The SPRi determination of cathepsin L and S in plasma and peritoneal fluid of women with endometriosis

Endometriosis is a common disease with a complex pathomechanism and atypical symptoms, often leading to delayed diagnosis. Currently, the sole method for confirming the presence of the disease is through laparoscopy and histopathological examination of collected tissue. However, this invasive procedure carries potential risk and complications, necessitating the exploration of non-surgical diagnostic methods for endometriosis. This study aims to analyze peritoneal fluid and plasma samples for the expression of cathepsin L and cathepsin S to identify potential biomarkers for non-invasive diagnostic approaches to endometriosis. In this cross-sectional study, plasma and peritoneal fluid samples were obtained during laparoscopy from 63 patients diagnosed with chronic pelvic pain or infertility. The study group consisted of women with confirmed endometriosis. The concentrations of cathepsins L and S were determined using an SPRi biosensor. The study did not reveal significant differences in the concentrations of cathepsin L and cathepsin S between the control group and the study group, both in peritoneal fluid and plasma. Based on the results of this study, it appears that cathepsins L and S are not suitable candidates as biomarkers for endometriosis.