Evaluation of the Endothelial Specific Isoform of Type XVIII Collagen (COL-18N) in Egyptian Patients with Hemophilia A

Abstract

ecurrent haemarthroses consequent to vascular ruptures is a major complication in haemophilia, contributing to progressive joint damage, which leads to haemophilic (HF) arthropathy. The annual bleeding rate (ABR) is related to haemophilia arthropathy and is the key parameter to assess the patients. There is no quantifiable method for specifically quantifying damage to the joints vascular endothelium, which subsequently leads to bleeding, and exposure of the basement membrane underlying the endothelial cells. Collagen IV, XV and XVIII represent the most well-known collagens of the vascular basement membrane, responsible for maintaining vessel wall structure and integrity of the membrane. Type XVIII collagen exists in three isoforms: short, intermediate, and long, localized in various basement membrane zones. The short isoform is found in blood vessels and around muscular structures. Following remodelling, damage and consequently degradation of the vascular basement membrane, the short isoform of collagen type XVIII may be affected and degraded, releasing measurable fragments of type XVIII collagen. In this study we aim to quantify the measurable fragments of the endothelial specific isoform of type XVIII