Serum and urinary cytokine homeostasis and renal tubular function in children with type 1 diabetes mellitus.

ABSTRACT

AIM: To explore the relationships between tumor necrosis factor-alpha (TNFalpha), interleukin-6 (IL-6) and urinary N-acetyl-beta-D-glucosaminidase (NAG) and the function of renal proximal tubules in children with type 1 diabetes mellitus (DM1). METHODS: Fifty-six children with DM1 and 35 healthy controls were analyzed. We measured NAG (A and B isoforms) in urine as well as serum TNFalpha and urinary IL-6. RESULTS: The children with DM1 with microalbuminuria (group A) had significantly higher urinary IL-6 and serum TNFa than the children without microalbuminuria (group B). The diabetic patients with no sign of nephropathy showed significantly higher TNFalpha and NAG and its A and B isoforms in urine compared to the healthy group. Additionally, groups A and B both showed a positive significant correlation between serum TNFalpha and urinary isoform B. CONCLUSIONS: From our pilot results it appears that TNFalpha might be a sensitive marker of damage to the renal proximal tubules occurring prior to microalbuminuria. Conversely, the increase in NAG and its isoform B activity in patients with no clinical sign of diabetic nephropathy may indicate the onset of microalbuminuria.