Prevalence of IA-2 antibody in patients suffering from diabetes and their first-degree relatives

Abstract

Type 1 diabetes mellitus (T1DM) is an autoimmune disorder accompanied by activation of auto-reactive B cells, autoantibody production, and consequently insulin-producing beta cell destruction. Some evidences support the value of autoantibodies such as anti-islet cell antigen (IA-2) auto-antibody in T1DM diagnosis and prognosis. The present study investigated the presence of IA-2 antibody in T1DM patients and their first-degree relatives as well as T2DM patients and healthy people to evaluate the diagnostic and prognostic value of anti-IA-2 in T1DM. In total 264 cases including 38 T1DM patients, 36 first-degree relatives, 88 T2DM patients, and 102 age-/sex-matched healthy controls participated in this study. After venous blood collection, sera were isolated and the level of IA-2 antibody was measured by ELISA method. Routine hematologic and biochemical tests including complete blood count (CBC), fasting blood sugar (FBS), hemoglobin A1c (HbA1C), urea, creatinine, as well as lipid profile and liver function tests were analyzed. Upregulated level of IA-2 antibody was observed in 47.4 and 5.6% of T1DM and their relatives, respectively; however, the level was significantly higher in T1DM compared to T1DM first-degree relatives (p < 0.05). In addition, none of the T2DM patients nor healthy controls were positive for IA-2 autoantibody. There was not any significant correlation between anti-IA-2 levels and total daily dose of insulin and the biochemical and hematological parameters. It seems that the measurement of anti-IA-2 antibody has no value in prediction or management of T1DM. Further studies need to reveal the reason for high anti-IA-2 titer in some patients.