Study of the changes in glomerular antigenicity in various renal diseases with anti-human renal monoclonal antibodies

We produced 22 different kinds of monoclonal antibody (Mab) by immunizing mice with human GBM antigens. In these Mabs, Mab-G1 to G5 recognized only GBM in the glomerulus, Mab-E1 and E2 recognized only glomerular epithelial cells, and Mab-M1 to M4 recognized mainly mesangium. The reactions of these Mabs with known GBM antigens such as type IV collagen, fibronectin and laminin were negative by immunoblotting. Using Mab-G1, Mab-E1 and Mab-M1, changes in the antigenicity of antigens recognized by Mabs were examined on kidney sections from the patients with various renal diseases by the indirect immunofluorescence test. When Mab-G1 recognizing GBM was used, there was no particular change of antigenicity in minimal change nephrotic syndrome (MCNS) and IgA nephropathy (IgA), whereas in membranous nephropathy (MN) thickened GBM was found to maintain antigenicity and the region of deposits was observed as negative punched-out region. In type I and III of membranoproliferative glomerulonephritis (MPGN), GBM was observed only outside of subendothelial deposits without showing double contour. In type II MPGN, GBM showed a double linear pattern and antigenicity of GBM in regions of dense deposits was not detected. When Mab-E1 recognizing glomerular epithelial cells was used, there was no change of antigenicity in the renal diseases. Further, in crescentic glomerulonephritis, the region of the cellular crescents was not stained. When Mab-M1 recognizing mesangium was used, extensive staining was observed in the increased mesangium in IgA, MPGN, and diabetic nephropathy. We feel that it is of significance in elucidating the pathogenesis of renal diseases to study the changes of glomerular antigenicity in diseased kidneys by using anti-human renal monoclonal antibodies.     

Renal distribution of collagen types III, IV and V in various glomerular diseases

The purpose of this study is to examine the immunochemical changes of the glomerular basement membrane (GBM) and the mesangium, in pretreated paraffin-embedded sections with trypsin by utilizing monoclonal antibodies to type III (anti-III), type IV (anti-IV) and type V (anti-V) collagens. We observed 6 normal kidneys and 44 kidneys with various renal diseases. In normal human kidney the staining with anti-IV demonstrated GBM, mesangium, Bowman's BM, tubular BM and capillary BM. Anti-V was also seen in the interstitium. On the other hand, anti-III stained only interstitium. Thickened GBM in membranoproliferative glomerulonephritis (MPGN) and diabetic nephropathy, and irregular GBM in Membranous Nephropathy and Alport's syndrome were also evident in anti-IV stain, while widened mesangial area was seen in anti-V rather than anti-IV stain. In severely proliferative GN, anti-III as well as anti-IV and anti-V was detected in the mesangium in spite of existence of neither adhesion nor Bowman's gap. In MPGN type II, anti-III was observed along the GBM. In obsolescent glomeruli, anti-IV was not always detected although anti-V was constantly seen. On the other hand, anti-III was markedly positive in the crescents and obsolescent glomeruli. These results suggest that it is possible for mesangial, endothelial and epithelial cell to produce several types of collagens and type III collagen is closely related to the process of the glomerular obsolescence.     

SLE nephritis: an ultrastructural immunogold study to evaluate the relationship between immune complexes and the basement membrane components type IV collagen, fibronectin and heparan sulphate proteoglycans

The nature of immune complexes and their relationship to the normal glomerular basement membrane (GBM) components type IV collagen, fibronectin, and heparan sulphate proteoglycans (HSPG) have been examined in the glomeruli of 7 cases of systemic lupus erythematosus (SLE) glomerulonephritis using an ultrastructural immunogold technique. In paraformaldehyde-fixed, Lowicryl resin-embedded tissue, the electron-dense deposits contained IgG, IgM, IgA, and C3 whether they were subepithelial, intramembranous, subendothelial, or mesangial and there was no particular relationship between the class of immunoglobulin and site of immune complex localization within the glomerulus. The normal GBM components type IV collagen, fibronectin, and HSPG were found within all the glomeruli, but did not have the same distribution. Type IV collagen and fibronectin were found predominantly on the inner aspect of the GBM and diffusely throughout the more central regions of the mesangial matrix. By contrast the HSPG was seen mainly on the outer aspect of the GBM and at the periphery of the mesangial matrix. In none of the cases were GBM antigens localized within the electron-dense deposits, results which suggest that autoantibodies to these GBM components may not play a role in the development of the glomerulonephritis.     

