Frequencies at three polymorphic sites of interleukin-10 gene promoter in Brazilian renal recipients

Abstract

We genotyped by PCR-RFLP 141 renal patients (77 men and 64 women with ages between 12 and 58, predominantly Caucasians) for allelic variants of three polymorphic sites of the interleukin-10 gene promoter, previously showed to be associated with different production of IL-10 cytokine: −1082 (G/A), −819 (C/T), and −592 (C/A). These polymorphisms may confer flexibility in the common immune responses and influence the outcome of allo-responses after transplantation. Our aim was to determine the frequencies of three functional polymorphic sites −1082, −819, and −592 of the interleukin-10 gene promoter in renal recipients of Curitiba, Paraná. Paraná State is located in southern Brazil, and its capital is Curitiba with approximately 1.5 million inhabitants. Genotypes were classified as follows: “low” IL-10 producer genotypes (ATA/ATA, ACC/ATA, ACC/ACC), “intermediate” genotypes (GCC/ACC, GCC/ATA), and “high” IL-10 producer genotype (GCC/GCC). In our population we observed linkage disequilibrium between alleles −819C and −592C and this haplotypic combination was more frequent (65%) than −819T and −592A. We found significantly reduced frequency of the genotype and haplotype responsible for high production of interleukin-10, maybe because we have a selected group (only renal patients) or maybe because Brazilian people are very heterogeneous (miscegenational), which may differ from other groups.