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The use of a flowcytometric basophil activation test (FAST) for the in vitro diagnosis of latex allergy
8284
Abstracts
68 Symptoms Behavioral Modifications in Response to Latex Glove-Induced Gary Stadtmauer, Matthew Chen, Alex Kaplan, Jacqueline Moline Mount Sinai School of Medicine, New York, NY BACKGROUND: The prevalence of sensitivity to natural rubber latex (NRL) has been studied in many different populations. While studies have addressed the prevalence, diagnosis and financial consequences, to our knowledge, none has focused on behavioral responses. OBJECTIVE: We conducted a questionnaire-based cross sectional survey of Mount Sinai Hospital personnel about the prevalence of symptoms and behavioral response to the usage of latex gloves. Medical and surgical specialties, obstetrics/gynecology, psychiatry and pediatric staff including medical students, housestaff and attendings, laboratory and nursing staff were surveyed. 1480 questionnaires were distributed and 414 were returned (28%). Symptoms were classified as localized (dermatitis) or allergic (lgEmediated). Localized skin symptoms included itching, chapping, cracking, rash, swollen hands, hives or blisters while reactions were deemed lgEmediated if ocular, nasal, palatal, chest or constitutional. RESULTS: Overall glove usage in this sample of healthcare workers (HCW) was 88.6% largely due to the inclusion of psychiatrists who had minimal glove usage. 116 of 414 (28.0%) respondents experienced at least one symptom to latex gloves. 112 of the 116 symptomatic subjects had localized cutaneous symptoms while 39 (39.4%) subjects had likely IgEmediated symptomatology. Thus the overall incidence of Type I NRL symptoms of 9.4% is compatible with results of other studies. We then measured the behavioral response to symptoms in latex glove wearers. Modifications included seeing a physician, taking medications to suppress symptoms, taking time off work, modifying the daily schedule or avoiding glove use altogether to avoid NRL exposure. Of 116 symptomatic HCWs, only 18 (15.5%) had seen a physician regarding their reactions to NRL. However, 44/116 (37.9%) had modified their activities of who 40/44 (90.9%) were effective in reducing latex glove related symptoms. 4 (3.4% of those symptomatic) persons had missed work while 27/116 (23.3%) took medications to suppress symptoms. 35/116 (30.2%) subjects had avoided using any gloves to reduce glove-related symptoms and subsequently 11/35 (31.4%) were exposed to body fluids or blood products. 5 of 84 housestaff (6.0%) were exposed to blood/body fluids, which is an incidence almost 4 times higher than other hospital staff (6/328; 1.8%) responding to the questionnaire. CONCLUSION: Personal avoidance behavior of latex, in the absence of an available substitute, may lead to exposure to infectious body fluids. Medical staff, especially overworked housestaff, should be routinely evaluated and treated for LA and glove-induced symptoms. Alternatives to latex gloves should be readily available.
869The Use of a Flowcytometric Basophil Activation Test (FAST)for the Diagnosis of Latex Allergy In Vitro
ML Sanz*, MC Garc(a-Avil~s*, PM Gamboa§, JP Maselli*, l Di~guez*, AL De Weck* *University Hospital of Navarra, Pamplona, Spain §Hospital de Basurto, Bilbao, Spain The use of a flowcytometric basophil activation test in the in vitro diagnosis of allergic diseases to different allergens has been recommended in recent years. In this study, we analysed the diagnostic reliability of the Flow-cytometric Allergen Stimulation Test (FAST) after latex-specific stimulation in vitro. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters. Forty three patients allergic to latex and 30 subjects with negative history, skin tests and negative serum specific IgE to latex were selected as controls. FAST uses flow cytometry to determine the percentage of basophils that
J ALLERGY CLIN IMMUNOL JANUARY 2002
express CD63 as an activation marker after in vitro stimulation with allergen (latex), Double labelling with monoclonal antibodies anti-CD63-PE and anti-IgE FITC was used. lntraclass correlation coefficient in FAST with latex was 0.995; (p<0.0001) which demonstrates an excellent reproducibility of this technique. Taking a cut-off point of 10% by means of ROC curves, FAST offers a sensitivity of 93% and specificity of 100%. FAST positive predictive value in latex allergy was 100 and the negative predictive value was 99.9. We found a positive and significant correlation between FAST and specific IgE (CAP, Pharmacia Upjohn), with histamine release test (HRT) and specific sulphidoleukotrien production (CAST, Biihlmann) (p<0.001). FAST is a highly reliable technique (93% sensitivity and 100% specificity), in the in vitro diagnosis of IgE-mediated latex allergy.
