant septum deviation, anatomic or nasal surgery 8 wk before study Epilepsy, current asthma attack, high blood pressure, myocardial infarction (<3 mo), aneurysm or stroke (<3 mo) Pregnancy or lactation Abbreviations: Df, Dermatophagoides farinae; Dpt, Dermatophagoides pteronyssinus; ENT, ear, nose, and throat; FEV1, forced expiration volume in 1 second; HDM, house dust mite; HDM, control group nonallergic to house dust mite; HDMþ, test group allergic to house dust mite; NPT, nasal provocation test; NSAIDs, nonsteroidal anti-inflammatory drugs.
Methods Subjects Eighty-eight subjects (27 men, median age 23 years, range 18e58) with rhinitis were recruited at the outpatient clinic of the Allergy Division of the Chest Diseases Department of Strasbourg University Hospital (Strasbourg, France). Two populations were studied. The first group was comprised of subjects with allergic rhinitis to HDM; this group (HDMþ; n ¼ 49) was defined by a clinical history of perennial rhinitis with a positive SPT reaction and a specific IgE reaction to HDM confirmed by an NPT-C. The second group was comprised of control subjects without an allergy to HDM (HDM; n ¼ 39). Inclusion and exclusion criteria are listed in Table 1. All subjects were questioned about allergic symptoms in relation to indoor exposure to dust (eg, during housework, making the bed, emptying the vacuum cleaner, cleaning the attic or the basement, handling dusty books, staying in an old dusty house). This study was approved by the local ethics committee. All subjects provided written informed consent before participating in the study. Study Design This prospective study was performed at the Allergy Division, Chest Diseases Department, Strasbourg University Hospital. One investigator performed all measurements. Allergy Tests Before SPTs and NPTs were conducted, all subjects underwent a specific washout period for certain drugs that might interfere with the test results. The washout period lasted 7 days for anti-H1, intranasal corticosteroids, nonsteroidal anti-inflammatory drugs, anti-leukotrienes, or nasal vasoconstrictors and 2 weeks for oral or intramuscular corticosteroids. Patients with a birch or grass pollen allergy were studied outside the pollen season. All eligible subjects
Skin Prick Tests The SPTs were performed with a battery of 20 common aeroallergens (Stallergenes SA, Antony, France), a positive control (10 mg/mL of histamine), and a negative control (0.9% saline). A positive reaction was defined as a wheal diameter 3 mm larger than that of the negative control observed after 20 minutes. The SET was performed with series of 10-fold dilutions of an HDM allergen (Dpt, stock concentration 100 IR/mL; Stallergenes SA) to determine the highest allergen concentration that could elicit a negative SPT reaction. For the non-HDM sensitized patients, only the 100-IR concentration was used. The same batch of Dpt allergenic extract was used for SETs and NPTs in all subjects. The Der p 1 concentration of the stock solution measured by an enzymelinked immunosorbent assay was 7.9 mg/mL (Indoor Biotechnology, Charlottesville, Virginia). Serum IgE Measurements Specific IgE was measured in serum samples obtained before the allergen exposure (Thermo Fischer, Uppsala, Sweden). The positive threshold was defined as at least 0.7 kU/L. Nasal Provocation Tests Before the NPT, and on a different day, the same physician performed an ear, nose, and throat examination to confirm the rhinitis and exclude nasal polyps or anatomic findings that might confound the NPT results. Patients were acclimated by waiting in the room for 20 to 30 minutes before the test. Nasal hyperresponsiveness was excluded before allergen exposure by performing an NPT with 0.9% saline. When the result was negative, the NPT was performed. For the NPT, 1 puff of Dpt was applied in each nostril at room temperature for each serial dilution. The spray output of the dispenser was measured with the gravimetric method (sensitivity 0.1 mg), and the same spray dispensers were used throughout the study. The mean volume of delivered solution was 101.4 mL/puff (interassay coefficient of variation 0.7%, n ¼ 3; intraassay coefficient of variation3%, n ¼ 6). Subjects were monitored for a 6-hour period after the NPT, but only the immediate nasal response was assessed. Classic NPT Subjects with a positive SPT response to an HDM allergen (Dpt and/or Df) underwent an initial NPT-C with Dpt at the highest concentration that did not induce a positive SPT reaction during the SET with the serial HDM allergen solutions (Dpt). When the NPT-C response was negative, the NPT was repeated with a 10-fold higher concentration of the Dpt solution until a positive response was obtained (up to 100 IR). For non-sensitized subjects, only 10- and 100-IR doses were administered. Nasal flow and resistance were measured with rhinomanometry (RHINOTEST 2000, Allergopharma, Reinbek, Germany) at baseline and 10 minutes after each exposure to the allergen.8,10 The NPT-C response was considered positive when the Lebel clinical score (sneezing, rhinorrhea, nasal blockage, nasal pruritus) was at least 5 and/or when nasal resistance increased by more than 100%.16,17 Rapid NPT For the NPT-R, concentrations of 1, 5, and 10 IR were tested at 10-minute intervals, and only the Lebel clinical score was determined. For safety reasons, the 100-IR concentration was not performed, and the intermediate 5-IR dose was used. For the non-HDM sensitized subjects, only the 5- and 10-IR doses were administered.
