Rationale and design of the Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study

INTRODUCTION

Disease subtyping and monitoring are essential for the management of nephrotic syndrome (NS). Although various biomarkers for NS have been reported, their clinical efficacy has not been comprehensively validated in adult Japanese patients.

METHODS

The Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study is a nationwide, multicenter, and prospective cohort study in Japan, enrolling adult (≥18 years) patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN), C3 glomerulopathy (C3G), and lupus nephritis (LN). Baseline clinical information and plasma and urine samples will be collected at the time of immunosuppressive therapy initiation or biopsy. Follow-up data and plasma and urine samples will be collected longitudinally based on the designated protocols. Candidate biomarkers will be measured: CD80, cytotoxic T-lymphocyte antigen 4, and soluble urokinase plasminogen activator receptor for MCD and FSGS; anti-phospholipase A2 receptor and thrombospondin type-1 domain-containing protein 7A antibodies for MN; fragment Ba, C3a, factor I, and properdin for MPGN/C3G; and CD11b, CD16b, and CD163 for LN. Outcomes include complete and partial remission, relapse of proteinuria, a 30% reduction in estimated glomerular filtration rate (eGFR), eGFR decline, and initiation of renal replacement therapy. The diagnostic accuracy and predictive ability for clinical outcomes will be assessed for each biomarker.

RESULTS

From April 2019 to April 2023, 365 patients were enrolled: 145, 21, 138, 10, and 51 cases of MCD, FSGS, MN, MPGN/C3G, and LN, respectively.

CONCLUSION

This study will provide valuable insights into biomarkers for NS and serve as a biorepository for future studies.

C3 Glomerulopathy and Related Disorders in Children: Etiology-Phenotype Correlation and Outcomes

BACKGROUND AND OBJECTIVES

Membranoproliferative GN and C3 glomerulopathy are rare and overlapping disorders associated with dysregulation of the alternative complement pathway. Specific etiologic data for pediatric membranoproliferative GN/C3 glomerulopathy are lacking, and outcome data are based on retrospective studies without etiologic data.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 80 prevalent pediatric patients with membranoproliferative GN/C3 glomerulopathy underwent detailed phenotyping and long-term follow-up within the National Registry of Rare Kidney Diseases (RaDaR). Risk factors for kidney survival were determined using a Cox proportional hazards model. Kidney and transplant graft survival was determined using the Kaplan-Meier method.

RESULTS

Central histology review determined 39 patients with C3 glomerulopathy, 31 with immune-complex membranoproliferative GN, and ten with immune-complex GN. Patients were aged 2-15 (median, 9; interquartile range, 7-11) years. Median complement C3 and C4 levels were 0.31 g/L and 0.14 g/L, respectively; acquired (anticomplement autoantibodies) or genetic alternative pathway abnormalities were detected in 46% and 9% of patients, respectively, across all groups, including those with immune-complex GN. Median follow-up was 5.18 (interquartile range, 2.13-8.08) years. Eleven patients (14%) progressed to kidney failure, with nine transplants performed in eight patients, two of which failed due to recurrent disease. Presence of >50% crescents on the initial biopsy specimen was the sole variable associated with kidney failure in multivariable analysis (hazard ratio, 6.2; 95% confidence interval, 1.05 to 36.6; P<0.05). Three distinct C3 glomerulopathy prognostic groups were identified according to presenting eGFR and >50% crescents on the initial biopsy specimen.

CONCLUSIONS

Crescentic disease was a key risk factor associated with kidney failure in a national cohort of pediatric patients with membranoproliferative GN/C3 glomerulopathy and immune-complex GN. Presenting eGFR and crescentic disease help define prognostic groups in pediatric C3 glomerulopathy. Acquired abnormalities of the alternative pathway were commonly identified but not a risk factor for kidney failure.

Heightened Crescentic Glomerulonephritis in Immune Challenged 129sv Mice Is TGF-β/Smad3 Dependent

The 129sv mouse strain is particularly sensitive to experimental immune-mediated nephritis. Previous studies have indicated that transforming growth factor-β (TGF-β) plays a critical role in both immune modulation and tissue fibrogenesis in various diseases and that its biological activities are exerted via the SMAD family. In this study, we aimed to determine whether TGF-β/SMAD signaling is essential for the development of immune-mediated nephritis in 129sv mice. Relative to C57BL/6J control mice with anti-glomeruli basement membrane (GBM) nephritis, 129sv mice with anti-GBM nephritis exhibited increased renal collagen deposition. Additionally, higher mRNA levels of pro-collagen and collagen IV, higher serum levels of active and total TGF-β1, and increased TGF-β1, TGF-βIIR, and phosphorylated SMAD expression were detected in these mice. Deletion of Smad3 in 129sv mice ameliorated anti-GBM induced nephritis, including crescentic glomerulonephritis. Collectively, these findings indicate that the heightened experimental nephritis and fibrotic disease in the 129sv strain of mice are regulated by SMAD3, which could be a potential therapeutic target for immune-mediated nephritis.

[Hypocomplementemic urticarial vasculitis syndrome: a rare but not always benign condition]

Although more than 45 years have passed since hypocomplementemic urticarial vasculitis (HUVS) was first described by McDuffie and colleagues at the Mayo clinic, data on epidemiology, disease outcomes, prognosis and clinical features are scarce. Recently, we published the first epidemiological study of HUVS including data on incidence, prevalence, disease outcomes, prognosis and clinical features using data from two separate Swedish regions during a period of 16 years. The estimation of incidence and prevalence rates indicates that HUVS is rare but not always benign. Renal and lung manifestations were severe in some cases, highlighting the need for careful screening and monitoring of this potentially serious condition. It is reasonable to suspect HUVS in patients with unexplained systemic inflammation combined with >6 months of urticaria. Special attention should be paid to patients with recent-onset dyspnea and proteinuria.

Plasma exchange and rituximab treatments in primary membranous nephropathy combined with crescentic glomerulonephritis: A case report

RATIONALE

Crescent formation is rare in primary membranous nephropathy (MN). Anti-phospholipase A2 receptor (PLA2R) antibodies are detectable in these patients. The mechanism and treatments are unknown.

