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M M Stilmant

Publications and source records attributed to M M Stilmant.

35 records · Page 2Linked to original sources
PubMed1979

Rapid recurrence of membranous nephropathy in a related allograft.

A patient with membranous nephropathy (MN) received a renal allograft from his brother. The allograft functioned immediately but nephrotic range proteinuria developed seven days after transplantation in the absence of any signs of rejection. Renal function deteriorated five weeks after transplantation due to ureteric obstruction. Nephrostomy drainage resulted in the return of renal function to normal and demonstrated that the allograft was the source of the nephrotic range proteinuria. An open renal biopsy of the allograft performed at the same time revealed the presence of recurrent MN. The recipient was investigated in an attempt to identify possible humoral immune mechanisms that may explain this very rapid recurrence of MN.

Adult↗
PubMed1979

Chronic interstitial nephritis and mixed cryoglobulinemia associated with drug abuse.

Two cases of chronic interstitial nephritis with renal insufficiency were associated with mixed cryoglobulinemia and parenteral drug abuse. Previously recognized causes of interstitial nephritis were not present in either case. Despite extensive interstitial inflammatory infiltrates, no substantial glomerular abnormalities or immune deposits were present in either patient. One patient had a history of intravenous injection of suspended methadone tablets containing talc crystals, and there was evidence of talc embolization in biopsy specimens of liver, spleen, and kidney. Interstitial nephritis associated with drug abuse has not been previously described to our knowledge, but the association in these cases seems not to have been fortuitous and warrants consideration in the evaluation of both parenteral drug abusers and patients with unexplained interstitial nephritis.

Adult↗
PubMed1978

Effect of aminonucleoside nephrosis on immune complex localization in autologous immune complex nephropathy in rats.

The effect of increased capillary permeability on glomerular immune complex localization was studied in rats immunized with proximal tubular antigen (Fx1A) to induce autologous immune complex nephropathy (AICN). AICN rats were made proteinuric by injection or unilateral renal perfusion with aminonucleoside of puromycin (PA) before developing subepithelial complex deposits. Control AICN kidneys developed diffuse granular deposits of IgG and Fx1A on the subepithelial surface of the glomerular basement membrane (GBM) at 3 wk by immunofluorescence and electron microscopy, and deposits increased in subsequent weekly biopsies. In contrast, PA-nephrotic AICN kidneys developed few or no GBM deposits and a significant increase in mesangial localization of IgG and Fx1A during the period of PA-induced proteinuria. These alterations in complex localization were documented both in rats with PA nephrosis and in unilaterally PA-nephrotic kidneys compared with contralateral controls in the same animals, thus excluding any effect of PA on the immunopathogenetic mechanism in AICN as an explanation for these findings. The absence of GBM deposits closely correlated with reduced staining for polyanionic glomerular sialoprotein in proteinuric kidneys, since PA-perfused kidneys studied 2 wk after resolution of proteinuria demonstrated return of normal staining for sialoprotein and development of subepithelial complex deposits similar to those in contralateral control kidneys. These studies demonstrate that properties of the glomerulus itself play an important role in determining the site of complex deposition in experimental AICN and suggest that electrophysical characteristics of the glomerular capillary wall may influence complex localization on the GBM.

Animals↗
PubMed1978

Experimental glomerulonephritis in the isolated perfused rat kidney.

The development of immune deposits on the subepithelial surface of the glomerular capillary wall was studied in isolated rat kidneys perfused at controlled perfusion pressure, pH, temperature, and flow rates with recirculating oxygenated perfusate containing bovine serum albumin (BSA) in buffer and sheep antibody to rat proximal tubular epithelial cell brush border antigen (Fx1A). Control kidney were perfused with equal concentrations of non-antibody immunoglobulin (Ig)G. Renal function was monitored by measuring inulin clearance, sodium reabsorption, and urine flow as well as BSA excretion and fractional clearance. Perfused kidneys were studied by light, immunofluorescence, and electron microscopy. All kidneys perfused with anti-Fx1A developed diffuse, finely granular deposits of IgG along the glomerular capillary wall by immunofluorescence. Electron microscopy revealed these deposits to be localized exclusively in the subepithelial space and slit pores. Similar deposits were produced in a nonrecirculating perfusion system, thereby excluding the formation of immune complexes in the perfusate caused by renal release of tubular antigen. Control kidneys perfused with nonantibody IgG did not develop glomerular immune deposits. Renal function and BSA excretion were the same in experimental and control kidneys. Glomerular deposits in antibody perfused kidneys were indistinguishable from deposits in rats injected with anti-Fx1A or immunized with Fx1A to produce autologous immune complex nephropathy. These studies demonstrate that subepithelial immune deposits can be produced in the isolated rat kidney by perfusion with specific antibody to Fx1A in the absence of circulating immune complexes. In this model deposits result from in situ complex formation rather than circulating immune complex deposition.

