Diagnostic value of autoantibodies to GAD65 and IA-2 in patients with latent autoimmune diabetes in adult (LADA)

Background : latent autoimmune diabetes in adults (LADA) accounts for11 % of all cases of diabetes and often misdiagnosed as type 2diabetes. LADA resembles type 1diabetes and shares common physiological characteristics of type 1 but it does not affect children and has been classified distinctly as being separate from juvenile diabetes. Autoantibodies against glutamic acid decarboxylase 65 (GADA) and tyrosine phosphatase (IA-2) are found frequently in patients with LADA. The presence of these autoantibodies in LADA predicts inevitable cell failure and poor response to oral hypoglycemic therapy i.e., patients with LADA do not respond to oral hypoglycemic therapy. Objective : to determine an immunological marker to diagnose patients not responding to oral hypoglycemic therapy. Patients and methods: A facility-based cross sectional study was conducted in Jabbir Abu Eliz Diabetes Center, located at Khartoum 2. Venous blood samples were obtained from the study patients. They were divided into three groups ; group1 included 27 diabetic patients treated with insulin, group2 included 15 diabetic patients of type 2 diabetes as controls, and group3 included 15 newly diagnosed patients older than 35 years at onset of diabetes. A standardized pre-tested administered questionnaire was used for data collection and the collected data were analyzed. Results : males encountered in the study were 28 (49.1 %). On patient recently diagnosed to have type 2 diabetes mellitus (T2DM) was positive for autoantibodies to GDA / IA-2. These autoantibodies were also positive in 15 patients with diabetes mellitus type 1 (T1DM) Conclusions : Autoimmune diagnostics is of particular importance in adults to discriminate between type 1 and type 2 diabetes and to assess the diagnosis of latent autoimmune diabetes in adults. The current study results revealed that autoantibodies to GAD / IA-2 are good marker for diagnosis of latent onset DM type 1. On the other hand, data indicate that the vast majority of cases of type 1 diabetes may be considered as immune-mediated, that multiple autoantibody to GAD / IA-2 analysis are of prognostic value to predict complications e.g., retinopathy. The current study recommends using of anti-GAD/IA-2 antibodies as marker for diagnosis of latent autoimmune diabetes in adults (LADA) who are not responding to oral hypoglycemic and may be at risk for getting complications. On the other hand, the study recommends using of anti-GAD / IA-2 antibodies for prognosis of