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High prevalence of Anisakis simplex hypersensitivity and allergy in Sicily, Italy
Ann Allergy Asthma Immunol 116 (2016) 146e150
Contents lists available at ScienceDirect
High prevalence of Anisakis simplex hypersensitivity and allergy in Sicily, Italy Enrico Heffler, MD, PhD; Maria Eva Sberna, MD; Stefania Sichili, MD, PhD; Rossella Intravaia, MD; Giuliana Nicolosi, MD; Morena Porto, MD; Maria Teresa Liuzzo, MD; Giuseppe Picardi, MD; Silvia Fichera, MD; Nunzio Crimi, MD, PhD Respiratory Medicine and Allergology, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
A R T I C L E
I N F O
Article history: Received for publication October 9, 2015. Received in revised form November 22, 2015. Accepted for publication December 14, 2015.
A B S T R A C T
Background: Anisakis simplex can elicit allergic reactions when ingested in raw or marinated fish. The prevalence of A simplex hypersensitivity and allergy in Sicily (Italy), an area where the consumption of raw or marinated fish is very common, has not been investigated thus far. Objective: To investigate the prevalence of A simplex sensitization and its clinical relevance in a large group of unselected patients. Methods: All consecutive patients referred to the authors’ allergy clinic during a 22 month-period were included in the study, evaluated for sensitization to A simplex and other allergens depending on their clinical history, and investigated for allergic symptoms after the ingestion of raw or marinated fish. Results: Of 3,419 patients screened, 527 (15.4%) were sensitized to A simplex and 29 of these (5.5% of sensitized patients) had a history of A simplex allergy. Approximately 30% of patients had mono-sensitization to A simplex. Co-sensitization to house dust mites or molds yielded an odds ratio of 1.98 or 3.18, respectively, for allergy to A simplex. Conclusion: A high prevalence of A simplex sensitization in a large proportion of patients with monosensitization was found, confirming that eating habits influence sensitization to this nematode. Allergic symptoms from A simplex ingestion in raw or marinated fish were quite frequent, with symptoms ranging from oral allergy syndrome to anaphylaxis. Patients sensitized to A simplex were more prone to have allergic symptoms when they had co-sensitization to house dust mites or molds, suggesting possible cross-reactive but clinically relevant allergens between these allergenic sources. Ó 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Introduction Anisakis simplex is a nematode and commonly parasitizes fishes, marine invertebrates, and sea mammals. Its life cycle is complex and involves several different hosts; adult A simplex nematodes reside in the gastrointestinal tract of marine mammals and lay nonembryonate eggs in the marine mammals’ feces, which are discharged into the water, where they develop into embryonate eggs and then larvae; crustaceans ingest A simplex larvae, which develop into a third stage that is infective to fish and squid. At the host’s death, larvae migrate to muscle tissues and are transferred from fish to fish through predation. Third-stage larvae also are infective to humans and marine mammals.1 Anisakis simplex larvae infect many species of fish and over a broad geographic area2; thus, eating Reprints: Enrico Heffler, MD, PhD, Pneumologia Riabilitativa e Allergologia, AOU “Policlinico-Vittorio Emanuele”, Via Santa Sofia 78-95123, Catania, Italy; E-mail: heffl[email protected]. Disclosures: Authors have nothing to disclose.
raw or undercooked infected fish can lead to larval infestation and cause severe gastrointestinal symptoms (anisakiasis).3 Several studies have suggested that A simplex can act as a food allergen and induce immunoglobulin E (IgE)-mediated reactions, mostly urticaria and angioedema, but also anaphylactic reactions.4 However, several aspects of this type of food allergy remain poorly defined. Because some A simplex allergens have been found to be stable with heat, it has been suggested that the ingestion of seafood contaminated with third-stage A simplex larvae might sensitize or induce clinical symptoms even if the food is cooked and the parasitic infestation ability has been abolished5e7; however, in accordance with the limited prevalence of A simplex allergy in the general population, recent studies do not seem to support this view, and raw fish (mainly anchovies) marinated in vinegar have been detected as the main risk factor for sensitization.8e10 Other important issues concern the prevalence and clinical relevance of cross-reactivity between A simplex allergens and other invertebrates including shrimps, worms, and insects such as cockroaches or mites.11e13
http://dx.doi.org/10.1016/j.anai.2015.12.014 1081-1206/Ó 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
E. Heffler et al. / Ann Allergy Asthma Immunol 116 (2016) 146e150
Tropomyosin has been proposed as a pan-allergen of invertebrates because it appears to be allergenic in many invertebrate sources as a food and as an inhalant allergen,14,15 but this finding has not been confirmed by other researchers.12 In a recent Italian multicenter study, IgE reactivity to tropomyosin was detected in fewer than 50% of patients allergic to shrimp, and other allergens were found in a substantial number of patients (60-, >90-, 14- to 18-, 25-, 43- to 50-, and 80-kDa IgE-reactive bands) at immunoblot analysis.16 Most studies of A simplex allergy have been carried out in the Iberian peninsula, and little is currently known about the situation in other countries.8,17e19 A multicenter epidemiologic study investigated A simplex hypersensitivity in different areas of Italy and found a mean prevalence of 4.5% in the general study population. The highest frequency of A simplex hypersensitivity was found along the Adriatic and Tyrrhenian coasts.10,13,20 The aim of this study was to assess the prevalence and clinical relevance of A simplex hypersensitivity in the eastern part of Sicily (Italy), where traditional eating habits include consuming different dishes of raw or marinated fish. Methods Study Design All consecutive patients referred to the authors’ center in Catania (on the eastern coast of Sicily), regardless of their clinical problems (suspected skin, respiratory, food, or drug allergy), from July 1, 2010 through April 30, 2012 were included in the study. The study was approved by institutional ethics committee of the University of Catania (Catania, Italy) and all patients signed an informed consent for the study of their clinical data. All study subjects underwent a thorough interview about previous adverse reactions after the ingestion of any type of food. A history of oral allergy syndrome (defined as local itching of the lips, tongue, palate, throat, and/or ears and nose, and/or angioedema of the same areas),21 acute generalized urticaria with or without angioedema,22 anaphylaxis,23 and/or gastrointestinal complaints occurring some minutes up to 2 hours after ingestion of the offending food(s) was considered possibly associated with a food allergy. Skin Prick Tests Anisakis simplex hypersensitivity was assessed by a skin prick test (SPT) with a commercial extract (ALK-Abellò, Madrid, Spain). All study subjects underwent the SPT with a series of commercial airborne allergens (grass, mugwort, ragweed, pellitory, mimosa, plantain, birch, olive, and cypress pollens; molds: Alternaria alternata, Aspergillus fumigatus, and Cladosporium herbarum; house dust mites: Dermatophagoides pteronyssinus and Dermatophagoides farina; animal dander: from cat, dog, and horse; Lofarma, Milano, Italy). Patients with a clinical history of possible food allergy also underwent the SPT with a standard panel of commercial food allergen extracts (hen’s egg, cow’s milk, wheat, soybean, peanuts, walnut, hazelnut, peach, apple, tomato, shrimp, and cod; Stallergenes, Antony, France). Histamine (1 mg/mL) and glycerol in buffer diluent were used as positive and negative controls, respectively. The reaction was evaluated 20 minutes after administration and categorized as positive if it produced a wheal larger than 4 mm compared with the negative control. Diagnosis of Sensitization vs Allergy to Anisakis simplex In this survey, A simplex allergy was diagnosed if a suggestive clinical history (ie, oral allergy syndrome, acute generalized urticaria with or without angioedema, anaphylaxis, and/or gastrointestinal complaints occurring some minutes up to 2 hours after ingestion of raw or marinated fish) was confirmed by a clear-cut positive SPT reaction.
