Selective Immunoglobulin A Deficiency in Type 1 Diabetes Mellitus: A Prevalence Study in Western Sicily (Italy)

BACKGROUND The association between type 1 diabetes and immunoglobulin A deficiency (IgA-D) has long been recognized in many populations. The aim of this study was to assess the prevalence of IgA-D in patients with type 1 diabetes mellitus all coming from a defined geographical area and to investigate the clinical features of these subjects. METHODS The records of 150 consecutive patients with type 1 diabetes mellitus referred in a period of one year were analyzed. A detailed history was obtained for each patient. Information was collected concerning age, gender, time of onset of diabetes, and presence of other autoimmune diseases. RESULTS Out of 150 patients with type 1 diabetes, eight (5.3%) had a diagnosis of IgA-D. There were one female and seven male; all these patients were diagnosed by screening: none of them had history of recurrent infections. Autoimmune thyroiditis was coexisting in five patients (62%). Although other associated autoimmune disorders were found in a number of patients, there was no different prevalence rate in IgA deficient patients. CONCLUSION This study shows the prevalence of IgA-D in Sicilian patients with type 1 diabetes as 5.3% which is much higher than reported in other Italian studies. Moreover, our data show a high prevalence of IgA-D in male gender and describe thyroiditis as the most frequent autoimmune disease present in these patients. Finally, in our case report, IgA-D diagnosis always followed routine IgA measurement when case finding for celiac disease with no history of recurrent infections in each patient.