Determination of urinary fibrin/fibrinogen degradation products by radioimmunoassay.

Abstract

Glomerular fibrin/fibrinogen related material is often found in the early stage of especially proliferative types of glomerulonephritis and during rejection of renal grafts after transplantation. The presence and concentration of urinary fibrin/fibrinogen degradation products (FDP) have been found to be correlated to the extent of glomerular fibrin deposits. Most methods for FDP determination hitherto available are not sensitive enough to detect such small amounts of the fibrin/fibrinogen related material in the urine as are found in early glomerulonephritis. A radioimmunoassay for determining urinary FDP is described, in which the high molecular weight degradation products (HMWDP) are first converted into end degradation products (D and E) by addition of plasminogen and streptokinase to the urine sample. In the test an antiserum against purified D-products is used, which avoids the influence of varying binding properties and therefore makes the method more specific.