Autoantibodies against glutamic acid decarboxylase and insulin: role of immunological markers in type 1 diabetes mellitus and their relatives

ABSTRACT

This study was performed on 180 child classified into three groups. Group I, consisted of 50 newly diagnosed type 1 diabetes mellitus [DM], group II included 65 non-diabetic child with a positive family history of type 1 DM and group III contained 65 non diabetic child with negative family history for type 1 DM. All individuals were subjected to routine blood investigations for diabetes [fasting and post-load serum glucose and HbAlc] in addition to the measurement of insulin autoantibodies [IAA] and glutamic acid decarboxylase autoantibodies [GADA]. The aim of this work was to assess the sensitivity and specificity of IAA and GADA as immune markers in type 1 DM as well as their role in the prediction of the disease among individuals with positive family history for type 1 DM. Results of this study showed significant positive correlation between IAA against fasting serum glucose, post-load serum glucose and HbAlc. Stronger positive correlation was found between GADA and the same parameters. GADA showed better sensitivity, specificity, positive and negative predictive values and test efficiency when compared to IAA. Combined assay [GADA and IAA] gave the same sensitivity, specificity, positive and negative predictive values and test efficiency when compared to GADA alone. It may be concluded from the present study that GADA has more significant role than IAA in predicting the risk of developing DM in individuals with positive family history of type 1 DM