Blood tests for prediction of deep endometriosis: A case-control study.

Background: Deep endometriosis (DE) is the most aggressive subtype of endometriosis. The diagnosis may be challenging, and no biomarkers that can discriminate women with DE from those without DE have been developed.

Aim: To evaluate the role of blood hemostatic parameters and inflammatory indices in the prediction of DE.

Methods: This case-control study was performed at the Women's Hospital, Zhejiang University School of Medicine between January 2015 and December 2016. Women with DE and women with benign gynecologic disease (control group) eligible for gynecological surgery were enrolled. Routine plasma hemostatic parameters and inflammatory indices were obtained before surgery. Univariate and multivariate analysis were performed. Receiver operating characteristic (ROC) curves were generated, and areas under the curve (AUC) were calculated to assess the predictive values of the selected parameters.

Results: A total of 126 women were enrolled, including 31 with DE and 95 controls. Plasma fibrinogen (Fg, < 0.01), international normalized ratio ( < 0.05), and C-reactive protein levels ( < 0.01) were significantly higher in women with DE compared with controls. Plasma hemoglobin (HB) levels ( < 0.05) and shortened thrombin time ( < 0.05) were significantly lower in women with DE than in controls. Plasma Fg levels [adjusted OR (aOR) 2.12, 95%confidence interval (CI): 1.31-3.75] and plasma HB levels (aOR 0.48, 95%CI: 0.29-0.78) were significantly associated with DE (both 0.05). ROC analysis showed that the diagnostic value of Fg or HB alone for DE was limited. The AUC of the combination of both markers as a dual marker index was 0.773 with improved sensitivity (67.7%) and specificity (78.9%) at cutoffs of 3.09 g/L and 126 g/L, respectively.

Conclusion: The combination of Fg and HB was a reliable predictor of DE. A larger study is needed to confirm the findings.