Preference for anti-phospholipase A2 receptor antibody assay in patients with suspected membranous nephropathy: a survey study on medical practice after publication of Japanese Guidelines for Nephrotic Syndrome 2020

BACKGROUND

International practice guidelines advocate for the use of anti-phospholipase A2 receptor (PLA2R) antibody testing to diagnose primary membranous nephropathy (pMN). This study aimed to clarify the current status of anti-PLA2R antibody testing in the diagnosis of pMN in Japan and to scrutinize the factors associated with the implementation of this antibody test.

METHODS

Utilizing a web-based questionnaire for nephrologists, responses were collected from 306 facilities and 427 nephrologists between November 2021 and December 2021. Preference for anti-PLA2R antibody testing was also investigated. Factors related to the experience of quantifying anti-PLA2R antibodies were estimated by generalized estimating equations using a robust analysis of variance with clusters of facilities of affiliation.

RESULTS

Of the 427 respondents, 140 (32.8%) had previous measurement experience at their current workplace and 165 (38.6%) had previous measurement experience overall. In pMN-suspected cases without contraindications to renal biopsy, 147 (34.4%) of the respondents opted to request anti-PLA2R antibody testing. The respondents' experience with anti-PLA2R antibody quantification at their current place of work was generally higher in university hospitals and increased with the annual number of kidney biopsies and the number of years since graduation.

CONCLUSION

The results of this study suggest that a significant proportion of nephrologists in Japan have no experience in performing anti-PLA2R antibody assays, and that the assays may be hampered by the limited capabilities of the current workplace and the financial burden on facilities and patients.

Nation-wide cohort study of remission induction therapy using rituximab in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis: Effectiveness and safety in the first 6 months

OBJECTIVES

The aim of this article is to evaluate the effectiveness and safety of rituximab (RTX) for microscopic polyangiitis and granulomatosis with polyangiitis in Japan.

METHODS

In this prospective observational study, all patients with microscopic polyangiitis and granulomatosis with polyangiitis administered RTX were enrolled at each institution. During the observation period of 2 years, data up to 6 months were analysed. Cox proportional hazards analysis was used to assess the factors associated with an outcome.

RESULTS

Of the 75 patients who received RTX for remission induction therapy, 53 achieved remission by the sixth month and 50 were in remission at the sixth month. During therapy, 38 serious adverse events were observed in 24 patients, 21 serious infections in 16 patients, and 9 patients died. No factors were associated with remission; however, there was a significant difference between patients with and without remission in serious adverse events (22.6% vs. 54.5%), serious infections (11.3% vs. 45.4%), and death (1.9% vs. 36.4%). The hazard ratio (95% confidence interval) for serious infection was 3.49 (1.29-9.74) for patients aged ≥ 75 years and 3.53 (1.31-9.53) for pulmonary complications. Four patients maintained remission for 6 months.

CONCLUSIONS

The effectiveness and safety of RTX for microscopic polyangiitis and granulomatosis with polyangiitis for up to 6 months was demonstrated.

Chemoprophylaxis against Pneumocystis jirovecii pneumonia in Japanese patients with ANCA-associated vasculitis: An observational study

OBJECTIVES

This study investigated the current practice of prophylactic treatment against Pneumocystis jirovecii pneumonia (PCP) and its effectiveness in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

This study included 319 patients registered from 53 institutions in Japan and newly diagnosed with AAV. During the 2-year observation period, we examined the frequency of usage, effectiveness and safety of prophylactic drugs against PCP.

RESULTS

Most patients received prophylactic drugs against PCP with the initiation of immunosuppressive agents, and >50% of them remained on chemoprophylaxis against PCP at 2 years after. The initial daily dose of oral prednisolone and the proportion of cyclophosphamide administration were higher in patients who received chemoprophylaxis against PCP than in those who did not. PCP occurred in nine patients (3%) and resulted in the death of four. The incidence rate of PCP in patients who received chemoprophylaxis was 1.13/100 patient-years (95% confidence interval, 0.38-2.68) and that in those who did not was 2.74 (1.04-6.02). The incidence rate ratio was 0.41 (0.11-1.53).

CONCLUSIONS

The markedly low incidence of PCP may be attributed to the continuous chemoprophylaxis against PCP received by >50% of Japanese patients with AAV, although the effectiveness of chemoprophylaxis against PCP was not statistically confirmed.

