Tumor necrosis factor-alfa and monocyte chemoattractant protein-1 gene polymorphisms in kidney transplant recipients

Abstract

Tumor necrosis factor-alfa (TNF-α) gene polymorphism is supposed to have a significant influence on the incidence of acute rejection in renal transplantation. The monocyte chemoattractant protein-1 (MCP-1) is another factor supposed to modulate graft rejection. We studied TNF-α and MCP-1 gene polymorphisms in 84 kidney allograft recipients with polymerase chain reaction and restriction fragment length polymorphism and their serum levels by enzyme-linked immunosorbent assay. The patients were classified into two groups based on their outcomes: Group I (n = 47) recipients with stable graft function as the control group and group II (n=37) recipients who experienced acute graft rejection episodes in the first 30 days post-transplantation. A significantly higher incidence of TNF 2 /TNF 2 genotype was observed among patients with acute graft rejection in comparison with the control group (40.5% and 19.2% respectively, P <0.05), while no statistically significant differences were observed in the TNF 1 /TNF 1 genotype between the groups (59.4% and 80.8%, respectively, P >0.05). A significant elevation of serum TNF-α levels was found in group II than group I and between TNF 2 genotype compared with that of TNF1 genotype within group II recipients. Distribution of MCP-1 genotypes in patients with and without acute rejection episodes was not significantly different (70.2% and 76.6% for MCP-1 A/A and 29.7% and 23.4% for MCP-1 G/G, respectively, P >0.05). The serum MCP-1 levels were not significantly different between the groups and between MCP-1 G/G genotype and MCP-1 A/A genotype in group II recipients. In conclusion, TNF-α gene polymorphism or its serum levels may identify patients at risk of acute rejection, where patients with TNF 2 /TNF 2 genotype or high serum TNF-α levels are more likely to have acute rejection episodes, while there was no relation between MCP-1 genotype or its serum levels and acute rejection.