Reduced trypsin-binding capacity of alpha 2-macroglobulin in the peritoneal fluid of women with endometriosis: possible relevance to alterations in macrophase function.

Alpha 2-macroglobulin (alpha 2M) is a plasma protein with proteinase inhibitor and immune modulatory capabilities. The amounts of alpha 2M in peritoneal fluid (PF) from women with endometriosis and women with noninflammatory gynecologic conditions were analyzed by functional (trypsin binding) and immunologic assays. The most important finding of this study was that a significant amount of the alpha 2M in the peritoneal fluid of patients with endometriosis had been inactivated by an as yet undetermined mechanism. The concentration and total amount of immunologically reactive alpha 2M in the samples varied widely and was not significantly different between the groups. However, women with endometriosis had significantly lower amounts of functional alpha 2M than did women without endometriosis. There was no significant difference between functional and immunologic measurements of alpha 2M in samples from women without endometriosis. Women with endometriosis, however, had less functional than immunologically reactive alpha 2M. This discrepancy was not due to inactivation of alpha 2M by having previously bound proteinase. Alpha 2M-proteinase complexes can down-regulate macrophase functions. It is possible that decreased proteinase-binding ability of alpha 2M may play a role in the pathogenesis of endometriosis and associated infertility by decreasing negative feedback control of macrophage activities.

Duke Scholars

Author Maureane Hoffman Pathology

Author Joe Brice Weinberg Medicine, Hematology