Cytokines and chemokines expression in serum of patients with neuromyelitis optica.

To study the differences in immunopathogenesis based on chemokine profile in neuromyelitis optica patients positive for AQP4 antibodies or MOG antibodies. We measured 52 cytokines/chemokines using ELISA in 59 serum samples, which were divided into three groups according to CBA results: HCs (n=16), AQP4+ (n=20) and MOG+ (n=23). The regression equation (R2>0.98) of the standard curve was calculated according to the standard concentration and the corresponding A value. And then the corresponding sample concentration was calculated according to the A value of the sample. Eleven of 52 measured serum cytokine/chemokines (CCL22/MDC, CCL13/MCP-4, CCL21/6Ckine, CCL27/CTACK, CCL8/MCP-2, CXCL14/BRAK, Contactin-1, Kallilrein 6/Neurosin, Midkine, VCAM-1 and Fas) were significantly different between MOG+ group and controls. Ten of 52 measured serum cytokine/chemokines (CCL1/I-309, CCL22/MDC, CCL28, CCL17/TARC, CCL27/CTACK, CXCL2/GRO beta, Contactin-1, Midkine, Chemerin and Synuclein-alpha) were significantly different between AQP4+ group and controls. There was no difference between serum AQP4+ and MOG+ groups for CC chemokines. All measured chemokines CXC except CXCL6/GCP-2 showed no significant differences in serum AQP4+ group compared to MOG+ group. However, there was significant difference between serum AQP4+ and MOG+ groups for C5/C5a and Midkine. C5/C5a and Midkine were significantly higher in AQP4+ group compared to MOG+ group (P<0.05). Our findings suggest that the differences of mean concentration in CXCL6/GCP-2, Midkine and C5/C5a probably reveal different immunologic mechanism between AQP4+ NMO and MOG+ NMO. This cytokine/chemokine profiling provides new insight into NMO pathogenesis associated with MOG antibody seropositivity and provides guidance to monitor inflammation and response to treatment in a way.