Development of a nonsurgical diagnostic tool for endometriosis based on the detection of endometrial leukocyte subsets and serum CA-125 levels.

Objective: To determine whether the proportion of several leukocyte subsets is modulated in the endometrium of patients with endometriosis and, if yes, whether it can be used for diagnostic purposes.

Design: Case-control study.

Setting: Eight clinical institutions of the Montreal area.

Patient(s): Women who underwent laparoscopy or laparotomy between 1997 and 2001, who had regular menstrual cycles and were not under hormone treatment for the previous 3 months were selected. This study included 368 women, 173 with surgically confirmed endometriosis and 195 controls with no surgical evidence of endometriosis.

Main Outcome Measure(s): Cytometry analysis was used to measure the proportion of several leukocyte subsets among CD45(+) endometrial cells.

Result(s): The proportion of CD3(+), CD16(+), CD3(-)HLADR(-), CD3(-)CD45RA(-), CD3(+)CD16(-), CD3(+)CD56(-), CD56(-)CD16(+), and CD16b(+) leukocytes was significantly altered in the endometrium of cases compared with controls. A multiple logistic regression model was adjusted with these endometrial leukocytes, serum CA-125 levels, risk factors, and confounders. The diagnostic performance of this predictive model was defined by a specificity of 95% and a sensitivity of 61%. Furthermore, the positive and negative predictive values were 91% and 75%, respectively.

Conclusion(s): This predictive model represents a novel diagnostic tool to identify women with a high likelihood of suffering from endometriosis.