The role of the macrophage polarization type in the pathogenesis of endometrioid disease

Abstract

Endometriosis today occupies one of the leading places in the structure of general gynecological pathology. Theories of the onset and progression of this disease are controversial. One of the most widespread theories is the assumption that endometriosis is a disease of macrophages. The question of which the macrophage phenotype, M1 or M2, is the leading one, however, remains controversial. The aim. To determine the type of macrophage polarization (M1/M2) and the quantitative activity of their marker enzymes (iNos/Arg1) in the endometrium and peritoneal fluid in endometrioid disease. Materials and methods. The total number of reproductive age (30.95±6.49) women enrolled in the study was 80. The main group consisted of 50 women with endometrioid disease. The control group included 30 women without signs of endometrioid disease. Women from the main group (n=24) and the control group (n=27) underwent endometrial sampling using an intrauterine Pipelle catheter in the first phase of the menstrual cycle before a surgery. During laparoscopic or laparotomy approaches, peritoneal fluid was taken (in the main group n=24, in the control group n=28). The type of macrophage polarization (M1 or M2) was determined based on the ratio of marker enzymes (Arg1, iNos) activity in each patient using a spectrophotometric method in the endometrium and peritoneal fluid. The polarization to the M1 phenotype was determined at iNos>Arg1, and at Arg1>iNos– the polarization to the M2 phenotype. Results. As a result of the study, it was revealed that in women with endometrioid disease, pelvic adhesions were much more common, 84.0% versus 46.7% in women without it, and especially 3 and 4 degree of severity (P<0.05). When assessing the type of macrophages in the peritoneal fluid, a significantly greater number of the main group women had the M2 phenotype of macrophage polarization compared to the control group (58.3% versus 28.6%, P=0.03). It was the macrophage polarization to the M2 phenotype that influenced the severity of endometrioid disease, especially the 4 degree of severity. The mean values of the iNOS activity in the main group women, both in the peritoneal fluid and in the endometrium, significantly differed from those in the control group patients (by 1.73 and 1.77 times, respectively). Conclusions. Thus, we can conclude that endometriosis is a disease, the development and progression of which is induced by the M2 phenotype of macrophages. Considering the increase in the mean levels of iNOS activity both in the peritoneal fluid and in the endometrium, it can be concluded that iNOS influences the pathogenesis of endometrioid disease.

Keywords

• endometriosis
• macrophages
• peritoneal fluid