The determination of fibrinolytic degradation products in concentrated urine after renal transplantation.

Fibrin/fibrinogen degradation products (FDP) were determined in concentrated as well as unconcentrated urine in 29 patients undergoing renal transplantation. When determined in unconcentrated urine, FDP was found for 3-4 weeks after an uneventful transplantation, compared with 12 weeks when determined in concentrated urine. After acute rejection episodes FDP was found in unconcentrated urine, but remained in the concentrated urine for 8 weeks longer when concentrated urine was used for determination. In early chronic rejection and glomerulonephritis, FDP appeared as a sign of glomerular lesion in concentrated urine before it was found in unconcentrated urine. It was concljded that the presence of FDP in concentrated urine is a diagnostic tool of value particular in detecting early glomerular lesions caused by chronic rejection or glomerulonephritis.