Hidekazu Shigematsu

Ultrastructural Glomerular Loop Abnormalities in IgA Nephritis

Glomerular capillary walls of 65 cases of IgA nephritis were observed electron microscopically. At least one-third of the cases showed local abnormalities including thinning and splitting. Usually suc

Renal Retinal Dysplasia with Diffuse Glomerular Cysts

A 32-year-old male with renal retinal dysplasia is presented. He also showed hearing loss and growth retardation. Laboratory data showed mild proteinuria, renal dysfunction and type-1 renal tubular acidosis. Computed tomography showed multiple cysts at the corticomedullary junction of both kidneys. Ocular examinations disclosed retinitis pigmentosa. On light microscopy of renal biopsy specimens, diffuse cystic dilatation of Bowmans space as well as dilated tubules with interstitial fibrosis and cellular infiltration were noted. Electron microscopy revealed a peculiar chromatin condensation of epithelial cell nuclei in Bowmans capsules, glomeruli and tubules. The association of renal retinal dysplasia with diffuse glomerular cysts has not, to our knowledge, been previously reported.

Shunt nephritis: histological dynamics following removal of the shunt. Case report and review of the literature.

Diffuse crescentic glomerulonephritis was observed in a 40-year-old male patient who had a ventriculoatrial shunt implanted after a traffic accident 10 years previously. Immediately after treatment with immunosuppressants and plasma pheresis, signs of meningitis and septicemia developed. The responsible organism isolated was Staphylococcus albus. After the shunt was removed, clinical signs and renal function improved, associated with normalization of hypocomplementemia and disappearance of cryoglobulin and circulating immune complexes. Repeat renal biopsy performed 5 months after the removal of the shunt revealed mild mesangial proliferative and sclerotic glomerulonephritis with fibrous crescents. No apparent deposits observed in the initial biopsy were found on ultrastructural and immunofluorescent examinations. The reported cases with serial renal biopsies before and after the removal of the shunt were reviewed.

Paramesangial Destructive Lesions in Immunoglobulin A Nephritis

Paramesangial lesions leading to segmental extracapillary damage were observed in the glomeruli of immunoglobulin A nephritis. Subepithelial accumulation of proteinaceous materials from the mesangium could result in the degeneration and exfoliation of podocytes, apparently with subsequent formation of segmental extracapillary lesions or adhesion to Bowmans capsule (or both). Paramesangial destructive lesions may be initiated by the overloading of the mesangial pathway in glomerular inflammation.

Modification of crescentic masugi nephritis in the rabbit by bredinin, a new immunosuppressant

SummaryExperiments were undertaken to ascertain whether progression of crescentic Masugi nephritis in rabbits could be prevented by the administration of Bredinin (BR). Crescentic glomerulonephritis can be induced with high reproducibility by intramuscular preimmunization on day 1, followed by intravenous injections on days 3 and 5 of nephrotoxic duck γ-globulin (NTD γ-gl). 30 rabbits were divided into 3 groups including controls (group 1). Two groups of 10 nephritic rabbits were each treated with 10 mg/kg of BR either after or before the development of proteinuria (groups 2 and 3). In group 3, the onset of proteinuria showed a significant delay and duration of survival was significantly prolonged, compared with controls. Serum antibody titers after day 8 and creatinine levels after day 10, as well as the initial amounts of proteinuria, were also significantly lower during treatment in group 3 than in controls. Histologically, the prominent diffuse intra- and extra-capillary proliferation with monocyte accumulations observed in the control group were markedly diminished in group 3. These results suggest that early treatment in crescentic glomerulonephritis with BR will suppress the production of humoral antibody and prevent progression of the glomerular lesions.

GLOMERULAR TISSUE INJURY IN IgA NEPHRITIS

The glomerular lesions In 129 cases of IgA nephritis were analyzed. The development of glomerular injury occurred in two ways, one being a chronic mesangial depositive and sclerosing lesion commonly found in most glomeruli, and the other an acute but local injury initiating from the local peripheral glomerular basement membrane abnormality, i.e., thinning and/or splitting, which was seen at least in one third of all cases. The activation of the local coagulatory process could add segmental glomerular changes including small crescents, adhesion, and local tuft necrosis to the mesangial lesion. ACTA PATHOL. JPN. 33; 367–380, 1983.

CHILDHOOD TYPE POLYMYOSITIS AND RAPIDLY PROGRESSIVE GLOMERULONEPHRITIS

A 21‐year‐old woman developed rapid muscle weakness and quickly deteriorating renal function. Pathological findings revealed prominent vasculitis in the muscle and crescentic glomerulonephritis. Combined steroid and heparin treatments could not prevent the development of the renal lesion, but the muscle involvement had soon improved. Although the pathogenesis remains unclear, immune complexes may be involved in this renal lesion.

Effect of methylprednisolone on progressive Masugi nephritis in the rabbit. I. Suppression of antibody production and crescent formation.

SummaryExperiments were undertaken to clarify whether a large dose of methylprednisolone (MPSL) could have any suppressive effect on progressive Masugi nephritis in the rabbit. Progressive crescentic Masugi nephritis could be induced with high reproducibility by preimmunization with a small amount of nephrotoxic duck γ-globulin incorporated with complete Freund’s adjuvant, followed by an intravenous injection 4 days later. Two groups of rabbits treated with 80 mg/kg of MPSL either before or after the development of proteinuria, showed a significant decrease in both antibody titers and serum creatinine levels during treatment. Histologically, the prominent diffuse intracapillary proliferation and crescent formation observed in controls, were markedly diminished. Accumulations of monocytes in the intra and extracapillary space were also decreased. These results suggest that suppression of antibody production by a large dose of MPSL is one of its most fundamental actions, and can prevent the processes leading to crescentic glomerular lesions.