Risk factors and outcomes of Pneumocystis jirovecii pneumonia in kidney transplant recipients: A case-control study of the United States Renal Data System.

Kidney transplant recipients are at increased risk for Pneumocystis jirovecii pneumonia (PJP). We aimed to determine risk factors and outcomes of the disease using a large national database. We first conducted a nested case-control study to identify risk factors associated with PJP in patients who received a kidney transplant from January 1, 1998, through December 31, 2019. We then performed a matched cohort study to evaluate clinical outcomes following the diagnosis of PJP. We matched 407 patients with PJP to 1625 uninfected controls. PJP was diagnosed at a median time of 55 months after transplant (85.3% of cases occurred after the first posttransplant year). Longer duration of pretransplant hemodialysis and higher Elixhauser comorbidity index were independent risk factors for disease. All-cause mortality within 12 months after infection was 25.8%. Older age, higher Elixhauser comorbidity index value, and chronic pulmonary disease were predictors of mortality. PJP was associated with an increased risk of mortality (hazard ratio, 5.47; 95% confidence interval, 2.46-12.15; P < .001) and allograft failure (hazard ratio, 5.58; 95% confidence interval, 3.31-9.42; P < .001) within 1 year after infection. Our study highlights the importance of timely transplantation after initiation of hemodialysis and the impact of PJP on survival and allograft function.