OBJECTIVETo study the clinicopathologic features of membranous nephropathy coexisting with IgA nephropathy.

METHODSThe renal biopsies performed in Peking University First Hospital during the period from January, 1998 to April, 2006 were retrospectively reviewed. The clinicopathologic features of 11 cases of membranous nephropathy coexisting with IgA nephropathy were studied. Electron microscopy with immunogold labeling for IgG and IgA were also performed.

RESULTSThe mean age of patients was 39.9 years. The male-to-female ratio was 1:2.9. The patients mainly presented with proteinuria. Proteinuria of nephrotic level was seen in 7 cases (63.6%). Seven cases also had associated microscopic hematuria. None of them showed evidence of renal insufficiency. Cases with secondary diseases, such as hepatitis virus infection and systemic lupus erythematosus, were excluded from the study. Histologically, vacuolation and thickening of glomerular basement membrane was seen. There was also mild mesangial hypercellularity and increase in mesangial matrix. Occasional glomeruli with crescent formation were identified in 2 cases. Immunofluorescence study showed granular staining for IgG and C3 along glomerular capillary walls, in addition to clumps of IgA deposits in mesangium. Electron microscopy revealed subepithelial and mesangial electron-dense deposits. Immunogold labeling showed IgG and IgA localized in the subepithelial and mesangial deposits respectively.

CONCLUSIONMembranous nephropathy coexisting with IgA nephropathy possesses the clinicopathologic features of both components. It might be caused by independent occurrence of the two entities.

Adult ; Female ; Glomerular Basement Membrane ; immunology ; pathology ; ultrastructure ; Glomerular Mesangium ; immunology ; pathology ; ultrastructure ; Glomerulonephritis, IGA ; complications ; immunology ; pathology ; Glomerulonephritis, Membranous ; complications ; immunology ; pathology ; Humans ; Immunoglobulin A ; metabolism ; Immunoglobulin G ; metabolism ; Kidney Glomerulus ; immunology ; pathology ; ultrastructure ; Male ; Middle Aged ; Retrospective Studies

Mesangial IgA nephropathy was experimentally induced in ddY mice by oral and parenteral administration of the poliomyelitis vaccine (POLIO), and we then tried to investigate if IgA deposition could be prevented by the concurrent use of sodium cromoglycate (SCG), which is known to inhibit the local mucosal immune reaction. Mucosal and systemic immunity could be induced by the administration of POLIO; proteinuria, increased serum IgA levels, mesangial cell proliferation, mesangial matrix widening, mesangial deposits of IgA, and large electron dense deposits in the mesangium were observed. Concurrent administration of SCG and POLIO resulted in a significant decrease in the serum IgA level and mesangial IgA deposits. The later addition or abstinence of SCG after the 70th day did not influence the glomerular mesangial IgA deposition. But the serum IgA level was still decreased by the continuous treatment of SCG even after the 70th day. Thus, mesangial IgA nephropathy simulating IgA nephropathy in humans could be induced in ddY mice using POLIO and its induction could largely be prevented by the concurrent use of SCG. However mesangial IgA deposits already present could not be cleared by the late administration of SCG.
Animal ; Cromolyn Sodium/*pharmacology ; Female ; Fluorescent Antibody Technique ; Glomerulonephritis, IGA/*immunology/metabolism/pathology ; Immunoglobulin A/metabolism ; Mice ; Microscopy, Electron ; Poliovirus Vaccine, Inactivated/*immunology

OBJECTIVETo study the expression of neonatal Fc receptor in podocytes in human nephritis and immune-induced rat nephritis models: anti-Thy1.1 nephritis and Heymann nephritis.