870 Latex Double-Blind, Placebo-Controlled, Oral Challenge Study With Glove Extract in Patients Allergic to Natural Rubber Latex C De Castro, Santiago Quirce, M Fernrndez-Nieto, A Alemcin, Joaquin Sastre Fundacirn Jimrnez Dfaz, Madrid, Spain Allergic reactions to natural rubber latex (NRL) may occur after ingestion of latex contaminated foodstuffs. It has been shown by immunologic methods that latex proteins can be transferred to food following contact with latex gloves. The goal of this study was to assess whether latex-contaminated food can provoke allergic symptoms in patients sensitized to NRL. An extract of NRL gloves was prepared at 10% w/v. Thirty 1-cm2 freshlycut glove pieces (500 mg total weight) were stirred for 30 min in 5 ml of sterile normal saline, finally it was passed through a 0.22/am filter. Six health care workers (range age 24-34 years old) allergic to NRL were recruited from our hospital. All of them suffered from rhinitis and contact urticaria with NRL gloves and four of them had latex-induced asthma. They all had a positive skin test with NRL extract (20 ktg/ml protein, ALK-Abel16. Spain) and specific IgE to NRL (Pharmacia, Sweden). A double-blind, placebo-controlled, oral challenge with latex glove extract was carried out. At 30-minute intervals, the subjects received 10 ml of sugar-water solution as placebo, followed by 0.2 and 0.5 ml of the aqueous solution with increasing concentrations (0.01,0. I, 1 and 10% w/v) of NRL glove extract. Three patients (50%) showed a positive DBPCOC test, whereas none of the 4 control subjects reacted to this challenge. All of the patients who experienced a positive response to DBPCOC had asthma due to latex, and two of them had food allergic symptoms with fruits (oral allergy syndrome to kiwi and anaphylaxis to banana, respectively). Five of the patients had positive skin tests with fruits (banana, avocado, chestnut and kiwi), but only two patients had allergic symptoms when eating them. These data point out that the intake of NRL-contaminated food by sensitized patients may elicit allergic symptoms. Thus, as part of the latex avoidance measures, we suggest that patients allergic to NRL should be warn about avoiding the ingestion of foodstuffs which have been handled or processed by personnel wearing NRL gloves.
Pt. I 2 3 4 5 6
Specific IgE (kU/L) 2.49 2.78 2 27.5 10.7 2.63
DBPCOC with NRL Dose of NRL 0.5 ml 10% 0.5 m110% 0.2 ml 10% 0.5 ml 0.001% 0.5 ml 0.01% 0.5 ml 10%
Latency
Symptoms
10 min 10min 15 min
R, PC, 1 PC, I PC, l, D
R = rhinitis, PC = pharyngeal congestion, I = pharyngeal itching, D = dysphonia.
Abstracts
68 Symptoms Behavioral Modifications in Response to Latex Glove-Induced Gary Stadtmauer, Matthew Chen, Alex Kaplan, Jacqueline Moline Mount Sinai School of Medicine, New York, NY BACKGROUND: The prevalence of sensitivity to natural rubber latex (NRL) has been studied in many different populations. While studies have addressed the prevalence, diagnosis and financial consequences, to our knowledge, none has focused on behavioral responses. OBJECTIVE: We conducted a questionnaire-based cross sectional survey of Mount Sinai Hospital personnel about the prevalence of symptoms and behavioral response to the usage of latex gloves. Medical and surgical specialties, obstetrics/gynecology, psychiatry and pediatric staff including medical students, housestaff and attendings, laboratory and nursing staff were surveyed. 1480 questionnaires were distributed and 414 were returned (28%). Symptoms were classified as localized (dermatitis) or allergic (lgEmediated). Localized skin symptoms included itching, chapping, cracking, rash, swollen hands, hives or blisters while reactions were deemed lgEmediated if ocular, nasal, palatal, chest or constitutional. RESULTS: Overall glove usage in this sample of healthcare workers (HCW) was 88.6% largely due to the inclusion of psychiatrists who had minimal glove usage. 116 of 414 (28.0%) respondents experienced at least one symptom to latex gloves. 112 of the 116 symptomatic subjects had localized cutaneous symptoms while 39 (39.4%) subjects had likely IgEmediated symptomatology. Thus the overall incidence of Type I NRL symptoms of 9.4% is compatible with results of other studies. We then measured the behavioral response to symptoms in latex glove wearers. Modifications included seeing a physician, taking medications to suppress symptoms, taking time off work, modifying the daily schedule or avoiding glove use altogether to avoid NRL exposure. Of 116 symptomatic HCWs, only 18 (15.5%) had seen a physician regarding their reactions to NRL. However, 44/116 (37.9%) had modified their activities of who 40/44 (90.9%) were effective in reducing latex glove related symptoms. 4 (3.4% of those symptomatic) persons had missed work while 27/116 (23.3%) took medications to suppress symptoms. 35/116 (30.2%) subjects had avoided using any gloves to reduce glove-related symptoms and subsequently 11/35 (31.4%) were exposed to body fluids or blood products. 5 of 84 housestaff (6.0%) were exposed to blood/body fluids, which is an incidence almost 4 times higher than other hospital staff (6/328; 1.8%) responding to the questionnaire. CONCLUSION: Personal avoidance behavior of latex, in the absence of an available substitute, may lead to exposure to infectious body fluids. Medical staff, especially overworked housestaff, should be routinely evaluated and treated for LA and glove-induced symptoms. Alternatives to latex gloves should be readily available.
