ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effect of cytomegalovirus (CMV) infection following kidney transplantation on long-term renal function and its mechanism.</p><p><b>METHODS</b>Ninety-six patients undergoing kidney transplantation between March 2000 and December 2005, who completed a 3-year follow-up investigation, were divided into 3 groups according CMV-pp65 antigenemia and clinical symptoms. Group A consisted of 33 recipients with symptomatic active CMV infection, group B included 33 with asymptomatic active CMV infection and group C included 30 with inactive infection. The relation of CMV infection, transforming growth factor-beta1 (TGF-beta1) mRNA in the peripheral blood mononuclear cells (PBMCs) and serum creatinine (Scr) were analyzed, and the grafts in 6 cases with renal dysfunction were biopsied.</p><p><b>RESULTS</b>The expression of TGF-beta1 mRNA in PBMCs was significantly higher in group A than in the other two groups 6 months after the transplantation (P<0.01), while Scr levels showed no significant difference between the 3 groups (P>0.05). Three years later, Scr levels in group A were significantly increased as compared with those in the other two groups (P<0.01), and the rate of renal dysfunction in group A (10/33) was significantly higher than those in group B (3/33) and C(3/30) (P<0.05). In the 16 with renal dysfunction, the expression of TGF-beta1 mRNA in PBMCs significantly higher than that in the other 80 patients with normal renal function (P<0.01). Renal allograft biopsies demonstrated mild or severe interstitial fibrosis, tubular atrophy and mononuclear cell infiltration in the 6 patients with renal graft dysfunction, supporting the diagnosis of chronic allograft nephropathy (CAN).</p><p><b>CONCLUSION</b>Symptomatic active CMV infection in renal allograft recipients is an important factor contributing to the occurrence of CAN. Monitoring of TGF-beta1 mRNA expression in PBMCs proves useful in identifying patients at risk of CAN.</p>