Introduction: The aim of the present study is to investigate the diagnostic value of the CD4+, CD8+ and CD103+ lymphocyte sub-groups in mediastinal lymph nodes, as an adjunctive marker in sarcoidosis.
Materials and methods: The present study is a single-center, prospective cohort study designed in a reference center for chest diseases. Forty-six patients who underwent endobronchial ultrasound (EBUS)-guided mediastinal lymph node sampling with a preliminary diagnosis of sarcoidosis were enrolled. The different lymphocyte subgroups were counted by flow cytomeytry in lymph node biopsy samples. Based on the final diagnosis, subjects were divided into two groups: sarcoidosis and non-sarcoidosis. Lymphocyte subset analysis were compared between the groups.
Result: The final diagnoses were sarcoidosis in 31 (67%) and non-sarcoidosis in 15 patients (33%). The total cell counts, lymphocyte ratios, CD8+ T lymphocyte ratios and CD4/CD8 ratios were similar in both groups (p> 0.05). CD4+ T lymphocyte rates were higher in patients with sarcoidosis (p= 0.017). CD103 subset analysis revealed significantly lower CD103+CD4+, CD103+CD8+ lymphocytes and CD103+CD4+/CD4+ ratios in sarcoidosis (p= 0.008, p= 0.048, p= 0.014, respectively).
Conclusions: Cytological examination of EBUS-guided lymph node samples may provide substantial findings in differential diagnosis of sarcoidosis. Patients with sarcoidosis have higher CD4+ lymphocytes, lower CD103+CD4+ lymphocytes and CD103+CD4+/CD4+ and CD103+CD8+ lymphocyte ratios. These subsets of lymphocytes in lymph node biopsies may be novel predictors of sarcoidosis diagnosis.