<i>Anisakis</i> <i>simplex</i> Recombinant Allergens Increase Diagnosis Specificity Preserving High Sensitivity

Abstract

Background: So far, the frequency of Anisakis simplex-specific IgE antibodies has been determined by skin prick tests (SPTs) and the ImmunoCAP system. These commercial methods have good sensitivity, but their specificity is poor because they use complete parasite extracts. Our aim was to determine the frequency of sensitization to A. simplex using recombinant Ani s 1, Ani s 3, Ani s 5, Ani s 9 and Ani s 10 and to evaluate these allergens for diagnosis, comparing their performance with the commercial methods. Patients and Methods: We conducted a descriptive, cross-sectional validation study performed in an allergy outpatient hospital clinic. Patients without fish-related allergy (tolerant patients, n = 99), and A. simplex-allergic patients (n = 35) were studied by SPTs, ImmunoCAP assays and detection of specific IgE to A. simplex recombinant allergens by dot blotting. Results: SPTs and ImmunoCAP assays were positive in 18 and 17% of tolerant patients, respectively. All A. simplex-allergic patients had positive SPTs and ImmunoCAP assays. Specific IgE against at least one of the A. simplex recombinant allergens tested was detected in 15% of sera from tolerant patients and in 100% of sera from A. simplex-allergic patients. Detection of at least one A. simplex recombinant allergen by dot blotting and ImmunoCAP assay using complete extract showed a diagnostic sensitivity of 100% with both methods. However, the specificity of dot blotting with A. simplex recombinant allergens was higher compared with ImmunoCAP (84.85 vs. 82.83%). Conclusions: There are 15% of tolerant patients with specific IgE against important A. simplex allergens. The recombinant allergens studied here increase the specificity of A. simplex diagnosis while keeping the highest sensitivity. A. simplex recombinant allergens should be included with A. simplex allergy diagnostic tests to improve their specificity.

<b><i>Anisakis</i></b> Allergy Component-Resolved Diagnosis: Clinical and Immunologic Differences between Patients from Italy and Spain

“…Population studies carried out in Spain and Italy pointed out that the rate of Anisakis sensitization is directly related to the habit of eating raw or undercooked fish [11,12]. Likewise, it seems clear that the food responsible for the high sensitization rates is homemade marinated anchovies, which are prepared with similar recipes in both countries.…”

“…The Italian group consisted of 42 Anisakis -allergic patients and 15 asymptomatic Anisakis -sensitized subjects, all living on the Adriatic coast (Ancona and Pescara) except 1 sensitized subject living in Milano. The Spanish group included 35 and 17 allergic and sensitized patients, respectively, all from Madrid [12]. The approval of the Hospital Carlos III ethical committee was obtained for this study.…”

Cross-Reactivity between <b><i>Anisakis</i></b> spp. and Wasp Venom Allergens

“…Membranes were processed as described [15] and scanned and quantified by densitometry using Quantity One software (Bio-Rad). Dots were scored as positives when their signal intensities were beyond the mean plus 5 standard deviation of the blots using 10 negative control sera.…”

“…Separated proteins were stained with Coomassie Blue or transferred onto nitrocellulose membranes by diffusion and incubated overnight with sera (diluted 1:20). IgE immunoblotting to detect specific IgE was performed with a monoclonal anti-human IgE (1:1,000; Ingenasa, Madrid, Spain) followed by an alkaline phosphatase-labeled goat anti-mouse antibody (1:5,000; BioSource International., Camarillo, Calif., USA) as described [15]. …”

Advances in allergen-microarray technology for diagnosis and monitoring of allergy: The MeDALL allergen-chip

“…The panel of pollen allergens contained allergens useful for the identification of the genuine sensitizing pollen species as well as cross-reactive allergens [53,54]. Furthermore, attempts were made to include relevant food allergens from, e.g., nuts, peanuts, milk and several other allergen sources [55][56][57][58][59]. Column "CCD" (cross-reactive carbohydrate determinants) in Table 1 indicates glycosylated allergen molecules with confirmed reactivity to CCD-specific IgE.…”