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Patients with a positive SPT reaction to A simplex but without a clear clinical history of adverse reactions induced by raw or marinated fish were considered sensitized but not allergic to the parasite. Statistics Descriptive analyses were performed. Continuous variables were evaluated with the Kolmogorov-Smirnov normality test and compared with analysis of variance or the Mann-Whitney test, depending on the normality of distribution. Categorical variables were compared using the Fisher exact test. All data were analyzed using SPSS 16.0 (SPSS, Inc, Chicago, Illinois). Results In total, 3,419 subjects (mean age 34.3 years, range 3e88 years, ratio of women to men 1.62) were screened for A simplex hypersensitivity during the study period. The number of subjects with atopy (those with at least 1 positive SPT reaction) was 1,562 (45.6%). In total, 527 subjects had a positive A simplex SPT reaction, which corresponds to a prevalence of 15.4% of the studied population (Fig 1A). Patients with a positive A simplex SPT reaction were slightly but significantly older than those with a negative SPT reaction (39.9 19.4 vs 33.3 18.7 years, P < .0001). Of 527 subjects sensitized to A simplex, 370 (70.2%) were sensitized to at least 1 other airborne or food allergen, whereas 157 (29.8%) were mono-sensitized to A simplex. In total, 276 of 527 patients (52.3%) with a positive A simplex SPT reaction also were sensitized to house dust mites compared with 683 of 2,892 patients (23.6%) sensitized to house dust mites but with a negative A simplex SPT reaction (P < .0001). Sensitization to house dust mites was associated with an increased risk of sensitization to A simplex (odds ratio 2.21, P < .0001). Based on clinical history, 66 patients (1.9% of studied population) reported symptoms suggestive of allergic reactions after the ingestion of raw or marinated fish (Fig 1B); 29 of these 66 patients (43.9%) were sensitized to A simplex and therefore considered allergic to A simplex (Fig 1C), corresponding to approximately 0.8% of the entire studied population. Having an SPT reaction positive for A simplex resulted in a odds ratio of 4.3 compared with those with a negative A simplex SPT reaction (P < .0001). Table 1 lists the main features of patients with vs without sensitization to A simplex. Patients with a positive A simplex SPT reaction represented a larger proportion of sensitization for all other considered classes of allergens (Table 1). Symptoms associated with allergy to A simplex were respiratory symptoms (dyspnea, chest tightness, wheezing, or rhinitis) in 12 of 29 patients (41.4%), gastrointestinal symptoms (abdominal pain, vomiting, or diarrhea) in 9 (31.0%), urticaria with or without angioedema in 4 (13.8%), oral allergy syndrome (local itching of lips, tongue, palate, throat, and/or ears and nose, and/or angioedema of the same areas) in 2 (6.9%), and anaphylaxis (defined according to the World Allergy Organization position paper23) in 2 (6.9%; Fig 2). Sixteen of 29 patients (55.2%) allergic to A simplex also were sensitized to house dust mites and 10 (34.5%) to molds (A alternata, A fumigatus, and/or C herbarum), whereas of the 3,390 subjects not allergic to A simplex, only 944 (27.8%) and 368 (10.8%) were sensitized to house dust mites and molds, respectively. Sensitization to house dust mites or molds resulted an odds ratio of 1.98 or 3.18, respectively, for allergy to A simplex (P ¼ .03 for house dust mites, P ¼ .002 for molds). There was no statistically significant difference in prevalence of allergy to A simplex between patients with mono-sensitivity to
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E. Heffler et al. / Ann Allergy Asthma Immunol 116 (2016) 146e150 Table 1 Comparison of patients sensitized vs not sensitized to Anisakis simplex
Age (y), mean (range) Ratio of women to men Clinical history of suspected allergic reaction to raw or marinated fish, n (%) Atopy, n (%)a Sensitizations, n (%) House dust mites Animal dander Grass pollen Parietaria pollen Tree pollensb Weed pollensc Moldsd Fishes
Patients sensitized to A simplex (n ¼ 527)
Patients not P value sensitized to A simplex (n ¼ 2,892)
39.9 (5e88) 1.64 29 (5.5)
33.3 (3e88) 1.62 37 (1.3)
<.0001 .9865 <.0001
370 (70.2)
1,190 (41.1)
<.0001
276 145 169 197 237 105 126 24
(52.3) (27.5) (32.1) (37.4) (45.0) (19.9) (23.9) (4.5)
683 358 479 598 684 263 252 51
(23.6) (12.4) (16.6) (2.7) (23.6) (9.1) (8.7) (1.8)
<.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001
a Atopy is defined as at least 1 positive skin prick test reaction to airborne and/or food allergens. b Cypress, olive, plane, and hazel trees. c Ragweed and Artemisia species. d Alternaria alternata, Cladosporium herbarum, and Aspergillus fumigatus.
