Objective To study the changes of plasma T helper type I (Th1)-and Th2-chemokine levels and analyze their roles in immune response and pathogenesis of early syphilis. Methods Heparin-anticoagulated peripheral blood was collected from 56 patients with early syphilis (primary syphilis, PS, n=22; secondary syphilis, SS, n=34) and healthy controls (HC, n=20). The levels of plasma Th1 chemokines including monokine induced by interferon-γ (MIG), interferon-γ inducible protein-10 (IP-10), interferon-inducible T-cell α chemoattractant (I-TAC) and Th2 chemokines including thymus-and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) were examined using ELISA. Meanwhile, the levels of plasma cytokines (IFN-γ, IL-4 and TNF-α) and C-reactive protein (CRP) were detected. Results The levels of plasma MIG, IP-10 and TARC, MDC in the patients with PS and SS were significantly higher than those in the healthy controls. Moreover, the level of I-TAC in the patients with SS was significantly higher than that in the healthy controls. In particular, the levels of plasma Th1 chemokines (MIG, IP-10 and I-TAC) in the patients with SS significantly increased compared with those with PS. However, no significant difference was observed in the levels of plasma Th2 chemokines (TARC and MDC) between the patients with PS and SS. The correlation analysis showed that there was an obvious positive correlation between IP-10 and MIG, I-TAC, IFN-γ, TNF-α levels in the patients with early syphilis. Furthermore, the levels of MIG and IP-10 were positively associated with plasma CRP in the patients with early syphilis. Conclusion Both Th1 chemokines and Th2 chemokines are involved in immune response of early syphilis.
