Serum endometrial IgG antibodies and soluble CD23 concentrations in patients with endometriosis

OBJECTIVE: Serum endometrial antibodies have been found inconsistently in patients with endometriosis. Soluble CD23 is elevated in diseases associated with B cell activation. We evaluated serum levels of soluble CD23 and endometrial IgG antibodies in patients with endometriosis to determine whether there is B cell activation in this condition. DESIGN: Fifty-seven patients with pelvic pain diagnosed as endometriosis and 40 patients without pelvic pain or endometriosis who had laparoscopic sterilisation were sequentially recruited into the study. Blood was collected and the sera assayed by ELISA for endometrial IgG antibodies and soluble CD23. RESULTS: There was a significant difference between endometriosis and control group in both the serum IgG endometrial antibodies (p < 0.05) and soluble CD23 (p < 0.05). There was significant but weak correlation between endometrial antibodies and soluble CD23 (r = 0.3, p = 0.039), particularly in mild but not severe endometriosis. CONCLUSIONS: These data suggest the existence of B cell activation in patients with endometriosis with a significant correlation between endometrial antibodies and soluble CD23. Mild endometriosis appears to be immunologically more active than the severe form. The value of soluble CD23 in the management of endometriosis needs further evaluation.