Evaluation of serum interleukin 6 and tumour necrosis factor alpha levels, and their association with various non-immunological parameters in renal transplant recipients

Abstract

Renal transplant rejection involves both immunological and non-immunological factors. The objective of the present study was to investigate the association between immunological factors, such as serum interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α), and non-immunological parameters, such as age, serum creatinine (SCr), creatinine clearance (CrCl) and dyslipidaemia, in renal transplant recipients (RTRs). This study included 90 RTRs and 90 healthy controls. Biochemical parameters, including serum IL-6 and TNF-α, were estimated using standard protocols. CrCl was calculated using the Cockroft-Gault equation, and the type of rejection was confirmed on biopsy. Student's t-test and univariate and multivariate analyses were performed using the Statistical Package for the Social Sciences for Windows version 15. The mean levels of serum IL-6 and TNF-αwere significantly higher in RTRs than in the control group (p < 0.001). These parameters were also found to be significantly different between the transplant rejection (TR) and transplant stable (TS) groups (p < 0.001). CrCl was significantly decreased in the TR group when compared to the TS group (p < 0.001). The two cytokines, IL-6 and TNF-α, correlated significantly with all metabolic parameters, such as SCr, CrCl and dyslipidaemia. Multiple regression analysis showed that TNF-α and CrCl were the strongest predictors of IL-6. We conclude that immunological factors, as well as non-immunological factors such as CrCl, SCr and dyslipidaemia, play important roles in the pathogenesis of graft rejection and renal graft dysfunction.