Objectives: The genetic and cellular processes involved in the etiopathology of benign prostatic hyperplasia (BPH) are unknown. Although evidence of BPH as an immune-mediated disease distinct from prostate cancer is growing, the cytokine gene polymorphisms associated with the risk of BPH have been explored less. The purpose of this study was to investigate the genetic association of polymorphisms of important cytokine genes (IL-4 and IL-1Ra) with the risk of BPH in a case-control study of a North Indian population.
Methods: The IL-4 and IL-1Ra gene polymorphisms were genotyped with variable number of tandem repeats-polymerase chain reaction in 150 patients with BPH and normal healthy controls. On the basis of their response to combined therapy of alpha-adrenergic inhibitor plus 5-alpha-reductase inhibitor, patients were grouped as responders and nonresponders. The genotype distribution and allelic frequencies between the patients and controls were compared, and odds ratios with 95% confidence intervals were calculated using Statistical Package for Social Sciences software, version 11.5.
Results: The difference in genotype frequency distribution for the IL-4 and IL-1Ra gene polymorphisms between the BPH and control groups were statistically significant (P <0.05). A significant difference (P <0.05) was also observed between the responder and nonresponder groups in the IL-4 gene variants.
Conclusions: IL-4 and IL-1Ra gene polymorphisms are associated with the risk of BPH. This study for the first time has demonstrated an association between the IL-4 polymorphism and BPH and particularly influences the therapeutic response of patients.