[Soluble fibrin is not excreted in urine and its plasma level is elevated in nephrotic syndrome]

Soluble fibrin (SF) is produced by activated blood coagulation reaction and is useful to diagnose thrombotic diseases. We measured plasma and urine SF levels in nephritic patients to assess the hypercoagulability state associated with the disease. Before they received anti-coagulation or anti-platelet therapies, 60 patients underwent measurement of plasma SF and D-dimer levels by Latex agglutination turbidimetric immnoassay (LA). Urinary SF levels were also measured by LA. Plasma and urinary thrombin antithrombin III complex (TAT) levels were measured by enzyme immunoassay (EIA). Plasma SF levels showed a good correlation with plasma TAT levels but only weak positive correlations were observed between plasma D-dimer and SF or TAT levels. Plasma SF and D-dimer levels were significantly higher in the Iatients with nephrotic-range hypoalbuminemia (< or =3 g/dL) than those without it. Contrarily there was no significant difference in plasma TAT levels between these two groups of patients. In almost all patients, urinary SF levels were under the detection limit. However, TAT was excreted into urine more frequently in patients showing the nephrotic range of hypoalbuminemia at 38.2% than in non-nephrotic patients at 8.0%. Thus, plasma SF levels more precisely indicate activated blood coagulation reaction than plasma TAT levels in nephrotic patients, probably because the plasma SF is not excreted into urine, while plasma TAT is.

[Clinical significance of urinary cholesterol/total protein ratio as a marker of selectivity of proteinuria: comparison with selectivity index]

Selectivity index (SI) has been reported to reflect the selectivity of proteinuria, and it has a relationship with tubulointerstitial damage. Moreover it has a predictive value on functional outcome. However, it is necessary to measure serum IgG, serum transferrin, urinary IgG, and urinary transferrin to calculate SI. We measured urinary micro-cholesterol (mCHO) levels in sixty-three patients with proteinuria (urinary total protein > or = g/gCr) and compared urinary mCHO/total protein(uTP) ratio and SI. The patients' diseases were minimal change nephrotic syndrome (MCNS, n = 12), focal and segmental glomerular sclerosis (FSGS, n = 12), membranous nephropathy (MN, n = 17), and diabetic nephropathy (DMN, n = 22). Urinary mCHO levels were measured by the ECC method using cholesterol ester hydrolase (CEH) and cholesterol dehydrogenase, and this method was performed conveniently by automatic analyzer. No correlation was observed between urinary mCHO/gCr and serum lipid levels. There was no difference of urinary protein levels among each disease group. We found urinary mCHO/uTP ratio has a good positive correlation with SI(R = 0.722, p < 0.001). Although the difference between ROC curves of SI and urinary mCHO/uTP ratio in distinguishing MCNS from other diseases (FSGS+MN+DMN) did not reach the statistical significance, the area under the curve was larger for mCHO/uTP ratio. These results suggest that measurement of urinary mCHO by ECC method can be a simple and useful tool for predicting selectivity of proteinuria and lipoprotein-loading tubulopathy.