Animals↗
PubMed1978

De novo development of membranous nephropathy in cadaver renal allografts.

Glomerulonephritis in transplant recipients often reflects recurrence of the immunopathogenetic mechanism causing the original renal disease. Membranous nephropathy (MN), a progressive immune complex mediated glomerular disease and the commonest cause of idiopathic nephrotic syndrome in adults, has been virtually unreported in transplant recipients. Two cases are reported here of typical MN (by clinical, light, immunofluorescent and electron microscopic criteria) developing de novo in the transplants of patients whose original diseases were anti-GBM nephritis and focal glomerular sclerosis. NM developed following episodes of viral hepatitis and renal infarction respectively. Possible mechanisms by which this lesion might develop in these patients are investigated and discussed. Chronic immune complex nephropathy (MN) can develop de novo in immunosuppressed transplant recipients apparently initiated by events in the post-transplant period.

Adolescent↗
PubMed1977

Complement-independent nephrotoxic nephritis in the guinea pig.

Immunologic mechanisms of proteinuria were investigated in guinea pigs (GP) injected with sheep antiserum (NTS) to GP glomerular basement membrane (GBM). Linear deposition of sheep gamma 1 and gamma 2 IgG led to a prompt but transient (36 hr) increase in albumin excretion from control values of 0.026 +/- 0.013 mg/hr to maximal values of 26+/-12.1 mg/rh at six hours without detectable histologic or electron microscopic changes except for decreased staining for glomerular polyanion and epithelial cell foot process fusion. GBM permeability to anionic ferritin was not increased during proteinuria. Anti-GBM antibody deposits did not fix GP C3 or C4 in vivo or in vitro. NTS-induced proteinuria was the same in guinea pigs that were normal, greater than 95% depleted of C3 through C9, genetically deficient in C4, and depleted of circulating polymorphonuclear leukocytes (PMN). Prior administration of antihistamines, steroids, azathioprine, colchicine, indomethacin, heparin, aprotinin (Trasylol), and niridazole also failed to reduced proteinuria. Initial proteinuria subsided by 36 hr, did not recur despite linear deposition of GP gemma 1 and gemma 2 after day seven, and antibody to GMB-bound sheep globlin. In the GP nephrotoxic nephritis model, anti-GBM antibody deposits apparently mediate increased permeability to albumin by a currently undefined mechanism which is independent of complement, PMN, and other know mediators of inflammation.

Animals↗
PubMed1976

The immunopathology of the aging rat kidney.

Immunofluorescence studies of rat kidneys from 3-24 mo. of age demonstrated deposition of immunoglobulins, predominately IgM, within the glomerular mesangium by age 3 mo. Immunoglobulins eluted in acid buffer, did not fix complement, were not associated with inflammatory changes, and increased markedly with the onset of proteinuria at about 12 mo. Rats 24 mo. old also had mesangial deposits of IgG and fibrin. No basement membrane deposits were seen, and autoantibodies to antigens in normal kidney, liver, spleen, and skeletal muscle were not demonstrable in serum or eluates of kidneys from aged animals. The focal and segmental glomerular sclerosis which develops in aged rats does not appear to be mediated by glomerular deposition of auto-antibody or immune complexes. Mesangial accumulation of macro-molecular material, perhaps as a consequency of the age-associated increase in glomerular permeability, may contribute to the development of the glomerular sclerosis of aging in the rat by impairing mesangial phagocytic or clearing mechanisms rather than through immunologically mediated tissue injury.

