Correlation between urine macrophage migration inhibitory factor (MIF)/creatinine ratio and time after kidney transplantation

Background: Despite the long-standing association of macrophage migration inhibitory factor (MIF) with delayed-type hypersensitivity response, the potential role of MIF in chronic allograft nephropathy is unknown. The association between upregulation of MIF expression, macrophage and T cell infiltration and the severity of chronic allograft nephropathy suggests that MIF may be an important mediator in the process of chronic allograft nephropathy. Therefore, the aims of this study were to measure urine concentration of MIF after renal transplantation, and to determine if it increases with time. Methods: In this prospective cross-sectional study twenty-two pediatric patients (case, group A) who received kidney transplants between 1999 and 2006, and forty healthy children (control, group B) were recruited. Urine MIF and creatinine were assessed in all patients. Urine MIF concentrations were quantitated by ELISA. Results: The mean ratios of urine MIF/Creatinine (Cr) were calculated as 5.046(SEM=2.04) pg/μmol creatinine in transplanted-kidney patients (group A) and 1.85(SEM=0.35) pg/μmol creatinine in healthy individuals (group B). Agood significant correlation was seen between urine MIF/Cr ratio and time after kidney transplantation in recipients (P=0.002, rSpearman = +0.633). Conclusion: This study shows significant correlation between urine MIF/Cr ratio and time passed after transplantation. Increasing MIF/Cr ratios were seen in patients with a longer post transplantation period. Therefore, it is necessary to determine the role of macrophages in chronic renal nephropathy especially chronic rejection with additive studies and then study the effect of anti-MIF antibodies in the treatment of this condition.