Prevalence of atopy in children with type 1 diabetes mellitus, hepatitis B virus carriers, and healthy children: Role of T helper 1 (Th1)-type immune response

The prevalence of allergic diseases such as asthma, hay fever, and atopic dermatitis has increased over the past few decades, especially in developed countries. They are characterized by a chronic inflammatory reaction mediated by T helper 2 (Th2) cells. Two common chronic diseases of childhood-an autoimmune disease, type 1 diabetes mellitus (DM), and a chronic viral infection, hepatitis B virus (HBV) carriers-are associated with a Th1-dominant and Th1-insufficient cytokine profile, respectively. The purpose of this study was to analyze the frequency of allergic disease in patients with type I DM and, in HBV carriers, to evaluate the role of Th1-type immune response in atopy and allergic disease. The study included patients with type 1 DM (group I, n = 52), HBV carriers (group III, n = 47), and a healthy control group (group III, n = 209). Participants were screened for allergic disease and atopic sensitization. Symptoms of asthma, eczema, and atopy were found more commonly in HBV carrier children compared with those with DM and healthy controls. This study supports the Th1/Th2 model. The prevalence of allergic disease and atopy is decreased in Th1-mediated autoimmune disease, type 1 DM, and, conversely, is increased in insufficient Th1 response, chronic HBV carriers. Additional studies arc needed to evaluate the effect of atopy and allergic diseases in glycemic control and long-term complications in patients with type I DM and the effect of atopy on progression of chronic HBV infection.