Background/aim: Cytokines play an important role in the pathogenesis of kidney diseases. The aim of the study was to investigate the impact of interleukin (IL)-1 cluster genes on diabetic nephropathy in Korean patients with type 2 diabetes mellitus (DM).
Methods: We investigated -511 C/T polymorphism of IL-1 beta and tandem repeat polymorphism in intron 2 of IL-1 receptor antagonist in type 2 DM patients with end-stage kidney failure as compared with patients without nephropathy.
Results: The IL1B2 allele was found more frequently in patients with kidney failure than in controls (57.4 vs. 46.1%, p < 0.05). An excessive homozygous carriage of IL1B2 was found in patients with kidney failure when compared with controls (30.5 vs. 18.3%, p < 0.05). The allelic frequency of IL1RN*2 was also higher in cases than in controls without nephropathy (8.4 vs. 2.8 %, p < 0.05). The carriage rate of IL1RN*2 was significantly associated with an increased risk of kidney failure (15.8 vs. 5.6%; OR 3.19, 95% CI 1.24-8.17). The risk of kidney failure was highest in those carrying both IL1RN*2 and IL1B2 (OR 3.90, 95% CI 1.34-11.40).
Conclusion: IL1B2 and IL1RN*2 genotypes of the IL-1 cluster genes are associated with diabetic nephropathy in Korean patients with type 2 DM.