Prevalencia de la sensibilización a Anisakis simplex en tres áreas españolas, en relación a las diferentes tasas de consumo de pescado. Relevancia de la alergia a Anisakis simplex / Prevalence of sensitization to Anisakis simplex in three Spanish areas, regarding the rates of fish consumption. Relevance of Anisakis simplex allergy

Antecedentes y objetivos: Anisakis simplex causa reacciones alérgicas tras la ingesta de pescado parasitado. Nuestros objetivos son conocer la prevalencia de sensibilización y de alergia a Anisakis simplex en España. Material y métodos: Estudiamos dos poblaciones: Grupo U: pacientes con un episodio de urticaria/angioedema; Grupo NU: sujetos sin historia de reacciones alérgicas. 434 sujetos en cada grupo, pareados por edad y sexo, se estudiaron mediante cuestionario, prick-tests con extractos de Anisakis simplex y pescados, y determinaciones de IgE total y específica. La muestra fue dividida en tres áreas según su consumo de pescado. Criterio de sensibilización: prick-test positivo o anticuerpos IgE específicos a Anisakis simplex; Criterio de alergia: Urticaria/angioedema tras la ingesta de pescado, sensibilización a Anisakis simplex y exclusión de la sensibilización a pescado. Resultados: La prevalencia de sensibilización fue de 38,1 por ciento en el grupo U y 13,1 por ciento en el grupo NU. El riesgo de sensibilización aumenta con la edad, la ingesta de pescado no cocinado y los títulos elevados de IgE total. El 19,2 por ciento de los pacientes del grupo U se diagnosticaron de alergia a Anisakis simplex. La IgE específica a Anisakis simplex es la única variable asociada independientemente a alergia al parásito. La prevalencia de sensibilización y alergia a Anisakis simplex es mayor en el área centro (consumo de pescado intermedio) donde la ingesta de pescado no cocinado es más frecuente. Conclusiones: Se detecta una elevada frecuencia de sensibilización y alergia a Anisakis simplex en España. La elevada frecuencia de anticuerpos IgE específicos a Anisakis simplex en sujetos con y sin reacciones alérgicas supone un importante factor de confusión para el diagnóstico. Las variables asociadas a la sensibilización sugieren que la parasitación es frecuente (AU)

Usefulness of currently available methods for the diagnosis of Anisakis simplex allergy.

BACKGROUND: Serodiagnosis of anisakiosis and Anisakis allergy is difficult since many Anisakis antigens show cross-reactivity complications. In the present study, we assess the usefulness of the major immunologic methods currently available for the diagnosis of Anisakis allergy. METHODS: Four tests (skin prick test, CAP-FEIA system, Western blotting, and an antigen-capture ELISA using O-deglycosylated antigen bound by the monoclonal antibody UA3) were applied to Anisakis-free subjects and subjects with confirmed Anisakis allergy. RESULTS: The skin prick test, CAP-FEIA, and the antigen-capture ELISA identified Anisakis allergy sera with 100% sensitivity, while Western blotting showed 96%/ sensitivity. The antigen-capture ELISA also showed 100% specificity, but CAP-FEIA showed a specificity of only 50%. In Western blotting, none of the bands detected were specific for either Anisakis-free or Anisakis allergy subjects. The skin prick test was not applied to the Anisakis-free subjects, so its specificity could not be determined. CONCLUSIONS: On the basis of these results, we suggest that the most appropriate procedure for diagnosis of Anisakis allergy suspected on clinical grounds is the antigen-capture ELISA using UA3, or, alternatively, a preliminary skin prick test with a positive result subsequently confirmed by UA3-ELISA.

Prevalence of pollinosis in the Basque Country.

BACKGROUND: The prevalence of allergic diseases, mainly pollinosis, has increased within the last decades. Our study aimed to determine the prevalence of sensitization to Poaceae pollen in the Basque Country. This is a region of northern Spain, with an area of 7261 km2 and a population of 2109009 inhabitants. Two different climatic regions may be distinguished in the Basque Country (the Atlantic and the Oceanic). METHODS: A transversal study was carried out on 2216 subjects, aged 10-40 years. A personal interviewwas carried out in order to compile study data, by means of a questionnaire that had been previously validated with a clinical history and an allergy study. RESULTS AND CONCLUSIONS: Our results show the prevalence of pollinosis in the Basque Country to be 10.6% (C.I. 95% 9.35-11.96%) without significant differences between men and women. The prevalence in the Atlantic climate area (9.71%) was lower than in the Oceanic climate area (13.61%). There were no differences between persons living in a rural environment (10.87%) and those living in an urban setting (10.51%). Pollinosis was more frequent in individuals aged 10-20 (11.41%) and 20-30 (12.54%) than those aged 30-40 years (7.43%). Three features significantly distinguished pollinic from nonpollinic patients: 1) a more common complaint of symptoms after ingestion of Rosaceae fruits or nuts (10.2%) 2) a family history of atopy (8.8%) 3) a greater occurrence of bronchial asthmatic symptoms (23%).