allergy clinic) and therefore the study population might have been biased, a large number of subjects was investigated, which might provide an estimate of allergic problems related to A simplex sensitization in Sicily. A high prevalence of A simplex sensitization (w15% of the studied population) was found; this prevalence rate is similar to that observed in Spanish studies18 and in coastal areas in the largest Italian survey on A simplex allergy, in which the mean prevalence was 12.7%.10 The study by the AAITO-IFIACI Anisakis Consortium10 also included a center in Messina on the eastern coast of Sicily, which had a surprisingly low prevalence of A simplex sensitization (w0.8% of their population), which was in contrast to the results of the cited study. The authors of the present study have no explanation for this very low prevalence of A simplex sensitization in the Messina center of the AAITO-IFIACI Anisakis Consortium study, although they believe their results are more in line with those of previously published populations living in coastal Mediterranean areas.10,13,18 The prevalence of A simplex sensitization differs widely among countries, accounting for 0.4% to 22%, depending on the studied population.8,13,17e20 In Italy, the prevalence of A simplex sensitization seems to be higher in coastal areas and in larger cities,10 probably because of traditional and imported eating habits.
Figure 1. (A) Prevalence of patients sensitized to Anisakis simplex. (B) Prevalence of patients with suspected allergic symptoms after ingestion of raw or marinated fish. (C) Prevalence of patients allergic to A simplex among those sensitized to it.
A simplex and those with multiple sensitizations (5.7% vs 5.4%, P > .05). Table 2 lists the main features of patients with vs without allergy to A simplex.
Discussion This study investigated the prevalence and clinical relevance of A simplex hypersensitivity in eastern Sicily, an area where the habit of eating raw or marinated fish is widely diffused. Although this was not an epidemiologic study in a strict sense (the study population was recruited from patients attending an
Figure 2. Distribution of allergic symptoms in 29 patients allergic to Anisakis simplex. G.I., gastrointestinal; SOA, oral allergy syndrome.
E. Heffler et al. / Ann Allergy Asthma Immunol 116 (2016) 146e150 Table 2 Comparison of patients allergic vs not allergic to Anisakis simplex
Age (y), mean (range) Ratio of women to men Clinical history of suspected allergic reaction to raw or marinated fish, n (%) Atopy, n (%)a Sensitizations, n (%) House dust mites Animal dander Grass pollen Parietaria pollen Tree pollensb Weed pollensc Moldsd Fish
Patients allergic to A simplex (n ¼ 29)
Patients not allergic to A simplex (n ¼ 3,390)
P value
48.4 (20e88) 1.66 29 (100)
34.1 (3e88) 1.61 37 (1.1)
<.0001 .8746 <.0001
1,542 (45.5)
.009
20 (69) 16 8 7 9 13 5 10 3
(55.2) (27.6) (24.1) (31.0) (44.8) (17.2) (34.5) (10.3)
944 496 643 787 910 363 368 72
(27.8) (14.6) (19.0) (23.2) (26.8) (1.7) (1.8) (2.1)
.013 .214 .526 .447 .116 .330 .003 .132
a Atopy is defined as at least 1 positive skin prick test reaction to airborne and/or food allergens. b Cypress, olive, plane, and hazel trees. c Ragweed and Artemisia species. d Alternaria alternata, Cladosporium herbarum, and Aspergillus fumigatus.
In Catania, the culinary traditions include several dishes of raw or marinated fish, which could be the primary source of sensitization in the present population. Another described determinant of increased A simplex sensitization is working as fishermen or in the processing and sale of fish.24,25 Although most subjects with A simplex sensitization in the present study also had sensitization to at least 1 other airborne or food allergen, the proportion of patients with mono-sensitization was still quite large (w30%) and similar to that reported in another Italian epidemiologic survey on A simplex sensitization.10 Particularly high was the prevalence of house dust mite sensitization, which was associated with an increased risk of sensitization to A simplex. This high prevalence could be due to house dust mites and A simplex sharing some relevant allergens and a possible cross-reactivity between the 2 allergenic sources.12,13 Unfortunately, the authors have no data on recombinant allergen-specific IgE (it was beyond the scope of this study) and therefore cannot define which proportion of patients might have had cross-reactive sensitization to A simplex and house dust mites. Moreover, house dust mite sensitization was a significant risk factor for allergic reactions to A simplex (and not merely sensitization), highlighting the possibility that functional allergens could be involved in inducing allergic symptoms. An interesting finding is the high prevalence of mold sensitization in the subjects allergic to A simplex (w3 times higher than in patients not allergic), which seems to be a relevant risk factor for developing symptoms from A simplex allergy. This seems to be a novel finding that has not been described in the literature. Molds and A simplex might have unknown cross-reactive allergens. The finding of an increased risk of allergy to A simplex in patients sensitized to house dust mites or molds could be interpreted another way. Nevertheless, the authors support the hypothesis that house dust mite and mold sensitizations in the present subjects likely started young in life, because A simplex sensitization is more frequent in older individuals, and that these subjects developed sensitization to airborne allergens before sensitization to the A simplex nematode. Although the detection of specific IgE reactivity to single A simplex recombinant allergen proteins in individual patients was beyond the scope of this epidemiologic study, this assay could help the clinician distinguish seropositivity toward cross-reactive and
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clinically minor allergens from those IgE-binding proteins that can induce severe allergic symptoms.26 Caballero et al,27 in a study of Spanish and Italian subjects, reported that the most frequently detected A simplex allergen in these subjects with allergy was Ani s 1, and the great majority of them exhibited recognition to at least 1 of the tested allergens, confirming that Ani s 1 can be considered the major A simplex allergen, although there were other relevant allergens that could induce symptoms in patients with sensitization. Approximately 5.5% of subjects with sensitization to A simplex (corresponding to w0.8% of the entire studied population) were classified as allergic to A simplex; a large of proportion developed respiratory or gastrointestinal symptoms, but a relevant proportion developed severe systemic reactions (w7% of subjects with anaphylaxis). In conclusion, in this very large survey on A simplex sensitization and allergy in a Sicilian population, there was a very high prevalence of A simplex sensitization that was related to a higher prevalence of house dust mite and mold sensitization. Further studies are needed to better understand the relation between A simplex and house dust mite and mold allergens and to elucidate whether these co-sensitizations might increase the probability of developing allergic symptoms from A simplex in patients who had only sensitization to the parasite.
