Evaluation of pulmonary infections in solid organ transplant patients: 12 years of experience

Recipients of solid organ transplants (SOTs) are at higher risk to develop pulmonary infections (PIs) owing to their immunocompromised state. Flexible bronchoscopy (FB) is frequently performed to diagnose nature of these infections. The aim of 12-year review was to evaluate the demographic characteristics of SOT recipients with PIs and to study diagnostic utility of FB in this group of patients.

Medical records of patients who underwent SOT as well as FB between 2000 and 2012 were retrospectively reviewed. Patients' demographics, type of transplantation, primary diagnoses, thoracic computed tomography (CT) findings, total blood count and chemistry, indication for FB, FB results, specimen culture results, and suspected and final diagnoses were all recorded. If the bronchoscopy findings altered medical management and produced improvement in PI, the procedure was considered diagnostic.

Ninety of 998 liver, heart, or kidney transplant recipients underwent FB (73 renal, 16 liver, and 1 heart; mean age, 42.3 ± 12.1 years) during the study period. CT findings were as follows: Consolidation (49.4%), lymphadenopathy (3.4%), nodular infiltrates (5.6%), and cavitary lesion (1.1%). FB was unremarkable in 29, but showed increased secretions in 33 patients (36.7%), chronic mucosal changes in 9 (10%), edema in 7 (7.8%), mucosal plaque in 7 (7.8%), friable mucosa in 3 (3.3%), and endobronchial lesion in 2 (2.2%). A total of 29 bronchial washings (BW; 32.6%) and 10 bronchoalveolar lavages (BAL; 11.2%) were performed. PI was diagnosed in 82% of the patients (n = 73). In 32 patients (36%), micro-organism growth was observed on either BW or BAL. Mycobacterium tuberculosis was detected in 6 (6.7%), Staphylococcus aureus in 4 (4.4%), Moraxella catharralis in 4 (4.4%), Candida albicans in 6 (6.7%), Klebsiella pneumonia in 2 (2.2%), Escherichia coli in 2 (2.2%), Streptococcus pneumoni in 2 (2.2%), Stenotrofomonas maltofilia in 1 (1.1%), Aspergillus fumigatus in 4 (4.5%), and Pseudomonas aeruginosa in 1 (1.1%). Final diagnosis was established by FB (n = 33) with a diagnostic yield of 36%. No significant finding was observed between the type of the transplant and the culture results (P > .05).

Suspected PI is the most common indication for FB in SOT recipients. It may identify the causative organism in >30% of patients. Tuberculosis was found to be the most frequent agent, which is not surprising from such an endemic area. Bacteria were more common than fungal or viral micro-organisms. FB should be considered in SOT recipients presenting with lung infiltrates and suspected to have PI.