Spectrum of biopsy-proven kidney diseases in northwest China: a review of 30 years of experiences

Purpose

Large-scale, contemporary studies assessing the spectrum of kidney diseases in northwest China are lacking. Therefore, we aimed to assess the profile of 30-year temporal changes in biopsy-proven kidney diseases in northwest China.

Methods

This cross-sectional study included all patients with a native kidney biopsy specimen in the First Affiliated Hospital of Xi'an Jiaotong University between 1989 and 2018. Data on demographic characteristics and pathological diagnosis were extracted from medical records and pathological reports. Changing patterns of kidney diseases over the study period and disease distributions in different gender and age groups were examined.

Results

This study included 13,620 patients with a mean age of 38.5?±?16.5 years and included 58.2% of men. Primary glomerulonephritis (PGN), second glomerulonephritis (SGN), tubulointerstitial disease, and other renal diseases accounted for 79.1, 18.3, 2.4, and 0.2% of all kidney diseases, respectively. In PGN, IgA nephropathy (IgAN) (25.1%) was the most common type, followed by non-IgA mesangial proliferative glomerulonephritis (MsPGN) (24.9%) and membranous nephropathy (MN) (17.4%). The frequency of MN dramatically increased (p?<?0.001) over the course of the study. Lupus nephritis (6.2%) and Henoch-Schönlein purpura nephritis (HSPN) (4.9%) were leading SGN diagnosis. The frequencies of IgAN, non-IgA MsPGN, and HSPN declined, while those of ANCA/pauci-immune glomerulonephritis and diabetic nephropathy significantly increased.

Conclusion

PGN continues to be the predominant kidney disease in northwest China, and IgAN is the most common type. The frequencies of MN and diabetic nephropathy significantly increased. These findings might be explained by behavioral and environmental exposures and provide implications on future hypothesis-driven research.

     

Renal entactin (nidogen): isolation, characterization and tissue distribution.

Entactin/nidogen (E/N) was isolated from bovine renal tubular basement membrane. Apparent molecular weight, amino acid composition, and molecular configuration by electron microscopy rotary shadowing were similar to that of nidogen from EHS mouse tumor. The identity of bovine E/N was confirmed using a thrombin derived peptide, the sequence of which corresponded to a region within mouse and human E/N. Monoclonal and polyclonal anti-E/N antibodies were used to determine the distribution of E/N in human kidney by immunofluorescent and immunoelectron microscopy. E/N was present in all renal basement membranes and was distributed through the full width of the glomerular basement membrane (GBM) with accentuation along its epithelial aspects. E/N distribution was similar to that of novel collagen chain alpha 3(IV) NC domain in the GBM. In the mesangium, E/N was distributed mainly in the peripheral mesangial region that is bounded by the GBM, while classical collagen chain alpha 1(IV) NC as present diffusely throughout the mesangium. In the developing nephron, E/N was present in basement membranes of the ureteric bud, primitive vesicle and S-form. In all instances, E/N co-localized with laminin B2 chain. Prominent E/N detection within the mesangium was observed in diseases where mesangial expansion was present. This process was also seen in early diabetic nephropathy, but disappeared with disease progression. However, all thickened diabetic renal basement membranes showed an increase in E/N which was also present in Kimmelstiel-Wilson lesions. E/N was observed in the GBM "spikes" of membranous glomerulonephritis and in epithelial crescents associated with various disorders. The association between E/N, laminin and type IV collagen chains observed in the normal kidney were maintained in disorders with altered E/N distribution. We could not detect any changes in the distribution of E/N in other acquired and hereditary kidney diseases. These observations reflect the involvement of E/N in the structure and disease alteration of renal basement membranes and mesangial matrix.     