Anisakis simplex, a relevant etiologic factor in acute urticaria.

Anisakis simplex, a parasite of fish and cephalopods, can induce IgE-mediated reactions. This study aimed to determine the etiologic role of A. simplex in patients affected by urticaria/angioedema (AE) or anaphylaxis. We studied 100 adult subjects suffering acute episodes of urticaria/AE, by anamnesis, prick tests with A. simplex and fish-mix extracts, and total and specific IgE to both A. simplex and cod. The following criteria of A. simplex allergy were considered: 1) urticaria/AE within 6 h after fish ingestion; 2) specific IgE to A. simplex; 3) positive prick test to A. simplex extract; 4) exclusion of other suspected causes. Double-blind, placebo-controlled food challenge was not carried out because ethical considerations forbid challenge with a parasite. Specific IgE to A. simplex (> 0.7 kU/l) was found in 22 subjects, but only eight were diagnosed as having A. simplex allergy. Other allergens were involved in 37 patients, and 55 cases were considered idiopathic. Specific IgE to fish (> 0.7 kU/l) was found in two patients, but only one was diagnosed as having fish allergy. We concluded that A. simplex is an important etiologic factor in acute urticaria. We suggest that it should be considered in cases of urticaria/AE or anaphylaxis, especially after fish ingestion.

The use of IgE immunoblotting as a diagnostic tool in Anisakis simplex allergy.

BACKGROUND: The fish parasite Anisakis simplex is the etiologic agent of anisakiasis and induces IgE-mediated reactions. Skin prick tests (SPTs) and the measurement of specific IgE to A. simplex were, in our experience, not valid tools with which to discriminate between allergic and nonallergic patients because many control subjects also had positive results. OBJECTIVE: The study was carried out to assess the usefulness of IgE immunoblotting in the diagnosis of allergy to A. simplex. METHODS: We have studied 61 patients with acute symptoms of urticaria, angioedema, or anaphylaxis and positive specific IgE to A. simplex. According to the anamnesis, time interval between ingestion of fish and clinical onset of symptoms, and exclusion of other causes of allergy, three different groups of patients were established: group A (allergic), group NA (non-allergic), and group D (doubtful). Fifty-one healthy donors were included as control subjects (group C). IgE immunoblotting with A. simplex whole-body extract was performed in all patients and control subjects. RESULTS: Four patterns of immunoblotting were observed: type 1, with a group of several bands of medium molecular weight and others of low molecular weight; type 2, two or more bands of medium molecular weight; type 3, only one band of medium molecular weight; type 4, without any band. There was a significant predominance of blotting type 1 in group A and type 4 in group C. CONCLUSION: These data suggest that IgE immunoblotting is the most useful approach to A. simplex allergy diagnosis.

Anisakis simplex induces not only anisakiasis: report on 28 cases of allergy caused by this nematode.

Anisakis simplex R., parasitizes several sea-fish and cephalopods. This parasite induces not only anisakiasis but also anaphylactic reactions, as has recently been confirmed. We present 28 patients with immediate hypersensitivity to Anisakis simplex, developed after parasitized fish ingestion. Each case was diagnosed by suggestive anamnesis, skin prick tests with an A. simplex extract, specific IgE detection in serum (CAP System), and histamine release test. The clinical manifestations were urticaria/angioedema in all 28 patients and respiratory arrest in one. Paradoxically, the patients reported tolerance to ingestion of the same kind of fish between and after the allergic episodes. Type 1 hypersensitivity to A. simplex was demonstrated by a positive skin-prick test reaction, specific IgE detection in all cases and positive histamine release in a representative case. Sensitization to the proteins of the fish themselves was ruled out by negative reactions of the same tests in all cases. It was also proven that the allergen/s involved may be resistant to cooking and deep freezing. Hence, anaphylactic reactions may result either from infection or, more frequently, from mere exposure to the allergen. The results confirm that A. simplex can develop IgE-mediated anaphylactic reactions, the clinical severity of which was pronounced in the patients examined. Physicians must take into account that the consumption of parasitized fish may cause severe reactions, even if fish of the same kind is subsequently tolerated. A higher frequency of reactions of this type can be expected in countries where fish is a staple diet.

