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.