ANTICYTOMEGALOVIRUS IGM AND IGG ANTIBODIES, ISLET CELL ANTIBODIES AND GAMMA-INTERFERON SERUM LEVELS IN NEWLY DIAGNOSED IDDM PATIENTS

To assess whether Cytomegalovirus (CMV) infection may be involved in the pathogenesis of insulin dependent diabetes mellitus (IDDM, type 1 diabetes) we studied the prevalence of: (i) anti-CMV IgM and IgG antibodies, of (ii) islet cell antibodies (ICA) and, (iii) the serum levels of gamma interferon (IFN) in 66 newly diagnosed IDDM patients. Neither IDDM patients nor controls were positive for specific anti-CMV IgM antibodies; on the other hand, anti-CMV IgG antibodies to higher titers than 1/160 (considered as a positive value) were found in 45/66 (68.2%) of newly diagnosed IDDM patients as opposed to 18/51 (35.3%) of control subjects (p < 0.0005). In addition, when considering type 1 diabetic patients with respect to the ICA status, we observed that 42/50 (84%) of ICA positive subjects had specific anti-CMV IgG antibodies to higher titers than 1/160, as compared to 3/16 (18.8%) of ICA negative patients (p < 0.0001). Detectable amounts of serum levels of gamma interferon, with values ranging from 1.2 to 1.9 UI/ml, were found in 9/66 (13.6%) of IDDM patients as opposed to 0/48 of the controls (p < 0.01). No correlation was found between the positivity for and/or the titers of gamma interferon and the presence and/or the titers of anti-CMV IgG antibodies and/or of ICA. Taken together these data may indicate that a chronic CMV infection may be involved in the production of ICA in genetically predisposed individuals; accordingly, assuming that ICA may have a pathogenetic role in the development of IDDM, these findings may provide evidence that CMV may be important in the pathogenesis of the disease.