The risk of cytomegalovirus infection after treatment of acute rejection in renal transplant recipients

The risk of cytomegalovirus infection (CMV) after rejection treatment is poorly understood. To investigate this, we conducted a case/control (1:2) analysis of adult renal transplant recipients between January 1, 2005 and December 31, 2015, via incidence density sampling and survival analysis. Our objective was to evaluate the association of prior acute rejection with subsequent CMV, including epidemiology and outcomes. There were 2481 eligible renal transplants within the study period and 251 distinct CMV infections. Despite the use of antiviral prophylaxis rejection was a significant risk factor for CMV on unadjusted (HR 1.73 [1.34, 2.24] P < 0.05) and adjusted analysis (HR 1.46 [1.06, 2.04] P < 0.05). When matching cases to controls patients with CMV had significantly more rejection prior to CMV diagnosis (26.7% vs 14.2%, P < 0.01). CMV was associated with a twofold increased risk of prior rejection on unadjusted (OR 1.94, 95%CI: 1.28‐2.96, P < 0.01) and adjusted analysis (OR 2.16, 95% CI: 1.31‐3.58, P < 0.01). Patients with rejection preceding CMV had significantly increased graft loss (HR 2.89, 95% CI: 1.65‐5.09, P < 0.01) and mortality (HR 1.82, 95% CI: 1.12‐4.24, P = 0.03) as compared to those CMV cases without rejection. In conclusion, rejection is a risk factor for CMV infection that appears to persist for 1 year. Preceding rejection events increased risk of graft loss and mortality in CMV patients. Given this, prolonged surveillance monitoring for CMV after rejection may be warranted. Studies are needed investigating optimal monitoring strategies.