THE CLEARANCE OF COMPLEMENT COMPONENTS IN CHRONIC MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS

In chronic membranoproliferative glomerulonephritis (CMPGN) the activation of the complement system through the C3-bypass mechanism plays an important role. The clearance of the complement components and of the C3-proactivator (C3-PA) have been determined in 22 patients. Haemolytically active C5, C6, C7, C8, C9 and C3-PA could be detected in the urine for the first time. The clearances of the complement components do not correlate with the clearances of other serum proteins with similar molecular weights and may reflect the immunologic process in the kidney. To determine the selectivity of a proteinuria the quotient clearance C8/clearance C9 is as reliable as the quotient clearance IgG/clearance transferrin, as introduced by Cameron and Blandford. The specificity of the single complement components in the urine were tested by specific complement inhibitors such as hydrazine, KSCN, Antrypol, EDTA and the C4-inactivating factor.