References [1] Audicana MT, Kennedy MW. Anisakis simplex: from obscure infectious worm to inducer of immune hypersensitivity. Clin Microbiol Rev. 2008;21:360e379. [2] Pravettoni V, Primavesi L, Piantanida M. Anisakis simplex: current knowledge. Eur Ann Allergy Clin Immunol. 2012;44:150e156. [3] Baird FJ, Gasser RB, Jabbar A, et al. Foodborne anisakiasis and allergy. Mol Cell Probes. 2014;28:167e174. [4] Nieuwenhuizen NE, Lopata AL. Allergic reactions to Anisakis found in fish. Curr Allergy Asthma Rep. 2014;14:455. [5] Carballeda-Sangiao N, Olivares F, Rodriguez-Mahillo AI, et al. Identification of autoclave-resistant Anisakis simplex allergens. J Food Prot. 2014;77:605e609. [6] Vida cek S, De Las Heras C, Solas MT, et al. Viability and antigenicity of Anisakis simplex after conventional and microwave heating at fixed temperatures. J Food Prot. 2011;74:2119e2126. [7] Rodríguez-Mahillo AI, González-Muñoz M, de las Heras C, et al. Quantification of Anisakis simplex allergens in fresh, long-term frozen, and cooked fish muscle. Foodborne Pathog Dis. 2010;7:967e973. [8] Valiñas B, Lorenzo S, Eiras A, et al. Prevalence of and risk factors for IgE sensitization to Anisakis simplex in a Spanish population. Allergy. 2001;56: 667e671. [9] Foti C, Fanelli M, Mastrandrea V, et al. Risk factors for sensitization to Anisakis simplex: a multivariate statistical evaluation. Int J Immunopathol Pharmacol. 2006;19:847e851. [10] AAITO-IFIACI Anisakis Consortium. Anisakis hypersensitivity in Italy: prevalence and clinical features: a multicenter study. Allergy. 2011;66:1563e1569. [11] Pascual CY, Crespo JF, San Martin S, et al. Cross-reactivity between IgEbinding proteins from Anisakis, German cockroach, and chironomids. Allergy. 1997;52:514e520. [12] Bernardini R, Mistrello G, Novembre E, et al. Cross-reactivity between IgEbinding proteins from Anisakis simplex and Dermatophagoides pteronyssinus. Int J Immunopathol Pharmacol. 2005;18:671e675. [13] Lin AH, Nepstad I, Florvaag E, et al. An extended study of seroprevalence of antieAnisakis simplex IgE antibodies in Norwegian blood donors. Scand J Immunol. 2014;79:61e67. [14] Gámez C, Sánchez-García S, Ibáñez MD, et al. Tropomyosin IgE-positive results are a good predictor of shrimp allergy. Allergy. 2011;66:1375e1383. [15] Boquete M, Iraola V, Morales M, et al. Seafood hypersensitivity in mite sensitized individuals: is tropomyosin the only responsible allergen? Ann Allergy Asthma Immunol. 2011;106:223e229. [16] Asero R, Mistrello G, Amato S, et al. Shrimp allergy in Italian adults: a multicenter study showing a high prevalence of sensitivity to novel high molecular weight allergens. Int Arch Allergy Immunol. 2012;157:3e10. [17] Falcão H, Lunet N, Neves E, et al. Anisakis simplex as a risk factor for relapsing acute urticaria: a caseecontrol study. J Epidemiol Community Health. 2008;62: 634e637. [18] Del Rey Moreno A, Valero A, Mayorga C, et al. Sensitization to Anisakis simplex s.l. in a healthy population. Acta Trop. 2006;97:265e269. [19] García-Palacios L, González ML, Esteban MI, et al. Enzyme-linked immunosorbent assay, immunoblot analysis and RAST fluoroimmunoassay analysis of serum responses against crude larval antigens of Anisakis simplex in a Spanish random population. J Helminthol. 1996;70:281e289.
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[20] Mladineo I, Poljak V, Martínez-Sernández V, et al. Anti-Anisakis IgE seroprevalence in the healthy Croatian coastal population and associated risk factors. PLoS Negl Trop Dis. 2014;8:e2673. [21] Amlot PL, Kemeny DM, Zachary C, et al. Oral allergy syndrome (OAS): symptoms of IgE-mediated hypersensitivity to foods. Clin Allergy. 1987;17: 33e42. [22] Sampson HA. Adverse reactions to foods. In: Adkinson NF, Yunginger JW, Busse WW, Bochner BS, Holgate ST, Simons FER, eds. Allergy. Principles and Practice. 6th ed. St Louis, MO: Mosby; 2003:1619e1643. [23] Simons FE, Ardusso LR, Bilò MB, et al. World Allergy Organization guidelines for the assessment and management of anaphylaxis. World Allergy Organ J. 2011;4:13e37.
[24] Mazzucco W, Lacca G, Cusimano R, et al. Prevalence of sensitization to Anisakis simplex among professionally exposed populations in Sicily. Arch Environ Occup Health. 2012;67:91e97. [25] Nieuwenhuizen N, Lopata AL, Jeebhay MF, et al. Exposure to the fish parasite Anisakis causes allergic airway hyperreactivity and dermatitis. J Allergy Clin Immunol. 2006;117:1098e1105. [26] Caballero ML, Umpierrez A, Perez-Piñar T, et al. Anisakis simplex recombinant allergens increase diagnosis specificity preserving high sensitivity. Int Arch Allergy Immunol. 2012;158:232e240. [27] Caballero ML, Asero R, Antonicelli L, et al. Anisakis allergy componentresolved diagnosis: clinical and immunologic differences between patients from Italy and Spain. Int Arch Allergy Immunol. 2013;162:39e44.
