Purpose: Bacterial pneumonia has been cited as the leading cause of infectious death in renal transplant recipients but has not been studied in a national transplant population.
Subject and methods: Retrospective analysis of the incidence, risk factors and mortality of hospitalized bacterial pneumonia (ICD9 Code 481.x486.x) for 33,479 renal transplant recipients in the United States Renal Data System transplanted from 1 July 1994-30 June 1997.
Results: Among all transplant recipients, 4.7% were hospitalized for a primary discharge diagnosis of pneumonia in the study period (2.86 episodes per 100 person years). 9.9% had bronchoscopy and 4.8% had open lung biopsy. A specific etiology was not identified in 72.5% of patients. The hospitalization rate for pneumonia and hazard for mortality due to hospitalized pneumonia were both constant over time. In logistic regression analysis, pneumonia prior to transplant (odds ratio 1.73, 95% confidence interval, 1.32-2.26), older recipient age, diabetes, delayed graft function, rejection (occurring at any time after transplant during the time of the study), duration of pre-transplant dialysis, and positive recipient cytomegalovirus serology were associated with pneumonia. In Cox Regression, hospitalization for pneumonia was associated with greater risk of mortality (hazard ratio 1.64, 95% CI, 1.42-1.89).
Conclusions: Renal transplant recipients with a previous history of pneumonia are at increased risk for subsequent pneumonia, which is associated with substantially decreased patient survival. Given the low rate of specific etiologies identified in this study, invasive diagnosis may be underutilized in this population.