Aging↗
PubMed1976

Autologous immune complex nephropathy. I. Sequential study of immune complex deposition, ultrastructural changes, proteinuria, and alterations in glomerular sialoprotein.

Experimental evidence suggests that barriers to glomerular filtration of macromolecules exist at the glomerular basement membrane itself and at the level of the epithelial cell and epithelial slit pores. The distribution of negatively charged glomerular sialoprotein (GSP) at the latter site and the reduction in histochemical staining for GSP reported in several clinical and experimental glomerular diseases suggest a role for this material in the regulation of glomerular permeability. Alternatively, reductions in GSP associated with proteinuria may reflect only epithelial cell swelling consequent to the proteinuria. The sequence of subepithelial immune complex deposition, epithelial cell swelling and foot process fusion, alterations in histochemical staining for GSP, and development of proteinuria was studied in 12 Lewis rats biopsied weekly during development of autologous immune complex (Heymann) nephropathy. Deposition of IgG was detectable 3 weeks after antigen injection by immunofluorescence. Electron-dense deposits were first seen by electron microscopy coincident with the appearance of complement at week 4. Proteinuria began at 6 to 8 weeks, 3 to 5 weeks after detectable immune complex deposition. Proteinuric animals had marked subepithelial immune complex deposition and extensive epithelial cell swelling and foot process fusion. Despite these changes, there was no detectable reduction in staining for GSP until week 14, 6 to 8 weeks after onset of proteinuria. Reductions in GSP apparently do not play a role in altering glomerular permeability early in autologous immune complex (Heymann) nephropathy, and proteinuria and epithelial cell swelling can be present in this model without detectable changes in GSP. These findings suggest that early alterations in GSP reported in some other proteinuric disorders may be of pathogenetic significance rather than simply a reflection of changes in epithelial cell morphology secondary to proteinuria. In this experimental model of membranous nephropathy, immunofluorescence was more sensitive than electron microscopy in the early detection of immune deposits.

Animals↗
PubMed1975

Experimental glomerulonephritis in the guinea pig. II. Ultrastructural lesions of the basement membrane associated with proteinuria.

Humoral immune processes mediate alterations in glomerular basement membrane (GBM) permeability by two mechanisms. One requires complement and polymorphonuclear leukocytes and the second is complement- and polymorphonuclear leukocyte-independent. The structural basis for enhanced GBM permeability induced by anti-GBM antibody is not clear. Experimental anti-GBM glomerulopathy was induced in guinea pigs by immunization with human GBM in complete Freund's adjuvant. Control animals received injections of complete Freund's adjuvant alone. Light, immunofluorescent, and electron microscopic studies were done on eight heavily proteinuric animals, four immunized nonproteinuric animals, three controls, and two normal animals. All animals that received injections of GBM had intense linear deposits of gamma2 anti-GBM antibody. Complement deposition was not demonstrable in vivo, and anti-GBM antibody deposits did not fix complement in vitro. Histologic abnormalities in proteinuric animals were confined to the GBM, which was of variable density and had a characteristic beaded thickening, with numerous areas of electron lucency most prominent in the outer aspect of GBM in peripheral portions of capillary loops. The inner margin and endothelium were normal. Ultrastructural tracer studies with ferritin demonstrated increased permeability confined to portions of GBM demonstrating ultrastructural lesions. The urine protein excreted by animals with ultrastructural GBM lesions was largely albumin. The absence of complement deposition accompanying anti-GBM antibody deposits in vivo and the unique GBM lesion in this model differ from the findings in nephritis induced by most heterologous nephrotoxic antibodies and suggest that GBM injury in this model is mediated by autologous antibody through complement-independent mechanisms. The selective proteinuria and ultrastructural lesions suggest a derangement in glomerular permeability functionally localized to the epithelial side of the GBM and could reflect an antibody-mediated abnormality in GBM biosynthesis.

Animals↗
PubMed1975

Successful renal transplantation in focal glomerular sclerosis: report of two cases.