Contents lists available at ScienceDirect
High prevalence of Anisakis simplex hypersensitivity and allergy in Sicily, Italy Enrico Heffler, MD, PhD; Maria Eva Sberna, MD; Stefania Sichili, MD, PhD; Rossella Intravaia, MD; Giuliana Nicolosi, MD; Morena Porto, MD; Maria Teresa Liuzzo, MD; Giuseppe Picardi, MD; Silvia Fichera, MD; Nunzio Crimi, MD, PhD Respiratory Medicine and Allergology, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
A R T I C L E
I N F O
Article history: Received for publication October 9, 2015. Received in revised form November 22, 2015. Accepted for publication December 14, 2015.
A B S T R A C T
Background: Anisakis simplex can elicit allergic reactions when ingested in raw or marinated fish. The prevalence of A simplex hypersensitivity and allergy in Sicily (Italy), an area where the consumption of raw or marinated fish is very common, has not been investigated thus far. Objective: To investigate the prevalence of A simplex sensitization and its clinical relevance in a large group of unselected patients. Methods: All consecutive patients referred to the authors’ allergy clinic during a 22 month-period were included in the study, evaluated for sensitization to A simplex and other allergens depending on their clinical history, and investigated for allergic symptoms after the ingestion of raw or marinated fish. Results: Of 3,419 patients screened, 527 (15.4%) were sensitized to A simplex and 29 of these (5.5% of sensitized patients) had a history of A simplex allergy. Approximately 30% of patients had mono-sensitization to A simplex. Co-sensitization to house dust mites or molds yielded an odds ratio of 1.98 or 3.18, respectively, for allergy to A simplex. Conclusion: A high prevalence of A simplex sensitization in a large proportion of patients with monosensitization was found, confirming that eating habits influence sensitization to this nematode. Allergic symptoms from A simplex ingestion in raw or marinated fish were quite frequent, with symptoms ranging from oral allergy syndrome to anaphylaxis. Patients sensitized to A simplex were more prone to have allergic symptoms when they had co-sensitization to house dust mites or molds, suggesting possible cross-reactive but clinically relevant allergens between these allergenic sources. Ó 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
Introduction Anisakis simplex is a nematode and commonly parasitizes fishes, marine invertebrates, and sea mammals. Its life cycle is complex and involves several different hosts; adult A simplex nematodes reside in the gastrointestinal tract of marine mammals and lay nonembryonate eggs in the marine mammals’ feces, which are discharged into the water, where they develop into embryonate eggs and then larvae; crustaceans ingest A simplex larvae, which develop into a third stage that is infective to fish and squid. At the host’s death, larvae migrate to muscle tissues and are transferred from fish to fish through predation. Third-stage larvae also are infective to humans and marine mammals.1 Anisakis simplex larvae infect many species of fish and over a broad geographic area2; thus, eating Reprints: Enrico Heffler, MD, PhD, Pneumologia Riabilitativa e Allergologia, AOU “Policlinico-Vittorio Emanuele”, Via Santa Sofia 78-95123, Catania, Italy; E-mail: heffl[email protected]. Disclosures: Authors have nothing to disclose.
raw or undercooked infected fish can lead to larval infestation and cause severe gastrointestinal symptoms (anisakiasis).3 Several studies have suggested that A simplex can act as a food allergen and induce immunoglobulin E (IgE)-mediated reactions, mostly urticaria and angioedema, but also anaphylactic reactions.4 However, several aspects of this type of food allergy remain poorly defined. Because some A simplex allergens have been found to be stable with heat, it has been suggested that the ingestion of seafood contaminated with third-stage A simplex larvae might sensitize or induce clinical symptoms even if the food is cooked and the parasitic infestation ability has been abolished5e7; however, in accordance with the limited prevalence of A simplex allergy in the general population, recent studies do not seem to support this view, and raw fish (mainly anchovies) marinated in vinegar have been detected as the main risk factor for sensitization.8e10 Other important issues concern the prevalence and clinical relevance of cross-reactivity between A simplex allergens and other invertebrates including shrimps, worms, and insects such as cockroaches or mites.11e13
http://dx.doi.org/10.1016/j.anai.2015.12.014 1081-1206/Ó 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
E. Heffler et al. / Ann Allergy Asthma Immunol 116 (2016) 146e150
Tropomyosin has been proposed as a pan-allergen of invertebrates because it appears to be allergenic in many invertebrate sources as a food and as an inhalant allergen,14,15 but this finding has not been confirmed by other researchers.12 In a recent Italian multicenter study, IgE reactivity to tropomyosin was detected in fewer than 50% of patients allergic to shrimp, and other allergens were found in a substantial number of patients (60-, >90-, 14- to 18-, 25-, 43- to 50-, and 80-kDa IgE-reactive bands) at immunoblot analysis.16 Most studies of A simplex allergy have been carried out in the Iberian peninsula, and little is currently known about the situation in other countries.8,17e19 A multicenter epidemiologic study investigated A simplex hypersensitivity in different areas of Italy and found a mean prevalence of 4.5% in the general study population. The highest frequency of A simplex hypersensitivity was found along the Adriatic and Tyrrhenian coasts.10,13,20 The aim of this study was to assess the prevalence and clinical relevance of A simplex hypersensitivity in the eastern part of Sicily (Italy), where traditional eating habits include consuming different dishes of raw or marinated fish. Methods Study Design All consecutive patients referred to the authors’ center in Catania (on the eastern coast of Sicily), regardless of their clinical problems (suspected skin, respiratory, food, or drug allergy), from July 1, 2010 through April 30, 2012 were included in the study. The study was approved by institutional ethics committee of the University of Catania (Catania, Italy) and all patients signed an informed consent for the study of their clinical data. All study subjects underwent a thorough interview about previous adverse reactions after the ingestion of any type of food. A history of oral allergy syndrome (defined as local itching of the lips, tongue, palate, throat, and/or ears and nose, and/or angioedema of the same areas),21 acute generalized urticaria with or without angioedema,22 anaphylaxis,23 and/or gastrointestinal complaints occurring some minutes up to 2 hours after ingestion of the offending food(s) was considered possibly associated with a food allergy. Skin Prick Tests Anisakis simplex hypersensitivity was assessed by a skin prick test (SPT) with a commercial extract (ALK-Abellò, Madrid, Spain). All study subjects underwent the SPT with a series of commercial airborne allergens (grass, mugwort, ragweed, pellitory, mimosa, plantain, birch, olive, and cypress pollens; molds: Alternaria alternata, Aspergillus fumigatus, and Cladosporium herbarum; house dust mites: Dermatophagoides pteronyssinus and Dermatophagoides farina; animal dander: from cat, dog, and horse; Lofarma, Milano, Italy). Patients with a clinical history of possible food allergy also underwent the SPT with a standard panel of commercial food allergen extracts (hen’s egg, cow’s milk, wheat, soybean, peanuts, walnut, hazelnut, peach, apple, tomato, shrimp, and cod; Stallergenes, Antony, France). Histamine (1 mg/mL) and glycerol in buffer diluent were used as positive and negative controls, respectively. The reaction was evaluated 20 minutes after administration and categorized as positive if it produced a wheal larger than 4 mm compared with the negative control. Diagnosis of Sensitization vs Allergy to Anisakis simplex In this survey, A simplex allergy was diagnosed if a suggestive clinical history (ie, oral allergy syndrome, acute generalized urticaria with or without angioedema, anaphylaxis, and/or gastrointestinal complaints occurring some minutes up to 2 hours after ingestion of raw or marinated fish) was confirmed by a clear-cut positive SPT reaction.
