Expression of chemokine receptors on peripheral blood lymphocytes in multiple sclerosis and neuromyelitis optica

BACKGROUND The role of different chemokine receptors in the pathogenesis of multiple sclerosis (MS) has been extensively investigated; however, little is known about the difference in the role of chemokine receptors between the pathogenesis of neuromyelitis optica (NMO) and MS. Therefore, we examined the expression of chemokine receptors on peripheral blood lymphocytes (PBL) in MS and NMO. METHODS We used flow cytometry to analyse lymphocyte subsets in 12 patients with relapsing NMO, 24 with relapsing-remitting MS during relapse, 3 with NMO and 5 with MS during remission. RESULTS Compared with healthy controls (HC), the percentage of lymphocytes in white blood cells was significantly lower in NMO and MS patients. The percentage of T cells expressing CD4+CD25+ and CD4+CD45RO+ was higher, while that of CD4+CC chemokine receptor (CCR)3+ (T helper 2, Th2) was significantly lower in MS patients than in HC. The ratios of CD4+CXC chemokine receptors (CXCR)3+/CD4+CCR3+ (Th1/Th2) and CD8+CXCR3+/CD8+CCR4+ (T cytotoxic 1, Tc1/Tc2) were higher in MS patients than in HC. The percentage of CD8+CXCR3+ T cell (Tc1) and CD4+CXCR3+ T cell (Th1) decreased significantly during remission in MS patients (P <0.05). No significant differences were identified in the expression of the chemokine receptors on PBL in NMO patients compared with MS patients and HC. CONCLUSIONS Th1 dominance of chemokine receptors on blood T cells and the correlation between CXCR3+ T cell (Th1 and Tc1) and disease activity in MS patients were confirmed by analysing chemokines receptors on PBL. In contrast, deviation in the Th1/Th2 balance was not observed in NMO patients.