The fate of renal allografts has provided much useful information about the pathogenesis of certain glomerular diseases. Idiopathic nephrotic syndrome with focal glomerular sclerosis (FGS) has been reported to recur in transplants. Two patients are reported with idiopathic nephrotic syndrome who progressed to renal failure. Immunopathologic and ultrastructural studies appeared to exclude immune pathogenic mechanisms in both patients, and light microscopic findings were characteristics of FGS. The nephrotic syndrome in one patient was initially steroid-dependent. Both patients underwent bilateral nephrectomy prior to renal transplantation. Graft function and urine protein excretion were normal in both patients 2 and 4 years respectively after transplantation, and transplant biopsies revealed no evidence of recurrent FGS. These results indicate that renal transplantation in patients with idiopathic nephrotic syndrome and FGS is not invariably followed by recurrent glomerular disease and suggest that the responsible pathogenetic mechanism(s) may not always persist.

Adult↗
PubMed1975

Experimental glomerulonephritis in the mouse associated with mesangial deposition ofautologous ferritin immune complexes.

Mice undergoing prolonged (5 to 8 weeks) immunization with cadium-free feeritin were studied 1 to 32 days following the last ferritin injection. Urine protein was measured and renal tissue examined by light, immunofluorescence, and electron microscopy. Immunized animals developed significant proteinuria and circulating antibody to ferritin.by light microscopy, proetinuric animals had a proliferative glomerular lesion with mesangial hypercellularity and martrix increase, focal and segmental necrosis, fibrin deposits, and occasional crescents. Iron stains revealed prominent mesangial iron deposition. In immunized animals, IgG and C3 deposits were localized mainly in the mesanglium. Electron microscopic studies revealed marked deposition of ferratin complexesexpanded mesangial matrix and mesangial interposition. Ferratin immune complexes were also visualized in epithelial spaces. In the latter location ferritin immune complexes occasionally formed characteristic electron-dense subepithelial deposits. In this model, mesangial and subepithelial localization of autologous ferritin immune complexes is associated with development of glomerulonephritis and characteristic mesangial lesions resembling those seen in some types of human glomerulonephritis.

Animals↗
PubMed1975

Mesangial lesions and focal glomerular sclerosis in the aging rat.

The pathogenesis of focal glomerular sclerosis (FGS) and its relation to proteinuria and idiopathic nephrotic syndrome are unknown. Urine protein excretion in Sprague-Dawley rats increased with age. Fifty per cent of 12-month and 90 per cent of 24-month-old animals were proteinuric (greater than 20 mg. per day). Heavily proteinuric old rats manifested biochemical changes characteristic of nephrotic syndrome without significant loss of renal function. Three-month, 6-month, and nonproteinuric 12-month-old animals had mesangial deposits of IgM in occasional lobules of some glomeruli and slight mesangial hyperplasia. Four proteinuric 12-month-old rats had diffuse 4+ deposits of IgM in the mesangium of most glomeruli, basement membrane thickening and epithelial cell foot process fusion without FGS. The mesangial IgM deposits eluted in acid buffer and did not fix complement. Six proteinuric 12-month-old rats had focal and segmental areas of glomerular sclerosis with adhesions to Bowman's capsule, foamy cells, intraluminal eosinophilic deposits and capillary wall wrinkling and collapse. These lesions were more advanced in 24-month-old animals. Nonproteinuric 24-month-old rats did not have detectable FGS. Mesangial uptake of colloidal carbon was normal in proteinuric and nonproteinuric animals without FGS. Mesangial uptake of colloidal carbon was normal in proteinuric and nonproteinuric animals without FGS and reduced in proteinuric animals with FGS. In the aging rat the development of proteinuria and mesangial IgM deposition apparently precede development of a focal sclerotic glomerular lesion with histologic and ultrastructural features similar to FGS in man. The generalized impairment of mesangial phagocytic function in proteinuric rats with FGS suggests that this lesion may result from mesangial overload and dysfunction consequent to the persistent increase in glomerular permeability and proteinuria.

Aging↗
PubMedDate not supplied

Cytologic evaluation of urine after kidney transplantation.

Over a ten-month period, 54 kidney transplant patients returning for routine clinic visits were prospectively evaluated utilizing urinary cytology; 101 urine specimens were examined. The incidence of undetected infection was low. Two patients were noted to have polyomavirus infections, and two had candiduria. No patient had urinary tract malignancy.

Adult↗