Japanese clinical practice patterns of primary nephrotic syndrome 2021: a web-based questionnaire survey of certified nephrologists

BACKGROUND

With the publication of the "Evidence-Based Clinical Practice Guideline for Nephrotic Syndrome 2020," we examined nephrologists' adherence to the recommendations of four of its clinical questions (CQs).

METHODS

This was a cross-sectional web-based survey conducted between November and December 2021. The target population comprised nephrologists certified by the Japanese Society of Nephrology who were recruited using convenience sampling. The participants answered six items regarding the four CQs about adult patients with nephrotic syndrome and their characteristics.

RESULTS

In total, 434 respondents worked in at least 306 facilities, of whom 386 (88.9%) provided outpatient care for primary nephrotic syndrome. Of these patients, 179 (41.2%) answered that they would not measure anti- phospholipase A2 receptor antibody levels in cases of suspected primary membranous nephropathy (MN) in which kidney biopsy was not possible (CQ1). Regarding immunosuppressants as maintenance therapy after relapse of minimal change nephrotic syndrome (CQ2), cyclosporine was the most common choice (290 [72.5%] and 300 [75.0%] of 400 respondents after the first and second relapses, respectively). The most common treatment for steroid-resistant cases of primary focal segmental glomerulosclerosis (CQ3) was cyclosporine (323 of 387, 83.5%). For the initial treatment of primary MN with nephrotic-range proteinuria (CQ4), corticosteroid monotherapy was the most common choice (240 of 403, 59.6%), followed by corticosteroid and cyclosporine (114, 28.3%).

CONCLUSION

Gaps in recommendations and practices regarding serodiagnosis and treatment of MN (i.e., CQ1 and 4) are observed, suggesting the need to address the barriers to their insurance reimbursement and the lack of evidence behind them.

Association of Familial Fanconi Syndrome with a Novel GATM Variant

Fanconi syndrome is a disorder of the proximal renal tubule. Recently, advanced genetic analysis technology has revealed that several genes cause familial Fanconi syndrome. We identified a family with autosomal dominant Fanconi syndrome and chronic kidney disease with a novel glycine amidinotransferase (GATM) variant. Case 1 was a 57-year-old Japanese woman. Her father and two siblings had Fanconi syndrome or chronic kidney disease. She presented to our hospital at the age of 34 years with recurrent glucosuria. Her height and weight were 151 cm and 46.6 kg, respectively. Laboratory tests showed glucosuria, hypophosphatemia, hypouricemia, and normal renal function. Her serum creatinine level gradually increased over the following next two decades, and she developed end-stage renal disease. Case 2, the daughter of Case 1, was a 26-year-old woman. Her height and weight were 151 cm and 37.5 kg, respectively. Glucosuria was detected at the age of 13 years, which led to a referral to our hospital. Urinalysis showed low-molecular-weight proteinuria. She was diagnosed with Fanconi syndrome. At the age of 26 years, she had glucosuria, low-molecular-weight proteinuria, hypouricemia, and normal renal function. Genetic testing of both cases revealed a novel missense variant in GATM. The heterozygous missense variants in GATM have been reported to cause familial Fanconi syndrome, which manifests early in life and progresses to renal glomerular failure by mid-adulthood. The novel GATM variant detected in our cases was suspected to be associated with the development of Fanconi syndrome. GATM variants should be tested in patients with idiopathic Fanconi syndrome.

Temporary central venous catheter at hemodialysis initiation and reasons for use: a cross-sectional study

Background

Creating permanent vascular access (VA) is recommended before hemodialysis initiation in patients with end-stage renal disease (ESRD). Although many patients are still introduced to hemodialysis with temporary central venous catheters (CVCs), the reasons for their use remain unclear. We aimed to clarify the characteristics of Japanese patients introduced to hemodialysis using temporary CVCs, the reasons for their use, and whether this rate can be reduced in the future.

Methods

We conducted this cross-sectional study in an acute care general hospital in Japan. We enrolled 393 patients aged ≥ 18 years who received a permanent VA creation for initiating hemodialysis. We classified participants into the temporary CVC group or the permanent VA group according to the VA type at hemodialysis initiation and compared their backgrounds. We identified why permanent VA could not be used at hemodialysis initiation for patients in the temporary CVC group.

