heparitin-sulfate and Glomerulonephritis--IGA

IgA nephropathy is diagnosed by renal biopsy, an invasive procedure with a risk of significant complications. Noninvasive approaches are needed for possible diagnostic purposes and especially for monitoring disease activity or responses to treatment. In this pilot project, we assessed the utility of urine samples as source of biomarkers of IgA nephropathy. We used spot urine specimens from 19 healthy controls, 11 patients with IgA nephropathy, and 8 renal-disease controls collected on day of renal biopsy. Urine samples were analyzed using untargeted metabolomic and targeted proteomic analyses by several experimental techniques: liquid chromatography coupled with mass spectrometry, immunomagnetic isolation of target proteins coupled with quantitation by mass spectrometry, and protein arrays. No single individual biomarker completely differentiated the three groups. Therefore, we tested the utility of several markers combined in a panel. Discriminant analysis revealed that combination of seven markers, three metabolites (dodecanal, 8-hydroxyguanosine, and leukotriene C

Topics: Adult; Aged; Aldehydes; alpha 1-Antitrypsin; Biomarkers; Case-Control Studies; Female; Glomerulonephritis, IGA; Guanosine; Heparitin Sulfate; Humans; Immunoglobulin A; Leukotriene C4; Male; Metabolome; Middle Aged; Proteome; Uromodulin

We measured the concentrations of urine glycosaminoglycans (GAG) by the modified dimethylmethylene blue method and the concentration of urine heparan sulfate (HS) by enzyme-linked immunosorbent assay (ELISA) in patients with various glomerular diseases. The GAG/creatinine(Crea) ratios in patients with IgA nephropathy (mean +/- SD, 0.31 +/- 0.056) and membranous nephropathy (0.41 +/- 0.115) were significantly greater than in healthy controls (0.18 +/- 0.045). Urine GAG/Crea ratios in minimal change nephrotic patients increased during remission (0.38 +/- 0.102) and decreased to normal values during the nephrotic stage (0.25 +/- 0.088). In contrast, urine HS/Crea ratios in patients with minimal change nephrotic syndrome decreased during remission (0.0069 +/- 0.0029) and increased markedly during the nephrotic period (0.047 +/- 0.0007 versus controls 0.0158 +/- 0.0046). Serial measurement in three minimal change nephrotic patients showed the similar change for the HS/Crea ratio and urine albumin excretion in the course of steroid therapy. The loss of HS from the glomerular basement membrane (GBM) may therefore be related to the pathogenesis of increased albumin excretion and measurement of urine HS excretion may be helpful for studying metabolism in renal disease, especially in patients with minimal change lesions.

Topics: Adult; Enzyme-Linked Immunosorbent Assay; Female; Glomerulonephritis, IGA; Glomerulonephritis, Membranous; Glycosaminoglycans; Heparitin Sulfate; Humans; Male; Methylene Blue; Nephrosis, Lipoid; Spectrophotometry; Urinalysis

The distribution of heparan sulphate proteoglycans (HSPG) has been investigated in normal human glomeruli, membranous glomerulonephritis, mesangial IgA disease, and anti-glomerular basement membrane disease. HSPG was localized using anti-bovine HSPG antibody and 10 nm gold-labelled secondary antibody on paraformaldehyde-fixed, Lowicryl K4M resin-embedded kidneys. HSPG was present in all glomeruli and there was a zonation of its distribution in that it was predominantly on the epithelial aspect of the glomerular basement membrane (GBM) and mesangium with little in the central regions of the mesangial matrix. In the cases of immune complex glomerulonephritis, no HSPG was found in the electron-dense deposits. These findings contrast with our previous studies using the same technique in which type IV collagen and fibronectin were found predominantly on the endothelial aspect of the GBM.

Topics: Adult; Aged; Aged, 80 and over; Basement Membrane; Chondroitin Sulfate Proteoglycans; Female; Glomerular Mesangium; Glomerulonephritis, IGA; Glomerulonephritis, Membranous; Glycosaminoglycans; Heparan Sulfate Proteoglycans; Heparitin Sulfate; Humans; Kidney Glomerulus; Male; Middle Aged; Proteoglycans; Reference Values