Soluble CD163 (sCD163)

CD163 is a membrane protein that is exclusively expressed on monocytes and macrophages. If these come into contact with inflammation-promoting stimuli such as bacterial molecules, CD163 is enzymatically cleaved off of the immune cell membrane, which results in the formation of soluble CD163 (sCD163). In glomerulonephritis, macrophages invade the tissue. sCD163 enters the urine via Bowman's capsule, where it can be measured as a biomarker. 

The more serious the inflammation, the more macrophages migrate into the tissue. Therefore, the concentration of sCD163 in urine provides clear information about the severity of the glomerulonephritis. The sCD163 level correlates with the disease activity. The higher its concentration, the more severe the inflammation. 

The sCD163 ELISA (European patent (EP3283889)) is particularly suitable for targeted monitoring of patients with diagnosed ANCA-associated vasculitis (AAV) with renal involvement. Indeed, unlike systemic inflammatory markers, sCD163 levels are a specific indicator of renal inflammation and respond rapidly to treatment or fluctuations in inflammatory activity. 

If regular examinations of patients show increased sCD163 levels after a period of normal values, these may indicate recurring renal inflammation. Treatment can be adjusted early and irreversible kidney damage can be avoided.