Results

Of the 393 patients, 137 (35%) initiated hemodialysis with a temporary CVC, and arteriovenous fistulas (AVFs) were created as the first VA in all patients during hospitalization following hemodialysis initiation. The remaining 256 patients (65%) initiated hemodialysis via AVF cannulation. The duration of predialysis nephrology care was significantly shorter in the temporary CVC group than that in the permanent VA group. The median time from AVF creation to the first successful cannulation was also shorter in the temporary CVC group (8 vs. 66 days, P < 0.001), but the estimated glomerular filtration rate values at hemodialysis initiation did not differ. Reasons for temporary CVC use were varied and complex. Problems on the part of healthcare providers, patient behavioral issues, and characteristics of causative kidney disease itself were underlying reasons. Delayed referral to a nephrologist was less frequent than expected (16%) and the most commonly reported reason (20%) was that a nephrologist was unable to predict the timing of hemodialysis initiation.

Conclusions

Patients with ESRD should be referred to a nephrologist earlier for AVF creation. However, given the already relatively high rate of hemodialysis initiation with permanent VA in Japan, we considered it surprisingly difficult to further reduce the temporary CVC usage rate in Japan.

Demographic, clinical characteristics and treatment outcomes of immune-complex membranoproliferative glomerulonephritis and C3 glomerulonephritis in Japan: A retrospective analysis of data from the Japan Renal Biopsy Registry

The reclassification of membranoproliferative glomerulonephritis (MPGN) into immune-complex MPGN (IC-MPGN) and C3 glomerulopathy (C3G) based on immunofluorescence findings in kidney biopsies has provided insights into these two distinct diseases. C3G is further classified into dense deposit disease and C3 glomerulonephritis (C3GN) based on electron micrographic findings. Although these diseases have poor outcomes, limited Japanese literature confined to small, single-center cohorts exist on these diseases. We retrospectively analyzed 81 patients with MPGN type I and III from 15 hospitals in the Japan Renal Biopsy Registry to compare demographic, clinical characteristics and treatment outcomes of patients with IC-MPGN to those with C3GN. Of the 81 patients reviewed by immunofluorescence findings in kidney biopsies, 67 patients had IC-MPGN and 14 patients had C3GN. Age at diagnosis and systolic and diastolic pressure were higher and proteinuria and impaired renal function were significantly more prevalent in patients with IC-MPGN than those with C3GN. About 80% of the patients in both groups were treated with immunosuppressive therapy. At last follow-up (median 4.8 years), complete remission rate of proteinuria was significantly higher in patients with C3GN (64.3%) than in those with IC-MPGN (29.9%; P = 0.015). The renal survival rate was lower in patients with IC-MPGN when compared to C3GN (73.1% vs. 100%; log-rank, P = 0.031). Systolic blood pressure and renal function at baseline were independent predictors of progression to end-stage kidney disease. The overall prognosis of patients with C3GN is more favorable than for patients with IC-MPGN.

First case report of monoclonal IgG3-heavy-chain glomerulonephritis with microtubular structures

Our patient was a 69-year-old woman admitted to our hospital for heavy proteinuria and hematuria. A renal biopsy showed findings similar to those of membranoproliferative glomerulonephritis associated with nodular lesions, and immunofluorescence showed marked deposits of IgG, C1q, and C3 on the peripheral capillary walls. IgG3 alone was observed on IgG subclass staining with no κ or λ light chains, and Congo red staining was negative. These findings suggested IgG3-heavy-chain deposition disease (HCDD). However, we did not find a deletion of the first heavy-chain constant domain, which is commonly observed in HCDD. Electron microscopy showed randomly arranged subendothelial microtubular structures with diameters of 70-90 nm. Altogether, the diagnosis of HCDD could not be made, although monoclonal IgG3 deposits in glomeruli were observed. This is the first case report of monoclonal IgG3-heavy-chain glomerulonephritis with subendothelial-based, randomly arranged microtubular structures with diameters of 70-90 nm.

Methylglyoxal as a prognostic factor in patients with chronic kidney disease

AIM

Advanced glycation end products and their precursors cause vascular damage through oxidative stress. We investigated the hypothesis that methylglyoxal (MG), 3-deoxyglucosone (3-DG) and pentosidine influence outcomes of chronic kidney disease (CKD) patients.

