Bronchoalveolar lavage fluid in scleroderma interstitial lung disease: technical aspects and clinical correlations: review of the literature

Abstract

Objectives: Bronchoalveolar lavage (BAL) has been used for clinical and research purposes in scleroderma interstitial lung disease (SSc-ILD). However, inconsistencies regarding technical aspects of BAL are obstacles in the reproducibility and interpretation of BAL results. This review summarizes clinical correlations and methodological issues of using BAL in the assessment of patients with SSc-ILD. In addition, we review the investigational use of BAL in SSc-ILD.

Methods: The PubMed database from inception through May 2008 was searched using the following keywords: "systemic sclerosis, scleroderma, interstitial lung disease, and bronchoalveolar lavage." The search was limited to English-language studies that included at least 15 SSc patients that had BAL.

Results: An increased percentage of neutrophils, eosinophils, and/or lymphocytes, often referred to as "alveolitis," was reported in a significant percentage of SSc patients (range, 38 to 100%) irrespective of patient selection criteria, cytological cutoff values, or technical aspects of BAL processing. Alveolitis is associated with more severe lung impairment as defined by lung function tests and overall lung high-resolution computed tomography scores, but there is insufficient evidence at this time to recommend BAL cytology as an independent predictor of outcome in SSc-ILD patients. Myofibroblasts have been cultured from BAL fluid, and inflammatory and fibrogenic mediators can be measured in the supernatant of BAL fluid from patients with SSc-ILD.

Conclusions: Further studies using standardized BAL protocols are required to establish the role of BAL fluid in the clinical evaluation of SSc-ILD. When performed for research purposes, BAL has provided valuable insight into the pathogenesis of SSc-ILD.