Fibrinogen and fibrinogen/fibrin degradation products in the urine of rabbits infected with Trypanosoma (Trypanozoon) brucei

Summary Studies have been carried out on the urine of rabbits infected with Trypanosoma (Trypanozoon) brucei to determine whether fibrinogen or fibrinogen/fibrin degradation products (FDP) could be detected. No fibrinogen was found but during the last two weeks of this 7-week infection low levels of FDP were present in the urine which did not exceed 5 g/ml. Rabbit urine was shown to contain a potent proteolytic enzyme capable of breaking down rabbit fibrinogen and both early and late FDP were present in the cleavage products. No deposits of fibrin were detected in the kidney, but casts were present in the urine suggesting renal damage. The most likely explanation of the urinary FDP is that either an increase in the glomerular permeability occurs allowing filtration of plasma FDP or a local fibrinogenolysis in the kidney tubules.