[Diagnostic significance of the demonstration of fibrin and fibrinogen degradation products in the urine].

The concentration of fibrin/fibrinogen degradation products in urine (FDPu) was measured in samples obtained from 114 patients and 63 clinically healthy volunteers, once or repeatedly. The FDP titers measured by the hemagglutination inhibition (HI) method corresponded to less than 2.6 mug/ml FDP in all samples from healthy controls. Slightly elevated FDP concentrations were found in urine obtained from a few patients with disorders not primarily involving the urinary tract. The clinical importance of these isolated findings remains unclear. Urinary tract infections were not frequently accompanied by elevated FDPu concentrations. In patients with glomerulonephritis FDP excretion correlated somewhat better with severity of the renal affection. A further group of patients showed an unequivocal correlation between FDP excretion in the urine and postoperative complications following renal transplantation. However, the clinical diagnosis of acute rejection crisis was usually established at the same time or even before an increase in FDPu was found. Our results suggest that among diagnostic procedures the measurement of FDPu contributes little specific information for the evaluation of urinary tract disease. FDPu measurements in the immediate postoperative phase following renal transplantation may however be important for prognostic evaluation and, in individual cases, predict transplant rejection. We also attempted to define the FDPu qualitatively by simultaneous measurements using HI and the staphylococcal clumping test (SCT). Immunoelectrophoresis confirmed the well-known fact that the SCT detects only high-molecular FDP; this limits its clinical usefulness, despite its high sensitivity.