Influence of cytokine gene polymorphisms on focal segmental glomerulosclerosis.

BACKGROUND: Recently, polymorphisms of cytokine genes have been associated with modified gene expression and increased cytokine production. We evaluated the influence of TGF-beta(1) gene Arg(25)-->Pro, TNF alpha gene G-308A and IL-6 gene G-174C polymorphisms on the clinical manifestations of focal segmental glomerulosclerosis (FSGS). METHODS: The clinical course of 71 patients with biopsy-proven primary FSGS followed up for 6.0 +/- 4.4 years was studied. Patients were classified according to the slope of reciprocal serum creatinine into slow (n = 49) and fast (n = 22) progressors. One hundred healthy volunteers were analysed as controls. Genetic polymorphisms were determined by PCR amplification. RESULTS: The genotype distribution of the studied polymorphisms was similar in patients and controls (n.s.). Age, initial renal function, proteinuria and blood pressure did not differ significantly between patients with different genotypes (n.s.). The investigated polymorphisms were not associated with the progression of FSGS as shown by the similar genotype frequencies among slow and fast progressors (n.s.) and the renal survival in the Kaplan-Meier analysis (n.s.). CONCLUSION: Our results indicate that TGF-beta(1) gene Arg(25)-->Pro, TNF alpha gene G-308A and IL-6 gene G-174C polymorphisms are not risk factors or markers of progression in focal segmental glomerulosclerosis.