Absolute count of T and B lymphocyte subsets is decreased in systemic sclerosis

BACKGROUND Previous reports on lymphocyte subpopulations in systemic sclerosis (SSc) are conflicting. Therefore, we aimed to investigate the lymphocyte subsets in SSc patients who were not on immunosuppressive therapy. METHODS Lymphocyte subsets were assessed in the peripheral blood of SSc patients (n = 29) and healthy controls (n = 29) using the four colour flow cytometry method. Correlation studies were also performed in order to assess the relationship between lymphocyte subsets and clinical parameters. RESULTS The absolute count of lymphocytes (P = 0.0042), CD3+ (P = 0.0014), CD4+ (P = 0.0070), CD8+ (P = 0.021), and CD19+ cells (P = 0.024) was significantly decreased in SSc patients when compared to healthy controls. CD4+/CD8+ ratio and the absolute count of CD56+ cells observed in SSc patients did not significantly differ from controls (P=0.165; P = 0.632, respectively). There was no substantial relationship between the lymphocyte subset levels and clinical features (i.e., SSc subtype, autoantibody profiles, organ involvement), except for a significant inverse correlation of CD19+ cells and the modified Rodnan skin score (r = -0.43, P = 0.020). CONCLUSION Our data support previous reports indicating that subsets of T lymphocytes as well as B lymphocytes play a role in the pathogenesis of SSc.