METHODSThirty-nine cases of renal biopsies were enrolled from September 2009 to February 2010, including 8 cases of minimal change disease, 4 cases of focal segmental glomerulosclerosis, 9 cases of membranous nephropathy, 12 cases of IgA nephropathy and 6 cases of lupus nephritis. Five normal kidney tissue samples adjacent to renal clear-cell carcinoma were served as normal controls. Laser capture microdissection and real-time RT-PCR were used to assess the expression level of FcRn mRNA in glomeruli of various glomerulonephritides, and immunohistochemistry (IHC) of FcRn by SuperVision method was performed. In addition, rat models of mesangial proliferative nephritis (anti-Thy1.1 nephritis) and passive membranous nephropathy (Heymann nephritis) were established and FcRn was examined in renal tissues by IHC.

RESULTSThe FcRn mRNA level in lupus nephritis was statistically higher than that of normal controls (P < 0.05). FcRn protein expression by IHC was seen in lupus nephritis (6/6), membranous nephropathy (6/9) and IgA nephropathy (7/12), significantly higher than that of normal controls (0/5), P < 0.05. Minimal change disease and focal segmental glomerular sclerosis showed minimal or none expression of FcRn (1/8, 0/4 respectively) and not statistically difference from that of normal controls. Furthermore, FcRn expression in podocytes was detected in rat anti-Thy1.1 (3/5) and Heymann nephritis models (2/7) but was not detected in normal controls.

CONCLUSIONSExpression of FcRn in podocytes was up-regulated in immune-induced human nephritis and rat nephritis models of anti-Thy1.1 nephritis and Heymann nephritis. FcRn may play a role in the development of immune-induced glomerulonephritis.

Animals ; Glomerulonephritis, IGA ; metabolism ; pathology ; Glomerulonephritis, Membranous ; metabolism ; pathology ; Glomerulosclerosis, Focal Segmental ; metabolism ; pathology ; Histocompatibility Antigens Class I ; genetics ; metabolism ; Humans ; Laser Capture Microdissection ; Lupus Nephritis ; metabolism ; pathology ; Male ; Nephritis ; genetics ; immunology ; metabolism ; pathology ; Nephrosis, Lipoid ; metabolism ; pathology ; Podocytes ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Receptors, Fc ; genetics ; metabolism ; Thy-1 Antigens ; immunology ; metabolism ; Up-Regulation

OBJECTIVETo study the expression and significance of nestin (a type of cytoskeletal protein) in normal and diseased human kidneys.

METHODSDiseased kidney tissues were obtained from needle biopsies in 32 patients with glomerulonephritis (including 8 cases of membranous glomerulopathy, 3 cases of focal segmental glomerulosclerosis, 17 cases of IgA nephropathy with proteinuria and 4 cases of IgA nephropathy without proteinuria). Control kidney tissues were obtained from nephrectomy specimens for renal tumors. The expression of nestin in the control kidney tissues was studied using immunoelectronic microscopy and immunohistochemistry. The expression of nestin in the diseased kidney tissues was detected by immunohistochemistry and real-time reverse transcription-polymerase chain reaction.

RESULTSIn normal kidney tissues, nestin was detected at the periphery of glomerular capillary loops. Semi-quantitative morphometric analysis showed that the glomerular nestin expression level in cases of IgA nephropathy without proteinuria did not differ from that in the normal controls. However, the glomerular nestin expression levels in cases of IgA nephropathy with proteinuria, membranous glomerulopathy and focal segmental glomerulosclerosis were significantly lower than those in the normal kidneys and IgA nephropathy without proteinuria. The glomerular nestin expression levels inversely correlated with the 24-hour urine protein results.

CONCLUSIONNestin may play an important role in maintaining the normal function of podocytes in human kidney.

Adult ; Gene Expression Regulation ; Glomerulonephritis, IGA ; immunology ; Humans ; Immunohistochemistry ; Intermediate Filament Proteins ; genetics ; metabolism ; Kidney ; Kidney Diseases ; metabolism ; pathology ; Kidney Glomerulus ; metabolism ; pathology ; Middle Aged ; Nephrectomy ; adverse effects ; Nerve Tissue Proteins ; genetics ; metabolism ; Nestin ; Proteinuria ; metabolism