PATIENT CONCERNS

A 72-year-old female patient who presented with nephrotic syndrome, hematuria, and rapidly progressive kidney dysfunction.

DIAGNOSES

Kidney biopsy was performed and the diagnosis was MN in combination with crescentic glomerulonephritis. Circulating anti-PLA2R IgG3 and IgG4 were detected of high level.

INTERVENTIONS

The patient received plasma exchange and rituximab besides corticosteroids.

OUTCOMES

The patient achieved complete remission of proteinuria and recovery of kidney function after the clearance of anti-PLA2R antibodies.

LESSON

This case suggests a pathogenic role of anti-PLA2R antibodies in the mechanism of crescent formation in MN, which may need intensive therapy to eliminate the antibodies quickly.

C3 glomerulopathy associated with monoclonal Ig is a distinct subtype

Monoclonal immunoglobulins (MIg) may play a causal role in C3 glomerulopathy (C3G) by impairing regulation of the alternative pathway of complement. Ninety-five patients with C3G were tested for MIg of which 36 were positive. Their mean age at diagnosis was 60 years and among patient 50 years and older, 65.1% had a MIg. At presentation, median serum creatinine and proteinuria were 1.9 mg/dL and 3.0 g/24 hours. Hematuria was present in 32 (88.9%) patients. Twelve (34.3%) patients had low C3 levels. C3 nephritic factor was detected in 45.8% patients; pathogenic variants in complement protein genes were rare. Hematologic evaluation revealed monoclonal gammopathy of renal significance in 26 patients, multiple myeloma in five, smoldering multiple myeloma in two, and chronic lymphocytic leukemia, lymphoma, or type I cryoglobulin each in one patient. After a median follow-up of 43.6 months, the median serum creatinine and proteinuria were 1.4 mg/dL and 0.8g/24 hours. Nine patients developed ESRD. Sixteen patients received MIg-targeted treatment, 17 patients received non-targeted treatment while three patients were managed conservatively. Of the 16 patients receiving MIg-targeted treatment, ten achieved complete/very good/partial hematologic response. Of these, seven achieved a complete/partial/stable renal response. Five patients receiving targeted treatment did not achieve hematologic response, none had a renal response. Patients receiving targeted treatment were more likely to have multiple myeloma/smoldering multiple myeloma. Patients receiving non-targeted treatment were more likely to have monoclonal gammopathy of renal significance. Thus, C3G with MIg is seen in older patients, C3 nephritic factor is the most common autoantibody detected, and MIg-targeted treatment may result in remission and stabilization of kidney function in a subset of these patients.

Successful therapy of C3Nef-positive C3 glomerulopathy with plasma therapy and immunosuppression

BACKGROUND

C3 glomerulopathies (C3G) are characterized by uncontrolled activation of the alternative pathway of complement. In most patients these diseases progress towards end-stage renal disease, and the risk of recurrence after renal transplantation is high. In the majority of patients, only antibodies against the C3 convertase, termed C3Nef, can be found as a potential pathogenic factor. Although a large variety of therapeutic approaches have been used, no generally accepted therapy exists.

METHODS

In four consecutive patients with C3G in whom all known complement factor mutations were excluded and only C3Nef could be identified as a potential cause of disease, a multimodal therapeutic regimen with plasma therapy, corticosteroids and mycophenolate mofetil was used.

RESULTS

The multimodal regimen achieved normalization of renal function in all four patients, with complete remission in two patients and a distinct reduction of proteinuria in the other two patients. The single patient with C3 glomerulonephritis (C3GN) and marked terminal complement complex elevation only showed partial remission; further improvement was achieved following the addition of eculizumab to the therapeutic regimen. Repeatedly measured C3Nef levels did not correlate with disease course or therapeutic response in any of the patients.

CONCLUSIONS

As this multimodal therapeutic approach was effective in all four treated patients with suspected autoimmune etiology of C3G, it offers a treatment option for severely affected patients with this rare disease until more specific regimens are available.

Hematologic characteristics of proliferative glomerulonephritides with nonorganized monoclonal immunoglobulin deposits

OBJECTIVE

To study the hematologic characteristics of proliferative glomerulonephritides (GNs) from nonorganized glomerular monoclonal immunoglobulin (MIg) deposition (MIPG).

PATIENTS AND METHODS

The pathology database at Mayo Clinic (Rochester, Minnesota) was used to find patients with MIPG who underwent a kidney biopsy between January 1, 2008, and December 31, 2013. Retrospective medical record review was conducted in the identified cohort (N=60).

RESULTS

The median patient age was 56 years (interquartile range, 47-62 years) and the estimated glomerular filtration rate was 36 mL/min/1.73 m(2) (interquartile range, 22-52 mL/min/1.73 m(2)). Most patients had IgG MIg deposits (90%; 54 of 60) and a membranoproliferative pattern (48%; 29 of 60). A circulating nephropathic MIg was detected by serum immunofixation (SIFE(+)) in 20% (12 of 59) and by abnormal serum free light chain ratio (sFLCR(+)) in 21% (12 of 56). The subsets of SIFE(+) and sFLCR(+) incompletely overlapped. The nephropathic clone was found by bone marrow testing (BM(+)) in 25% (10 of 40; 6 plasma cell clones [5 IgG; 1 IgA], 3 chronic lymphocytic leukemia [all IgG], and 1 lymphoplasmacytic clone [IgM]). The clone detection rate was significantly higher in patients with SIFE(+) (P<.001) and in those with SIFE(+) and/or sFLCR(+) (P<.001). Patients with SIFE(+) and BM(+) frequently had IgG1-restricted MIg deposits on renal biopsy immunofluorescence (P=.005). Most BM(+) patients required flow cytometry and immunohistochemical analysis of the marrow specimen for accurate diagnosis.

CONCLUSION

Undetectable circulating nephropathic MIg and pathologic clones characterize most MIPG. Immunoglobulin isotype may predict detectability of MIg and clone by currently available technology. Bone marrow evaluation, including flow cytometry and immunohistochemical analysis, should be performed for SIFE(+) and/or sFLCR(+). More sensitive clone-identifying techniques in the marrow and extramedullary tissue are needed when SIFE and sFLCR test negative.

