Diagnostic Utility of Bronchoalveolar Lavage in Immunocompromised Patients with Lung Infiltrates.

Introduction: Lung infections are associated with a high mortality rate in immunocompromised patients. Achieving an accurate and rapid diagnosis is vital to help guide management, and thus improve survival. Objective: To establish the diagnostic yield, clinical value, and safety of bronchoscopy with bronchoalveolar lavage (BAL) in immunocompromised adult patients with pulmonary infiltrates. Methods: This retrospective study included all immunocompromised adult patients who underwent bronchoscopy with BAL for investigation of radiologically confirmed pulmonary infiltrates at a tertiary care hospital between January 01, 2014, and June 30, 2021. Clinically significant findings of BAL were defined as a positive microbiological result of a potential pathogen determined using routine culture, acid-fast bacilli smear, mycobacterial culture, tuberculosis PCR, fungal culture, Aspergillus antigen, and multiplex PCR panel and/or positive cytology. Results: A total of 103 unique patients were included (mean ± SD age: 44.5 ± 14.1 years), of which the majority were male (60.2%). The BAL diagnostic yield was 52.4% (95% CI: 42.6-62.2%). In the multiple logistic regression model, positive BAL was predicted by symptom of sputum (aOR 4.01, 95% CI: 1.27-12.70, P = 0.018). Almost half of the procedures (43.7%, 95% CI: 33.9-53.4%) resulted in a change in the management plan, with positive BAL findings more than twice as likely to result in a change (OR 2.39, 95% CI: 1.07-5.33, P = 0.033). Only three (2.9%) procedures resulted in complications and required ventilator support and/or oxygen escalation. Conclusions: BAL is a safe clinical tool that can be useful in impacting clinical management in a significant proportion of immunocompromised patients with pulmonary infiltrates.

Pneumonia due to Mycobacterium cosmeticum in a renal transplant recipient.

A 69-year-old man renal transplant recipient for 4 years, presented with 4-day history of cough and dyspnoea. He was diagnosed with community-acquired pneumonia and treated accordingly. He deteriorated requiring intensive care unit admission and intubation. Mycobacterial culture from bronchoalveolar lavage grew colonies within 7 days of incubation while Mycobacterium tuberculosis PCR was negative. The antibiotic regimen was adjusted to cover for rapidly growing mycobacteria with imipenem, amikacin and clarithromycin. The final culture reported Mycobacterium cosmeticum He improved on the antibiotic regimen given which the organism turned to be sensitive to. We reported the second case with M. cosmeticum that fulfilled the diagnostic criteria for non-tuberculous mycobacterial lung infection. Improvement of patient's lung infection on appropriate antibiotics points to a causal relationship.