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Safety Any asthma exacerbations that occurred during the study were noted. Subjects were monitored for 6 hours after the NPTs. The forced expiration volume at 1 second (FEV1) was measured before the NPT and at 6 and 24 hours after the NPT. Total exposure to allergen also was determined. Statistical Analysis The main objective of the study was to validate the NPT-R by determining its sensitivity and specificity. The number of subjects required was based on the expected accuracy of the estimations. To simultaneously establish 2 confidence intervals (CIs), an individual a risk of 2.53% (1 exp [Ln {0.95}/2]) was selected to calculate the 95% CI; this individual value maintained an overall risk of 5%. To achieve 95% sensitivity and specificity values, it was necessary to recruit 100 subjects. This sample size yielded a 16% CI range (expected asymmetric interval 83.2e99.4%). Taking into account incomplete data and study withdrawals, it was necessary to recruit 120 subjects. However, based on the results obtained with 88 patients, the sensitivity was higher than estimated; therefore, this number was sufficient without compromising the power of the analysis. Data were described as number (percentage) for categorical variables and as mean, median, quartiles, minimum, and maximum for continuous variables. Categorical variables were compared with the c2 or Fisher exact test, and continuous variables were compared with the Wilcoxon test. The sensitivity, specificity, and positive and negative predictive values were calculated for the NPT-R. Correlations among the SET, IgE, and SPT and between the SPT and IgE results were evaluated with the Spearman rank test. Receiver operating characteristic analyses were performed between the specific IgE (against Dpt) and the NTP-C and NPT-R results. Univariate logistic regressions were performed to identify predictive factors for allergic rhinitis triggered by HDM. Factors with a P value less than .20 were included in a multivariate analysis with a stepwise selection, and factors with a P value less than .10 were retained. P values less than .05 were considered significant. Analyses were performed with SAS 9.2 (SAS Institute, Cary, North Carolina) and R Software (R Development, Vienna, Austria). Results Study Population Eighty-eight subjects were included in the study: 49 subjects were allergic to HDM (HDMþ) and 39 subjects were not allergic to HDM (HDM) according to the inclusion criteria. All subjects had rhinitis, and 24% of subjects reported asthma. Rhinitis was classified as perennial for most subjects (91%) and the severity was mostly moderate to severe (96%). The 2 groups were well balanced for demographic characteristics, symptoms, FEV1, and rhinitis history. However, there were notable differences between the 2 groups. Proportionally more subjects with HDMþ than with HDM experienced a worsening of rhinitis symptoms over time (18% vs 2.5%, P < .05). Moreover, more subjects with HDMþ than with HDM experienced rhinitis on contact with an animal (49% vs 20.5%, P < .01) or at home (31% vs 5%, P < .001). Results are presented in Table 2. In addition, rhinitis had started more recently in subjects with HDMþ (mean SD 10.3 8.2 years old) than in subjects with HDM (18.0 12.4 years old, P < .01). The triggering factor for rhinitis most often reported by subjects with HDMþ was performing housework (94%). The authors investigated whether this criterion alone could be used as a predictive factor for identifying subjects with HDM allergic rhinitis, and they found that doing
