The objective of the study was to analyse levels IL-12 and to relate the findings to the clinical course of type 1 diabetes mellitus (DM1).
Material and methods: We examined a group of 102 children with DM1 and 39 healthy children (as the control). All the children with DM1 had their daily urine albumin excretion, HbA1c, C-peptide measured, 24hrs blood pressure monitoring and ophthalmologic examination. In accordance to the ophthalmologic examination and level IL-12 in the serum the diabetic children were divided into 3 groups: group A: IL-12>0 pg/ml; group B: IL-12=0 pg/ml; group C: IL-12=0 pg/ml and IL12>0 pg/ml. Serum levels of IL-12 and TNFalpha were measured by the immunoenzymatic ELISA method, Quan-tikine High Sensitivity Human by R&D Systems (USA).
Results: Children of group A were characterized by significantly high level of IL-12 and by the absence of TNFalpha as compared with the children of group B, who had undetectable IL-12 along with high TNFalpha level. Additionally, children of group A had significantly lower urine albumin excretion and had only developed retinopathy. However, the children of group B not only had retinopathy, nephropathy but also arterial hypertension. The patients of group A were also analysed against the children of group C, who were characterized by high IL-12 level and some of them had also detectable TNFalpha, but without retinopathy and nephropathy.
Conclusions: The results of our study imply the existence of balance between IL-12 and TNFalpha in type 1 DM children, which seems to warrant the stage of disease without diabetic complications. However, the IL-12 domination tends to prevent or delay nephropathy development but does not protect from retinopathy.