Comparison of laboratory findings in patients with glomerulonephritis classified according to histopathologic diagnosis

AIM

The aim of the present study was to assess whether laboratory investigations have predictional values for histopathological diagnosis of glomerulonephritis before performing renal biopsy.

METHODS

The study enrolled 452 patients, who underwent kidney biopsy and were examined retrospectively; 128 patients with the histopathological diagnosis of glomerulonephritis were included in the study. Serum CRP, albumin, uric acid levels, 24 hour urine protein presence, leucocyte count, C3, C4, IgG, IgA and IgM levels were assessed.

RESULTS

The most common diagnosis of glomerulonephritis was IgAN with the percentage of 29.7% within the groups. Male gender was predominant except lupus group. Only the ones with crescentic glomerulonephritis had higher CRP levels. In 20% of patients with IgAN, in 8.3% of the ones with MN, in 35% of crescentic group, in 42% of FSGS group, in 30% of patients with MPGN and in 33% of the ones with lupus nephritis uric acid levels were found as elevated. In IgAN, FSGS and lupus nephritis normoalbuminemia and nephritic proteinuria, in MN and crescentic glomerulonephritis hypoalbuminemia, nephrotic proteinuria, in MPGN hypoalbuminemia, nephritic proteinuria were established. Serum Ig G levels were lower in MN and MPGN. Serum IgA levels were found as elevated in IgAN. Serum C4 levels were found as lower in lupus nephritis and MPGN.

CONCLUSION

In patients admitted in clinical picture of glomerulopathy, since measurements of serum CRP, albumin, uric acid, C3, C4,IgG, IgA, IgM levels, leucocyte count and 24 hour urine protein amount can lead to predict the histopathological diagnosis, their significance in routine investigations has been suggested also in our study.

Complement factor H-related hybrid protein deregulates complement in dense deposit disease

The renal disorder C3 glomerulopathy with dense deposit disease (C3G-DDD) pattern results from complement dysfunction and primarily affects children and young adults. There is no effective treatment, and patients often progress to end-stage renal failure. A small fraction of C3G-DDD cases linked to factor H or C3 gene mutations as well as autoantibodies have been reported. Here, we examined an index family with 2 patients with C3G-DDD and identified a chromosomal deletion in the complement factor H-related (CFHR) gene cluster. This deletion resulted in expression of a hybrid CFHR2-CFHR5 plasma protein. The recombinant hybrid protein stabilized the C3 convertase and reduced factor H-mediated convertase decay. One patient was refractory to plasma replacement and exchange therapy, as evidenced by the hybrid protein quickly returning to pretreatment plasma levels. Subsequently, complement inhibitors were tested on serum from the patient for their ability to block activity of CFHR2-CFHR5. Soluble CR1 restored defective C3 convertase regulation; however, neither eculizumab nor tagged compstatin had any effect. Our findings provide insight into the importance of CFHR proteins for C3 convertase regulation and identify a genetic variation in the CFHR gene cluster that promotes C3G-DDD. Monitoring copy number and sequence variations in the CFHR gene cluster in C3G-DDD and kidney patients with C3G-DDD variations will help guide treatment strategies.

Causes of alternative pathway dysregulation in dense deposit disease

BACKGROUND AND OBJECTIVES

This study was designed to investigate the causes of alternative pathway dysregulation in a cohort of patients with dense deposit disease (DDD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Thirty-two patients with biopsy-proven DDD underwent screening for C3 nephritic factors (C3Nefs), factor H autoantibodies (FHAAs), factor B autoantibodies (FBAAs), and genetic variants in CFH. C3Nefs were detected by: ELISA, C3 convertase surface assay (C3CSA), C3CSA with properdin (C3CSAP), two-dimensional immunoelectrophoresis (2DIEP), and immunofixation electrophoresis (IFE). FHAAs and FBAAs were detected by ELISA, and CFH variants were identified by Sanger sequencing.

RESULTS

Twenty-five patients (78%) were positive for C3Nefs. Three C3Nef-positive patients were also positive for FBAAs and one of these patients additionally carried two novel missense variants in CFH. Of the seven C3Nef-negative patients, one patient was positive for FHAAs and two patients carried CFH variants that may be causally related to their DDD phenotype. C3CASP was the most sensitive C3Nef-detection assay. C3CASP and IFE are complementary because C3CSAP measures the stabilizing properties of C3Nefs, whereas IFE measures their expected consequence-breakdown of C3b.

CONCLUSIONS

A test panel that includes C3CSAP, IFE, FHAAs, FBAAs, and genetic testing for CFH variants will identify a probable cause for alternative pathway dysregulation in approximately 90% of DDD patients. Dysregulation is most frequently due to C3Nefs, although some patients test positive for FHAAs, FBAAs, and CFH mutations. Defining the pathophysiology of DDD should facilitate the development of mechanism-directed therapies.

[Combined therapy of membranoproliferative glomerulonephritis in older patients]

The aim of the study was to investigate the effectiveness of combined long-term therapy by cytostatics and steroid hormones in older patients with membranoproliferative glomerulonephritis to halt renal failure progression. 27 patients older than 60 years with morphologically proved membranoproliferative glomerulonephritis have been treated. Nephrosclerosis was detected in 40% of studied patients according to results of kidney biopsies. The mean age of the patients was 65.8 +/- 1.5 years. The activity of the disease depended on presence and severity of nephrotic syndrome. 17 (62.9%) patients had coronary heart disease, 7 (25.9%) patients had chronic bronchitis, 7 (25.9%) patients had peptic ulcer disease in a remission phase. Patients received therapy by cyclophosphamide in a dose of 2 mg/kg daily and prednisolone in a dose of 1 mg/kg daily during 2 years. Tolerability of assigned treatment was satisfactory. The main clinical and laboratory signs of nephrotic syndrome were significantly reduced and the proof remission was reached after 8-12 months of combined therapy. During the observation (24 month) the glomerular filtration rate in studied patients didn't decreased over 30-59 mL/min/1.73 m2 and corresponded to stage 3 of chronic kidney disease.

