Identification of molecular markers for endometriosis in blood lymphocytes by using deoxyribonucleic acid microarrays

Objective: To identify molecular biomarkers for endometriosis in peripheral blood lymphocytes by using DNA microarrays. Design: Case-control. Setting: Multicenter academic research programs. Patient(s): Premenopausal women with or without endometriosis, determined by obstetrics and gynecology specialists during surgery. Microarray analysis included six endometriosis patients and five controls; 15 endometriosis patients and 15 controls were analyzed by using real-time reverse-transcription polymerase chain reaction (RT-PCR). Patients with all disease stages were included. Intervention(s): Peripheral blood samples were collected by venipuncture. Main Outcome Measure(s): The expression levels of mRNAs in blood lymphocytes from endometriosis patients and controls were compared with those of a standard total RNA. Gene expression data were validated by real-time RT-PCR analysis. Result(s): A gene selection program identified genes that were differentially expressed in samples from endometriosis patients. To validate the gene expression data, the nine most discriminatory genes were analyzed by real-time RT-PCR. Two of the nine genes identified, IL2RG and LOXL1, were shown to be significantly differentially expressed. Conclusion(s): This is the first report of genes that are differentially expressed in peripheral blood lymphocytes of patients with endometriosis, which may provide important clues regarding the pathogenesis of this disease. Moreover, they could be considered potential targets for noninvasive diagnostic assays for endometriosis and need to be validated in a larger population.