Role of Bronchoalveolar Lavage for Diagnosing Pulmonary Infection in Patients With Rheumatic Autoimmune Diseases and Lung Infiltrates

Objectives: The aims of the study were to evaluate the effectiveness of bronchoalveolar lavage (BAL) for diagnosing pulmonary infection in patients with rheumatic autoimmune diseases and lung infiltrates and to evaluate factors that affect the diagnostic yield. Methods: A retrospective study was performed in patients with rheumatic autoimmune diseases and lung infiltrates whose BALs were sent for microbial assays at Peking Union Medical College Hospital from January 2009 to June 2013. Patient characteristics, clinical symptoms, medication history, laboratory parameters, radiographic findings, lung lobe lavaged, and diagnostic yield were retrieved. Results: Seventy BALs were performed in 69 patients. The overall diagnostic yield of BAL for pulmonary infection was 17.1%(12/70), sensitivity was 35.5%, and specificity was 97.4%. Twelve microorganisms were isolated from 12 different BALs conforming to diagnostic criteria, including 4 Aspergillus, 3 Pneumocystis jirovecii, 3 gram-negative bacilli, 1 gram-positive coccus, and 1 mycobacterium. Patients with clinical symptoms of fever, cough, or expectoration had a higher diagnostic yield than patients without either symptom (25.6% vs 3.7%, P = 0.042). Patients with ground-glass opacity, mass, or consolidation radiographically had a higher yield than did patients with reticular or nodular infiltrates (20.3% vs 0, P < 0.001). Conclusions: Bronchoalveolar lavage is a useful tool for patients with rheumatic autoimmune diseases and lung infiltrates, especially in cases where initial antimicrobial therapy is ineffective. Opportunistic pathogens are important in patients with rheumatic autoimmune diseases and lung infiltrates and should be considered when antibacterial treatment is ineffective.