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T Melvin

Publications and source records attributed to T Melvin.

24 records · Page 2Linked to original sources

Idiopathic linear glomerular IgA deposition.

Linear deposition of IgA immunoglobulin was found along the glomerular basement membrane in two patients with normal renal function and no pulmonary abnormalities. One patient had recurrent gross hematuria and a mild focal proliferative glomerulonephritis without deposits on electron microscopy; the second patient had a renal cell carcinoma. This observation of linear IgA antibody deposition in the absence of Goodpasture's syndrome or diabetes mellitus extends the spectrum of diseases associated with glomerular basement membrane-IgA deposition.

Adolescent↗

No evidence for a specific role of IgM in mesangial proliferation of idiopathic nephrotic syndrome.

To define the relationship of mesangial IgM to various morphologic categories of idiopathic nephrotic syndrome (INS), an analysis of 100 patients was carried out in which five morphologic subgroups were evaluated: group 1, minimal glomerular change (38 patients); group 2, minimal change with focal global sclerosis (18 patients); group 3, focal segmental glomerulosclerosis ( FSG ) (23 patients); group 4, mesangial proliferation (12 patients); group 5, focal segmental glomerulosclerosis with mesangial proliferation (9 patients). Immunohistochemical studies failed to demonstrate any differences between these five groups. The intensities of immunofluorescence and the percentage of tissue samples demonstrating IgM and/or C3 in the glomerular mesangium and subendothelial regions were similar. In addition, the presence or intensity of mesangial IgM did not predict the patients' current status or responsiveness to steroid therapy. Morphologic transitions were observed in patients who had more than one biopsy: one of five in group 2 and two of eight in group 3 developed mesangial proliferation; and nine of ten patients with mesangial proliferation in the first biopsy continued to show this finding in the second. In general, a complete response to steroid therapy and a favorable outcome is less likely in patients with this morphologic abnormality. In nine of the 27 repeat biopsies, there was lack of agreement between the first and second tissue samples with respect to the presence or absence of mesangial IgM. Although mesangial proliferation is a consistent feature of the morphology of certain patients with INS, these studies do not support a unique association with mesangial IgM.

Adolescent↗

Selective binding of IgG4 and other negatively charged plasma proteins in normal and diabetic human kidneys.

Renal tissue from 9 patients with diabetes mellitus (4 with mild and 5 with end-stage disease) and 3 with antiglomerular basement membrane (GBM) nephritis, as well as 5 normal human kidneys, were examined by immunofluorescence microscopy for the presence of plasma proteins of varying isoelectric point (pI). In normal and diabetic kidneys, IgG deposition in basement membranes was restricted to IgG4 (pI 5.5-6.0), the subclass present in lowest concentration in human plasma. IgG1, IgG2, and IgG3 (pI 7.0-9.5) were not detected. In contrast, in anti-GBM nephritis, all four subclasses were present in a linear pattern in GBM. Other plasma proteins of low isoelectric point were detected in basement membranes: albumin (pI 4.9), alpha-1-acid glycoprotein (pI 2.7), amyloid P (pI 3.9-4.8), and alpha-1-antitrypsin (pI 4.5). These studies are consistent with the hypothesis that circulating anionic plasma proteins are electrostatically bound in vivo to positively charged moieties in normal and especially diabetic basement membranes.

Antibodies, Monoclonal↗

Experimental IgA nephropathy in bile duct ligated rats.

Polymeric IgA and polymeric IgA-containing immune complexes are transported from blood to bile through hepatocyte-bound secretory component. In order to investigate interruption of this transport and its effect on the glomerulus, Sprague-Dawley rats underwent bile duct ligation. Renal tissue obtained at the time of sacrifice was stained by immunofluorescent techniques with antibodies to IgG, IgM, and IgA, and secretory component (SC) and C3. A progressive selective increase in the staining intensity of the glomerular mesangium was observed for IgA, C3, and SC in bile duct ligated rats. These changes were paralleled by a rise in serum IgA and C3. These findings are consistent with the view that glomerular deposition of IgA, C3, and SC in bile duct ligated rats may result from impairment of normal handling of polymeric IgA and polymeric IgA-containing immune complexes.

Animals↗