Low serum levels of tumor necrosis factor-alpha in insulin-dependent diabetic children

We measured serum levels of tumor necrosis factor-alpha (TNF-alpha) in 48 children with insulin-dependent diabetes mellitus (IDDM), divided into two groups according to disease duration (group I < 6 months and group II > 3 years): group I 15 patients, aged 2.2-13.7 years, and group II 33 patients, aged 4.5-25.5 years. Thirty-six age- and sex-matched healthy subjects served as controls. TNF-alpha levels were measured by immunoradiometric assay. We found that TNF-alpha levels were lower in all IDDM patients (29.65 +/- 3.83 pg/ml) than in controls (74.74 +/- 10.17 pg/ml) (p < 0.0001), as well as in group I (24.07 +/- 3.65 pg/ml) and group II (32.16 +/- 5.29 pg/ml) as compared to controls (p < 0.001). TNF-alpha levels were significantly lower in patients with antibodies than in those without antibodies and in controls. Similar results were found in longstanding IDDM patients. No correlation was found between serum TNF-alpha and chronologic age, duration of disease, metabolic control, insulin requirement and HLA typing. During a 1-year follow-up study in 12 group I patients no significant variations in TNF-alpha levels were observed. It has been reported that the administration of exogenous TNF suppresses the development of diabetes in nonobese diabetic mice, low producers of endogenous TNF. The results suggest that aberrant TNF-alpha synthesis may contribute to immune dysregulation thus favoring the development of autoimmune diseases.