Diagnostic role of BAL fluid CD4/CD8 ratio in different radiographic and clinical forms of pulmonary sarcoidosis

Abstract

Abstract Introduction: Bronchoalveolar lavage (BAL) as a method of sampling cells is useful in the diagnosis and differential diagnosis of sarcoidosis. However, CD4/CD8 ratio in BAL fluid (BALF) is highly variable and it generates continuous discussions about its diagnostic role. Objective: To prospectively evaluate diagnostic role of BALF CD4/CD8 ratio in pulmonary sarcoidosis manifested in different radiographic and clinical forms in the real clinical practice. Material and methods: The study population consisted of 318 sarcoid patients with a newly diagnosed disease. Comparator groups consisted of 55 healthy subjects and 130 patients with other disorders who underwent BAL and examination of CD4/CD8 ratio in BALF as a step of diagnostic pathway. Diagnostic accuracy of CD4/CD8 ratio in BALF using receiver‐operating characteristic analysis has been calculated. Results: The percentage of BALF lymphocytes in sarcoid patients was significantly different from comparator groups. Normal BALF cell counts were found in 7% of sarcoid patients. However, typical sarcoid BALF cellular pattern was found in 6.2% of all control subjects. We have found that optimal cutoff points for CD4/CD8 ratio are 3.5 and 4.0 for asymptomatic and symptomatic patients, respectively. Sensitivity of the optimal cutoff points of CD4/CD8 ratio was lower in asymptomatic patients compared with symptomatic patients. Sensitivity of the optimal cutoff points decreased with the increased stage of sarcoidosis. Conclusions: BAL is a valuable method in diagnostic pathway of pulmonary sarcoidosis. However, results of BALF examination must be interpreted considering a specific clinical case. BALF CD4/CD8 ratio depends on clinical and radiographic manifestation. Please cite this paper as: Danila E, Norkūnienė J, Jurgauskienė L and Malickaitė R. Diagnostic role of BAL fluid CD4/CD8 ratio in different radiographic and clinical forms of pulmonary sarcoidosis. The Clinical Respiratory Journal 2009; 3: 214–221.