四川地区肾活检2330例临床病理分析

目的：探讨四川地区肾穿刺活检病理类型的分布特点以及疾病谱的变迁。方法回顾性分析2330例肾活检患者的临床病理资料,分析本地区肾脏疾病的临床病理特征。结果2330例肾活检患者中,男女比例为1∶1.15,发病高峰年龄为20~40岁。2330例患者中,原发性肾小球疾病1896例（占81.37%）,常见的病理类型依次为 IgA 肾病820例（占35.19%）、系膜增生性肾小球肾炎372例（占15.97%）、膜性肾病298例（占12.79%）、微小病变肾病200例（占8.58%）和局灶节段性肾小球硬化症78例（占3.35%）;继发性肾小球疾病367例（占15.75%）,以狼疮性肾炎最常见（134例,占5.88%）,其次为紫癜性肾炎127例（占5.45%）、糖尿病肾脏疾病35例（占1.5%）和淀粉样变性肾病20例（占0.86%）;肾小管间质疾病50例（占2.15%）;遗传性肾病17例（占0.73%）。2330例肾脏疾病患者的临床表现依次为肾病综合征1015例（占43.56%）、慢性肾炎综合征681例（占29.22%）、急性肾炎综合征392例（占16.82%）、隐匿性肾小球肾炎121例（占5.29%）、慢性肾衰竭72例（占3.09%）、急性肾衰竭47例（占2.02%）。近年来,膜性肾病构成比呈逐渐增加趋势。结论本地区肾脏疾病多见于青壮年,以原发性肾小球疾病最常见,其中 IgA 肾病和系膜增生性肾小球肾炎是最多见的病理类型,膜性肾病的检出率有增高趋势。继发性肾小球疾病以狼疮肾炎和紫癜性肾炎最常见。     

The spectrum of children's kidney diseases—9925 renal biopsy-proven cases from a single center of China between 2004 and 2017

Objective To analyze the spectrum of children's kidney pathology by renal biopsy. Methods The clinical and pathological data of the cases in Jinling Hospital involving the patients younger than 18 years old who received renal biopsy from April 1st, 2004 to December 31th, 2017 were retrospectively collected, and compared with the renal pathological data of 1611 children aged 0-18 years from June 1982 to March 2004. Results This study included 9925 cases of kidney diseases proven by renal biopsy. The ratio of male to female was 1.79∶1. Primary glomerulonephritis (PGN) accounted for 66.14%, and secondary glomerulonephritis (SGN) accounted for 28.00%. Top five of the PGN were IgA nephropathy (IgAN, 19.11%), mesangial proliferative glomerulonephritis (MsPGN, 16.07%), minimal change disease (MCD, 14.20%), focal segmental glomerulosclerosis (FSGS, 6.19%) and membranous nephropathy (MN, 4.70%) in whole children, IgAN (13.12%), MsPGN (11.20%), MCD(10.63%), FSGS (4.55%) and MN (2.54%) in males, and IgAN (5.99%), MsPGN (4.87%), MCD (3.57%), MN (2.16%) and FSGS (1.63%) in females. Top three of the SGN were Henoch-Schonlein purpura nephritis (HSPN, 17.74%), lupus nephritis (LN, 8.23%) and vasculitis nephropathy (1.82%). The male was in a dominant position in all kinds of pathologic types than female except LN. HSPN was the most frequent type in adolescents between 6-13 years old. LN was the commonest one in 14-18-year-old girls, while IgAN was the the most common in 14-18-year-old boys. Post infective nephritis was the most popular in 12-14-year-old teenagers. It was also found that MN ascended in female. When compared with the data before 2004, HSPN and LN accounted for a greater proportion in SGN, post infective nephritis displayed a smaller proportion. Conclusions PGN is the mainly kind of glomerular disease as before, and immune disorder related to glomerular diseases increase and post infective nephritis decreases in proportion. This study provides the reference and epidemic data for diagnosis, treatment and prevention of children's renal diseases.     

Heparan sulfate proteoglycan in the glomerular basement membrane in type 1 diabetes mellitus.