METHODS

We conducted a 3 years prospective observational study involving 150 outpatients at CKD stages 3-5. At enrolment, MG, 3-DG and pentosidine plasma concentrations were measured; patients were divided into tertiles according to the concentration of each substance. The primary endpoint was death, a cardiovascular event or end-stage renal disease. Survival analysis was performed using the Cox regression model.

RESULTS

The patients' mean age was 62 ± 12 years, 97 were men, and 20 had diabetic nephropathy. The mean estimated glomerular filtration rate was 25.0 ± 12.1 mL/min per 1.73 m² , which negatively correlated with MG but not with 3-DG and pentosidine. Forty-eight patients reached the primary endpoint. Compared with the lowest MG tertile, the hazard ratio for the primary endpoint was 7.57 (95% confidence interval (CI): 1.71-33.54) in the middle tertile and 27.00 (CI: 6.46-112.82) in the highest tertile. When adjusted for characteristics at baseline, the corresponding hazard ratio decreased to 2.09 (CI: 0.37-11.96) and 6.13 (CI: 0.97-38.82), but MG tertile remained an independent risk factor for the primary endpoint. However, 3-DG and pentosidine were not related to the primary outcome.

CONCLUSION

Methylglyoxal has a close clinical association with CKD. Higher MG concentrations may contribute renal function deterioration in CKD. In CKD patients, MG concentration might be useful when determining the prognosis.

Liddle's-like syndrome associated with nephrotic syndrome secondary to membranous nephropathy: the first case report

Background

Liddle’s syndrome is a rare monogenic form of hypertension caused by truncating or missense mutations in the C termini of the epithelial sodium channel (ENaC) β or γ subunits. Patients with this syndrome present with early onset of hypertension, hypokalemia, metabolic alkalosis, hyporeninemia and hypoaldosteronism, and a potassium-sparing diuretics (triamterene or amiloride) can drastically improves the disease condition. Although elderly patients having these characteristics were considered to have Liddle’s syndrome or Liddle’s-like syndrome, no previous report has indicated that Liddle’s-like syndrome could be caused by nephrotic syndrome of primary glomerular disease, which is characterized by urinary excretion of > 3 g of protein/day plus edema and hypoalbuminemia, or has explained how the activity function of ENaC could be affected in the setting of high proteinuria.

Case presentation

A 65-year-old Japanese man presented with nephrotic syndrome. He had no remarkable family history, but had a medical history of hypertension and hyperlipidemia. On admission, hypertension, spironolactone-resistant hypokalemia (2.43 mEq/l), hyporeninemic hypoaldosteronism, and metabolic alkalosis, which suggested Liddle’s syndrome, were observed. Treatment with triamterene together with a steroid for nephrotic syndrome resulted in rapid and remarkable effective on improvements of hypertension, hypokalemia, and edema of the lower extremities. Renal biopsy revealed membranous nephropathy (MN) as the cause of nephrotic syndrome, and advanced gastric cancer was identified on screening examination for cancers that could be associated with the development of MN. After total gastrectomy, triamterene was not required and proteinuria decreased. A mutation in the β or γ subunits of the ENaC gene was not identified.

Conclusion

We reported for the first time a case of Liddle’s-like syndrome associated with nephrotic syndrome secondary to MN. Aberrant activation of ENaC was suggested transient during the period of high proteinuria, and the activation was reversible with a decrease in proteinuria.

Potential Benefit Associated With Delaying Initiation of Hemodialysis in a Japanese Cohort

Introduction

Late referral to a nephrologist, the type of vascular access, nutritional status, and the estimated glomerular filtration rate (eGFR) at the start of hemodialysis (HD) have been reported as independent risk factors of survival for patients who begin HD. The aim of this study was to clarify the influence of the HD-free interval from the time of an eGFR of 10 ml/min per 1.73 m² (I_GFR10-HD) on patient outcome.

Methods

We enrolled 124 patients aged older than 20 years who had HD initiated in a general hospital. The predictive factor was the HD-free I_GFR10-HD. The primary outcome was the relationship of the HD-free interval on death or the onset of a cardiovascular event. Survival analysis was performed using the Cox regression model.