147
Patients with a positive SPT reaction to A simplex but without a clear clinical history of adverse reactions induced by raw or marinated fish were considered sensitized but not allergic to the parasite. Statistics Descriptive analyses were performed. Continuous variables were evaluated with the Kolmogorov-Smirnov normality test and compared with analysis of variance or the Mann-Whitney test, depending on the normality of distribution. Categorical variables were compared using the Fisher exact test. All data were analyzed using SPSS 16.0 (SPSS, Inc, Chicago, Illinois). Results In total, 3,419 subjects (mean age 34.3 years, range 3e88 years, ratio of women to men 1.62) were screened for A simplex hypersensitivity during the study period. The number of subjects with atopy (those with at least 1 positive SPT reaction) was 1,562 (45.6%). In total, 527 subjects had a positive A simplex SPT reaction, which corresponds to a prevalence of 15.4% of the studied population (Fig 1A). Patients with a positive A simplex SPT reaction were slightly but significantly older than those with a negative SPT reaction (39.9 19.4 vs 33.3 18.7 years, P < .0001). Of 527 subjects sensitized to A simplex, 370 (70.2%) were sensitized to at least 1 other airborne or food allergen, whereas 157 (29.8%) were mono-sensitized to A simplex. In total, 276 of 527 patients (52.3%) with a positive A simplex SPT reaction also were sensitized to house dust mites compared with 683 of 2,892 patients (23.6%) sensitized to house dust mites but with a negative A simplex SPT reaction (P < .0001). Sensitization to house dust mites was associated with an increased risk of sensitization to A simplex (odds ratio 2.21, P < .0001). Based on clinical history, 66 patients (1.9% of studied population) reported symptoms suggestive of allergic reactions after the ingestion of raw or marinated fish (Fig 1B); 29 of these 66 patients (43.9%) were sensitized to A simplex and therefore considered allergic to A simplex (Fig 1C), corresponding to approximately 0.8% of the entire studied population. Having an SPT reaction positive for A simplex resulted in a odds ratio of 4.3 compared with those with a negative A simplex SPT reaction (P < .0001). Table 1 lists the main features of patients with vs without sensitization to A simplex. Patients with a positive A simplex SPT reaction represented a larger proportion of sensitization for all other considered classes of allergens (Table 1). Symptoms associated with allergy to A simplex were respiratory symptoms (dyspnea, chest tightness, wheezing, or rhinitis) in 12 of 29 patients (41.4%), gastrointestinal symptoms (abdominal pain, vomiting, or diarrhea) in 9 (31.0%), urticaria with or without angioedema in 4 (13.8%), oral allergy syndrome (local itching of lips, tongue, palate, throat, and/or ears and nose, and/or angioedema of the same areas) in 2 (6.9%), and anaphylaxis (defined according to the World Allergy Organization position paper23) in 2 (6.9%; Fig 2). Sixteen of 29 patients (55.2%) allergic to A simplex also were sensitized to house dust mites and 10 (34.5%) to molds (A alternata, A fumigatus, and/or C herbarum), whereas of the 3,390 subjects not allergic to A simplex, only 944 (27.8%) and 368 (10.8%) were sensitized to house dust mites and molds, respectively. Sensitization to house dust mites or molds resulted an odds ratio of 1.98 or 3.18, respectively, for allergy to A simplex (P ¼ .03 for house dust mites, P ¼ .002 for molds). There was no statistically significant difference in prevalence of allergy to A simplex between patients with mono-sensitivity to
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E. Heffler et al. / Ann Allergy Asthma Immunol 116 (2016) 146e150 Table 1 Comparison of patients sensitized vs not sensitized to Anisakis simplex
Age (y), mean (range) Ratio of women to men Clinical history of suspected allergic reaction to raw or marinated fish, n (%) Atopy, n (%)a Sensitizations, n (%) House dust mites Animal dander Grass pollen Parietaria pollen Tree pollensb Weed pollensc Moldsd Fishes
Patients sensitized to A simplex (n ¼ 527)
Patients not P value sensitized to A simplex (n ¼ 2,892)
39.9 (5e88) 1.64 29 (5.5)
33.3 (3e88) 1.62 37 (1.3)
<.0001 .9865 <.0001
370 (70.2)
1,190 (41.1)
<.0001
276 145 169 197 237 105 126 24
(52.3) (27.5) (32.1) (37.4) (45.0) (19.9) (23.9) (4.5)
683 358 479 598 684 263 252 51
(23.6) (12.4) (16.6) (2.7) (23.6) (9.1) (8.7) (1.8)
<.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001
a Atopy is defined as at least 1 positive skin prick test reaction to airborne and/or food allergens. b Cypress, olive, plane, and hazel trees. c Ragweed and Artemisia species. d Alternaria alternata, Cladosporium herbarum, and Aspergillus fumigatus.
