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.

Acute Disease↗

PubMed1997

Periodate treatment of Anisakis simplex allergens.

Anaphylactic reactions after parasitized fish consumption are mediated by an IgE response. However, positive skin tests and specific IgE can also be found in many asymptomatic subjects who recognize a single medium-mol.-wt. antigen by IgE immunoblot. The study aimed to find out whether this unspecificity was due to the carbohydrate moieties of parasite antigens. Sixty-two patients with suspected parasite allergy, 51 blood donors, 18 bakers, and 38 atopic patients were studied by blotting. Parasite proteins were treated with periodate. Several selected sera were inhibited with a crude wheat extract and fungal amylase. Twelve patients (19%), eight donors (16%), six bakers (33%), and one atopic patient (3%) recognized a single medium-mol.-wt. band in blotting and should be considered false-positive. This band was periodate-sensitive, but specific IgE to this allergen could not be inhibited by a wheat extract nor by fungal amylase and was clinically irrelevant. Diagnosis of Anisakis simplex hypersensitivity by skin tests and/ or specific IgE values should always be confirmed by specific IgE immunoblotting in order to detect the presence of clinically unrelated antibodies directed to periodate-sensitive allergens. These allergens are probably not a carbohydrate moiety of a parasite glycoprotein.

Amylases↗

PubMed1996

Laboratory determinations in Anisakis simplex allergy.

BACKGROUND: Anaphylactic reactions caused by the fish nematode, Anisakis simplex, after ingestion of parasitized fish, have been described. OBJECTIVE: This study was undertaken to confirm, by histamine release tests, that A. simplex is able to trigger IgE-mediated reactions and to describe the serologic profiles in this sensitization. METHODS: Twelve patients who had anaphylactic symptoms after ingestion of cooked fish and positive prick test results and determinations of IgE to A. simplex were studied by indirect IgG ELISA and IgG and IgE immunoblotting. Sera from subjects parasitized with other nematodes, patients with fish allergy, and healthy donors were included as controls. A histamine release test was performed in a representative case. RESULTS: IgE immunoblotting was a specific test to detect A. simplex allergy. IgE-reacting bands were found in serum samples from 11 of our patients. Specific IgG antibodies were found by ELISA and immunoblotting, but this response was less specific. Histamine release was positive with A. simplex extract and negative with fish. CONCLUSION: A specific and intense immune response to an A. simplex extract was found in our patients. A. simplex is able to elicit anaphylactic reactions, and A. simplex allergy should be suspected in patients with allergic symptoms after ingestion of fish. A positive prick test response to A. simplex and a negative response to fish is a good indication for a diagnosis of A. simplex allergy.

Adult↗

PubMed1995

Recurrent anaphylaxis caused by Anisakis simplex parasitizing fish.

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Anaphylaxis↗

PubMedDate not supplied

Rheumatic manifestations in the course of anaphylaxis caused by Anisakis simplex.

Human anisakidosis is a parasitic infection caused by the larvae of Anisakis simplex. Classical clinical manifestations include epigastric pain, occlusion, diffuse abdominal pain, appendicitis, and anaphylactoid reactions. Arthralgias or arthritis have been infrequently reported. We present three patients with proven hypersensitivity to A. simplex together with rheumatologic complaints after ingestion of parasitized fishes. A. simplex must be considered in the differential diagnosis of arthralgias/ arthritis especially if associated with urticaria.

Adult↗