Results

The median I_GFR10-HD was 159 days (range: 2–1687 days). The median eGFR at the initiation of HD was 5.48 ml/min per 1.73 m². Sixty-seven of 124 patients (54.0%) reached the primary outcome. Of these, 29 died and 38 experienced a cardiovascular event. In univariate analysis, older age, a history of cardiovascular disease, nephrologic care for <6 months, higher modified Charlson comorbidity index score, poor performance status, temporary catheter, edema, diabetic retinopathy, and nonuse of erythropoiesis-stimulating agent were statistically related to the primary outcome. The unadjusted hazard ratio per log-transformed I_GFR10-HD was 0.393 (95% confidence interval [CI]; 0.244−0.635; P < 0.001) and the hazard ratio adjusted for confounding factors was 0.507 (95% CI: 0.267−0.956; P = 0.036).

Discussion

A longer HD-free I_GFR10-HD was associated with a lower risk of death or a cardiovascular event. The interval could be considered an independent prognostic factor for outcomes in patients on HD.

Immunoglobulin A nephropathy with massive paramesangial deposits caused by anti-vascular endothelial growth factor therapy for metastatic rectal cancer: a case report and review of the literature

Background

Bevacizumab, a recombinant humanized monoclonal antibody for vascular endothelial growth factor, has been widely used in various cancers offering substantial clinical benefit. It is reportedly associated with development of high-grade proteinuria and nephrotic syndrome with the histology of thrombotic microangiopathy, but there has been no report describing the development of immunoglobulin A nephropathy in bevacizumab-treated patients.

Case presentation

A 68-year-old man with metastatic rectal cancer was treated with bevacizumab. He presented with hematuria and proteinuria 15 and 17 months, respectively, after bevacizumab initiation. Bevacizumab was stopped at 17 months. Renal biopsy at 19 months revealed immunoglobulin A nephropathy, with numerous paramesangial hemispherical deposits and thrombotic microangiopathy. Electron microscopy showed numerous paramesangial electron-dense deposits of various sizes, and subendothelial injuries. Proteinuria almost completely resolved 8 months after bevacizumab cessation, although hematuria persisted. Follow-up renal biopsy 11 months after bevacizumab cessation showed a marked decrease in mesangial immunoglobulin A deposits and paramesangial electron-dense deposits, which correlated with a gradual decrease in serum immunoglobulin A.

Conclusion

This is the first case report that confirmed histologically the development and resolution of immunoglobulin A nephropathy during and after bevacizumab therapy. This case shows that there may be other mechanisms of glomerular injury by bevacizumab besides glomerular endothelial injury leading to thrombotic microangiopathy.

Long-term outcome and efficacy of cyclophosphamide therapy in Japanese patients with ANCA-associated microscopic polyangiitis: a retrospective study

OBJECTIVE

The aim of this study was to elucidate the efficacy of cyclophosphamide (CY) in Japanese patients with antineutrophil cystoplasmic antibody (ANCA)-associated microscopic polyangiitis (MPA).

METHODS

Sixty-four patients, newly diagnosed with ANCA-associated MPA were included in this retrospective study. The patients were divided into two groups based on whether they received combination therapy of CY and corticosteroid (CS) (CY group, n=29) or CS alone (CS group, n=35) for remission induction. The primary outcome was all-cause mortality.

RESULTS

Most patients in the CY group were treated with oral CY. Between the two groups, there were no differences in the baseline characteristics except for a higher proportion of male patients in the CY group. The remission rate was not substantially different between the two groups (86.2% in the CY group vs. 91.4% in the CS group). The survival rate was slightly higher in the CY group than in the CS group (not statistically significant; 0.86 vs. 0.77 at 1 year and 0.73 vs. 0.64 at 5 years, p=0.648). In the CY group, the hazard ratio after adjusting for age, sex, Birmingham vasculitis activity score values, serum albumin levels and C-reactive protein (CRP) levels was 0.657 (95% CI, 0.254-1.699; p=0.386).

CONCLUSION

We observed no increased efficacy of CY in ANCA-positive MPA in the Japanese patients, and hence, its efficacy may be limited in these patients.

