Risk and prognosis of hospitalization for pneumonia among individuals with and without functioning renal transplants in Denmark: a population-based study.

BACKGROUND Pneumonia is commonly diagnosed in immunosuppressed individuals. The risk and attributable morbidity of first hospitalization for pneumonia among renal transplant candidates and recipients were compared to those of population controls. METHODS This population-based cohort study was conducted from 1 January 1990 to 31 December 2009. Each member of a Danish population-based, nationwide cohort of first-time renal transplant recipients was matched by age and sex with up to 19 population controls. Information on hospital discharge diagnosis, emigration, and mortality was obtained from nationwide administrative databases. Individuals were observed from diagnosis of end-stage renal disease until first hospitalization for pneumonia. Risk factors were assessed by Poisson regression. RESULTS The study included 4729 renal transplant candidates and recipients and 81 757 controls, providing 25 546 and 704 329 person-years of observation, respectively. Compared with population controls, the incidence rate ratio of first hospitalization for pneumonia was 10.2 (95% confidence interval [CI], 8.74-11.8) for renal transplant candidates, 8.02 (95% CI, 7.29-8.83) for renal transplant recipients, and 13.7 (95% CI, 11.5-16.3) for patients with graft loss. Among renal transplant recipients, risk factors included male sex, age ≥50 years, diabetes, chronic interstitial nephritis, polycystic kidney disease, and 1-3 years of prior dialysis. Patients with pneumonia had a 78% (95% CI, 1.52-2.10) increased risk of graft loss. Thirty-day mortality of patients was comparable to that of the background population. CONCLUSIONS The risk of first-time hospitalization for pneumonia remains high among renal transplant candidates and recipients. The attributable morbidity and mortality are of great clinical and public health concern and preventive measures are warranted.