allergy clinic) and therefore the study population might have been biased, a large number of subjects was investigated, which might provide an estimate of allergic problems related to A simplex sensitization in Sicily. A high prevalence of A simplex sensitization (w15% of the studied population) was found; this prevalence rate is similar to that observed in Spanish studies18 and in coastal areas in the largest Italian survey on A simplex allergy, in which the mean prevalence was 12.7%.10 The study by the AAITO-IFIACI Anisakis Consortium10 also included a center in Messina on the eastern coast of Sicily, which had a surprisingly low prevalence of A simplex sensitization (w0.8% of their population), which was in contrast to the results of the cited study. The authors of the present study have no explanation for this very low prevalence of A simplex sensitization in the Messina center of the AAITO-IFIACI Anisakis Consortium study, although they believe their results are more in line with those of previously published populations living in coastal Mediterranean areas.10,13,18 The prevalence of A simplex sensitization differs widely among countries, accounting for 0.4% to 22%, depending on the studied population.8,13,17e20 In Italy, the prevalence of A simplex sensitization seems to be higher in coastal areas and in larger cities,10 probably because of traditional and imported eating habits.
Figure 1. (A) Prevalence of patients sensitized to Anisakis simplex. (B) Prevalence of patients with suspected allergic symptoms after ingestion of raw or marinated fish. (C) Prevalence of patients allergic to A simplex among those sensitized to it.
A simplex and those with multiple sensitizations (5.7% vs 5.4%, P > .05). Table 2 lists the main features of patients with vs without allergy to A simplex.
Discussion This study investigated the prevalence and clinical relevance of A simplex hypersensitivity in eastern Sicily, an area where the habit of eating raw or marinated fish is widely diffused. Although this was not an epidemiologic study in a strict sense (the study population was recruited from patients attending an
Figure 2. Distribution of allergic symptoms in 29 patients allergic to Anisakis simplex. G.I., gastrointestinal; SOA, oral allergy syndrome.
E. Heffler et al. / Ann Allergy Asthma Immunol 116 (2016) 146e150 Table 2 Comparison of patients allergic vs not allergic to Anisakis simplex
Age (y), mean (range) Ratio of women to men Clinical history of suspected allergic reaction to raw or marinated fish, n (%) Atopy, n (%)a Sensitizations, n (%) House dust mites Animal dander Grass pollen Parietaria pollen Tree pollensb Weed pollensc Moldsd Fish
Patients allergic to A simplex (n ¼ 29)
Patients not allergic to A simplex (n ¼ 3,390)
P value
48.4 (20e88) 1.66 29 (100)
34.1 (3e88) 1.61 37 (1.1)
<.0001 .8746 <.0001
1,542 (45.5)
.009
20 (69) 16 8 7 9 13 5 10 3
(55.2) (27.6) (24.1) (31.0) (44.8) (17.2) (34.5) (10.3)
944 496 643 787 910 363 368 72
(27.8) (14.6) (19.0) (23.2) (26.8) (1.7) (1.8) (2.1)
.013 .214 .526 .447 .116 .330 .003 .132
a Atopy is defined as at least 1 positive skin prick test reaction to airborne and/or food allergens. b Cypress, olive, plane, and hazel trees. c Ragweed and Artemisia species. d Alternaria alternata, Cladosporium herbarum, and Aspergillus fumigatus.
In Catania, the culinary traditions include several dishes of raw or marinated fish, which could be the primary source of sensitization in the present population. Another described determinant of increased A simplex sensitization is working as fishermen or in the processing and sale of fish.24,25 Although most subjects with A simplex sensitization in the present study also had sensitization to at least 1 other airborne or food allergen, the proportion of patients with mono-sensitization was still quite large (w30%) and similar to that reported in another Italian epidemiologic survey on A simplex sensitization.10 Particularly high was the prevalence of house dust mite sensitization, which was associated with an increased risk of sensitization to A simplex. This high prevalence could be due to house dust mites and A simplex sharing some relevant allergens and a possible cross-reactivity between the 2 allergenic sources.12,13 Unfortunately, the authors have no data on recombinant allergen-specific IgE (it was beyond the scope of this study) and therefore cannot define which proportion of patients might have had cross-reactive sensitization to A simplex and house dust mites. Moreover, house dust mite sensitization was a significant risk factor for allergic reactions to A simplex (and not merely sensitization), highlighting the possibility that functional allergens could be involved in inducing allergic symptoms. An interesting finding is the high prevalence of mold sensitization in the subjects allergic to A simplex (w3 times higher than in patients not allergic), which seems to be a relevant risk factor for developing symptoms from A simplex allergy. This seems to be a novel finding that has not been described in the literature. Molds and A simplex might have unknown cross-reactive allergens. The finding of an increased risk of allergy to A simplex in patients sensitized to house dust mites or molds could be interpreted another way. Nevertheless, the authors support the hypothesis that house dust mite and mold sensitizations in the present subjects likely started young in life, because A simplex sensitization is more frequent in older individuals, and that these subjects developed sensitization to airborne allergens before sensitization to the A simplex nematode. Although the detection of specific IgE reactivity to single A simplex recombinant allergen proteins in individual patients was beyond the scope of this epidemiologic study, this assay could help the clinician distinguish seropositivity toward cross-reactive and
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clinically minor allergens from those IgE-binding proteins that can induce severe allergic symptoms.26 Caballero et al,27 in a study of Spanish and Italian subjects, reported that the most frequently detected A simplex allergen in these subjects with allergy was Ani s 1, and the great majority of them exhibited recognition to at least 1 of the tested allergens, confirming that Ani s 1 can be considered the major A simplex allergen, although there were other relevant allergens that could induce symptoms in patients with sensitization. Approximately 5.5% of subjects with sensitization to A simplex (corresponding to w0.8% of the entire studied population) were classified as allergic to A simplex; a large of proportion developed respiratory or gastrointestinal symptoms, but a relevant proportion developed severe systemic reactions (w7% of subjects with anaphylaxis). In conclusion, in this very large survey on A simplex sensitization and allergy in a Sicilian population, there was a very high prevalence of A simplex sensitization that was related to a higher prevalence of house dust mite and mold sensitization. Further studies are needed to better understand the relation between A simplex and house dust mite and mold allergens and to elucidate whether these co-sensitizations might increase the probability of developing allergic symptoms from A simplex in patients who had only sensitization to the parasite.