3
Table 2 Subjects’ clinical characteristics HDMþ (n ¼ 49) Sex, n (%) Women Men Age (y) Mean (SD) Median (min; max) Asthma, yes, n (%) Aggravation of rhinitis over time, yes, n (%) Seasonality, n (%) Perennial only Perennial with seasonal worsening Seasonal only Allergy to animals, yes, n (%) Symptoms at home, yes, n (%)
31 (63.5) 18 (36.7) 28.4 24 14 9
(9.6) (18; 58) (28.6) (18.0)
HDM (n ¼ 39)
30 (76.9) 9 (23.1) 26.6 23 7 1
(8.9) (18; 53) (17.9) (2.5)
Total (n ¼ 88)
61 (69.3) 27 (30.7) 27.8 23 21 10
(9.3) (18; 58) (24) (11.3)
P valuea
NS
NS NS <.05
24 (49.0) 25 (51.0)
9 (23.1) 2 (5.1)
33 (37.5) 27 (30.7)
<.05 <.0001
0 (0.0) 24 (49.0)
28 (71.8) 8 (20.5)
28 (31.8) 32 (36.4)
<.0001 <.01
15 (30.6)
2 (5.1)
17 (19.3)
<.01
Abbreviations: HDM, subjects not allergic to house dust mite (including those sensitized to house dust mite and allergic or nonallergic to another allergen); HDMþ, subjects allergic to house dust mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus); max, maximum; min, minimum; NS, not significant. a P < .05 considered statistically significant.
housework was a statistically significant factor in triggering rhinitis from HDM (P < .0001). Allergy Tests The HDMþ group was comprised of subjects with monosensitization (n ¼ 9) and poly-sensitization (n ¼ 40) and HDM allergies. The control group (HDM) was comprised of subjects without (n ¼ 9) and with (n ¼ 30) atopy (Table 3). The HDMþ group was highly sensitized to HDM; the SPT wheal diameters were 6.9 2.6 mm (mean SD) to Dpt and 5.9 2.4 mm to Df. The IgE concentrations were 19.3 23.0 kU/L (mean SD) to Dpt and 23.4 25.3 kU/L to Df. There was no correlation between HDM specific IgE levels and SPT results. The highest concentrations that did not induce a positive SPT reaction during the SET were 10 IR (2.0%), 1 IR (36.7%), 101 IR (49.0%), and 102 IR (12.2%). Nasal Provocation Tests Of the 52 subjects sensitized to HDM, 49 had a positive NPT-C result. This finding confirmed the HDM allergic rhinitis diagnosis (HDMþ). The NPT-C result was considered positive when the
Table 3 Skin prick tests results SPT
HDMþ (n ¼ 49)
HDM (n ¼ 39)
HDM (Dpt and/or Df) Cat Dog Grass Birch Ash Ragweed Alternaria Cockroach None
49 25 12 28 28 20 3 3 2 0
3 6 4 20 15 2 2 1 0 9
Abbreviations: Df, Dermatophagoides farinae; Dpt, Dermatophagoides pteronyssinus; HDM, house dust mite; HDM, subjects not allergic to house dust mite (including those sensitized to house dust mite and allergic or nonallergic to another allergen); HDMþ, subjects allergic to house dust mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus) based on a clinical history of perennial rhinitis with a positive SPT reaction and a specific IgE reaction to HDM and confirmed by classic nasal provocation testing; SPT, skin prick test.