Heparan sulfate proteoglycans (HSPG) are negatively charged constituents of the renal extracellular matrix including the glomerular basement membrane (GBM) and mesangial matrix. Biochemical and functional studies of patients with type-1 insulin dependent diabetes mellitus (IDDM) suggest that alterations of HSPG may occur in diabetic nephropathy. We have utilized a specific cytochemical method and electron microscopy to quantitate the distribution of HSPG in the GBM of 10 normal people and in 16 IDDM patients with a spectrum of clinical and structural changes. Enzyme incubation studies of normal infant kidney demonstrated that heparitinase removed 94% of the stainable anionic sites in the lamina rara externa (LRE) and 77% of the sites in the lamina rara interna (LRI) of the GBM. In contrast, incubation in the enzyme chondroitinase ABC did not reduce the number of sites in the LRE but reduced the number of sites in the LRI by 26%. The HSPG anionic sites in normal subjects were distributed in the LRE as 20.9 +/- 1.3, and in the LRI as 13.1 +/- 2.2 per micron GBM length. Anionic sites were slightly reduced (19.6 +/- 1.3, P less than 0.04) in the LRE of IDDM patients with normal urinary albumin excretion rates (UAE), or microalbuminuria, and were reduced in both the LRE and LRI of IDDM patients with clinical proteinuria (13.1 +/- 2.3, P less than 0.001 and 8.9 +/- 2.1, P less than 0.001, respectively). The number of anionic sites in the LRE and LRI, respectively, correlated with UAE (r = +0.78, P less than 0.001, r = +0.58, P less than 0.02), with GBM thickness (LRE, r = +0.81, P less than 0.001; LRI, r = +0.67, P less than 0.01) and with the volume fraction of mesangium (LRE, r = +0.59, P less than 0.02; LRI, r = +0.58, P less than 0.03). These data confirm earlier biochemical findings of a reduction of HSPG in the GBM in advanced diabetic nephropathy but do not provide evidence for the loss of HSPG in the GBM as a mechanism for early microalbuminuria.     

Expression of megsin mRNA, a novel mesangium-predominant gene, in the renal tissues of various glomerular diseases

Mesangial cells play an important role in maintaining a structure and function of the glomerulus and in the pathogenesis of glomerular diseases. Recently, we discovered a new mesangium-predominant gene termed "megsin." Megsin is a novel protein that belongs to the serine protease inhibitor (serpin) superfamily. To elucidate the pathophysiologic role of megsin in the kidney, the expression and localization of megsin mRNA in renal tissues of patients with IgA nephropathy (IgA-N), diabetic nephropathy (DN), minimal change nephrotic syndrome (MCNS), membranous nephropathy (MN), and normal human kidney (NHK) was evaluated by in situ hybridization using digoxigenin-labeled oligonucleotide. Individual cells positive for megsin mRNA were observed only in glomeruli in all renal tissues. Their localization coincided with those of mesangial cells. The percentage of positive cells for megsin mRNA in total glomerular cells was significantly greater in IgA-N than in MCNS, MN, and NHK. It was also significantly greater in DN than in MCNS and NHK. In IgA-N, the percentage of megsin mRNA-positive cells was greater in tissues from those with mesangial cell proliferation and slightly mesangial matrix expansion (periodic acid-Schiff-positive area in the total glomerulus area, <30%; cell number in mesangial matrix area, >30; assessed in cross-sections through their vascular poles) than in tissues from those with severe mesangial matrix expansion (periodic acid-Schiff-positive area in total glomerulus area, >30%; cell number in mesangial matrix area, <30). In conclusion, megsin mRNA was predominantly expressed in glomerular mesangial cells in all renal tissues. The expression of megsin mRNA was upregulated in IgA-N and DN, both of which are diseases accompanied with mesangial cell proliferation and/or mesangial matrix expansion. These data suggest a link of megsin expression to the pathogenesis of IgA-N and DN, two major causes of end-stage renal failure.     

