Quantity and quality of retrograde menstruation: a case control study

Abstract

BackgroundThe purpose of this study was to test the hypothesis that menstruation is associated with a higher concentration of endometrial cells in peritoneal fluid(PF) and with increased white and red blood cell concentration in PF when compared to nonmenstrual phases of the cycle.MethodsPF was obtained at laparoscopy from 107 women with endometriosis (n = 59) and controls with a normal pelvis (n = 48) during the luteal (n = 46), follicular (n = 38) or menstrual (n = 23) phase of the cycle. Endometriosis was classified according to the classification of the American Society for Reproductive Medicine (rAFS into minimal (n = 25), mild(n = 20), moderate(n = 6) and severe(n = 8) disease. Cell counts (leucocytes, erythrocytes, thrombocytes) were determined on a cell counter. In a subset of 32 patients (13 controls and 19 women with endometriosis), PF was fixed, processed and thinlayers were prepared and stained with Papanicolaou method and with immunocytochemistry using monoclonal antibodies against cytokeratin 7(CK 7), CK 8/18, Ber-Ep4, vimentin, calretinin and CD68. Ber-Ep4 is a marker for cells with epithelial origin (in some cases for mesothelial cells as well). CD68 is specific for cells from monocyte/macrophage lineage; CK7 and CK8/18 are markers for both endometrial epithelial and mesothelial cells, whereas calretinin and vimentin are markers for both endometrial stromal and mesothelial cells.ResultsIn comparison with the nonmenstrual phase of the cycle, analysis of PF during menstruation showed an increased concentration of leucocytes (3.3 × 109/L vs 0.8 × 109/L, P = 0.03), erythrocytes (0.3 × 1012/L vs 0.02 × 1012/L, P = 0.006), hematocrit (0.03 L/L vs 0.003 L/L, P = 0.01) and hemoglobin (0.8 g/dL vs 0.1 g/dL, P = 0.01). Mesothelial cells stained positively with CK7, CK8/18, vimentin, and calretinin. Cells positive for Ber-Ep4 were not observed, except in 2 patients with endometriosis investigated during menses. In all patients 50-98% of single cells were strongly positive for both vimentin and CD68.ConclusionWhen compared to nonmenstrual phases of the cycle, menstruation is associated with an increased concentration of red and white blood cells in PF. However, the presence of EM cells that are detectable by immunohistochemistry in PF is low during all phases of the cycle, including menstruation.

Endometriosis, a disease of the macrophage

“…During menstruation red blood cells, hemoglobin, and leucocytes accumulate in the peritoneal fluid of most healthy women (Bokor et al, 2009): this indicates that retrograde menstruation is a fairly common event. Interestingly, retrograde menstruation appears not to be per se more frequent or abundant in endometriotic women (Bokor et al, 2009): therefore, the presence of endometrial tissue in the peritoneal cavity is not sufficient to cause endometriosis (Bulun, 2009). The role of the genetic background and/or of environmental factors deserves better attention and will be a hot topic for researchers in the next years.…”

The Presence of Endometrial Cells in Peritoneal Fluid of Women With and Without Endometriosis

“…9,16,17,[33][34][35][36] In our current study, we report the presence of endometrial epithelial cells in PF collected during the menstrual cycle phase in 5 (55.56%) of the 9 cases with endometriosis and 6 (75%) of the 8 controls and the presence of endometrial stromal cells in 6 (66.67%) of the 9 cases with endometriosis and 3 (37.5%) of the 8 controls.…”

“…18 Indeed, we found a higher prevalence of PF samples containing endometrial epithelial cells compared with the previous report by our group. 9 Cryosectioning was also used by van der Linden et al 17 whose results corresponded with ours, yet our study specified the serial staining of 195 consecutive sections, ensuring the reliable representation of the entire PF pellet content.…”

“…Four other studies using immunological methods reported results from patients in the menstrual phase of the cycle, 9,16,17,33 and none of these studies showed a difference in the presence of endometrial cells between cases with endometriosis and controls in this cycle phase (summarized in Table 5). …”

“…16,17 However, in a recent study, our group demonstrated a low prevalence of endometrial cells in PF during menstruation, as detected by Prep-stain methodology, 9 challenging the concept that retrograde menstruation is associated with a high number of endometrial cells floating in PF. It is possible that the low prevalence of PF endometrial cells was related to limitations of the Prepstain technology used in our previous study, 9 such as the type of fixation 18 and the limited amount of possible stainings. Therefore, in this study, we cryosectioned PF pellets, a method that is more representative to obtain the full cellular content of PF than Prep-stain monolayers, to test the hypothesis that the prevalence of PF samples containing endometrial single cells and endometrial fragments (strands of epithelial cells and clusters of stromal cells) is higher in women with endometriosis than in controls.…”