References [1] Audicana MT, Kennedy MW. Anisakis simplex: from obscure infectious worm to inducer of immune hypersensitivity. Clin Microbiol Rev. 2008;21:360e379. [2] Pravettoni V, Primavesi L, Piantanida M. Anisakis simplex: current knowledge. Eur Ann Allergy Clin Immunol. 2012;44:150e156. [3] Baird FJ, Gasser RB, Jabbar A, et al. Foodborne anisakiasis and allergy. Mol Cell Probes. 2014;28:167e174. [4] Nieuwenhuizen NE, Lopata AL. Allergic reactions to Anisakis found in fish. Curr Allergy Asthma Rep. 2014;14:455. [5] Carballeda-Sangiao N, Olivares F, Rodriguez-Mahillo AI, et al. Identification of autoclave-resistant Anisakis simplex allergens. J Food Prot. 2014;77:605e609. [6] Vida cek S, De Las Heras C, Solas MT, et al. Viability and antigenicity of Anisakis simplex after conventional and microwave heating at fixed temperatures. J Food Prot. 2011;74:2119e2126. [7] Rodríguez-Mahillo AI, González-Muñoz M, de las Heras C, et al. Quantification of Anisakis simplex allergens in fresh, long-term frozen, and cooked fish muscle. Foodborne Pathog Dis. 2010;7:967e973. [8] Valiñas B, Lorenzo S, Eiras A, et al. Prevalence of and risk factors for IgE sensitization to Anisakis simplex in a Spanish population. Allergy. 2001;56: 667e671. [9] Foti C, Fanelli M, Mastrandrea V, et al. Risk factors for sensitization to Anisakis simplex: a multivariate statistical evaluation. Int J Immunopathol Pharmacol. 2006;19:847e851. [10] AAITO-IFIACI Anisakis Consortium. Anisakis hypersensitivity in Italy: prevalence and clinical features: a multicenter study. Allergy. 2011;66:1563e1569. [11] Pascual CY, Crespo JF, San Martin S, et al. Cross-reactivity between IgEbinding proteins from Anisakis, German cockroach, and chironomids. Allergy. 1997;52:514e520. [12] Bernardini R, Mistrello G, Novembre E, et al. Cross-reactivity between IgEbinding proteins from Anisakis simplex and Dermatophagoides pteronyssinus. Int J Immunopathol Pharmacol. 2005;18:671e675. [13] Lin AH, Nepstad I, Florvaag E, et al. An extended study of seroprevalence of antieAnisakis simplex IgE antibodies in Norwegian blood donors. Scand J Immunol. 2014;79:61e67. [14] Gámez C, Sánchez-García S, Ibáñez MD, et al. Tropomyosin IgE-positive results are a good predictor of shrimp allergy. Allergy. 2011;66:1375e1383. [15] Boquete M, Iraola V, Morales M, et al. Seafood hypersensitivity in mite sensitized individuals: is tropomyosin the only responsible allergen? Ann Allergy Asthma Immunol. 2011;106:223e229. [16] Asero R, Mistrello G, Amato S, et al. Shrimp allergy in Italian adults: a multicenter study showing a high prevalence of sensitivity to novel high molecular weight allergens. Int Arch Allergy Immunol. 2012;157:3e10. [17] Falcão H, Lunet N, Neves E, et al. Anisakis simplex as a risk factor for relapsing acute urticaria: a caseecontrol study. J Epidemiol Community Health. 2008;62: 634e637. [18] Del Rey Moreno A, Valero A, Mayorga C, et al. Sensitization to Anisakis simplex s.l. in a healthy population. Acta Trop. 2006;97:265e269. [19] García-Palacios L, González ML, Esteban MI, et al. Enzyme-linked immunosorbent assay, immunoblot analysis and RAST fluoroimmunoassay analysis of serum responses against crude larval antigens of Anisakis simplex in a Spanish random population. J Helminthol. 1996;70:281e289.
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[20] Mladineo I, Poljak V, Martínez-Sernández V, et al. Anti-Anisakis IgE seroprevalence in the healthy Croatian coastal population and associated risk factors. PLoS Negl Trop Dis. 2014;8:e2673. [21] Amlot PL, Kemeny DM, Zachary C, et al. Oral allergy syndrome (OAS): symptoms of IgE-mediated hypersensitivity to foods. Clin Allergy. 1987;17: 33e42. [22] Sampson HA. Adverse reactions to foods. In: Adkinson NF, Yunginger JW, Busse WW, Bochner BS, Holgate ST, Simons FER, eds. Allergy. Principles and Practice. 6th ed. St Louis, MO: Mosby; 2003:1619e1643. [23] Simons FE, Ardusso LR, Bilò MB, et al. World Allergy Organization guidelines for the assessment and management of anaphylaxis. World Allergy Organ J. 2011;4:13e37.
[24] Mazzucco W, Lacca G, Cusimano R, et al. Prevalence of sensitization to Anisakis simplex among professionally exposed populations in Sicily. Arch Environ Occup Health. 2012;67:91e97. [25] Nieuwenhuizen N, Lopata AL, Jeebhay MF, et al. Exposure to the fish parasite Anisakis causes allergic airway hyperreactivity and dermatitis. J Allergy Clin Immunol. 2006;117:1098e1105. [26] Caballero ML, Umpierrez A, Perez-Piñar T, et al. Anisakis simplex recombinant allergens increase diagnosis specificity preserving high sensitivity. Int Arch Allergy Immunol. 2012;158:232e240. [27] Caballero ML, Asero R, Antonicelli L, et al. Anisakis allergy componentresolved diagnosis: clinical and immunologic differences between patients from Italy and Spain. Int Arch Allergy Immunol. 2013;162:39e44.