Ultrastructural distribution of von Willebrand factor in human glomerular diseases

The distribution of the von Willebrand factor (vWF) as the factor-VIII-related antigen in glomeruli was examined by immunoelectron microscopy in 10 patients with idiopathic membranous nephropathy (MN), 8 patients with minimal-change nephrotic syndrome (MCNS), and 11 patients with IgA nephropathy (IgA-N). Electron-dense reaction products of vWF were observed in the endothelium and mesangium in all specimens examined. However, they were not detected in subepithelial electron-dense deposits of MN. The amount of electron-dense reaction products of vWF in the endothelium was significantly higher in MN than that in MCNS or IgA-N. This finding suggests that the glomerular endothelium in MN is the site of the local activation of coagulation and platelet aggregation system in glomerular capillary wall lesions.     

Assay of GBM antigen in urine and serum with an anti-human renal monoclonal antibody

Using a monoclonal antibody (Mab-G3) recognizing glomerular basement membrane (GBM), we assayed GBM antigen (G3-Ag) in the urine and serum of renal disease patients by sandwich ELISA. The subjects included normal control (NOR), minimal change nephrotic syndrome (MCNS), IgA nephropathy (IgA), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN) and chronic renal failure (CRF). The urine and serum was used as the material. With urinary G3-Ag, there were no statistically significant differences among the NOR, MCNS, IgA, MN, MPGN and CRF groups. Although no correlation was observed with proteinuria, hematuria, serum creatinine, serum beta 2 microglobulin and urinary NAG, urinary G3-Ag showed a significant (p less than 0.05) increase in excretion in the group of progressive CRF patients with s-Cr more than 1.0 mg/dl/month as compared to the stationary CRF group with s-Cr less than 1.0 mg/dl/month. Serum G3-Ag showed lower values in almost all cases, and there were no significant differences among the renal disease groups. The above findings led us to believe that the assay of urinary G3-Ag was useful in determining the degree of GBM disorder. It was also presumed that assay of renal antigens in urine and serum with the respective anti-human renal monoclonal antibodies could be a new tool in diagnosing renal diseases.     

Glomerular expression of connective tissue growth factor mRNA in various renal diseases

SUMMARY:   Connective tissue growth factor (CTGF) is a cysteine-rich member of a new family of growth regulators. It is an important factor in the pathogenesis of mesangial matrix accumulation and progressive glomerulosclerosis. The present study was designed to elucidate the role of CTGF in diabetic nephropathy (DN), immunoglobulin A nephropathy (IgA-N), membranous nephropathy (MN), and minimal change nephrotic syndrome (MCNS). We evaluated the expression and localization of CTGF mRNA in surgically excised renal tissue samples from 10 patients with DN, 10 with IgA-N, 10 with MN, 10 with MCNS, and 10 normal human kidney (NHK) tissue samples, by using high-resolution in situ hybridization with digoxigenin-labelled oligonucleotide. To quantify CTGF mRNA expression, we counted all nuclei, and nuclei surrounded by CTGF-positive cytoplasm, in at least 10 randomly selected cross-sections of non-sclerotic glomeruli, and expressed the results as a percentage of total glomerular cells. In all glomeruli, CTGF mRNA was expressed mainly in glomerular intrinsic cells, including glomerular mesangial and epithelial cells and some cells of Bowman's capsule. The percentage of cells positive for CTGF mRNA was significantly higher in DN and IgA-N than in MN, MCNS and NHK. However, there was no significant difference in the percentage of CTGF mRNA-positive cells between DN and IgA-N. Our study indicates that CTGF may play an important role in the development and progression of glomerulosclerosis in DN and IgA-N, which are both accompanied by mesangial matrix expansion and comprise two major causes of end-stage renal failure.     

