Fiberoptic bronchoscopy and BAL were performed as previously described. BAL was conducted, after macroscopic examination for KS lesions and bronchial suppuration, in the middle lobe or in the most affected lung segment seen on the chest radiograph, using four 50-mL aliquots of warm sterile isotonic saline solution. The macroscopic aspect of recovered BAL fluid was noted, with special attention to signs of hemorrhage. BAL smears were stained for differential cell counts, the identification of pathogens (ie, mycobacteria, viruses [CMV and herpes viruses], fungi, and parasites), and the detection of hemosiderin-containing alveolar macrophages. Briefly, 200 macrophages were examined after staining by Perl’s Prussian blue method. Each cell was ranked for hemosiderin content by using the following scale: 0, no color; 1, faint blue in one portion of the cytoplasm; 2, deep blue in a minor portion of the cell; 3, deep blue in most areas of the cytoplasm; and 4, deep blue throughout the cell. The total score for an average of 200 cells was divided by two to obtain the Golde score (GS). As reported by Kahn et al, AH was defined by a GS > 20 and was considered mild and severe when the GS was 20 to 100 and > 100, respectively. The percentage of Prussian blue-stained siderophages among the alveolar macrophage population was noted. Aliquots of BAL fluid also were cultured for bacteria, mycobacteria, fungi, and viruses (ie, CMV and herpes viruses).
Bronchial, transbronchial, and protected brush specimens, bacteriologic assessment of sputum, blood culture, and pleural fluid, and transparietal biopsies were performed when indicated by clinical and radiologic findings.
Diagnostic Criteria for Pulmonary Disorders
The diagnosis of Pneumocystis carinii, Toxoplasma gondii, Cryptococcus neoformans, Mycobacterium tuberculosis, or nontuberculosis mycobacterial pneumonia was established by the presence of these organisms in BAL fluid or histologic samples, as identified by specific staining, immunofluorescence, or culture. The diagnosis of invasive Aspergillosis pneumonia was based on the presence of the organism in BAL fluid or bronchial aspirates that was associated with histologic evidence of invasive infection. Bacterial pneumonia was defined by the presence of > 104 colony-forming units/mL in BAL fluid or > 103 colony-forming units/mL on the protected brush specimen, or by positive results of pleural fluid cultures or blood cultures in patients with focal pulmonary infiltrates.