Systemic and rapidly progressive light-chain deposition disease initially presenting as tubulointerstitial nephritis

A 42-year-old woman was admitted to a hospital after first-time detection of proteinuria and hematuria during a routine medical check-up. Because her serum creatinine level had rapidly increased from 0.9 to 3.2 mg/dl since measurement 3 months earlier, she was referred to our hospital. Renal biopsy revealed extensive tubular atrophy and interstitial fibrosis with mild leukocyte infiltration. Glomeruli showed minimal changes, and no immunoglobulin or complement deposition was observed by immunofluorescence. Oral prednisolone was commenced under the diagnosis of chronic tubulointerstitial nephritis, and she discharged once. However, its effects were transient; her renal function deteriorated rapidly and hemodialysis was initiated 5 months after her initial check-up. On readmission, urinary Bence-Jones protein κ-type was detected, and examination of bone marrow led to a diagnosis of Bence-Jones κ-type multiple myeloma. Light-chain staining using a renal biopsy specimen obtained 2 months earlier showed κ-light-chain deposition on tubular basement membranes but not glomeruli. Despite undergoing chemotherapy with vincristine, doxirubicin, and dexamethasone, the patient died suddenly from a cardiac arrhythmia. Autopsy showed κ-light-chain deposition in the heart, thyroid, liver, lungs, spleen, and ovaries. Congo red staining yielded negative results. Typical light-chain deposition disease (LCDD) characterized by nodular glomerulosclerosis was observed in the kidneys. This case demonstrates that tubulointerstitial nephritis can be an early pathological variant of LCDD, which may be followed by accelerated and massive light-chain deposition in glomeruli.

Possible IgG4-related kidney disease requiring a differential diagnosis of membranous lupus nephritis

A 25-year-old woman presented with fever, arthralgia and proteinuria exhibiting leukopenia, hypocomplementemia, increased serum IgG and IgG4, and positive antinuclear and anti-double-stranded DNA antibodies. Renal biopsy revealed membranous nephropathy with tubulointerstitial nephritis. IgG subclass immunofluorescence revealed intense IgG4 expression in glomeruli, but no expression of IgG2. Observations resembled membranous lupus nephritis with tubulointerstitial nephritis; however, elevated IgG4, low titers of antinuclear and anti-double-stranded DNA antibodies, IgG4-bearing cell infiltration, and characteristic IgG subclass deposition in glomeruli prompted diagnosis of IgG4-related tubulointerstitial nephritis with membranous nephropathy. It is challenging but important to distinguish lupus nephritis from IgG4-related kidney disease.

Management of asymptomatic hyperuricaemia in patients with chronic kidney disease by Japanese nephrologists: a questionnaire survey

AIM

Hyperuricaemia is associated with chronic kidney disease (CKD) progression and cardiovascular events (CVE). In a US study, only 4% of rheumatologists initiated urate-lowering therapy in patients with asymptomatic hyperuricaemia (AHU). The present study aimed to clarify how Japanese board-certified nephrologists manage AHU in CKD patients.

METHODS

Questionnaires on management of AHU in CKD stage 3 or more were mailed to 1500 Japanese board-certified nephrologists, excluding paediatricians and urologists, randomly selected from the directory of the Japanese Society of Nephrology (n = 2976).

RESULTS

Five hundred and ninety-five nephrologists (40%) responded. Most nephrologists (84-89%) recommended that AHU in patients in CKD stages 3-5 should be treated, but fewer nephrologists (63%) recommended that AHU in patients of CKD stage 5D should be treated. The serum urate level to start urate-lowering therapy and the target serum urate level to be achieved (mg/dL) were 8.2 ± 0.9 and 6.9 ± 0.9, 8.4 ± 0.9 and 7.0 ± 1.0, 8.6 ± 1.0 and 7.3 ± 1.1, and 9.1 ± 1.2 and 7.8 ± 1.3 at stages 3, 4, 5 and 5D, respectively. The most frequently used maximal dosage of allopurinol was 100 mg/day at each stage. Benzbromarone was used in 52% of patients at stage 3, but only in 29%, 13% and 5% of patients at stages 4, 5 and 5D, respectively. The most important reasons to treat AHU at CKD stages 3-5 were prevention of CKD progression (45%), CVE (33%), gout (18%) and urolithiasis (3%).

CONCLUSION

Most Japanese nephrologists treat AHU in pre-dialysis CKD with an aim to prevent CKD progression or CVE mainly by allopurinol.