Immunotherapy with a standardized Dermatophagoides pteronyssinus glutaraldehyde-modified extract against an unmodified extract: a comparative study of efficacy, tolerance and in vivo and in vitro modification of parameters.

We comparatively studied clinical efficacy, tolerance and modifications of different in vivo and in vitro parameters induced by two biologically standardized Dermatophagoides pteronyssinus extracts (HEP units), one glutaraldehyde-modified, in patients with allergic rhinitis and/or bronchial asthma after a year of treatment. A decrease in drug consumption was observed in both treatment groups (p < 0.0001). Of all the in vivo parameters studied (cutaneous, conjunctival and bronchial reactivity to the allergen), a decrease in specific bronchial reactivity was only observed in the group treated with the modified extract (p < 0.05). The modifications in total IgE, specific IgE and specific total IgG levels are superimposable on those described in previous papers on immunotherapy. However, IgG4 levels remained stable with respect to time. Tolerance was good and very similar for both treatments; both types of extracts are equally efficacious and safe.

Pickled onion-induced asthma: a model of sulfite-sensitive asthma?

BACKGROUND: Asthma elicited by sulfite ingestion has been mainly described in steroid-dependent and in non-atopic asthmatics. We have studied a group of 18 young extrinsic asthmatics who presented with asthma attacks immediately after eating pickled onions. OBJECTIVE: The aim of this study is to ascertain if these asthma attacks are elicited by sulfites contained in pickled onions and the influence of the dose and pH of onions. METHODS: The bronchial hyperreactivity of the patients was assessed by a methacholine challenge test. Oral challenge tests were performed with sodium metabisulfite (MSB) diluted in lemon juice at pH 4.2 and at pH 3.3 (only in patients who did not react with pH 4.2). Two types of pickled onions, Spanish and Dutch pickled onions, were used for oral challenge in seven of the patients. The Monier-Williams method was used to measure the SO2 concentration in pickled onions. RESULTS: The oral provocation test with MBS, pH 4.2, elicited a positive response in six patients (33.3%) and the test at pH 3.3 was positive in three out of 12. No significant difference in PD20 values was found between these groups. Three of the seven patients challenged with Spanish pickled onions had a positive reaction but had no reaction with Dutch pickled onions. The SO2 concentration in Spanish pickled onions varied between 765 and 1182 ppm while in Dutch pickled onions were 200 ppm; this exceeded the permitted level (100 ppm). SO2 release in Spanish pickled onion samples was nearly 2.5 times higher when the pH of the sample decreased from 4.2 to 3.3. CONCLUSION: High levels of SO2 in Spanish pickled onions, and their low pH (3.3) would be the responsible factors of the asthmatic outbreaks after ingestion of Spanish pickled onions by these patients.

Quantitation of major allergens in dust samples from urban populations collected in different seasons in two climatic areas of the Basque region (Spain).

We present the results of allergen content evaluation in 80 dust samples from 31 homes of atopic patients from two climatic areas (humid and subhumid), collected in two seasons of the year (autumn and winter). Monoclonal antibody-based immunoassays were used to quantify Der p 1, Der f 1, Der 2, Lep d 1, and Fel d 1. The results were compared according to climate, season, and the type of sensitization (Pyroglyphidae mites, storage mites, or grass pollens). We underline the predominance of Dermatophagoides pteronyssinus (89% of samples) over D. farinae (16% of samples) in our environment. Der p 1 rates were higher in the humid area (Mann-Whitney P < 0.001), especially in the autumn (Wilcoxon P < 0.05). Lep d 1 was detected in 23% of samples and Lep d 1 levels were higher in the homes of patients sensitized to storage mites (Mann-Whitney P < 0.05), whereas this allergen was not detected in the homes of pollen-allergic patients. Fel d 1 was detected in nine of the 31 homes (16% of samples) although there was a cat in only one home.