Detection of Respiratory Pathogens in Bronchoalveolar Lavage Cytology Specimens of Lung Transplant Recipients
F Schneider, LG Dodd. Duke University Medical Center, Durham, NC
Background: Lung transplant recipients are monitored closely for features of allograft dysfunction. Infection is a frequent reversible cause of allograft dysfunction and its identification an important part of patient management. Bronchoalveolar lavage (BAL) is a commonly employed diagnostic method to detect respiratory pathogens and rule out infectious disease. To assess the diagnostic usefulness of cytologic preparations in the detection of infectious agents, we correlated the results of cytologic examination of BAL specimens by a pathologist with microbiology culture results.
Design: We identified 208 BAL cytology specimens obtained between 1998 and 2007 from 60 lung transplant recipients for which concomitantly microbiology culture results were available. The cytology specimens consisted of a liquid-based ThinPrep preparation, an air-dried centrifuge preparation, and two centrifuge preparations stained with Gomori methenamine silver and a Kinyoun acid fast stain, respectively. The presence of bacteria, fungal hyphae and yeasts, mycobacteria and viral cytopathic effect in the cytology specimens was correlated with the microbiology culture results. Detection of oropharyngeal flora by cytology or culture was not considered pathologic and not counted.
Results: Pathogenic fungi were found in 63 of 208 (30%) cultures. Cytology detected 20 of these 63 (32%) cases. Mycobacteria were found in 9 of 207 (4%) cultures. Cytology detected none of these 9 cases. Pathogenic bacterial strains were found in 16 of 208 (8%) cultures. Cytology detected 4 of these 16 (25%) cases. Viral pathogens were found in 29 of 208 (14%) cultures. Cytologically, a viral cytopathic effect was noted in 2 of these 29 (7%) cases. Only 1 of 208 (0.5%) cytology preparations contained fungal elements while the concurrent microbiology culture did not show any growth. Cytology did not detect viral, bacterial, or mycobacterial agents in any of the cases in which cultures were negative.
Conclusions: Detection of infectious agents in cytologic preparations of BAL specimens has a low sensitivity, and concomitant microbiologic culture should be performed. Cytologic preparations do not increase sensitivity when performed in addition to microbiology cultures. If the difference in turnaround time between cytologic examination and microbiology techniques is less important, ceasing performance of special stains for organisms on BAL cytologic preparations may offer time and cost savings.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 45, Wednesday Afternoon