Systemic non-amyloidotic fibril deposition disease: a probable variant form of fibrillary glomerulonephritis

Fibrillary glomerulonephritis (FGN) is characterized by deposition of non-amyloidotic fibrillary material in glomeruli, and most patients with the disease show heavy proteinuria and hematuria, and progress into end-stage renal failure. We report a 62-year-old woman with FGN who showed mild proteinuria without hematuria and developed rapidly progressive renal failure requiring hemodialysis. Renal biopsy showed severe tubulointerstitial injury associated with non-amyloidotic fibrillary deposits in the tubular basement membrane, interstitium and vessel walls, in addition to glomeruli. The patient died from liver abscess 1 year after the introduction of hemodialysis. Postmortem examination showed the presence of non-amyloidotic fibrillary deposits arranged in tightly packed electron-dense and bundle-shaped structures in many organs. These findings suggest systemic non-amyloidotic fibril deposition in FGN.

A case of γ1-heavy chain deposition disease successfully treated with melphalan and prednisolone therapy

Heavy chain deposition disease (HCDD) is characterized by glomerular and tubular deposition of non-amyloidotic monoclonal heavy chains without associated light chains. We describe a case of gamma1-HCDD who presented with nephrotic syndrome, microhematuria, and hypocomplementemia. Renal biopsy showed lobular and nodular glomerulosclerosis along with IgG and C3 deposition. Electron microscopy revealed electron-dense deposits on the glomerular and tubular basement membranes and mesangium. Congo red staining was negative. Staining was positive for IgG1 on glomerular and tubular basement membranes but negative for IgG2-4, kappa and lambda light chains. Staining for the constant heavy chain domains showed the deletion of the first constant heavy chain domain. Thus, we diagnosed gamma1-HCDD. She was considered to be early-stage HCDD because proteinuria and hematuria were not observed before the nephrotic syndrome onset. Melphalan and prednisolone (MP) therapy reduced proteinuria as well as improved renal function and complement levels. Although renal prognosis of HCDD is poor, aggressive chemotherapy with MP may be effective in early-stage HCDD patients.

Isolated granulomatous renal arteritis: a variant form of giant cell arteritis with few macrophages

A 64-year-old woman with hypertension and hyperlipidemia was admitted to our hospital for the investigation and management of general fatigue, anorexia, a 5-kg weight loss, and a 4-week history of high-grade fever. She had no symptoms of headache, myalgia, or arthralgia, and the physical examination was unremarkable. The laboratory tests revealed renal dysfunction with urine abnormalities that had not been observed 1 year earlier. A renal biopsy showed granulomatous small arteritis without necrotic lesions or glomerular pathology. An immunohistochemical study of the infiltrating leukocytes showed a predominance of CD4+ T cells followed by CD8+ T cells, and only a few macrophages. The condition drastically improved after treatment with 30 mg/day of oral prednisolone. The granulomatous renal arteritis was considered a variant of giant cell arteritis, because it showed the peculiar finding of a few macrophages in the granulomatous lesions.

[Massive colonic bleeding and crescentic glomerulonephritis in an elderly man with Henoch-Schönlein purpura]

A 79-year-old man with an artificial anus constructed during surgical repair of colon perforation of unknown etiology in 1995 was admitted to our hospital for sudden appearance of purpura in the lower extremities. Two weeks before admission, he complained of flu-like symptoms and abdominal pain. He was diagnosed with Henoch-Schonlein purpura (HSP), which responded to treatment with 30 mg day oral prednisolone (PSL). Subsequently, however, rapid deterioration of renal function associated with severe hematuria and proteinuria was noted. Renal biopsy on hospitalization day 14 showed cellular crescent formation in more than half of the glomeruli with granular deposits of IgA, C3 and fibrinogen in the mesangium and on the capillary walls. PSL was tapered to 20 mg day from hospitalization day 14 because of a further decrease in purpura and a decrease in C-reactive protein. On hospitalization day 19, serum creatinine increased to 3.1 mg dL and a massive bloody stool was observed. Colonoscopy revealed extensive oozing from the colonic mucosa around the artificial anus. Since the bleeding was considered to result from HSP activity, methylprednisolone pulse therapy was applied, followed by increasing the dose of oral PSL to 30 mg/day. Co-administration of cyclophosphamide (25 mg day) from hospitalization day 39 led to improvement of renal dysfunction and a decrease in proteinuna at the outpatient clinic.

