Value of s-ACE, BAL lymphocytosis, and CD4+/CD8+ and CD103+CD4+/CD4+ T-cell ratios in diagnosis of sarcoidosis

Abstract

To the Editors: Sarcoidosis is one of the most common causes of idiopathic lung disease. The international standard for diagnosis of sarcoidosis is based on three criteria: 1) a compatible clinical and/or radiological presentation; 2) histological evidence of noncaseating granulomas; and 3) exclusion of other diseases that produce a similar histological or clinical picture [1]. The diagnosis of sarcoidosis is supported by an elevated CD4+/CD8+ T-cell ratio, bronchoalveolar lavage (BAL) lymphocytosis and elevated serum angiotensin-converting enzyme (s-ACE). However, these parameters are variable in sarcoidosis [2–4]. The integrin CD103 is expressed on CD4+ T-cells in BAL. Due to the high influx of circulating T-cells to the granulomata in sarcoidosis, a reduction in the fraction of BAL CD103+CD4+ T-cells has been suggested as a marker of sarcoidosis, in combination with lymphocytosis and CD4+/CD8+ ratio [5]. In selected groups of patients, decreases in the fraction of CD103+CD4+ T-cells are significantly associated with sarcoidosis [6,7]. The purpose of this study was to evaluate these parameters as diagnostic markers of sarcoidosis in consecutive patients in a tertiary hospital setting. The study included patients who underwent BAL with subsequent flow cytometric analyses at the Dept of Respiratory Medicine, Aarhus University Hospital (Aarhus, Denmark) from August 2007 until April 2009 (n=107). The descriptive parameters and paraclinical findings, including s-ACE (U·L−1), BAL lymphocytosis (determined by differential count), and CD4+/CD8+ and CD103+CD4+/CD4+ T-cell ratios …