Evaluation of two commercial peach extracts for skin prick testing in the diagnosis of hypersensitivity to lipid transfer protein. A multicenter study.

Summary: The clinical usefulness of two commercial peach extracts for SPT (by Lofarma SpA and ALK-Abellò, respectively) was compared in a multicenter study carried out in Italy. Peach allergic patients were tested with the two extracts in parallel and underwent the detection of IgE specific for all three peach allergens currently available (Pru p1, Pru p3, and Pru p4, respectively). The two extracts were almost identical in terms of sensitivity and specificity, being able to detect virtually all patients sensitized to stable peach allergens (lipid transfer protein (LTP) and, presumably, peamaclein) but scoring negative in patients exclusively sensitive to labile allergens (either PR-10 and/or profilin). Thus, the two extracts represent an excellent tool to carry out a preliminary component-resolved diagnosis of peach allergy at the first patient visit.

Use of a comprehensive diagnostic algorithm for Anisakis allergy in a high seroprevalence Mediterranean setting.

Summary: Background.Diagnosis of anisakis allergy (AA) is based on the skin prick test (SPT) and specific IgE (sIgE) determination. Anyway, false positivity cases are due to cross reactivity with numerous allergens. The aim of the study was to evaluate the reliability of a comprehensive diagnostic algorithm for the AA. Methods.An observational study was conducted on a sample of consecutive subjects accessing the allergology outpatient ambulatories of two hospitals located in Western Sicily. All the recruited outpatients were tested by Skin Prick Test performed using anisakis extracts by ALK-Abellò (Madrid, Spain). Specific IgE dosage for anisakis extracts was then performed by using ImmunoCAP250 (Immunodiagnostics Uppsala, Sweden). Consequently, outpatients who tested positive to first line tests underwent sIgE testing for ascaris and tropomyosin. Lastly, outpatients positive to the first line were invited to be further tested by basophil activation test (BAT) by using Flow CAST kit and anisakis commercial extract (Bühlmann Laboratories AG, Schönenbuch, Switzerland), as confirmatory analysis. Results.One hundred and eleven outpatients with an anamnesis suggestive of sensitization to anisakis (AS) and 466 subjects with chronic urticaria (CU) were recruited in the study. Of these, 22 with AS and 41 with CU showed a sensitization to anisakis allergens. The diagnostic algorithm revealed that 8.8% of outpatients who tested positive to sIgE determination were affected by CU, while 82.5% of all the sIgE positivity was related to cross-reactivity. Overall, a genuine anisakis seroprevalence of 2.3% was documented. Within a sub-sample of 15 subjects with clinical symptoms related to AA, n. 8 showed a real positivity after BAT. A greater response to A. pegreffii allergens as compared to A. simplex was reported. Conclusions.Our preliminary findings support the high clinical specificity of BAT for AA diagnosis, suggesting implementing this method in a comprehensive diagnostic algorithm.