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subject had a positive Lebel score (n ¼ 42) and/or a positive rhinomanometric level (n ¼ 28). The NPT-R was performed more rapidly than the NPT-C (mean SD 22 8 vs 97 20 minutes, respectively). The NPT-R results were positive in 41 of 49 of the HDMþ group and in none of the HDM group. Results are shown in the online supplement (eFig 1). Therefore, the NPT-R was not as sensitive as the NPT-C (83.7%), but the 2 tests were equally specific (100%; Table 4). The correlation between the 2 NPTs was excellent (0.833, 95% CI 0.756e0.888, P < .0001; Table 5). The concentrations that induced a positive response in the NPT-R or NPT-C also were correlated (0.35, P < .05). The median amount of Der p 1 that induced a positive NPT result was lower in the NPT-R group (47.4 ng, range 7.9e126.4) than in the NPT-C group (87.7 ng, range 0.08e877.7; Fig 1). Eight subjects in the HDMþ group had negative NPT-R results; in those 8 cases, the eliciting concentrations during the NPT-C were 100 IR (n ¼ 4) and 10 IR (n ¼ 4). Correlation among SPT, Specific IgE, and NPT The SET was inversely correlated to the specific IgE (Dpt, r ¼ 0.56, P < .05) and to the SPT wheal diameter (Dpt, r ¼ 0.55, P < 0.0001; Df, r ¼ 0.45, P < .005). The areas under the curve obtained with the receiver operating characteristic analyses between the IgE Dpt and NPT results were high for the NPT-C and NPT-C (0.948 and 0.910, respectively); this finding showed that the IgE Dpt results were strongly linked to the NPT results (Fig 2). Safety The 2 versions of the NPT were found to be equally safe; only 1 subject experienced an asthma exacerbation during the study. That episode was a mild asthma attack, which occurred after the NPT-C and the NPT-R. It might have been associated with hyperventilation syndrome, and it resolved after 2 puffs of a short-acting b2-agonist. In addition, the FEV1 remained constant before and after the 2 NPTs for all subjects (Table 6). Discussion The main objective of this work was to evaluate the sensitivity, specificity, and the safety of a rapid version of the NPT (NPT-R) for the diagnosis of HDM allergic rhinitis. The authors studied 2 populations, one with allergic rhinitis triggered by HDM, based on a positive NPT-C result, and one with rhinitis that was not triggered by HDM (allergic to other allergens or no allergy), based on a negative NPT-C result. The NPT-R had a positive predictive value of 100%, although the control group was comprised mainly of subjects with atopy (n ¼ 30); only approximately 23% did not have atopy (n ¼ 9). This result highlighted the high specificity of the NPT-R. The results of the 2 NPT methods were strongly correlated (0.8, P < .0001) and the eliciting concentrations were significantly correlated (0.35, P < .05). However, the negative predictive value of the NPT-R was slightly low (83%). This low negative predictive value
Table 5 Correlation between NPT-C and NPT-Ra NPT-R positive NPT-C positive NPT-C negative Correlation between NPTs
NPT-R negative
41 8 0 39 0.833 (0.756e0.888, P < .0001)
Abbreviations: NPT-C, classic nasal provocation test; NPT-R, rapid nasal provocation test. a Data are presented as number of patients.
might be explained by the absence of a 100-IR exposure in the NPTR. Indeed, the amount of Der p 1 that induced a positive NPT result was lower for the NPT-R (47.4 ng, range 7.9e126.4) than for the NPT-C (87.7 ng, range 0.08e877.7); nevertheless, 4 of 8 subjects with a negative NPT-R result reacted to 100 IR with the NPT-C (corresponding to 790 ng of Der p 1). It was difficult to compare the present results with those of previous studies that documented an eliciting dose in HDM allergic rhinitis, because previous reports were scattered, and they used different allergenic extracts, NPT methods (allergen application techniques and increments), and positivity criteria. However, Kirerleri et al,5 who used the same Dpt extract as that used in the present study, found that 92% of the population responded to an eliciting concentration lower than or equal to 3.2 IR. In addition, it was estimated that 20 ng of Der p 1 was necessary to induce an immediate bronchial response, and that 12 ng of Der p 1 was necessary to induce respiratory symptoms at home.18 Therefore, those results brought into question the clinical significance of a positive nasal response obtained with a high dose of mite allergens, such as 100 IR. Another potential reason that the NPT-R showed lower sensitivity than the NPT-C might have been that rhinomanometry was not used. The use of an objective measurement of nasal patency (peak nasal inspiratory flow, rhinomanometry, acoustic rhinometry) combined with a symptom score has been recommended,9,16 but adequate standardization remains lacking.11 In the present study, the value of adding rhinomanometry was only slightly useful for the correct diagnosis, because only 7 of 49 cases had positive rhinomanometric results combined with a negative Lebel score during NPT-C. However, 14% (7 of 49 cases) cannot be considered negligible; but the practical advantages of the NPT-R could compensate for its low added value, because the NPT-R was designed to confirm HDM allergic rhinitis diagnosis.7 The second objective of this work was to propose a more rapid, safe method for the NPT. The NPT-R was performed considerably faster than the NPT-C (22 8 vs 97 20 minutes, respectively). The time saved was due to a decrease in the number of allergen nasal delivery steps, the elimination of rhinomanometry, and the
Table 4 Sensitivity, specificity, PPV, and NPV of NPT-R with HDM allergen Positive NPT-R HDMþ
HDM
41/49
0/39
Sensitivity
83.7%
Specificity
PPV
NPV
100%
100%
83%
Abbreviations: HDM, house dust mite; HDM , subjects not allergic to house dust mite (including those sensitized to house dust mite and allergic or nonallergic to another allergen); HDMþ, subjects allergic to house dust mite (Dermatophagoides farinae and/or Dermatophagoides pteronyssinus) based on a clinical history of perennial rhinitis with a positive skin prick test reaction and a specific IgE reaction to HDM and confirmed by classic nasal provocation testing; NPT-R, rapid nasal provocation test; NPV, negative predictive value; PPV, positive predictive value.