[Influence of immunoglobulins on clinical laboratory picture and morphological changes in patients with mesangial-proliferative glomerulonephritis: age aspects]

The article presents data of 77 mesangial proliferative glomerulonephritis (MezPGN) patients, aged 20 to 71 years. The effect of deposits of immunoglobulins in the kidney tissue to the index of blood pressure and laboratory parameters of disease activity in MezPGN patients regardless of age is shown. The data demonstrate that the presence of IgM deposits in kidney tissue is unfavorable prognostic sign of MezPGN flow.

[Age-related features of the mesangial proliferative glomerulonephritis]

This article presents the data of 118 patients (77 men and 41 women) with mesangial proliferative glomerulonephritis, aged 22-70 years. It is concluded that the rate of progression and severity of chronic glomerulonephritis, even within the same morphological form, is determined by age.

[Alveolar hemorrhage in pulmonary-renal syndrome anti-SCL/70 and anti-MPO-ANCA positive]

We describe a case of pulmonary-renal syndrome on autoimmune basis, with alveolar hemorrhage and worsening renal failure. The patient was positive for anti-MPO and anti-SCL/70. Immunosuppressive therapy was effective to treat the pulmonary condition, but chronic renal failure emerged. The clinical condition did not improve after plasmapheresis, thus chronic dialysis was required.

Factor I is required for the development of membranoproliferative glomerulonephritis in factor H-deficient mice

The inflammatory kidney disease membranoproliferative glomerulonephritis type II (MPGN2) is associated with dysregulation of the alternative pathway of complement activation. MPGN2 is characterized by the presence of complement C3 along the glomerular basement membrane (GBM). Spontaneous activation of C3 through the alternative pathway is regulated by 2 plasma proteins, factor H and factor I. Deficiency of either of these regulators results in uncontrolled C3 activation, although the breakdown of activated C3 is dependent on factor I. Deficiency of factor H, but not factor I, is associated with MPGN2 in humans, pigs, and mice. To explain this discordance, mice with single or combined deficiencies of these factors were studied. MPGN2 did not develop in mice with combined factor H and I deficiency or in mice deficient in factor I alone. However, administration of a source of factor I to mice with combined factor H and factor I deficiency triggered both activated C3 fragments in plasma and GBM C3 deposition. Mouse renal transplant studies demonstrated that C3 deposited along the GBM was derived from plasma. Together, these findings provide what we believe to be the first evidence that factor I-mediated generation of activated C3 fragments in the circulation is a critical determinant for the development of MPGN2 associated with factor H deficiency.

Tubulointerstitial nephritis associated with IgG4-related systemic disease

We report three patients with tubulointerstitial nephritis (TIN) with high serum IgG4 concentrations. None of the patients had notable pancreatic lesions when the TIN developed, although one had a history of autoimmune pancreatitis (AIP). Nevertheless, the clinicopathological findings were quite similar to those of AIP. They were all middle-aged to elderly men. Sialadenitis and lymphadenopathy were often evident. Serum total IgG and IgG4 concentrations were elevated and hypocomplementemia was observed. Although antinuclear antibodies were positive, anti-Ro and anti-La antibodies were negative. Renal biopsy showed dense lymphoplasmacytic infiltration with fibrosis in the renal interstitium, and the infiltrated plasma cells had strong immunoreactivity for IgG4. Furthermore, lymphoplasmacytic infiltration and abundant IgG4-positive plasma cells were observed in the salivary glands of a patient. Steroid therapy was effective for TIN in all three patients. The present findings support the recently proposed concept of IgG4-related systemic disease, and suggest that IgG4 is associated not only with AIP but also with other systemic lymphoplasmacytic diseases, including TIN. The conditions responsible for the pathogenesis of TIN need to be considered, irrespective of the presence of AIP.

Roles of coagulation pathway and factor Xa in rat mesangioproliferative glomerulonephritis

Tissue factor initiates the extrinsic coagulation pathway by activating coagulation factor X to factor Xa, and factor V is a cofactor for the prothrombin activation by factor Xa. As factor Xa is known to promote the proliferation of mesangial cells in culture, the roles of the coagulation pathway and factor Xa were studied in an animal model of mesangioproliferative glomerulonephritis (MsPGN). MsPGN was induced in Wistar rats by an intravenous injection of anti-Thy 1.1 monoclonal antibody, OX-7. To clarify the role of factor Xa in MsPGN, a specific factor Xa inhibitor, DX-9065a, was injected intravenously at 2.5 or 10 mg/kg at the same time as OX-7, and kidney involvement was assessed by immunohistological analyses. We also examined p44/42 mitogen-activated protein (MAP) kinase activation. Time-course study revealed that expressions of tissue factor, factor V, and protease-activated receptor 2 (PAR2) were peaked on day 3, followed by factor X accumulation and mesangial proliferation. DX-9065a treatment significantly ameliorated proteinuria in a dose-dependent manner on day 8. Histological analyses showed a significant reduction in the size of glomeruli, the total number of glomerular cells, and crescent formation by DX-9065a treatment. Macrophage infiltration, which was rapidly observed on day 1 in disease control rats was not inhibited on days 1-3 by DX-9065a treatment, however it was suppressed on days 5-8. The deposition of fibrin, the number of PCNA-positive cells, and phosphorylation of p44/42 MAP kinase were markedly increased in the disease control group, whereas they were significantly reduced in the treatment group. Tissue factor and factor V induction may accelerate MsPGN through the activation and accumulation of factor X via proinflammatory and procoagulant mechanisms, and the inhibition of factor Xa would be a promising method to regulate the disease process.

Fatty acid composition of plasma and kidney in rats with anti-Thy1.1 nephritis

BACKGROUND

n-3 Polyunsaturated fatty acids (PUFA) are reported to ameliorate atherosclerotic and inflammatory diseases because they compete with arachidonic acid and reduce its inflammatory metabolites. In the present study, the fatty acid composition of plasma and kidney in rats with anti-Thy1.1 nephritis was investigated.

