C4A and Schwartz-Jampel syndrome: Among those 119 SjS patients, the titer of IgG-anti-EA antibody was inversely related to the levels of C3 (r = -0.31, P < 0.001) and C4 (r = -0.20, P = 0.03), and a marginally significant inverse correlation between IgG-anti-VCA antibody titer and C3 level was also observed (r = -0.17, P = 0.06) (Table 2).