Abstract

Background—Selective immunoglobulin A (IgA) deficiency (SIgAD) is associated with coeliac disease (CD).

Aim—To make a retrospective study of the association of SIgAD with CD in Italy.

Methods—Hospital medical records of 2098 patients consecutively diagnosed as having CD were reviewed.

Results—Of 2098 patients with CD, 54 (2.6%) had SIgAD, representing a 10–16-fold increase over that in the population in general. This increase was not influenced by age or geographical factors. Patients with SIgAD had a higher incidence of silent forms (7/54, 13%), recurrent infections (16/54, 29.6%), and atopic diseases (7/54, 13%) than those without. The association with autoimmune and malignant diseases and the outcome after eating a gluten free diet were similar in patients with or without SIgAD. In all patients with SIgAD, antibodies for IgA gliadin and endomysium were absent, but serum levels of IgG anti-gliadin antibodies were high in almost all of them (51/54).

Conclusions—Serum IgA should be measured in order to be able to interpret negative results for IgA anti-gliadin antibodies and anti-endomysial antibodies in patients being screened for CD. Since some patients with CD and SIgAD may be negative for IgG anti-gliadin antibodies, an intestinal biopsy should be performed in all suspected cases.