Constituents of the extracellular matrices in diabetic glomerulosclerosis

This study was undertaken to elucidate the distributions of laminin, fibronectin, type I, III, IV, V and VI collagen and heparan sulfate proteoglycan (HSPG) in diabetic nephropathy, using immunohistochemical procedures. The pathological features of diabetic glomerulosclerosis were characterized as diffuse and nodular lesions, showing an expanded mesangial matrix associated with a thickened glomerular basement membrane (GBM). In the thickened GBM, laminin was present throughout the whole membrane, type IV collagen occurred along the subendothelial side, and HSPG was present with no change in its amount. On the other hand, the components detected in the slightly expanded mesangial matrix were type IV, V and VI collagen, fibronectin and HSPG, but not laminin. When the matrix was expanded markedly, collagenous components were increased over the other components. In the typical Kimmelstiel-Wilson nodules, the mesangial matrix was occupied mainly by type V and VI collagen with a relative decrease in type IV collagen. When a nodular lesion adhered to Bowman's capsule, type I and III collagen occurred not only in Bowman's space but also within the lesion itself. Furthermore, laminin and HSPG became detectable on the outside of the lesion, but not within it. These results suggested that there was a difference in the distribution and proportion of extracellular matrix components between diffuse and nodular lesions. It appeared that the nodular lesion was not simply an advanced form of the diffuse lesion.     

Alport综合征患者肾组织层粘连蛋白α2链异常分布

目的 观察Alport综合征(AS)患者肾组织层粘连蛋白α2链、α5链和γ1链的分布。方法 采用免疫荧光方法,运用普通荧光和激光共聚焦扫描显微镜观察抗层粘连蛋白α2链、α5链和γ1链单克隆抗体在肾组织中的沉积情况。肾组织标本来自11例AS患者,其中男8例,女3例,年龄11~52岁。10例患者符合X伴性显性遗传(XLAS),1例女性患者符合显性遗传。8例男性XLAS患者肾小球基底膜(GBM)、远端肾小管基底膜均无Ⅳ型胶原α3、5链沉积,表皮基底膜(EBM)无α5(Ⅳ)链沉积;2例女性XLAS患者肾组织α3、5(Ⅳ)链和EBM α5(Ⅳ)链均呈不连续表达,另1例女性患者则同正常肾组织。正常人肾组织标本作为正常对照,9例IgA肾病(IgAN)、6例局灶节段硬化性肾小球病(FSGS)、5例薄基膜病(TBMD)和6例肾小球轻微病变(GML)患者作为疾病对照。结果 正常人肾组织层粘连蛋白α2链主要沉积于肾小球系膜区,层连蛋白α5、γ1链沉积于GBM、所有肾小管基底膜和入球小动脉基底膜。10例XLAS和1例显性遗传AS患者肾组织除了肾小球系膜区外,层粘连蛋白α2链在GBM上亦出现表达。IgAN、TBMD和FSGS患者层粘连蛋白α2链仅在肾小球系膜区沉积。层粘连蛋白α5、γ1链在AS患者和其他肾脏病组织沉积同正常肾组织。结论 层粘连蛋白α2链在AS患者GBM出现异位表达,为继Ⅳ型胶原α链异常之后发现的又一AS基底膜成分的异常,其对于AS可能具有重要的诊断价值。     

A monoclonal antibody (1G10) recognizes a novel human mesangial antigen.

We have identified a unique mesangial matrix protein of the human glomerulus by using a monoclonal antibody, 1G10, generated against culture human glomerular cells. By immunofluorescence, the antigen recognized by 1G10 (1G10 antigen) is present in mesangium and smooth muscle tissue and cannot be detected in any other tissue examined. Immunoelectron microscopy of glomeruli indicated that 1G10 antigen is present exclusively in the mesangial matrix at the endothelial-mesangial interface. The 1G10 antigen is also expressed by cultured mesangial cells, but not by cultured glomerular epithelial cells, umbilical endothelial cells or fibroblasts. 1G10 did not react with the mesangial matrix proteins [fibronectin (FN), laminin (LAM), collagen types I, III, IV, V, and VI (Col I, III, IV, V, VI), heparin sulfate proteoglycan (HSPG), or thrombospondin (TS)] present under normal and diseased states or smooth muscle antigens (myosin, actin), but did react with a 4 M urea extract of renal cortex and a 0.3% deoxycholate extract of isolated glomeruli. Two dimensional immunoblot analysis using the urea extract demonstrated the binding of 1G10 to an approximately 200 KDa polypeptide with pI 6.0. On one dimensional immunoblot this band did not show cross react with polyclonal antisera to FN, LAM, Col IV, V, VI, HSPG or TS. This mesangial matrix component is trypsin and periodate sensitive, suggesting that it has the character of glycoprotein. In renal biopsy specimens from patients with mesangial proliferative glomerulonephritis (GN) and membranoproliferative GN, the expression of the 1G10 antigen increased along with mesangial hypercellularity or increased accumulation of mesangial matrix, but decreased in completely sclerosed glomeruli. No significant changes in 1G10 antigen expression was observed in membranous GN or minimal change nephrosis compared to normal glomeruli. This study suggests that the 1G10 antigen may not only be a useful marker for the clinical assessment of GN, but may also serve as a potential tool for the study of the pathogenesis of glomerular diseases characterized by cellular proliferation and mesangial matrix expansion.     