MATERIALS AND METHODS

A group of male Wister rats weighing about 200 g was injected with anti-Thy1.1 antibody (1.25 mL/kg) through their tail veins (nephritis group). Rats in the control group were injected with saline. Five days after the injection, urinary protein levels were determined. All rats were then sacrificed and fatty acid composition of plasma and kidney were analyzed.

RESULTS

Eicosapentaenoic acids (EPA) levels in the kidney phospholipid (PL) fraction in the nephritis group were significantly lower than those in the control group (0.67 +/- 0.06 mol% vs. 0.96 +/- 0.06 mol%, p < 0.05). EPA levels in the plasma PL fraction in the nephritis group were also significantly lower than those in the control group (0.38 +/- 0.05 mol% vs. 0.59 +/- 0.03 mol%, p < 0.05). Urinary protein levels 5 days after the injection were inversely correlated with EPA levels in the kidney PL fraction (r2 = 0.65, p = 0.01). These results suggested that decreased EPA levels in the kidney PL fraction might play an important role in anti-Thy1.1 nephritis.

Terminal complement complexes in childhood type I membranoproliferative glomerulonephritis

BACKGROUND

The role of terminal complement complexes (TCCs), which are the final products of complement activation, in the pathogenesis of human glomerulonephritis has not been completely elucidated. To clarify the clinical significance of TCCs in type I membranoproliferative glomerulonephritis (MPGN), we studied TCCs in plasma, renal tissue and urine in pediatric patients with this disease.

PATIENTS AND METHODS

We measured the concentrations of TCC in plasma (n=25) and urine (n=13) using enzyme-linked immunosorbent assay. Frozen tissue from 18 renal biopsies were evaluated for the presence of TCC by direct immu-noperoxidase staining.

RESULTS

At the early stage of the disease, TCC concentrations in plasma were elevated to above 0.5 arbitrary units (AU)/mL in 14 of 25 patients (high-TCC group), while the remaining 11 patients showed less than 0.5 AU/mL (low-TCC group). In the high-TCC group, TCCs were deposited more diffusely and intensely in the glomerulus, compared with those in the low-TCC group (p=0.034). Furthermore, urinary TCC concentrations in the high-TCC group were higher than those in the low-TCC group (p=0.0001). The high-TCC group showed not only a poorer response to steroid treatment, but also poorer prognosis than the low-TCC group.

CONCLUSIONS

These results suggest that, in pediatric patients with type I MPGN, TCCs in circulation may play a particular role in TCC formation in the glomerulus and in urine. The TCC concentration in plasma could be used as a marker of responsiveness to steroid treatment and long-term prognosis.

A case of Takayasu arteritis complicated with glomerulonephropathy mimicking membranoproliferative glomerulonephritis: a case report and review of the literature

In this report, we describe the case of a 50-year-old Japanese woman with Takayasu arteritis who developed severe proteinuria and renal dysfunction. Abdominal computed tomography did not show narrowing of both renal arteries. Although her levels of C-reactive protein were negative, plasma vascular endothelial growth factor (VEGF) and serum interleukin (IL)-6 levels were elevated. Renal biopsy showed glomerulonephropathy mimicking membranoproliferative glomerulonephritis (MPGN) with glomerular capillary wall thickening (double contour). This was accompanied by mesangial cell proliferation and moderate increase of mesangial matrix without deposits of C3. These findings are quite different from MPGN as electron microscopy did not show subendothelial deposit and circumferential mesangial interposition. Here, we present the case of Takayasu arteritis associated with MPGN-like renal manifestation and elevated VEGF and IL-6. The presence of elevated VEGF and IL-6 could be factors that might contribute to MPGN-like appearance.

Urinary glycosaminoglycan composition in chronic glomerulonephritis

BACKGROUND

Glycosaminoglycans (GAG) play an important role in regulating glomerular permeability, and a reduction in their plasmatic concentration or urinary loss has been implicated in the pathogenesis of diseases associated with increased albumin permeability. The purpose of this study was to evaluate GAG excretion in renal pathology by analyzing the composition of urinary GAG in antibody mediated glomerular injury, such as mesangial glomerulonephritis (IgAGN) and primitive membranous glomerulonephritis (MGN), to verify the effects of glomerular capillary wall lesion with and without mesangial cell injury.

METHODS

Urinary GAG excretion was analyzed in 20 patients with IgAGN, 18 patients with MGN, and in 18 healthy subjects (controls). GAG were isolated from 24-hr urine using ion-exchange chromatography on DEAE-Sephacel, and the results are expressed as mg hexuronate/g creatinine (Cr). GAG composition was determined by cellulose acetate electrophoresis and expressed as relative percentages by densitometric scanning of Alcian Blue stained strips.

RESULTS

We found total GAG levels significantly higher in the urine of patients with MGN in comparison with controls and patients with IgAGN. The electrophoretic pattern analysis demonstrated low sulfated chondroitin sulfate proteoglycan (LSC-PG) in all patients compared to 44% in controls (8/18), but also low sulfated chondroitin sulfate (LSC) in 18.4% of patients (7/38) and slow migrating LSC (SM-LSC) in 8% of patients (3/38), only in the MGN group. Moreover, in patients with MGN, the LSC-PG relative content was significantly higher when compared to that observed in controls. Finally, in IgAGN and MGN patients, a significant reduction in chondroitin sulfate (CS) relative content was observed.

CONCLUSIONS

It seems likely that an increase in total GAG levels takes place when a reduction in renal function occurs, but the alteration of CS and herapan sulfate (HS) relative contents, and the presence of LSC-PG and free LSC also in the urine of IgAGN patients, allows us to suggest that the GAG distribution pattern becomes abnormal before an increase in total urine GAG excretion. In addition, the quali-quantitative determination of urinary GAG and GAGprotein complex could constitute an additional non-invasive marker to appraise the metabolism of renal connective tissue in some renal diseases.

Membranoproliferative glomerulonephritis type II in a 10-year-old girl

The clinical course of a 10-year-old female patient who presented with hematuria, proteinuria, and hypertension is described. Four months after being diagnosed with acute glomerulonephritis, the child was referred to a pediatric nephrologist due to persistent hematuria and unresolved proteinuria. A renal biopsy was performed due to the persistent urinary abnormalities and a family history of renal failure. The renal biopsy demonstrated pathological findings characteristic of membranoproliferative glomerulonephritis type II. The child was treated with an antihypertensive agent and steroids. Despite poor prognostic clinical and pathological features, she has minimal urinary abnormalities, normal renal function, and normal blood pressure on antihypertensive medication six years after the diagnosis of membranoproliferative glomerulonephritis type II.

