Expression of the 60 kDa heat shock protein in peritoneal fluids from women with endometriosis: Implications for endometriosis-associated infertility

Abstract

Proinflammatory cytokines and activated macrophages and T lymphocytes have been detected in peritoneal fluids of women with endometriosis and may impair fertility. Expression of the 60 kDa heat shock protein (hsp60) is one mechanism leading to a localized activation of macrophages and T lymphocytes and cytokine release. Peritoneal fluids, obtained from 68 women undergoing a diagnostic laparoscopy, were assayed for hsp60. As independent evidence of local immune activation, the fluids were analysed for interferon γ (IFNγ). Fluids were also tested for antibodies to Chlamydia trachomatis because a chronic asymptomatic infection by this organism may also release hsp60. At laparoscopy, 26 women were diagnosed with pelvic adhesions, 19 had endometriosis, 16 had a visibly normal pelvis, four had ovarian cysts while three had myomas. The prevalence of hsp60 was higher in peritoneal fluids from the women with endometriosis than in the other subjects (P = 0.005). Hsp60 was detected in seven (36.8%) of the endometriosis patients and in only one each of the women with adhesions, a normal pelvis or an ovarian cyst; all women with myomas were negative. Detection of IFNγ in peritoneal fluids was highly correlated with the presence of hsp60 (P = 0.0003). IFNγ was present in seven of nine (77.8%) women with hsp60 and in only five of 40 (12.5%) women lacking hsp60. Women with pelvic adhesions had an increased prevalence of immunoglobulin G antibodies to C.trachomatis compared with the other women (P = 0.01). There was no relationship between evidence of exposure to C.trachomatis and hsp60 in peritoneal fluids. These data suggest that hsp60 may be released into the peritoneal fluid as a consequence of implanted ectopic endometrium, Hsp60-mediated immune activation may be one mechanism leading to endometriosis-associated infertility.