[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.
Sugai
Hisako
H
Department of Clinical Research, Sendai Shakaihoken Hospital, Sendai 981-8501, Japan. labo@sendai-shaho.com
Kitamura
Hiroshi
H
Yusa
Naoko
N
Kishi
Kouji
K
Ohba
Ikuko
I
Taguma
Yoshio
Y
Hotta
Osamu
O