Impact of Broncho-Alveolar Lavage on the Diagnosis and Management of Pulmonary Complications Following Hematopoietic Cell Transplantation

Background: Bronchoalveolar lavage (BAL) are commonly used in hematopoietic cell transplantation (HCT) to differentiate infectious from non-infectious etiologies. We now report a large case series of patients that underwent BAL at a single center. We examined the incidence and type of pathogens identified, as well as the overall impact of the BAL on clinical management. Methods: Case records from all HCT recipients that underwent BAL between 2001 and February 2016 were reviewed, using a free text search of medical records (EMERSE). The identification of pathogenic and non-pathogenic organisms, time to pathogen identification, changes in clinical management (based upon BAL results), duration of antibiotics preceding the BAL, procedural complications (including the need for mechanical ventilation 24 hr after bronchoscopy) were reviewed. Results: Five hundred and ninety-three patients (17% of HCT) underwent BAL during this time period, with a median age 51 years (0-75 years). BAL were more frequently performed in recipients of allogeneic vs autologous HCT (29% vs 7%) (P < .001), reduced vs full intensity conditioning (33% vs 15%) (P < .001), and patients 41-60 years in age (P < .001). Overall, pathogens were identified in 30% of cases (n = 180), including viral (n = 77), fungal (n = 57), and bacterial (n = 45). Common pathogens included Aspergillus sp.(n = 46), cytomegalovirus (CMV) (n = 35), and mycobacterium sp. (n = 25), identified a median 195, 84 and 220 days post-HCT, respectively. The likelihood of isolating a pathogen was highest when the BAL was performed >1 year post-HCT, (P = .001) (Table 1). The duration of empiric broad-spectrum antimicrobials administered prior to the BAL did not impact the likelihood of pathogen (bacterial) identification on the subsequent BAL (P = .50). The BAL led to changes in patient management in 55% of cases, including alterations in antibiotics in (37%) and immunosuppression (25%). BAL complications included hypoxemia (3%), hemorrhage (2%), and respiratory failure (1%), in patients not requiring mechanical ventilation prior to the BAL.Table 1Days post-HCTNo. BALPathogen Present0-10026328%101-36520025%>36513043% Open table in a new tab Conclusion: The current report serves as the largest case series of HCT patients undergoing broncho-alveolar lavage in the literature to date. The utility of BAL to identify pathogens was greatest in patients >1-year post-HCT, with pathogen identification not affected by the duration of pre-BAL antimicrobials. Mycobacterium were not uncommon, typically noted >6 months post-HCT.