Urinary Fibrin and Fibrinogen Degradation Products and the Origin of Hematuria

We examined urinary fibrin and fibrinogen degradation product (U‐FDP) concentrations in pediatric patients with hematuria using the rapid and highly‐sensitive latex particle agglutination test (LPAT), and assessed the value of this test for the localization of the site of hematuria. Patients with hematuria were divided into two groups: 60 with glomerular hematuria and 46 with non‐glomerular hematuria. If U‐FDP concentrations less than 0.25 μg/ml are Accepted as an indicator of glomerular bleeding, the sensitivity and specificity of localization of glomerular hematuria in the present study were 78% (47/60) and 89% (41/46), respectively. The high U‐FDP concentrations observed in patients with non‐glomerular hematuria may reflect direct bleeding into the urinary tract. Since all 13 patients with glomerular hematuria and U‐FDP concentrations of 0.25 μg/ml or more had coexistent erythrocyte cylindruria, the U‐FDP test seems to be compensated with combined urinalysis for the relatively lower sensitivity. We conclude that a knowledge of U‐FDP concentrations by LPAT can be of help in localizing the site of bleeding in hematuria.