CLINICAL, RADIOLOGICAL, MICROBIOLOGICAL PROFILE AND OUTCOMES OF PULMONARY INFECTIONS IN RENAL TRANSPLANT RECIPIENTS: A PROSPECTIVE STUDY

ABSTRACT

Introduction: Pulmonary infections in renal transplant recipients (RTR) may range from diverse forms lung parenchyma and pleura involvement with different typical and atypical bacteria, viruses, fungi and mycobacteria. Radiological and microbiological diagnosis is essential to plan management. This study assesses the clinico-radiological, microbiological and outcomes of pulmonary infections in RTR. Methods: This study was a single-center prospective observational study, conducted over 4 years in a tertiary care hospital in Mumbai. The study included RTR > 18 years with pulmonary infections. Pulmonary infections were defined as typical clinical features like cough, expectoration, fever, dyspnea, hemoptysis, etc with radiological findings like new infiltrates/consolidation on chest X-ray / CT scan with or without microbiological abnormality on sputum/ broncho-alveolar lavage (BAL) fluid/ pleural fluid. COVID-positive cases were excluded from the study. The clinical details of transplant, risk factors, induction, and maintenance regimens were recorded. All investigations done and treatment undertaken were part of standard management protocols. Patients were followed up for the assessment of outcome and resolution. Appropriate IEC approval was taken. Results: 50 RTR patients were included, predominantly males (60%), mean age 39.62 ±12.14 years, with 37 (74%) having live-related renal transplants. 9 (18%) patients presented 6 months of transplant, 5 (10%) from 6-12 months, 12 (16%) from 1-2 years and 24 (48%) ≥ 2 years since transplant. Risk factors included history of acute rejection in 6 patients (12%), NODAT in 5 (10%), prior diabetes in 8 (16%), and ATG induction in 19 (38%). Fever was the chief presenting complaint in 47 cases (94%), cough with expectoration in 32 (64%), and breathlessness in 24 (48%). Associated graft dysfunction was seen in 21 (42%) patients. 10 (28%) patients needed mechanical ventilation support while 18 (36%) had features of severe sepsis with MODS. Sputum was contributory in 16 patients with features of Streptococcus spp in 04 (8%), H. influenza in 1 (2%), gram-negative bacteria (GNB) in 4 (8%), AFB positive in 04 (6%), fungal/PCP in 3 (6%). BAL showed positive findings in 35 cases with positive bacteria (culture/ staining) in 15 (30%) [gram positive in 9 (18%) and GNB in 6 (12%)], BAL AFB/gene expert positive in 8 (16%), fungal stain/culture in 5 (Aspergillus 03, Mucor 01, candida 01), PCP stain/culture in 05 (10%) and CMV PCR positive in 2 (4%). In 14 cases, no organism could be isolated and was treated empirically. 2 patients who had exudative pleural effusion with raised ADA were treated for tuberculosis. Multivariate regression analysis showed that the statistically significant factors associated with pulmonary infections were diabetes/ NODAT, ATG induction. Mean duration of hospital stay was 14.26 ±4.22 days. Most patients recovered completely while death occurred in 06 (12%). Conclusions: Pulmonary infections were a significant cause of morbidity and mortality in RTR patients, with an increased risk in patients who were exposed to ATG induction or diabetes. HRCT chest and BAL were the key diagnostic modalities. Bacterial organisms are the commonest followed by fungal/mycobacterial or viral. High index suspicion and early antimicrobial therapy are key to successful therapy. No conflict of interest