Tissue transglutaminase and anti-gliadin antibodies in children with IgA nephropathy

Abstract

Objectives and study : Etiology of IgA-nephropathy (IgAN) is unknown. Coeliac disease (CD) is an autoimmune enteropathy with definite etiology - wheat, rye and barley prolamines cause CD. The finding of increased levels of IgA against food antigens in patients with IgA nephropathy hypothesize of an association between IgAN and CD and with the progression of IgA NP. The aim of this study was to establish the frequency of CD in children with IgAN. Methods : The study was done at Vilnius University Children Hospital between 2003-2005. We examined 25 IgAN children (10 girls and 15 boys ; median age at examination 15.9yr, range 1.9 - 19yr) for the IgA antibodies to tissue transglutaminase (IgA-tTG) and IgA anti-gliadin antibodies (IgA-AGA). The diagnosis of IgAN were confirmed by kidney biopsy. IgA antibodies to tTG were analysed with recombinant human antigenwith a commercially available kit from IBL, Hamburg (Germany). Patients who has positive IgA-TG or IgAAGA were advised to undergo small bowel endoscopy. Results : Elevated IgA-tTG antibodies were detected in 3 of 25 IgAN patients (12%). IgA-AGA were positive in 1 of 25 children (4%). No patient had elevated both types of antibodies. Small bowel endoscopy was suggested for 4 patients who were positive for IgA-tTG or IgA-AGA but performed only in one patient with positive IgA-tTG. It was normal. Other three patients were not willing to undergo endoscopy (Table 1). Conclusions : 1. Coeliac disease antibodies is common in IgAN (12% IgAtTG and 4% IgA-AGA) 2. Patients with IgAN should be checked for coeliac disease.