Markers of endothelial glycocalyx dysfunction in Clarkson disease

Background Clarkson disease is a rare idiopathic condition marked by transient, relapsing-remitting episodes of systemic microvascular hyper-permeability, which liberates plasma fluid and macromolecules into the peripheral tissues. This pathology manifests clinically as the abrupt onset of hypotensive shock, he-moconcentration, and hypoalbuminemia. Methods We analysed endothelial glycocalyx (eGCX)-related markers in plasma from patients with SCLS dur-ing acute disease flares and convalescence by ELISA and comprehensive proteomic profiling. eGCX-related components and gene expression in cultured endothelial cells were evaluated by RNA-sequencing, real-time PCR, and fluorescence. Results Serum levels of eGCX-related core components including hyaluronic acid (HA) and/or the core pro-teoglycan soluble syndecan-1 (sCD138) were elevated at baseline and during acute SCLS flares. Se-rial measurements in several patients demonstrated that sCD138 levels peaked during the recovery (post-leak) phase of the illness. Proteomic analysis of matched acute and convalescent SCLS plasma revealed increased abundance of eGCX-related proteins, including glypicans, thrombospondin-1 (TSP-1), and eGCX-degrading enzymes in acute plasma compared to remission plasma. Abundance of endothelial cell damage markers did not differ in acute and baseline plasma. Expression of several eGCX-related genes and surface carbohydrate content in endothelial cells from patients with SCLS did not differ significantly from that observed in healthy control cells. Conclusions eGCX dysfunction, but not endothelial injury, may contribute to clinical symptoms of acute SCLS. Serum levels of of eGCX components including sCD138 may be measured during acute episodes of SCLS to monitor clinical status and therapeutic responses. Overall design: Blood outgrowth endothelial cells (BOECs) were cultured from whole blood samples from 5 systemic capillary leak syndrome (SCLS) patients and 6 controls