Serum soluble CD163 and interleukin-6 levels in women with ovarian endometriomas

BACKGROUND: CD163 is a hemoglobin scavenger receptor exclusively expressed in the monocyte-macrophage system and its soluble form (sCD163) has not yet been studied as a serum marker in women with endometriosis. The purpose of this study was to evaluate whether serum levels of sCD163 and interleukin-6 (IL-6) could be possible markers for ovarian endometriomas discriminating adnexal benign cystic tumors. METHODS: The concentrations of sCD163 and IL-6 were determined using commercial ELISA kits in frozen sera collected from 95 women prior to surgery for adnexal benign cystic tumors: 44 with ovarian endometriomas, 24 with mature cystic teratomas, 10 with mucinous cystadenomas, 8 with serous cystadenomas and 9 with parovarian cysts. Serum levels of CA-125 were also recorded preoperatively. The volume of cysts was evaluated in women with ovarian endometriomas. RESULTS: The serum levels of sCD163 and IL-6 were not significantly different among the women with various adnexal benign cystic tumors. In patients with endometriomas (n = 44), the levels were similar to those with nonendometriotic benign cystic tumors (n = 51): 3,431.7 +/- 343.9 vs. 3,231.0 +/- 391.7 ng/ml for sCD163 and 5.3 +/- 0.9 vs. 12.9 +/- 4.0 pg/ml for IL-6 (mean +/- SEM). No correlation was noted between serum levels of two markers with volume of endometriomas. CONCLUSION: Our findings suggest that serum levels of sCD163 as well as IL-6 are not useful markers for ovarian endometriomas