Study of selective immunoglobulin A deficiency among Egyptian patients with food allergy.

INTRODUCTION: IgA deficiency is one of the commonest primary antibody deficiencies. Although many affected individuals could be asymptomatic, selected patients suffer from recurrent mucosal infections, allergies, and autoimmune diseases. AIM OF THE STUDY: To investigate the prevalence of IgA deficiency among Egyptian patients with food allergy. MATERIAL AND METHODS: We studied 100 patients (62 males, 38 females; mean age, 28.6 years) with multiple food allergies who were recruited on the basis of adequate immunological assessment by history, skin prick test, and confirmed by open challenge test as well as 50 healthy controls. Measurement of levels of IgE and IgA using ELISA technique were performed for all patients and controls. RESULTS: Deficiency of IgA was detected in 67% of patients with food allergy. Serum IgA levels were significantly lower among patients with food allergy (67.3 µg/ml; range, 56.7-72.0 µg/ml) as compared to healthy control (78.6 µg/ml; range, 72.8-84 µg/ml). Both IgA and IgE levels were not statistically different between patients with food allergy only and those with combined food and aeroallergen. Among food allergic group, serum IgA levels were inversely correlated with serum IgE levels (r = -0.314, p < 0.001). CONCLUSIONS: Manifestations of atopy, such as food allergy might be a present feature before diagnosis of primary immune deficiency diseases as IgA deficiency.