Etiology of Increased Enzymuria in Different Morphological Forms of Glomerulonephritis

BACKGROUND

High urinary excretion of lysosomal enzymes is thought to reflect tubulointerstitial damage and is observed both in the acute and chronic phases of various morphological forms of glomerulonephritis (GN). It is related to the degree of proteinuria and secondary interstitial inflammatory process. N-acetyl-beta-D-glucosaminidase (NAG) and beta-glucuronidase (beta-GR) are the most commonly used markers of tubulointerstitial injury. NAG and beta-GR are also contained in azurophilic granulations of polymorphonuclear leukocytes (PMNs) and may be released during the activation of PMNs.

AIMS

The aim of this study was to elucidate the role of PMN degranulation in causing the increase of urinary excretion of lysosomal enzymes that is observed in glomerulonephritis.

MATERIAL AND METHODS

We analyzed the urinary excretion of NAG, its B isoenzyme NAG-B, beta-GR and leukocyte elastase (EL), in 91 patients with morphologically different primary and secondary glomerulopathies, and in 12 healthy controls.

RESULTS

Excretion of NAG, NAG-B and beta-GR were statistically significantly higher in all GN patients in comparison to healthy controls. In the whole analyzed GN population significant correlations between amount of proteinuria and excretion of NAG, NAG-B and beta-GR were ascertained. In subgroup analysis NAG excretion was significantly correlated with proteinuria in patients with diffuse proliferative GN (PGN), mesangiocapillary GN (MCGN), and minimal change disease (MCD). There was a significant correlation between NAG-B and proteinuria in MCD and PGN patients. There was a significant relationship of beta-GR and EL with proteinuria and EL with NAG in the PGN group. Significant relationships between serum creatinine and excretion of EL but not NAG, NAG-B, or beta-GR were observed in the whole examined group.

CONCLUSIONS

Increased urinary excretion of elastase, with concomitant high proteinuria and NAG excretion in patients with proliferative GN may indicate that leukocyte degranulation is an additional source of enzymuria in the primary i.e. glomerular inflammatory process. Significant relationship between EL excretion and serum creatinine may indicate that EL released from PMN may also participate in the secondary i.e. interstitial injury that is decisive in the progression of GN.

Shunt nephritis with positive titers for ANCA specific for proteinase 3

The authors report a case of shunt nephritis with antineutrophil cytoplasmic autoantibody (ANCA) and review 2 similar cases. A 55-year-old man was admitted to our hospital for continuous fever and foot edema in 2002. A ventriculoperitoneal shunt was implanted because of a brain abscess and subsequent hydrocephalus in 1987; it was changed to a ventriculoatrial (VA) shunt in 1995. Urinary analysis showed proteinuria (5.4 g/d) and microscopic hematuria. Laboratory data showed renal dysfunction and hypocomplementemia. ANCA specific for proteinase 3 (PR3-ANCA) was positive in his serum, and blood culture grew Propionibacterium acnes. Renal biopsy results showed membranoproliferative glomerulonephritis type I. Therefore, the VA shunt was replaced, and antibiotics were administered. Oral prednisolone was initiated at a dose of 50 mg/d. Proteinuria and the serum levels of creatinine were improved concomitant with normalization of the serum complement levels and the decrease in serum PR3-ANCA titer. Similarly, another 2 cases reported in the literature of PR3-ANCA-positive shunt nephritis caused by P acnes and Gemella morbillorum showed good outcomes after removal of the shunt and administration of antibiotics with or without steroid therapy.

Membranoproliferative glomerulonephritis associated with hereditary deficiency of the 4th component of complement

A 10-year-old female patient was found positive for urine protein and occult blood on Japanese school urinary screening. Examination of the blood was normal except low values of the complement system with CH50 13.5 U/ml, C3 45 mg/dl and C4 3 mg/dl. Renal biopsy demonstrated a focal membranoproliferative glomerulonephritis (MPGN). As for the activity of each component of the complement in the early stage of the disease, the C4 activity was markedly declined and the activity of classical pathway component was also decreased, but the activity of alternative pathway component was normal. On the HLA examination, the patient demonstrated a C4 double null haplotype (C4A2, Q0, BQ0 phenotype). A null C4 gene at both the C4A and C4B loci was found in her mother, aunt and grandfather on the mother's side and C4B null allele in her father and her grandmother on the mother's side. The development of the disease is found in 1 case and not in the other, although both have the genetic defect and the mechanism by which the complement is activated remains unknown. Thus, there appear to be many subjects to be studied as to the relationship between the defect of C4 gene and immune competence.

[Membranoproliferative glomerulonephritis associated with autoimmune thyroiditis]

Several cases of glomerular disease have been associated to thyroid diseases. The most frequent lesion described is membranous glomerulopathy, presented as a nephrotic syndrome. Here we report a 67-year-old man who developed a nephrotic syndrome accompanied by rapid derangement of renal function shortly after the onset of a primary hypothyroidism due to autoimmune thyroiditis. High titers of circulating anti-thyroglobulin and anti-microsomal thyroid antigen antibodies were detected. Serum levels of C3 and C4 fractions of complement were markedly decreased. Renal biopsy showed a membranoproliferative glomerulonephritis with severe mesangial proliferation, a type of glomerular involvement non-described previously in the literature, in relation with thyroid diseases. Four boluses of intravenous steroids were administered, followed by oral prednisone for three months. A dramatic recovery of renal function, together with normalization of urinary sediment, proteinuria decrease and normalization of serum complement were observed. Three years later, the patient suffered from a similar event, with a positive response to steroids again. One year later, the patient had a new recurrence and was treated with mycophenolate mofetil , improving his clinical situation.

