Epidemiology and risk factors for late infection in solid organ transplant recipients

Abstract

Background: Information concerning the risk factors and outcome of late infection (LI) after solid organ transplantation (SOT) still remains scarce.

Methods: We prospectively analyzed all patients undergoing SOT from July 2003 to March 2008, who survived the first 6 months after surgery and with a minimum 1-year follow-up. Risk factors associated with the development of bacterial and cytomegalovirus (CMV) LI and survival were identified.

Results: Overall, 942 SOT recipients (491 kidney, 280 liver, 65 heart, and 106 double transplants) were included. During the study period 147 patients (15.6%) developed 276 episodes of LI (incidence rate, 0.43 per 1000 transplantation-days). Bacteria were the most prevalent etiology (88.0%). Primary sources of infection included urinary tract (36.9%), intra-abdominal (16.7%), and sepsis without source (13.4%). Independent risk factors for late bacterial infection were: age (hazard ratio [HR] [per year] 1.0; 95% confidence interval [CI]: 1.0-1,0), female gender (HR 1.7; 95%CI: 1.1-2.6), anti-hepatitis C virus (HCV) positive serostatus (HR 1.8; 95%CI: 1.1-3.0), chronic allograft dysfunction (HR 3.2; 95%CI: 1.7-6.1), early CMV disease (HR 2.2; 95%CI 1.2-4.1), and early bacterial infection (HR 2.5; 95%CI 1.6-3.8). The occurrence of chronic allograft dysfunction was an independent risk factor for late CMV disease (HR 6.5; 95%CI: 1.7-24.6), whereas immunosuppression based on mammalian target of rapamycin inhibitors protected against the development of late CMV disease (HR 0.3; 95%CI: 0.1-1.0). Cox model selected anti-HCV positive serostatus (adjusted HR [aHR] 2.67; 95%CI: 1.27-5.59), age (aHR [per year] 1.06; 95%CI: 1.02-1.10), and the occurrence of LI (aHR 9.12; 95%CI: 3.90-21.33) as independent factors for mortality.

Conclusions: LI did not constitute an uncommon complication in our cohort, and patients at risk may benefit from close clinical monitoring.