Figure 1. Histogram comparing the classic (dark gray bars) with the rapid (light gray bars) nasal provocation test (NPT) in a population allergic to house dust mite. Data are expressed as the percentage of all positive NPT results at eliciting each house dust mite allergen concentration (IR). Only 1-, 5-, and 10-IR doses were tested when using the rapid NPT and 5 IR was not tested when using the classic NPT.
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5
Table 6 FEV1 values before and after NPT-C and NPT-R FEV1 (L)
NTP-C Mean SD (%) Min (%); max (%) NPT-R Mean SD (%) Min (%); max (%)
P value
Before
1 h After
6 h After
3.4 0.73 (98)
3.4 0.70 (98)
3.4 0.71 (98)
1.8 (72); 5.2 (120) 1.8 (72); 5 (117)
1.6 (71.2); 5.2 (116)
3.5 0.69 (98.1)
3.4 0.64 (98)
3.5 0.87 (98)
1.9 (77); 5 (117)
1.8 (77); 4.8 (105) 2.1 (108); 7.8 (117)
NS
NS
Abbreviations: FEV1, forced expiration volume in 1 second; max, maximum; min, minimum; NPT-C, classic nasal provocation test; NPT-R, rapid nasal provocation test; NS, not significant.
Figure 2. Receiver operating characteristic (ROC) curves of specific IgE against Dermatophagoides pteronyssinus and the (A) classic and (B) rapid nasal provocation test results.
elimination of the SET. The SET has been recommended to determine the initial dose for safety purposes. However, its elimination did not increase the rate of adverse events, and no correlation was found between the SET results and the eliciting NPT-R dose. Importantly, there were no safety concerns during this study; no exacerbation of asthma was observed, although one fourth of subjects (24%) had asthma. This finding was consistent with that of Clarke19 who reported no complications among more than 1,000 NPTs. The authors also investigated the correlation between allergy tests and the NPT. Receiver operating characteristic analysis between the IgE Dpt and the NPT results confirmed a strong link between the
Dpt IgE and the NPT results. To the authors’ knowledge, this is the first study to show a link between specific IgE and NPT results in HDM allergic rhinitis. Some works have shown a link between NPT and SPT wheal size,4,6 but others have not observed that link.3,5 In the present study, nearly all patients (49 of 52, 94.2%) who had consulted for a suspected HDM allergy (perennial rhinitis and HDM sensitization) were found to have a positive NPT-C reaction (eFigure 1). Those results were unexpected, because the prevalence was higher than in other studies. In previous studies, only 70% to 80% of patients with positive SPT responses to HDM allergens had a positive NPT result.3,4,6,19,20 The high rate of positivity found in the present study might be explained by the fact that this study population consisted of relatively young adults (mean 28.4 years, range 18e59) who were highly sensitized to HDM allergens. In younger populations (6e18 years), positive NPT results were found in 92%5 and 94%21 of subjects. In an older population, King et al22 reported a positive predictive value of only 42.86% for a positive SPT reaction. In a population the same age as that in the present study, others have reported 89% to 100% of subjects with positive NPT reactions in those sensitized to HDM.23,24 In HDM allergy, the relation between symptoms and HDM exposure can be difficult to assess, unlike allergies to cat and pollen.25 In the present study, only 30% of the HDMþ group had symptoms at home, but when asked whether doing housework was a trigger for rhinitis, a positive answer was strongly linked to HDM allergy (P < .0001). Indeed, HDM allergens in house dust become airborne only after disturbance.26 These characteristics reinforced interest in using the NPT for a specific diagnosis of HDM-triggered allergic rhinitis. This study had some limitations. First, the study could not be randomized. The provocation tests were applied in the same order for all subjects, and this order effect could lead to a bias. A