The role of sulfatides in autoimmunity in children with various glomerular disease]

Previous studies have suggested that autoimmunity to a number of kidney antigens may exist in glomerular disease. Our own work suggested that sulfatide which is one of the major acidic glycolipids of human kidney may be antigenic. Glycolipids were isolated from lipid extract of human kidney using thin-layer chromatography (TLC). As the major acidic glycolipids, sulfatide, CDH-sulfate, GM3, GD3 were identified. Acidic fraction of lipid extract were chromatographed and then tested for antigen by immunostaining. Sera from patients with IgA nephropathy (IgAN) and Henoch-Sch?nlein purpura nephritis (HSPN) contained antibody to the sulfatide of human kidney as determined by the direct binding of antibody to TLC. In addition, we measured the presence of sulfatide antibodies by enzyme linked immunosorbent assay (ELISA) in sera of patients with various glomerular disease: IgAN, HSPN, mesangial proliferative glomerulonephritis, membranoproliferative glomerulonephritis (MPGN), focal and segmental glomeruosclerosis (FSGS), membranous nephropathy (MN), minimal change nephrotic syndrome (MCNS), acute post streptococcal glomerulonephritis (PSAGN), and lupus nephritis (LN). IgM class sulfatide antibody were demonstrated in many cases of them. The incidence of IgA class sulfatide antibody in HSPN and IgAN was significantly high, and also the high incidence of IgG class sulfatide antibody occurred in IgAN. On the other hand, we evaluated cellular hypersensitivity to sulfatide in IgAN, HSPN, and FSGS using an active E-rosette assay. Positive results occurred in IgAN and HSPN. It was suggested that delayed hypersensitivity to sulfatide may generate an autoimmune inflammatory process. It has been reported that laminin binds specifically to sulfatide. Autoimmunity to sulfatide may disturb the laminin binding and consequently interfere with renal function. These results suggested sulfatide antigen may play important role in occurrence and aggravation of glomerular disease.     

Changes in urinary and serum concentrations of macrophage-colony stimulating factor (M-CSF) in patients with renal diseases

Background. The infiltration of monocytes/macrophages into renal tissues is a typical feature of progressive renal diseases. Macrophage-colony stimulating factor (M-CSF) is one of the cytokines that are required for the activation of macrophages. It was previously reported that the glomerular expression of M-CSF was increased in patients with mesangial proliferative glomerulonephritis and that the urinary and serum M-CSF concentrations were increased in IgA nephropathy. In this study, we measured the urinary and serum M-CSF concentrations in patients with renal diseases to elucidate the role of M-CSF and macrophages in the progression of renal diseases. Methods. We examined urinary and serum M-CSF concentrations in patients with IgA nephropathy (IgA-N), lupus nephritis (LN), minimal change nephrotic syndrome (MCNS), and membranous nephropathy (MN), and in normal controls. The M-CSF concentrations were compared with the clinical parameters and the histological changes. These concentrations were also compared with the number of glomerular macrophages in the IgA-N group. In addition, the effects of prednisolone therapy on the M-CSF concentrations were examined in the patients with IgA-N. Results. Urinary and serum M-CSF concentrations were increased in the severe IgA-N group, the severe LN group, and the MCNS group (nephrotic) compared with concentrations in the control group. Urinary and serum M-CSF concentrations were correlated with the degree of proteinuria, mesangial proliferation, and the number of glomerular macrophages in IgA-N and LN. In addition, the urinary and serum M-CSF concentrations were decreased with prednisolone therapy in the patients with IgA-N. Conclusions. Urinary and serum M-CSF concentrations were elevated in patients with severe stage of mesangial proliferative glomerulonephritis and were correlated with the amount of urinary protein excretion, mesangial proliferation, and glomerular macrophage infiltration. Urinary and serum M-CSF concentrations may be useful markers with which to assess the extent of glomerular changes in mesangial proliferative glomerulonephritis. Received: August 20, 2001 / Accepted: January 8, 2002     