869The Use of a Flowcytometric Basophil Activation Test (FAST)for the Diagnosis of Latex Allergy In Vitro
ML Sanz*, MC Garc(a-Avil~s*, PM Gamboa§, JP Maselli*, l Di~guez*, AL De Weck* *University Hospital of Navarra, Pamplona, Spain §Hospital de Basurto, Bilbao, Spain The use of a flowcytometric basophil activation test in the in vitro diagnosis of allergic diseases to different allergens has been recommended in recent years. In this study, we analysed the diagnostic reliability of the Flow-cytometric Allergen Stimulation Test (FAST) after latex-specific stimulation in vitro. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters. Forty three patients allergic to latex and 30 subjects with negative history, skin tests and negative serum specific IgE to latex were selected as controls. FAST uses flow cytometry to determine the percentage of basophils that
J ALLERGY CLIN IMMUNOL JANUARY 2002
express CD63 as an activation marker after in vitro stimulation with allergen (latex), Double labelling with monoclonal antibodies anti-CD63-PE and anti-IgE FITC was used. lntraclass correlation coefficient in FAST with latex was 0.995; (p<0.0001) which demonstrates an excellent reproducibility of this technique. Taking a cut-off point of 10% by means of ROC curves, FAST offers a sensitivity of 93% and specificity of 100%. FAST positive predictive value in latex allergy was 100 and the negative predictive value was 99.9. We found a positive and significant correlation between FAST and specific IgE (CAP, Pharmacia Upjohn), with histamine release test (HRT) and specific sulphidoleukotrien production (CAST, Biihlmann) (p<0.001). FAST is a highly reliable technique (93% sensitivity and 100% specificity), in the in vitro diagnosis of IgE-mediated latex allergy.
870 Latex Double-Blind, Placebo-Controlled, Oral Challenge Study With Glove Extract in Patients Allergic to Natural Rubber Latex C De Castro, Santiago Quirce, M Fernrndez-Nieto, A Alemcin, Joaquin Sastre Fundacirn Jimrnez Dfaz, Madrid, Spain Allergic reactions to natural rubber latex (NRL) may occur after ingestion of latex contaminated foodstuffs. It has been shown by immunologic methods that latex proteins can be transferred to food following contact with latex gloves. The goal of this study was to assess whether latex-contaminated food can provoke allergic symptoms in patients sensitized to NRL. An extract of NRL gloves was prepared at 10% w/v. Thirty 1-cm2 freshlycut glove pieces (500 mg total weight) were stirred for 30 min in 5 ml of sterile normal saline, finally it was passed through a 0.22/am filter. Six health care workers (range age 24-34 years old) allergic to NRL were recruited from our hospital. All of them suffered from rhinitis and contact urticaria with NRL gloves and four of them had latex-induced asthma. They all had a positive skin test with NRL extract (20 ktg/ml protein, ALK-Abel16. Spain) and specific IgE to NRL (Pharmacia, Sweden). A double-blind, placebo-controlled, oral challenge with latex glove extract was carried out. At 30-minute intervals, the subjects received 10 ml of sugar-water solution as placebo, followed by 0.2 and 0.5 ml of the aqueous solution with increasing concentrations (0.01,0. I, 1 and 10% w/v) of NRL glove extract. Three patients (50%) showed a positive DBPCOC test, whereas none of the 4 control subjects reacted to this challenge. All of the patients who experienced a positive response to DBPCOC had asthma due to latex, and two of them had food allergic symptoms with fruits (oral allergy syndrome to kiwi and anaphylaxis to banana, respectively). Five of the patients had positive skin tests with fruits (banana, avocado, chestnut and kiwi), but only two patients had allergic symptoms when eating them. These data point out that the intake of NRL-contaminated food by sensitized patients may elicit allergic symptoms. Thus, as part of the latex avoidance measures, we suggest that patients allergic to NRL should be warn about avoiding the ingestion of foodstuffs which have been handled or processed by personnel wearing NRL gloves.
Pt. I 2 3 4 5 6
Specific IgE (kU/L) 2.49 2.78 2 27.5 10.7 2.63
DBPCOC with NRL Dose of NRL 0.5 ml 10% 0.5 m110% 0.2 ml 10% 0.5 ml 0.001% 0.5 ml 0.01% 0.5 ml 10%
Latency
Symptoms
10 min 10min 15 min
R, PC, 1 PC, I PC, l, D
R = rhinitis, PC = pharyngeal congestion, I = pharyngeal itching, D = dysphonia.