Immunogenetics of type 1 diabetes mellitus Azza

Introduction Type 1 diabetes mellitus (T1D) is one of the most common autoimmune diseases with several million people already affected around the globe. It can occur at any age, but is most commonly diagnosed from infancy to the late thirties. It is characterized by an absolute loss of insulin secretion, and results from an autoimmune process that destroys insulinproducing ß cells within the pancreatic islet. Similar to other autoimmune diseases, the etiology of T1D remains obscure but develops on a genetically susceptible background and also involves a variety of factors, ranging from immune dysregulation to environmental triggers. The outcome is the production of auto-antibodies as well as an expansion of auto-aggressive T cells. The incidence of T1D worldwide varies between as high as 30-40 per 100 000 children in Finland and Sardinia to values as low as 30-40 per 100 000 children in Japan and China 2 .In Egypt , the prevalence of T1D in school aged children varies between 1.121.9 per 1000 in various studies . Worldwide, the incidence of T1D is increasing, particularly in the under-5-years age group. The standardized mortality ratio for T1D has been estimated as 4-fold for females and 2.7-fold for males in the Western countries. Even with tight glucose control, there is a significant risk of neuropathy, retinopathy and nephropathy, as well as a 3-fold increase in the risk of severe hypoglycaemia. Understanding the pathology of T1D may help improve prevention and management. This review will focus on the immunology of T1D, and how this understanding may influence the clinical management, and development of new treatments for this disease.