Risk factors for Pneumocystis jirovecii pneumonia in kidney transplant recipients and appraisal of strategies for selective use of chemoprophylaxis.

Risk stratification-based duration of trimethoprim-sulfamethoxazole (TMP-SMX) chemoprophylaxis to prevent Pneumocystis pneumonia (PCP) in kidney transplant recipients is not a universally adapted strategy and supporting evidence-based sources are limited. We performed a large retrospective study to identify risk factors for PCP in kidney transplant recipients and to define parameters for use in clinical prophylaxis guidelines. Fifty consecutive patients with confirmed PCP and 2 time-matched controls per case were enrolled. All patients were participants of the kidney transplantation program of the Leiden University Medical Center, a tertiary care hospital in the Netherlands. Potential risk factors were compared between groups by uni- and multivariate matched analyses. At transplantation, age >55 years (adjusted odds ratio [OR] 2.7, 95% confidence interval [CI] 1.3-5.9) and not receiving basiliximab induction therapy (adjusted OR 4.3, 95% CI 1.1-17.1) predicted development of PCP. In the final multivariate analysis, only cytomegalovirus infection (adjusted OR 3.0, 95% CI 1.2-7.9) and rejection treatment (adjusted OR 5.8, 95% CI 1.9-18) were found to be independently associated with PCP. Using the variables identified by the multivariate analyses, effects of different hypothetical chemoprophylaxis strategies were systematically evaluated. Exploring different scenarios showed that chemoprophylaxis in the first 6 months for all renal transplant patients - and during the first year posttransplantation for patients >55 years of age or those treated for rejection - would result in very low PCP incidence and optimal avoidance of TMP-SMX toxicity. The results provide a rationale for further prospective study on targeted provision of chemoprophylaxis to prevent PCP in kidney transplant patients.