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Recently, the high prevalence of autoantibodies against antigens expressed in exocrine pancreatic cells such as carbonic anhydrase II (ACA) and lactoferrin (ALF) was found in sera from adult Japanese patients with type 1 diabetes. Hence, we determined by ELISA the presence of ACA and ALF both in children (n = 27) and adult (n = 15) Caucasian patients with type 1 diabetes at diagnosis. Among children, ACA were found in one patient (3.7%) and ALF in three (11.1%). Among adults, CAA and ALF were detected in three patients (20%) and in one patient (6.7%), respectively. The prevalence of ACA and ALF observed in our Caucasian patients with type 1 diabetes at diagnosis did not reach the high value previously reported in adult Japanese patients.

The presence of antibodies reacting with the p53 tumor suppressor protein has been described in patients with some autoimmune disorders. In this study we looked for serum anti-p53 antibodies in 64 patients with autoimmune type 1 diabetes mellitus within 4 mo of diagnosis. The presence of anti-p53 antibodies was observed in 6/64 (9.4%) subjects with type 1 diabetes, and in 1/44 (2.3%) subjects with other organ-specific autoimmune diseases (18 primary biliary cirrhosis, 10 autoimmune hepatitis, 16 thyroid diseases), but in none of 45 control subjects. No relationship was found between antibodies directed against islet- and non-islet-specific antigens and anti-p53 antibodies. These findings support a possible role for p53 in some autoimmune disorders.

Development of type 1 insulin-dependent diabetes mellitus has been recently reported in patients who underwent interferon-alpha (IFN-alpha) therapy because of chronic viral hepatitis. Furthermore IFN-alpha seems to be involved in the immunological events that lead to beta-cell destruction and development of type 1 diabetes. To evaluate whether IFN-alpha treatment could elicit an autoimmune response against beta-cell antigens, we determined the occurrence of islet cell antibodies and insulin autoantibodies in the sera of 60 patients with HCV- or HBV-related chronic hepatitis who had been treated with IFN-alpha for 6 or 12 months. The presence of antibodies against thyroglobulin, thyroid microsomal antigen, gastric parietal cells, and non-organ-specific antigens was also investigated. Insulin autoantibody positivity was observed in 2/60 (3.3%), 8/60 (13.3%), and 4/30 (13.3%) patients, before IFN-alpha treatment, and after 6 months and 12 months of therapy, respectively. None of the studied patients developed islet cell antibodies or type 1 diabetes. Before IFN-alpha therapy four patients showed thyroid autoantibodies and four others developed antibodies against thyroglobulin and/or thyroid microsomal antigen during the treatment. Coexistence of insulin autoantibodies and thyroid autoantibodies was observed in only two patients. Our results showed that IFN-alpha therapy in patients with chronic viral hepatitis is capable of inducing development of autoantibodies against insulin. This event seems to be not related to other autoimmune disorders.