Seroconversion of reticulin autoantibodies predicts coeliac disease in insulin dependent diabetes mellitus.
Serum IgA class reticulin autoantibody test was performed prospectively once a year on 238 children and adolescents with insulin dependent diabetes mellitus (IDDM). At the initial testing, within one year after onset of IDDM, five were positive and 233 were negative. During follow up a further 11 of the initially antibody negative children became positive (6.7%). Jejunal biopsy was performed at the appearance of the autoantibodies and silent coeliac disease was shown in nine (3.8%). One of these children showed on initial biopsy after the onset of IDDM to have normal jejunal mucosal architecture deteriorating later to a flat lesion. Jejunal immunohistochemical studies of another of the patients positive for reticulin autoantibodies but normal on routine biopsy showed an increased density of intraepithelially located gamma/delta T cells and aberrant HLA-DR expression in the crypts pointing to ongoing mucosal inflammation and potential coeliac disease. This study shows that in IDDM patients, reticulin autoantibody negative subjects become antibody positive, which may be followed by coeliac disease. Repeated serological screening and rebiopsy should be considered to detect late developing clinically silent coeliac disease among patients with IDDM.