Focal segmental membranoproliferative glomerulonephritis in children

Eight patients with focal segmental membranoproliferative glomerulonephritis (FSMPGN) were followed for 5-16 years. Their urinary abnormalities were detected by school urinary screening in seven, and one patient presented with nephrotic syndrome. All but one patient were treated with alternate-day (ALD) prednisolone. With time, urinalysis became normal in six and two continued to have proteinuria with or without hematuria. Serum albumin, cholesterol, and creatinine levels were normal at the last follow-up. Serum C3 returned to normal levels in six, but remained persistently decreased in two. Mesangial proliferation and matrix changes in glomeruli without MPGN lesions were mild. Subendothelial and mesangial electron-dense deposits and deposits containing C3 along capillary walls and mesangium were observed. MPGN lesions and mesangial proliferation improved. No severe growth retardation was observed, but the duration and dosage of ALD prednisolone could be reduced further, since the patients with FSMPGN seemed to have an excellent prognosis.

[Effect of ligustrazine on proliferative glomerulonephritis]

OBJECTIVE

To investigate the therapeutic effect of ligustrazine on proliferative nephritis.

METHODS

45 patients with mesangial cell proliferation were randomly divided into two groups according to age, clinical manifestations and the pathological lesions. Steroid, cyclophosphamide, losartan and dipyridamole were given to 20 patients in the control group. Ligustrazine with the dosage of 80 mg twice a day was given to 25 patients in the treatment group by intravenous perfusion besides the medicine used in the control group. The course of ligustrazine treatment lasted three weeks.

RESULT

The proteinuria and hematuria were decreased significantly with the increases of urine volume, serum albumin and creatinine clearance after ligustrazine treatment. The improvement of serum albumin, proteinuria and hematuria in the treated group were significant compared with control group after treatment.

CONCLUSION

Ligustrazine is eutherapeutic in treating proliferative glomerulonephritis, with the less risk of hemorrhage, ligustrazine can be used for long-term treatment without special monitored.

Effective chemical preservation of morphology of urinary erythrocytes

Between 2 and 4 h after miction the morphology of urinary erythrocytes has changed, clouding the distinction between glomerular and non-glomerular bleeding in pediatric patients. Glomerular bleeding is characterized by microscopically visible alteration in urinary erythrocytes due to glomerular disease. Fixation by Cellfix, a formaldehyde-based fixative, allows the preservation of the morphology for at least 24 h and can be recommended for clinical practice. In our experience, thiomersal was not effective for preservation of the morphology of erythrocytes.

Renal involvement in monoclonal (type I) cryoglobulinemia: two cases associated with IgG3 kappa cryoglobulin

Renal involvement has been described rarely in monoclonal (type I) cryoglobulinemia, although this complication is frequent among patients with mixed (type II or III) cryoglobulin. We report two patients with glomerulonephritis and monoclonal IgGkappa cryoglobulin. Both patients presented with nephrotic syndrome, microscopic hematuria, and impaired renal function. Hepatitis C serology was negative, bone marrow aspiration was normal, and the renal biopsy specimen showed membranoproliferative glomerulonephritis with glomerular subendothelial deposits of monoclonal IgGkappa. In both cases, circulating cryoglobulin and monotypic tissue deposits were found to be IgG3kappa, suggesting that this isotype may have a particular propensity to cause this type of membranoproliferative glomerulonephritis. Although 18 cases of type I cryoglobulinemia with biopsy-proven glomerulonephritis have been reported to date, this is the first characterization of immunoglobulin heavy-chain isotype in this disease.

[Clinical observation on effect of shenle capsule in treating mesangial proliferating glomerulonephritis]

OBJECTIVE

To study the therapeutic effect of Shenle capsule (SLC) in treating mesangial proliferating glomerulonephritis (MsPGN) and to explore its therapeutic mechanism and clinical indication.

METHODS

Adopting case control method, taking angiotensin-converting enzyme inhibitor (benazepril) as control agent, the 142 cases of MsPGN were randomly divided into 3 groups, treated with SLC (Group A, n = 36), SLC plus benazepril (Group B, n = 68) and benazepril alone (Group C, n = 38) respectively. Changes of fibrinogen, lipids, renal function and urinary protein were observed.

RESULTS

The total effective rate in Group A was higher than that in Group C, but with insignificant difference. The total effective rate in Group B after 3 courses of treatment was 89.74%, which was higher than that in Group C and Group A (P < 0.05). Levels of cholesterol (CH), triglyceride (TG), serum creatinine, fibrinogen and urinary protein (UP) were significantly lowered in Group A after treatment, with the levels of CH, TG and UP lower than those in Group C, while CH, TG and fibrinogen were unchanged in Group C after treatment.

CONCLUSION

SLC is superior in higher efficacy and less side-effects in treating MsPGN, its effect is related with the degree of kidney pathological changes, it is more effective in treating patients with mild pathological change than in those with severe change. The outcome of combined use of SLC and angiotensin-converting enzyme inhibitor would be better.

Renal involvement in juvenile rheumatoid arthritis: report of two cases

Renal involvement is a rare occurrence in juvenile rheumatoid arthritis (JRA). We report on two JRA patients with kidney disease. The first was a 14-year-old African-American female with a 12-month history of polyarthritis. On presentation she was found to have an ESR of 127 mm/h and a positive ANA, rheumatoid factor (RF), perinuclear antineutrophil cytoplasmic antibodies (pANCA), haematuria, proteinuria with normal BUN and creatinine. Renal biopsy showed focal segmental glomerulosclerosis. Her renal function deteriorated to end-stage renal failure requiring dialysis within a few months, despite aggressive treatment with steorids and monthly i.v. pulses of cyclophosphamide. The second patient presented with a 6-week history of polyarthritis and intermittent fever, and had a salmon-coloured evanescent rash. On presentation his laboratory evaluation was significant for elevated ESR and negative ANA, RF and ANCA tests. Within 8 months the patient had developed a persistent microscopic haematuria. Renal biopsy showed mild mesangial glomerulonephritis. On low-dose methotrexate therapy his JRA went into remission and his renal function remained normal. The haematuria persisted for 1 year and then resolved spontaneously. This is the first time that focal segmental glomerulosclerosis and mesangial glomerulonephritis have been described in JRA. Although the association may be just coincidental, further studies are needed to define the role of JRA in these renal conditions. In patients with JRA, urinalysis and renal function should be routinely monitored.

