Urinary cross-linked fibrin degradation products in glomerular disease with crescents

The concentration of cross-linked fibrin degradation products (XLFDP) in urine were determined by enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA) in patients with several types of glomerulonephritis with crescents (CrGN). In patients with "active" cellular crescents, increased levels of XLFDP correlated with the percentage of glomeruli containing crescents. Dysmorphic erythrocytes, suggestive of glomerular bleeding, were observed in all of the patients with CrGN, and the urinary red cell counts (URCC) also correlated with percentage of glomeruli containing crescents. The absence of correlation between urinary XLFDP and URCC or urinary protein suggested that lysis of fibrin within crescents may contribute to the urinary excretion of XLFDP in CrGN. The measurement of urinary XLFDP in CrGN is likely to be of value in assessing the activity of glomerular lesions but not renal function.