crossover study design might have been more appropriate to avoid this effect. However, because the 2 tests were separated by at least 4 weeks, the authors presumed that the carryover effect due to a “priming effect” would be negligible; thus, the order effect could be ignored. Second, the allergen concentrations used for the NPT were different between subjects sensitized to HDM and those not sensitized to HDM. From a methodologic viewpoint, to evaluate the effects of omitting the SET and rhinomanometry, it would be preferable to use the same Dpt concentrations in the NPT-R and the NPT-C. However, the authors also aimed to propose an easy, safe NPT method; thus, only 3 Dpt deliveries and lower concentrations were used. The 1-, 5-, and 10-IR doses were chosen for the NPT-R protocol based on experience and on a study by Kirerleri et al.5 The present results showed that the NPT-R could facilitate confirmation of a HDM allergic rhinitis diagnosis; thus, its use could identify a false-positive HDM allergic rhinitis diagnosis before initiating immunotherapy, as recommended by international
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guidelines. Indeed, clinical studies that have assessed the effect of desensitization in adults generally included subjects 18 to 70 years old and subjects potentially less sensitized than the subjects included in the present study. Therefore, there might be a higher rate of false-positive diagnoses.8,12 In conclusion, the present study demonstrated that the NPT-R is a highly specific, rapid, safe tool for confirming the clinical relevance of HDM allergy. This tool might be particularly useful for evaluating patients with perennial rhinitis who are sensitized to HDM, because diagnosing HDM allergic rhinitis with current methods remains problematic or uncertain. Thus, this test could decrease the number of unnecessary, lengthy, and costly HDM desensitization procedures. Acknowledgment The authors thank Brigitte Sbinne and Mael Bellier for technical support. Supplementary Data Supplementary data related to this article can be found online at http://dx.doi.org/10.1016/j.anai.2015.07.014. References [1] Huet S, Grimberg P, Autegarden JE, Leynadier F. Study of validation of a questionnaire by skin testing in house dust mite allergy. Rev Fr Allergol Immunol Clin. 2001;41:712e719. [2] Bousquet J, Khaltaev N, Cruz AA, et al. Allergic Rhinitis and its Impact on Asthma (ARIA) 2008 update (in collaboration with the World Health Organization, GA(2)LEN and AllerGen). Allergy. 2008;63:8e160. [3] Stenius B. Skin and provocation tests with Dermatophagoides pteronyssinus in allergic rhinitis. Comparison of prick and intracutaneous skin test methods and correlation with specific IgE. Acta Allergol. 1973;28:81e100. [4] Kanthawatana S, Maturim W, Fooanan S, Trakultivakorn M. Skin prick reaction and nasal provocation response in diagnosis of nasal allergy to the house dust mite. Ann Allergy Asthma Immunol. 1997;79:427e430. [5] Kirerleri E, Guler N, Tamay Z, Ones U. Evaluation of the nasal provocation test for its necessity in the diagnosis of nasal allergy to house dust mite. Asian Pac J Allergy Immunol. 2006;24:117e121. [6] Chusakul S, Phannaso C, Sangsarsri S, Aeumjaturapat S, Snidvongs K. Housedust mite nasal provocation: a diagnostic tool in perennial rhinitis. Am J Rhinol Allergy. 2010;24:133e136. [7] Agache I, Bilò M, Braunstahl GJ, et al. In vivo diagnosis of allergic diseasesallergen provocation tests. Allergy. 2015;70:355e365. [8] Malm L, Gerth van Wijk R, Bachert C. Guidelines for nasal provocations with aspects on nasal patency, airflow, and airflow resistance. International Committee on Objective Assessment of the Nasal Airways, International Rhinologic Society. Rhinology. 2000;38:1e6. [9] Gosepath J, Amedee RG, Mann WJ. Nasal provocation testing as an international standard for evaluation of allergic and nonallergic rhinitis. Laryngoscope. 2005;115:512e516.
