Patient characteristics and clinical features of Japanese sarcoidosis patients with low bronchoalveolar lavage CD4/CD8 ratios.

Background: Previous studies have shown that there is an association between low BALF (bronchoalveolar lavage fluid) CD4/CD8 ratio and lower remission rates in sarcoidosis patients.
Aim: To investigate the patient characteristics and clinical features of Japanese sarcoidosis patients with low BALF CD4/CD8 ratios.
Methods: 322 Japanese sarcoidosis patients were retrospectively analyzed, and 3 groups were selected according to BALF CD4/CD8 ratios as follows: patients with the BALF CD4/CD8 ratio in the lowest 5 percentile (Group 1: 0.43-1.41), median 5 percentile (Group II: 4.68-5.47), and top 5 percentile (Group III: 12.6-60.1). Each group consisted of 16 patients (5% of 322 patients). The patient characteristics, clinical features, and the short-term prognosis for at least 2 years (average 116 months) were compared among the groups. Multivariate analysis was performed for 322 patients to investigate the determinants of BALF CD4/CD8 ratios.
Results: The number of BALF CD8+ cells were greater in Group I than in the other two groups. In Group I, there were higher incidences of younger age, male gender, and lower number of extrathoracic lesions compared with Group III. Multivariate analysis showed that younger age and male gender were independently associated with low BALF CD4/CD8 ratios. The frequency of treatment with corticosteroid and progression to pulmonary fibrosis tended to be higher in Group I.
Conclusions: Low BALF CD4/CD8 ratios were due to increased number of BALF CD8+ cells. Younger age and male gender were independently associated with low BALF CD4/CD8 ratios in sarcoidosis patients.