Endometriosis Is Associated with Increased Serum and Peritoneal Fluid Concentrations of Chromogranin A and Its Derivatives

Background/Objectives: Endometriosis is a prevalent gynecological illness associated with chronic pain, inflammation, and infertility, as ectopic endometrial lesions are formed. No fully effective treatment is available, and the pathogenesis of this disease is unclear. The survival of ectopic endometrial cells is facilitated by their low susceptibility to apoptosis, an immunosuppressive environment, and local angiogenesis. Chromogranin A (CgA), a glycoprotein prohormone, modulates various processes including angiogenesis and innate immunity, and its higher levels are detected in neuroendocrine tumors and inflammatory disorders. Since endometriosis may be considered an autoinflammatory disorder, this study aimed to evaluate serum and peritoneal fluid concentrations of CgA and its derivatives, catestatin and pancreastatin, and to correlate these levels with disease severity. Methods: The study was conducted on samples of serum and peritoneal fluid (PF) obtained from 65 women diagnosed with endometriosis and from 60 control individuals who underwent surgery for other reasons. The concentrations of CgA, catestatin, and pancreastatin were assessed in the collected samples by specific enzyme-linked immunosorbent assays. Results: CgA, catestatin, and pancreastatin concentrations were significantly higher in the sera and PF of endometriosis patients compared to controls. There was a correlation between their serum and PF levels, and all tested factors were correlated with each other in both serum and PF. Serum concentrations of CgA, catestatin, and pancreastatin were also associated with disease progression. Receiver operating characteristic (ROC) analysis further confirmed that endometriosis is associated with increased circulating CgA, catestatin, and pancreastatin levels, suggesting that they may be considered markers of endometriosis. Conclusions: The upregulation of CgA and its derivatives in endometriosis may indicate their role in the disease pathogenesis and implicate them as potential diagnostic markers and/or therapeutic targets.