Bronchoscopy and BAL Procedures
Twenty-two children with therapy-resistant, inadequately-controlled asthma had clinically-indicated bronchoscopy with bronchoalveolar lavage (BAL) and assessment of air space and blood inflammatory markers two weeks following HHe-3 MRI. Samples were shared between the clinical and research laboratories under protocols approved by the University of Virginia Institutional Review Board (IRB # 17555, IRB # 19180, and IRB # 10905). A detailed description of the clinical pathway and methods for bronchoscopy and BAL has been published previously19.
To compare granulocyte constituents in BAL from lung segments with and without visible ventilation defects, 13 children underwent MR image-guided BAL in bronchial segments to lobes with and without visible ventilation defects. The images were reviewed by a pediatric radiologist (TAA) in advance, lobes with and without ventilation defects were identified for BAL in the main bronchial segments or sub-segments accordingly. Fresh BAL was submitted to the cytopathology laboratory and examined for total and differential cell count using manual procedures. Paired BAL aliquots were labeled 1 and 2 for cytospin preparation of smears for differential cell counts, done in triplicate, by a cytopathologist blinded to the ventilation status of the segment from which the sample was obtained. Safety of the bronchoscopy procedures has been reported previously with no unexpected major adverse events19, 22.