Interleukin-12 and tumour necrosis factor-alpha equilibrium is a prerequisite for clinical course free from late complications in children with type 1 diabetes mellitus.

The objective of the study was to analyse levels of IL-12 and TNF-alpha and relate the findings to the occurrence of microangiopathy in children with type 1 diabetes mellitus (DM). We examined a group of 123 children with type 1 DM. Serum levels of IL-12 and TNF-alpha were measured by an immunoenzymatic ELISA technique. TNF-alpha and IL-12 tended to be simultaneously present or absent in the sera of 50% of the children who had not developed complications, thus indicating a state of cytokine's equilibrium. Among the patients with an established retinopathy, two IL-12/TNF-alpha combinations were visible. Either a lack of detectable TNF-alpha was accompanied by measurable IL-12 serum concentrations or TNF-alpha incidence was associated with undetectable IL-12 values. Simultaneous lack of TNF-alpha and presence of IL-12 was associated with a better prognosis as these patients had a significantly lower albumin excretion rate. The state of equilibrium between TNF-alpha and IL-12 is beneficial in patients at early stages of the disease, prior to the occurrence of complications. Shifting the equilibrium towards TNF-alpha seems to promote late complications. It may suggest that a disharmony between pro- and anti-angiogenic function of these cytokines underlie the mechanism by which TNF-alpha and IL-12 shape the disease course.