Potential urinary protein biomarkers for the diagnosis of endometriosis

Endometriosis is a debilitating disease. Oestrogen seemingly promotes its growth and the generation of chronic pain symptoms. The prevalence of the disease is unclear but it is commonly accepted that it affects 10-15% of reproductive age women. The disease is defined as the growth of endometrial-like tissue, glands and stroma, outside the uterine cavity. It causes chronic pelvic pain and 30-50% affected women are infertile. The aetiology and the pathogenesis of the disease are poorly understood. Endometriosis has a wide range of symptoms or can be asymptomatic, this makes the diagnosis of the disease difficult. The definitive diagnosis is surgical, usually via laparoscopy with histological confirmation. There is often a long delay in diagnosis, 8-12 years, from the onset of symptoms till a definitive diagnosis is made. Endometriosis is a progressive disease and long delays before effective treatment allows the disease to advance. There is a need for sensitive and specific test for a definitive diagnosis of endometriosis. This project aimed to identify a urinary protein biomarker or a panel of urinary protein biomarkers for the diagnosis of endometriosis. Using the rapidly advancing proteomic technologies, 2-Dimensional Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis in conjunction with Progenesis SameS pots softwares, 26 spots were uniquely found in patients with endometriosis. Matrix-assisted Laser Desorption Ionization coupled to Mass Spectrometry, eleven protein candidates were identified by the Mascot Database Search engine. The proteins of interest identified included, zinc finger protein, tRNA-splicing endonuclease subunit, actin cytoplasmic 1, aminoacylase-1, serpinB3, vesicular integral-membrane protein, glutathione $-transferase P, lysosomal alpha-glucosidase, coiled-coil domain-containing protein141, lambda-crystallin homolog and chain A laminin G like domain 3 from human perlecan. These are undoubtedly potential urinary protein biomarkers. Further investigation of these proteins is planned. The exclusive presence of these eleven proteins in urine from patients with endometriosis is a significant discovery and their potential biological roles in endometriosis may contribute towards the elucidation of the pathogenesis of the disease. The detection of these proteins in urine from patients with endometriosis is novel and significant. Further investigation will be undertaken to develop and translate this novel discovery into clinical practice. A successful development of a sensitive and specific screening test for endometriosis will have a huge social and economic impact worldwide and additionally, the true prevalence of the disease will be established.