Pulmonary infections after renal transplantation: a prospective study from a tropical country

Pulmonary infection is a leading cause of morbidity and mortality in renal transplant recipients. In a prospective study, we characterized their epidemiology in a tropical country with high infectious disease burden. Adult renal transplant recipients presenting with pulmonary infections from 2015 to 2017 were evaluated using a specific diagnostic algorithm. 102 pulmonary infections occurred in 88 patients. 32.3% infections presented in the first year, 31.4% between 1 and 5, and 36.3% beyond 5 years after transplantation. Microbiological diagnosis was established in 69.6%, and 102 microorganisms were identified. Bacterial infection (29.4%) was most common followed by tuberculosis (23.5%), fungal (20.6%), Pneumocystis jiroveci (10.8%), viral (8.8%), and nocardial (6.9%) infections. Tuberculosis(TB) and bacterial infections presented throughout the post-transplant period, while Pneumocystis (72.7%), cytomegalovirus (87.5%) and nocardia (85.7%) predominantly presented after >12 months. Fungal infections had a bimodal presentation, between 2 and 6 months (33.3%) and after 12 months (66.7%). Four patients had multi-drug resistant(MDR) TB. In 16.7% cases, plain radiograph was normal and infection was diagnosed by a computed tomography imaging. Mortality due to pulmonary infections was 22.7%. On multivariate Cox regression analysis, use of ATG (HR-2.39, 95% CI: 1.20-4.78, P = 0.013), fungal infection (HR-2.14, 95% CI: 1.19-3.84, P = 0.011) and need for mechanical ventilation (9.68, 95% CI: 1.34-69.82, P = 0.024) were significant predictors of mortality in our patients. To conclude, community-acquired and endemic pulmonary infections predominate with no specific timeline and opportunistic infections usually present late. Nocardiosis and MDR-TB are emerging challenges.