Bronchoalveolar Lavage (BAL) Cellular Analyses as a Diagnostic Intervention for Patients with Suspected ILD in Conjunction with HRCT Imaging

BACKGROUND: Bronchoalveolar lavage (BAL) has gained acceptance to diagnose interstitial lung disease (ILD). Advent of high resolution computed tomography (HCRT) reduced the clinical utility of BAL. The present work utilized the recommendations of American thoracic society (ATS) to optimize BAL procedure and associated the finding with clinical examination and HRCT to precisely narrow down the cause for ILD. METHOD: BAL was performed on ILD suspects at target site chosen based on HRCT. The procedure, transport, processing and analysis of BAL fluid were performed as per ATS guidelines. The clinical data, HRCT findings and BAL report were used to narrow the diagnosis of ILD. Two tailed student T test was used to assess the significance. RESULT: We were able to optimize the BAL procedure as per the recommendations of ATS. In the cohort of 50 patients, Idiopathic pulmonary fibrosis (8), hypersensitivity pneumonitis (17), connective tissue disorder (9), sarcoidosis (3), pneumoconiosis (5), ARDS (2), eosinophilic lung disease (2) and lymphangitic carcinomatosa (2), aspiration bronchiolitis (1) and pulmonary histocytosis (1) were diagnosed. Statistically significant variation in differential counts was found in different ILDs. We were able to classify different ILDs based on the criteria described by ATS. CLINICAL SIGNIFICANCE: BAL along with clinical and HRCT findings improved the diagnostic accuracy by incorporating the disease diagnosis, acute or chronic nature of the disease and cause for acute exacerbation, which helped in better management of ILDs. CONCLUSIONS 1. BAL cellular profile obviates the need for surgical lung biopsy in certain ILDs namely lymphangitis carcinomatosis, Eosinophilic lung diseases and Langerhans cell histiocytosis. 2. BAL cellular profile could be supportive of diagnosis in the presence of clinical and radiological features typical of a specific ILD. 3. BAL plays an important role in establishing infection as the cause of an acute exacerbation of ILD. If infection is not established, guides the clinician to look for an alternate cause such as a thromboembolic event or a left heart failure BAL cellular analysis has documented the presence of inflammatory cells in asymptomatic patients with HRCT evidence of early ILD, which could predict an exacerbation in the near future. 4. BAL is a relatively safe procedure, and maybe a routine test in ILD(in the absence of contraindications to bronchoscopy), along with clinical evaluation and HRCT