The relationship between C3a-des-Arg and endometriosis

Abstract

OBJECTIVE: Endometriosis is a benign gynaecological condition, associated with pelvic pain and infertility.The lack of a reliable and specific method for the early detection of endometriosis often results in delayed diagnosis. Recent studies have shown that the complement system can be involved in the pathogenesis of endometriosis.The aim of this study was to test the hypothesis that the plasma concentration of complement factor C3a (anaphylatoxin) can be used as a non-invasive test in the diagnosis of endometriosis. DESIGN: Patients with endometriosis were compared with controls. MATERIALS AND METHODS: Plasma was collected during menstruation (n=49), the follicular (n=55) and the luteal phase (n=56) in 160 patients with (n=109) or without (n=51) laparoscopically and histologically confirmed endometriosis. Endometriosis was staged according to the American Society of Reproductive Medicine (ASRM) in minimal (n=27), mild (n=27), moderate (n=26) or severe (n=29) endometriosis. The C3a-des-Arg concentration in plasma was measured by Elisa according to the instructions of the manufacturer (Quidel, San Diego, USA). The sensitivity was 34ng/ml and the Intra assay coefficient of variation ranged from 1.5, 2.8% and Inter assay coefficient of variation ranged from 11, 23%. All data are presented as mean +/− SD and were analyzed using t-tests and ANOVA with Dunn's Multiple Comparison test. Power calculation for this experiment was 90%. RESULTS: The plasma C3a-des-Arg concentration was comparable between patients with (123±103ng/ml) and without (128±112ng/ml) endometriosis & was also comparable between patients with minimal (123±54ng/ml), mild (119±49ng/ml), moderate (97±43ng/ml) and severe (152±182ng/ml) endometriosis. The Dunn's Multiple Comparison test revealed no significant difference between control and diseased (control and stage I-II, control and stage III-IV and between stage I-II and stage III-IV).The plasma C3a-des-Arg concentration was also comparable in women with and without endometriosis during menstruation (110±86ng/ml and 123±69ng/ml, respectively), during the follicular phase (111±49ng/ml and 146±159 ng/ml, respectively) & during the luteal phase (146±146ng/ml and 116±92ng/ml, respectively). CONCLUSIONS: In this study, we did not confirm our hypothesis that plasma C3a levels can be used as diagnostic test for endometriosis.