Kidney biopsy prior to cyclophosphamide therapy in primary nephrotic syndrome

The study includes 30 children, 10 each with minimal change nephropathy (MCNS), diffuse mesangial proliferative glomerulonephritis (MesPGN) and focal segmental glomerulosclerosis (FSGS). Indications for kidney biopsy were: steroid resistance in 12 cases, and frequent relapses on maintenance steroid therapy in 18 cases. A 2-year remission was achieved by cyclophosphamide therapy in 6 patients with FSGS, 8 patients with MCNS and 8 patients with MesPGN. In terms of initial response to corticosteroids, only 3 of 8 patients with early steroid resistance responded to cyclophosphamide therapy compared with 3 of 4 with late steroid resistance and 16 of 18 with frequent relapses on maintenance steroid therapy. Response to cyclophosphamide therapy correlates better with the initial corticosteroid response than renal histopathology. A kidney biopsy prior to administration of cyclophosphamide is not essential in patients who respond to initial corticosteroid therapy.     

Clinical significance of IgM deposition in the mesangium and mesangial hypercellularity in adult minimal change nephrotic syndrome

Minimal change nephrotic syndrome(MCNS) typically shows no abnormalities in light microscopy. However, there are some minor light microscopic abnormalities that are considered to be MCNS variants. In pediatric nephrology, some researchers have reported that IgM deposition in the mesangium and mesangial hypercellularity are related to the response to steroid therapy and the long-term course. However, it is not clear whether IgM deposition in the mesangium and mesangial hypercellularity is responsible for the clinical course or the steroid response of patients with adult MCNS. To investigate the clinical importance of IgM deposition in the mesangium and mesangial hypercellularity, clinical records, follow up data, and renal samples of 47 patients with MCNS were reviewed. We also compared the histological data with those of a normal control group (n = 5). In our study, the presence of mesangial IgM deposition did not predict the patient's clinical course or responsiveness to steroid therapy. Increase in the number of nuclei in the glomeruli and PAS-positive area also did not correlate with the clinical course or responsiveness to steroid therapy. The data suggest that mesangial IgM deposits and increased mesangial cellularity in adult MCNS may not predict the clinical course or steroid response. However, we investigated only 47 samples in this study, therefore, further studies are necessary to identify the importance of IgM deposition in the mesangium and mesangial hypercellularity in adult MCNS.     

C1q nephropathy and minimal change nephrotic syndrome

C1q nephropathy (C1qN) is an uncommon disorder seen in children and adults with nephrotic syndrome and non-specific urinary findings. It has been described with minimal change nephrotic syndrome (MCNS), focal segmental glomerulonephritis and isolated mesangial proliferative glomerulonephritis. We describe nine children with MCNS and mesangial C1q deposition. These children had a median age of 2.7 years at diagnosis (range 1.3–15 years), 56% were male and 78% were Hispanic. We compared these children to concurrent patients with nephrotic syndrome and biopsy-proven MCNS. We found that the C1qN patients were more likely than MCNS children to require chronic immunosuppression with calcineurin inhibitors or mycophenolate mofetil to maintain remission. However, all children were able to achieve and sustain clinical remission of nephrotic syndrome. Children with C1qN and minimal change histology have an increased frequency of frequently relapsing and steroid-unresponsive disease, but they can attain prolonged remission and stable renal function with calcineurin inhibitor or mycophenolate mofetil therapy.