Blood leukocyte subsets are modulated in patients with endometriosis.

Objective: To determine whether blood leukocyte populations could be modulated in endometriosis.

Design: Case-control study.

Setting: Eight clinical institutions of the Montreal area.

Patient(s): Women with regular menstrual cycles who underwent laparoscopy or laparotomy between 1997 and 2001 and who were not under hormonal treatment for at least 3 months were selected. This study includes 175 cases and 131 controls.

Main Outcome Measure(s): The proportion of blood leukocytes expressing markers for T, B lymphocytes, monocytes, or natural killer (NK) cells were compared by flow cytometric analysis between cases and controls.

Result(s): Age and parity were identified as important confounders. Given that smoking, history of acute infection, and previous use of oral contraceptives strongly correlate with the level of some blood leukocyte populations, these parameters were taken into account in addition with age and parity when the level of blood leukocyte subsets were evaluated in cases and controls. Blood monocytes expressing CD14 and CD44 molecules were increased in patients with endometriosis. Alternatively, B lymphocytes were shown to be significantly decreased in cases compared with controls.

Conclusion(s): Although these results suggest that endometriosis is associated with some systemic manifestations, the exact role of these modulations remains unclear.