Type 1 diabetes is a chronic autoimmune disease with a subclinical prodromal period characterized by the presence of circulating antibodies to various islet cell proteins. Our main objective is to estimate the prevalence of diabetes-associated autoantibodies in a group of 1st degree relatives, compared to healthy control subjects. Also, we tried to assess the insulin secretory capacity in subjects having multiple antibodies using first phase insulin response (FPIR) to intravenous glucose.
Eighty children and adolescents of the 1st degree relatives of diabetic patients attending the out patient clinic in the diabetic institute participated in our study. They were (34 boys and 46 girls, 50 siblings and 30 offspring of diabetic parents, aged 820 years with mean age 13.23+3.6). 20 age and sex matched control subjects with negative family history of diabetes were enrolled from the child health clinic in the NRC. Sera of all subjects and controls were monitored for: islet cell antibodies (ICA), anti-insulin autoantibodies (IAA) and glutamic acid decarboxylase antibodies (GAD) using ELIZA technique, and (IA-2) antibodies using radioligand binding assay. It was found that: according to the considered cut off point for positivity, 23 out of the 80 relatives (28.75%) showed positive ICA. 21 out of 80 relatives (26.25%) showed positive IAA. 17 out of 80 relatives (21.25%) showed positive GAD antibodies. 5/80 relatives (6.25%) showed positive IA-2 antibodies. As regard the control group only one subject tested positive for ICA and another one tested positive for IAA. None of the control group tested positive for GAD or IA-2 antibodies. On studying different combinations of positive antibodies, it was found that only two subjects of the study group (2.5%) had three positive antibodies, 10% had positive ICA and IAA, 3.75% had positive ICA and anti-GAD. The same percent of the study group had positive IAA and anti-GAD. Those subjects showing more than one positive antibody underwent IVGTT to determine FPIR to predict subjects at high risk for developing type 1 diabetes. One subject was found to be at risk and four subjects were found to be at high risk for developing type 1 diabetes.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.