Complement analysis in children with idiopathic membranoproliferative glomerulonephritis: a long-term follow-up

Fifty children with idiopathic membranoproliferative glomerulonephritis (MPGN), aged 2-14 years at apparent onset, were monitored for the presence of C3 nephritic factor (C3 NeF) and signs of complement activation in serum. In addition, C3 allotyping was performed in 32 patients. Observation time ranged from 2 to 20 (median 11) years. C3 NeF activity was detected at least once in 60% of the patients (in 11 of 26 with type I, in 15 of 17 with type II, and in four of seven with type III). C3 NeF-positive patients had significantly reduced levels of CH50 and C3 and elevated levels of C3dg/C3d. During follow-up, C3 levels were persistently normal in 62% of the patients with MPGN type I and in 43% with type III but in only 18% with type II. C3 allotype frequencies differed from those found in healthy controls with a significant shift to the C3F/C3FS variants in C3 NeF-positive patients. C3b(Bb)P as a marker for alternative pathway activation was not increased in C3 NeF-positive patients. Despite the presence of C3 NeF activity, C3 levels remained normal in six patients throughout the observation period. C3 NeF became undetectable in six patients, whereas seven developed C3 NeF activity during follow-up. There was no significant difference in renal survival probability in patients with or without C3 NeF activity. Neither C3 variants nor continuous low C3 or low CH50 levels had any prognostic value for the clinical outcome. No factor H deficiency was detected.

Predictive power of the second renal biopsy in lupus nephritis: significance of macrophages

BACKGROUND

A new Biopsy Index containing the Glomerular Activity (GAI), Tubulointerstitial Activity (TIAI), Chronic Lesion (CLI), and Immunofluorescence (IFI) indices was developed, showing better correlations with clinical and outcome parameters than the National Institutes of Health Activity and Chronicity Indices (AI and CI) in lupus nephritis. This report examines the ability of these indices and individual morphologic variables to predict doubling of serum creatinine (SCr; CRX2).

METHODS

Renal biopsies from 71 patients with lupus nephritis with an initial biopsy (Bx1) and systematic control biopsy (Bx2) after six months of therapy were studied. Kaplan-Meier survival curves were developed for each index and morphologic variable at each biopsy. A subset of 30 biopsies was stained with the macrophage marker PGM1.

RESULTS

At Bx1, only the TIAI and the quantity of C3 and vascular staining on IF were predictive of CRX2. At Bx2, particularly predictive of CRX2 were the GAI, IFI, Biopsy Index, and BxInfl, a composite variable comprised of all of the inflammatory variables. Among individual variables, glomerular and tubular macrophages correlated the best with clinical and outcome parameters. Crescents and karyorrhexis/fibrinoid necrosis also correlated with outcome. Neither the NIH CI or our CLI, nor the TIAI correlated with outcome. In 30 biopsies stained with PGM1, PGM1+ cells correlated well with glomerular and tubular macrophages identified on routine stains and showed even better correlations with SCr, proteinuria, and progression to renal insufficiency than the latter. A diffuse membranoproliferative (MPGN) pattern was seen in seven patients at Bx1. In four of the seven patients, MPGN disappeared with therapy, and all finished with normal renal function. However, among the three patients in whom MPGN persisted and eight patients in whom MPGN, focal or diffuse, appeared under therapy, six reached end-stage renal disease, and a seventh died with marked renal insufficiency.

CONCLUSIONS

The biopsy index and its components correlate modestly with CRX2 at Bx1, but strongly at Bx2, particularly IFI, BxInfl, and glomerular and tubular macrophages. Stains for macrophage markers form a valuable adjunct in interpretation of renal biopsies in systemic lupus erythematosus (SLE). MPGN features do not have an ominous significance at Bx1, but their persistence or appearance under therapy are associated with poor outcome.

Castleman's disease and mesangial proliferative glomerulonephritis: the role of interleukin-6

Renal complications of Castleman's disease (angiofollicular lymph node hyperplasia) are uncommon. The reported cases are very heterogeneous and their renal pathology ranged from minimal change disease, mesangial proliferative glomerulonephritis, to amyloidosis. We have previously reported two cases of Castleman's disease with renal complications. We now present two more such cases. In contrast to other reports, all our cases are of the plasma cell type and their renal pathology showed remarkable similarities, namely mesangial proliferation, interstitial plasma cell infiltration and negative immunofluorescence. The level of serum interleukin-6 (IL-6) in both patients was elevated at presentation and came down with immunosuppressive therapy.

Serum levels of soluble Fas and disease activity in patients with IgA nephropathy

Using a sandwich ELISA, we studied 48 patients with IgA nephropathy and 10 patients with diffuse mesangial proliferative glomerulonephritis without IgA deposition (non-IgA PGN) to determine if levels of serum soluble Fas (s-Fas) might reflect the disease activity. The levels of serum s-Fas in patients with the advanced stage of IgA nephropathy were significantly higher than those in patients with the mild stage of the disease, in non-IgA PGN or in healthy controls. The results showed that advanced stage IgA nephropathy patients who showed heavy proteinuria and the presence of urinary casts revealed high levels of serum s-Fas. It was thus suggested that the measurement of serum s-Fas is useful in evaluating the degree of renal injury in patients with IgA nephropathy.

Enhanced tumor necrosis factor in the serum and renal hypoperfusion in nephrosis associated with focal segmental glomerulosclerosis

Enhanced tumor necrosis factor alpha associated with immunocirculatory imbalance expressed as increased ratio between proinflammatory (TNFalpha) and antiinflammatory (IL-10) cytokines was observed in the serum of nephrosis associated with focal segmental glomerulosclerosis. Such altered immunocirculatory balance correlated with the reduction in renal plasma flow determined by the intrarenal hemodynamic study by which it implies that a glomerular endothelial cell injury associated with impaired renal perfusion is likely to be spontaneously induced by enhanced tumor necrosis factor in the presence of inadequate release of antiinflammatory cytokine (IL-10).