Evidence of circulating interferon-gamma in newly diagnosed diabetic children.

Acid-stable interferons (IFN-alpha or IFN-beta) are produced by nucleated cells infected by virus, while acid-labile interferon (IFN-gamma) is synthesized by activated T-lymphocytes. IFN-gamma or an atypical form of acid-labile IFN-alpha have been observed in the circulation of some patients with autoimmune disease. It is believed that autoimmunity and/or viral infections are involved in the pathogenesis of insulin dependent diabetes mellitus. We therefore examined the sera of newly diagnosed diabetic children for the presence of virus-induced or acid-labile IFN. Significant IFN levels (greater than or equal to 8 U/ml) were observed in 11 of 29 patients when compared to 31 healthy children in the same age range. The inhibitor is characterized by species specificity, acid-lability and neutralization with anti-serum for IFN-gamma.