[10] Riechelmann H, Bachert C, Golschmidt O, et al. Application of the nasal provocation test on diseases of the upper airways. Position paper of the German Society for Allergology and Clinical Immunology (ENT Section) in cooperation with the Working Team for Clinical Immunology. Laryngorhinootologie. 2003;82:183e188. [11] Pfaar O, Demoly P, Gerth van Wijk R, et al. Recommendations for the standardization of clinical outcomes used in allergen immunotherapy trials for allergic rhinoconjunctivitis: an EAACI Position Paper. Allergy. 2014;69: 854e867. [12] European Medicines Agency. Pre-authorsation evaluation of medicines for human use. Document HMP/EWP/18504. http://www.ema.europa.eu/docs/en_GB/ document_library/Scientific_guideline/2009/09/WC500003605.pdf. Published November 20, 2008. [13] Melillo G, Bonini S, Cocco G, et al. EAACI provocation tests with allergens. Report prepared by the European Academy of Allergology and Clinical Immunology subcommittee on provocation tests with allergens. Allergy. 1997;52(suppl):1e35. [14] Scadding G, Hellings P, Alobid I, et al. Diagnostic tools in rhinology EAACI position paper. Clin Transl Allergy. 2011;1:2. [15] Hellings PW, Scadding G, Alobid I, et al. Executive summary of European Task Force document on diagnostic tools in rhinology. Rhinology. 2012;50: 339e352. [16] Dordal MT, Lluch-Bernal M, Sánchez MC, et al. Allergen-specific nasal provocation testing: review by the rhinoconjunctivitis committee of the Spanish Society of Allergy and Clinical Immunology. J Investig Allergol Clin Immunol. 2011;21:1e12. [17] Lebel B, Bousquet J, Morel A, Chanal I, Godard P, Michel FB. Correlation between symptoms and the threshold for release of mediators in nasal secretions during nasal challenge with grass-pollen grains. J Allergy Clin Immunol. 1988;82:869e877. [18] de Blay F. Provocation tests as measure of efficacy and dosage. Allergy. 2011; 66:47e49. [19] Clarke PS. The diagnosis of perennial rhinitis due to house dust mite (Dermatophagoides pteronyssinus) demonstrated by nasal provocation tests. Ann Allergy. 1987;59:25e28. [20] Riechelmann H, Mewes T, Weschta M, Gropper G. Nasal allergen provocation with Dermatophagoides pteronyssinus in patients with chronic rhinitis referred to a rhinologic surgical center. Ann Allergy Asthma Immunol. 2002;88: 624e631. [21] Anantasit N, Vilaiyuk S, Kamchaisatian W, et al. Comparison of conjunctival and nasal provocation tests in allergic rhinitis children with Dermatophagoides pteronyssinus sensitization. Asian Pac J Allergy Immunol. 2013;31: 227e232. [22] King MJ, Tamulis T, Lockey RF. Prick puncture skin tests and serum specific IgE as predictors of nasal challenge response to Dermatophagoides pteronyssinus in older adults. Ann Allergy Asthma Immunol. 2008;101:12e17. [23] Riechelmann H, Epple B, Gropper G. Comparison of conjunctival and nasal provocation test in allergic rhinitis to house dust mite. Int Arch Allergy Immunol. 2003;130:51e59. [24] Rondón C, Romero JJ, López S, et al. Local IgE production and positive nasal provocation test in patients with persistent nonallergic rhinitis. J Allergy Clin Immunol. 2007;119:899e905. [25] Droste JH, Kerhof M, de Monchy JG, Schouten JP, Rijcken B. Association of skin test reactivity, specific IgE, total IgE, and eosinophils with nasal symptoms in a community-based population study. The Dutch ECRHS Group. J Allergy Clin Immunol. 1996;97:922e932. [26] de Blay F, Heymann PW, Chapman MD, Platts-Mills TA. Airborne dust mite allergens: comparison of group II allergens with group I mite allergen and cat-allergen Fel d I. J Allergy Clin Immunol. 1991;88:919e926.
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eFigure 1. Results of the SPT, IgE, and NPT in the study group. Df, Dermatophagoides farinae; Dpt, Dermatophagoides pteronyssinus; HDM, house dust mite; IgE, immunoglobulin E; NPT-C, classic nasal provocation test with clinical score, skin end-point titration, and rhinomanometry; NPT-R, rapid nasal provocation test with clinical score; SPT, skin prick test.
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