Publications of Faculty of Medicine:STUDY OF PHENOTYPIC CHARACTERISTICS AND HLA TYPES IN EGYPTIAN NIDDM PATIENTS WITH AND WITHOUT GLUTAMIC ACID DECARBOXYLASE ANTIBODIES UNDER DIFFERENT MODALITIES OF TREAMENT: Abstract

The present work was designed to study the prevalence of glutamic acid decarboxylase antibodies (GAD ab) in representatives of Egyptian NIDDM patients and to establish the phenotypic characteristics and HLA types of this subgroup. One hundred non-insulin treated type 2 diabetic patients (Group 0, 50 insulin treated type 2 diabetic patients (Group 11) and 50 healthy volunteers serving as controls (Group III) constituted the subjects of our study. The age of patients ranged between 35-60 years. The phenotype was assessed by patient's age, age of onset of diabetes, body mass index (HMI), plasma glucose, percentage hemoglobin Ale (Hb Ale), serum cholesterol, serum triglycerides and serum C-peptide level GAD ab was measured using ELISA methoct Class 1 HLA (ILA-A and B) and class II HLA (HLA-DR) types were assessed using cytotoxicity test.The prevalence of GAD ab was 2e4 among group 1 patients, am among group II patients and 4% among controls. The GAD ab positivse patients were significantly younger and experienced diabetes onset at an earlier age compared with GAD abnegative patients The GAD ab positive patients had lower fasting C-peptide concentration in comparison with GAD ab negative patients. With respect to featu res of metabolic syndrome, the GAD ab positive patients had lower BML lower serum cholesterol, lower serum triglycerides, higher plasma glucose and higher Jib A lc compared with GAD ab negative patients. Compared with GAD ab negative patients and controls, group II patients had an increased frequency of HLA DR3 and DR4 types. There were no differences between NIDDM and normal controls in the frequen cyof a particular HLA antigen except for an increased frequency of IMA BIS in both group land 11 patients and increased frequency of HLA DR3/DR4 in group II patients.These results suggest that type 2 diabetes is a heterogeneous disorder including at least 2 major subgroups characterized by GAD ab and HL DR3 / DR4 types.