Role of Recombinant Parvalbumin Gad c 1 in the Diagnosis and Prognosis of Fish Allergy.

BACKGROUND AND OBJECTIVES: The prevalence of fish allergy has increased in recent years. The parvalbumin Gad c 1 is a major cod allergen that is used as a follow-up marker in patients with fish allergy. Objectives: To determine the clinical and laboratory characteristics of a population of patients with fish allergy. To analyze the role of the specific IgE (sIgE) of recombinant Gad c 1 (rGad c 1) and skin prick tests (SPTs) in confirming the acquisition of tolerance to fish. METHODS: We performed a retrospective study of patients with fish allergy from July 1, 2005 to December 31, 2016. The population was characterized according to demographic data, species of fish associated with allergic reactions, and symptoms. The SPT wheal diameter and sIgE for fish and rGad c 1 were evaluated before acquisition of tolerance (T0) and afterwards (T1). RESULTS: The study population comprised 81 patients (68% male). Most reactions were triggered by hake (51%), mackerel (30%), and cod (26%). The most frequent manifestations were urticaria/angioedema (72%), gastrointestinal symptoms (35%), and eczema (33%); 42% of patients experienced anaphylaxis. At T0, the average sIgE values were as follows: cod, 32.2 kUA/L; sardine, 18.4 kUA/L; hake, 17.5 kUA/L; salmon, 13.9 kUA/L; tuna, 4.5 kUA/L; and rGad c 1, 22.9 kUA/L. In patients who acquired tolerance to at least 1 fish species (n=60; 74%), the mean value of rGad c 1 at T1 (5.1 kUA/L) was significantly lower than at T0 (16.8 kUA/L) (P=.001). Significant values were also recorded for the average diameter of the SPT wheal and the evaluations at T0 and T1 for hake (9.42 mm/3.79 mm) and salmon (7.8 mm/2.8 mm) (P=.002 and P=.026, respectively). CONCLUSION: The decrease in sIgE to rGad c 1 and the mean wheal diameter of SPT for hake and salmon can be used as markers of prognosis in the acquisition of tolerance by fish-allergic patients.

Latex and chickpea (Cicer arietinum) allergy: first description of a new association.

In this paper we describe the existence of cross-reactivity between allergens from latex and chickpea, a food from the Leguminosae family, which is common in the Mediterranean diet. We present the case report of a spina bifida boy with a clinical relevant food allergy to chickpea (oral syndrome + dysphonia), developing after the appearance of latex allergy symptoms (lip angioedema + intraoperative anaphylaxis). Specific IgE to latex and chickpea was demonstrated by skin prick tests, measurement of patient's serum specific IgE and IgE-immunoblotting. Cross-reactivity was studied by means of EAST-inhibition and western blotting-inhibition. A strong inhibition was observed in several IgE-binding bands when latex extract was used in solid phase and patient serum was preincubated with chickpea extract (chickpea extract as inhibitor phase). As far as we know, this is the first report of cross-reactivity between latex and chickpea, a food which should therefore be added to the extensive list of latex cross-reactive foods.