Biopsy ; methods ; Glomerulonephritis, IGA ; pathology ; Humans ; Kidney ; pathology ; Kidney Diseases ; pathology ; Lupus Nephritis ; pathology

Biopsy, Needle ; methods ; China ; Humans ; Kidney ; pathology ; Kidney Diseases ; pathology ; Kidney Neoplasms ; pathology ; Specimen Handling

Animals ; Biopsy ; Disease Models, Animal ; Fluorescent Antibody Technique ; Glomerulonephritis, Membranoproliferative ; pathology ; Humans ; Kidney ; pathology ; Kidney Diseases ; pathology ; Plastic Embedding

Carcinoma, Renal Cell ; classification ; genetics ; pathology ; Humans ; Kidney Neoplasms ; classification ; genetics ; pathology ; World Health Organization

Humans ; Immunoglobulin Light Chains ; genetics ; immunology ; Immunoglobulin kappa-Chains ; genetics ; immunology ; Kidney ; immunology ; metabolism ; pathology ; Kidney Diseases ; immunology ; pathology ; therapy ; Mutation ; Transforming Growth Factor beta ; metabolism

OBJECTIVETo observe the transdifferentiation of renal tubular epithelial cells in tubulointerstitial fibrosis.

METHODSThe renal tubulointerstitial fibrosis model in Wistar rats was established by unilateral renal vein ligature. The rats were kept 25 days after renal vein ligature. The kidneys were dissected every 5 days by killing 5 rats. The morphological changes of the kidney were observed by light microscopy, electron microscopy, polarizing microscopy and immunohistochemistry method.

RESULTSThe histological changes showed tubular atrophy and disappearance, widening of intertubular spaces with increased lymphocytes and mononuclear cells infiltration and fibrosis. The CK marker in injured and atrophic epithelial cells gradually weakened, but the alpha-SMA, vimentin, TGF-beta(1), collagen I and III showed gradually stronger positivity for immunohistochemistry. Some interstitial cells became positive for CK. Electron microscopy revealed decreased mitochondria, increased endoplasmic reticulum and microfilament of the tubular epithelial cells which merged into the interstitium. During the early stage of tubulointerstitial fibrosis, there was proliferation of type III collagen and then followed by type I collagen at later stage when observing the Sirius Red stained sections under the polarizing microscope.

CONCLUSIONTubular epithelial cells can transdifferentiate to fibroblasts during the process of tubulointerstitial fibrosis.

Actins ; analysis ; Animals ; Cell Differentiation ; Collagen ; analysis ; Epithelial Cells ; cytology ; Fibrosis ; Immunohistochemistry ; Keratins ; analysis ; Kidney Tubules ; chemistry ; pathology ; ultrastructure ; Male ; Rats ; Rats, Wistar

Aristolochic Acids ; adverse effects ; Child ; Drugs, Chinese Herbal ; adverse effects ; Female ; Humans ; Male ; Nephrosis ; chemically induced

Aged ; Diagnosis, Differential ; Fibronectins ; metabolism ; Glomerulonephritis, Membranoproliferative ; pathology ; Humans ; Immunohistochemistry ; Kidney Diseases ; metabolism ; pathology ; Kidney Glomerulus ; metabolism ; pathology ; ultrastructure ; Male ; Microscopy, Electron

Adult ; Biopsy, Needle ; Diagnosis, Differential ; Humans ; Kidney ; pathology ; Kidney Diseases ; pathology ; therapy ; Male ; Nephritis, Interstitial ; pathology ; Renal Dialysis ; Sarcoidosis ; pathology ; therapy ; Tuberculosis, Renal ; pathology

OBJECTIVETo investigate the clinicopathological manifestations of early renal amyloidosis (AL) and its diagnostic criteria.

METHODSFifteen cases with early renal amyloidosis admitted from 1994 to 2001 were collected from the hospital, and their clinical and pathological features were reviewed. Of them, the initial diagnoses were not made by depending findings from the light microscopy (LM) and immunofluorescense (IF), but confirmed by electron microscopy (EM) afterwards. Immuno-electron microscopy (IEM) were applied for amyloidosis typing.

RESULTSMost patients of early renal AL were in the middle to old age. Nephrotic syndrome was the most prominent symptoms and signs accompanying with rare microscopic hematuria and hypertension. Most of them had a normal renal function. Pathological examinations of renal biopsies using LM and IF showed mild mesangial proliferation and mild thickening of glomerular basement membrane (GBM). Immunoglobulins and complements were negative or only scanty in certain cases, but in all cases there was a light chain protein deposition homogeously. There were 4 cases of minimal change glomerulopathy, 5 cases of mild mesangial proliferative glomerulonephritis, 5 cases of stage I membranous nephropathy, and 1 case of cast nephropathy diagnosed with LM. The amyloid fibrils (diameter 8 - 10 nm) were randomly distributed in the mesangium, along GBM and at the arteriolar wall under EM. Additionally, Congo red staining was positive. IEM demonstrated that amyloid fibrils labeled with colloid gold was combined with a kind of light chain protein which was confirmed as the light chain type of AL.

CONCLUSIONSThe diagnosis of early renal AL was occasionally neglected by depending only findings of LM and LF. However, special amyloid fibrils can be detected using EM. EM observation is an indispensable technique for the diagnosis of early renal AL and the typing of AL may further be determined by using IEM.

Adult ; Aged ; Amyloidosis ; metabolism ; pathology ; Basement Membrane ; metabolism ; Female ; Humans ; Immunoglobulin Light Chains ; metabolism ; Kidney Diseases ; metabolism ; pathology ; Kidney Glomerulus ; metabolism ; pathology ; Male ; Microscopy, Immunoelectron ; Middle Aged