Cellulose acetate membrane electrophoresis in the analysis of urinary proteins in patients with tubulointerstitial nephritis

Abstract

Urinary proteins from 14 patients with tubulointerstitial nephritis were analyzed by cellulose acetate membrane electrophoresis. Urinary total protein concentrations were measured, and urinary 15 proteins (prealbumin, albumin, alpha(1)-microglobulin, alpha(1)-antitrypsin, alpha(2)-macroglobulin, haptoglobin, retinol binding protein, transferrin, beta(2)-microglobulin, IgA, IgG, kappa- and lambda-light chains, cystatin C, and lysozyme) were identified by the use of a rapid and highly sensitive colloidal silver staining reagent suited for use with cellulose acetate membranes, as reported previously by Matsuda et al. (J Clin Lab Anal 15:171-174, 2001; Clin Chem47:763-766, 2001) and Hiratsuka et al. (J Clin Lab Anal 10:403-406, 1996). We also analyzed urinary total protein concentration and urinary protein fractions according to the presence of acute or nonacute interstitial nephritis. In addition, the relationship between urinary protein fraction and complications of interstitial nephritis was analyzed. The goal of this work was to find a useful index for the diagnosis of tubulointerstitial nephritis.

Measurement of urinary cystatin C by particle-enhanced nephelometric immunoassay: precision, interferences, stability and reference range

“…This method o¡ers rapid, automated and precise measurement of cystatin C in comparison to earlier methods which were slower, semi-quantitative, less precise, or not commercially available. 4,7,8,14 Additional bene¢ts are the high stability of urinary cystatin C, the lack of interference and the lack of variability with the method of urine collection, age and gender. These features are particularly important when urinary cystatin C is used as a routine biochemical test of tubular injury in clinical practice.…”

“…PENIA is commercially available and should permit rapid, automated and quantitative measurement of urinary cystatin C. 4,7,8,14 Despite the diagnostic significance of urinary cystatin C, there are few data on analytical performance, interfering factors or reference range of urinary cystatin C analysis. The present study was designed to evaluate the performance of urinary cystatin C measurement by PENIA, to assess potential pre-analytical factors in the urine in£uen-cing its measurement, and to determine the reference range for urinary cystatin C. In addition, urinary cystatin C was normaliz ed for urine creatinine to compensate for di¡erences in diuresis and timing of urine sampling; the respective reference values were also calculated.…”

Prognostic Value of Tubular Proteinuria and Enzymuria in Nonoliguric Acute Tubular Necrosis

“…Our findings are consistent with recent studies indicating that urinary concentrations of lipocalin-type prostaglandin D synthase and neutrophil gelatinase-associated lipocalin, which are, like ␣ 1 -microglobulin, low-molecular-weight proteins of the lipocalin superfamily, may reflect the severity of tubular injury in human chronic renal disease and of ATN in animal models (39,40 ). Additionally, methods for measuring of urinary cystatin C and ␣ 1 -microglobulin are precise, simple, and readily available in clinical chemistry laboratories (20,35 ). Recently, the high stability of cystatin C in urine at routine storage conditions, such as those used in the present study, and the independence of urinary cystatin C from the mode of urine collection were demonstrated, as have also been described for ␣ 1 -microglobulin (35,41,42 ).…”

Serum protein fractionation using supported molecular matrix electrophoresis

“…Therefore, the membrane must be rendered transparent using appropriate reagents before applying densitometry. Cellulose acetate membranes are rendered transparent by immersing into decahydronaphthalene or liquid paraffin . For SMME membranes, we used 1‐nonene, a colorless and volatile organic solvent in which proteins and dyes are insoluble.…”