alcian-blue and Nephrosis--Lipoid

A study was undertaken to clarify the usefulness of two cationic dyes, alcian blue (AB) and ruthenium red (RR) in demonstrating the defect in cellular membranes noted in minimal change nephropathy (MCN). The binding of both dyes to RBC membranes purified from normal and nephrotic children was evaluated by electrophoretic titration curves. When examined separately, AB was found to precipitate spontaneously, producing macro-aggregates with no electrophoretic mobility at pH 5. This was presumed to be the result of hydrophobic interaction of the dye with itself. The same phenomenon was observed when this dye was incubated at 37 degrees C with RBC ghost's from normal children, when AB presented a sigmoidal curve with a net positive charge for pHs higher than 5.5 and lower than 5 and no electrophoretic mobility at pH 5. However, incubation of AB with RBC ghosts from children with MCN resulted in an improvement of the solubility of the dye which then migrated with a net positive charge along the whole gradient of pH from 3.5 to 9. The presence of zwitterionic neutral detergents such as CHAPS, but not of a charged substance such as protamine sulphate, inhibited precipitation at pH 5 when incubated with membranes from normal children, supporting the hydrophobic nature of the phenomenon. When RR was used instead of AB, it was fully protonated (i.e. did not precipitate) when analysed alone, but when incubated with normal RBC ghosts, it also revealed no electrophoretic mobility at pH 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Alcian Blue; Child; Child, Preschool; Electrophoresis; Erythrocyte Membrane; Humans; Kidney Glomerulus; Nephrosis, Lipoid; Ruthenium Red

Red blood cells have a negative charge on their surface which prevents Rouloau formation. This charge may reflect the charge on glomerular capillaries. Using alcian blue, we measured the negative charge on red blood cells in patients with IgA nephropathy (IgAN), membranous nephropathy (MN), minimal change nephropathy (MCN) and focal glomerular sclerosis (FGS), for which the diagnosis was determined by renal biopsy. The alcian blue values for the normal control, IgAN, MCN (nephrotic phase), MCN (remission) and MN were 155.3 +/- 12.3, 140.9 +/- 23.9, 101.7 +/- 18.4, 152.9 +/- 11.2 and 140.9 +/- 23.6 ng per 1 x 10(6) red blood cells, respectively. The charge was more significantly decreased in MCN during nephrotic phase than other renal diseases and the normal control. The charge in MCN was within the normal range on remission. When we studied the correlation between the charge on red blood cells and proteinuria during steroid therapy, the charge in MCN was found to increase with reduction of proteinuria, while there was no change in MN and FGS with reduction of proteinuria, i.e. it was usually within normal range. The reduced charge was associated with the nephrotic phase in MCN. The difference in the charge on the red blood cells between MCN and FGS during nephrotic phase seems to suggest a different etiology of proteinuria. Measurement of the charge on red blood cells could be an useful method for differentiating MCN from other renal diseases in the nephrotic phase.

Topics: Adolescent; Adult; Aged; Alcian Blue; Erythrocyte Membrane; Erythrocytes; Female; Glomerulonephritis; Humans; Male; Middle Aged; Nephrosis, Lipoid

The negative charge on the surface of red blood cells may reflect the charge on the glomerular capillaries. Measurements were made of the charge on the red cells of patients with minimal change nephropathy (MCN), membranous nephropathy (IMN), and IgA nephropathy (IgAN) during complete or partial remission. The charge was significantly less in patients with MCN and IMN than in patients with IgAN. Since blood was taken during clinical remission, the differences probably represent the pre-morbid state. Low charge was associated with MCN and IMN, which usually present with heavy proteinuria, and high charge with IgA nephropathy, in which heavy proteinuria is rare. Patients with low red-cell charge are, therefore, susceptible to the development of heavy proteinuria and patients with high charge are protected. The site of deposition or formation of immune complexes may also be determined indirectly by charge.

Topics: Adolescent; Adult; Aged; Alcian Blue; Erythrocyte Membrane; Female; Glomerulonephritis; Glomerulonephritis, IGA; Humans; Immunoglobulin A; Ions; Male; Middle Aged; Nephrosis, Lipoid; Proteinuria; Sex Factors