Endometrial CXCL13 Expression Is Cycle Regulated in Humans and Aberrantly Expressed in Humans and Rhesus Macaques With Endometriosis

AbstractC-X-Cligand13(CXCL13),aregulatorofmucosalimmunity,issecretedbyhumanendometrialepitheliumandmaybeinvolvedinembryo implantation. However, cyclic expression of human endometrial CXCL13 in health and disease is not well studied. Thisstudy examines cycle stage-specific endometrial CXCL13 expression in normal humans when compared to those with biopsy-confirmed, stage 1 to 4 endometriosis using real-time reverse transcriptase, real-time polymerase chain reaction and immuno-histochemistry. Eutopic endometrial CXCL13 expression was also compared between normal, control Rhesus macaques, andmacaqueswith advancedendometriosis.Inhealthywomen,CXLC13messenger RNAexpression wasminimalintheproliferativephase and maximal in the secretory phase. However, in the presence of endometriosis, proliferative-phase endometrial expres-sion markedly increased in both humans and rhesus subjects (P < .05). The cross-species and cross-stage concordance suggests apathophysiologic role for CXCL13 in endometriosis and its use as a biomarker for disease.KeywordsCXCL13, endometriosis, proliferative phase