Thyroid crisis following interstitial nephritis

A 54-year-old man with Graves' disease had been treated with thiamazole (5 mg/day). His thyroid hormone level was increased after exodontia in February 2006. Although his prescribed dose of thiamazole was increased after exodontia on the fourth day, he developed thyroid crisis on exodontia 52 nd day. Laboratory findings also showed renal dysfunction (from Cr 1.0 mg/dL in July 2005 to Cr 1.8 mg/dL on exodontia 37th day). His thyroid hormone level was normalized after subtotal thyroidectomy; however, serum Cr level was still high. He was diagnosed with interstitial nephritis as a result of renal biopsy, and he was treated with prednisolone 30 mg/day. This present case developed thyroid crisis even though the quantity of thiamazole was increased after exodontia. It seems that interstitial nephritis, as well as exodontia, is an aggravation factor of thyroid function. After a poor response to anti-thyroid drugs, it is necessary to prevent thyroid crisis by determining the aggravating factor and to then provide appropriate treatment.

Blockade of IP-10/CXCR3 Promotes Progressive Renal Fibrosis

BACKGROUND/AIM

Fibrosis is a hallmark of progressive organ disease. The 10-kDa interferon-inducible protein IP-10/CXCL10 is a potent chemoattractant for activated T lymphocytes, natural killer cells, and monocytes. However, the involvement of IP-10 in the pathogenesis of renal diseases via its receptor, CXCR3, remains unclear. To contribute to the clarification of this issue was the aim of this study.

METHODS

The impacts of IP-10 on renal fibrosis were investigated in a unilateral ureteral obstruction model in CXCR3-deficient mice and mice treated with anti-IP-10-neutralizing monoclonal antibody. Anti-IP-10 monoclonal antibody (5 mg/kg/day) was injected intravenously once a day until sacrifice on days 1, 4, or 7 after treatment. The effects of IP-10 were confirmed in cultured tubular epithelial cells.

RESULTS

IP-10 and CXCR3 were upregulated in progressive renal fibrosis. Blockade of IP-10/CXCR3 promotes renal fibrosis, as evidenced by increases in interstitial fibrosis and hydroxyproline contents, concomitant decrease in hepatocyte growth factor expression, and converse increase in transforming growth factor-beta1 in diseased kidneys. IP-10 blockade affected neither macrophage nor T cell infiltration in diseased kidneys.

CONCLUSION

These results suggest that blockade of IP-10 via CXCR3 contributes to renal fibrosis, possibly by upregulation of transforming growth factor-beta1, concomitant with downregulation of hepatocyte growth factor.

Effect of sevelamer hydrochloride on markers of bone turnover in Japanese dialysis patients with low biointact PTH levels

BACKGROUND

In hemodialysis patients, adynamic bone disease has been reported to be closely associated with low levels of parathyroid hormone (PTH) due to exposure to high levels of serum calcium following the administration of calcium carbonate (CaCO3) or vitamin D agents. This study was conducted to clarify the therapeutic effect of a non-calcemic phosphate binder, sevelamer hydrochloride (sevelamer), for hypoparathyroidism in hemodialysis patients with or without diabetes mellitus.

METHODS

Based on entry criteria, 40 Japanese chronic hemodialysis patients (22 males and 18 females with a mean age of 60.6, 14 diabetic patients and 26 non-diabetic patients) were switched from CaCO3 to sevelamer for 48 weeks. Serum calcium, phosphate, intact (i) PTH and PTH-(1-84) were analyzed. Bone remodeling activity was evaluated by determining intact osteocalcine (iOC), bone-specific alkaline phosphatase (BAP).

RESULTS

The switch from CaCO3 to sevelamer significantly decreased the serum levels of calcium, resulting in the elevation of iPTH levels from 31+/-18 pg/mL to 95+/-96 pg/mL by 48 weeks. In contrast, serum phosphate levels remained similar to those in patients with CaCO3 treatment. Concomitantly, the levels of BAP and iOC were elevated. Further, these beneficial effects on bone turnover were observed in both diabetic and non-diabetic patients.

CONCLUSION

Sevelamer reduced the calcium concentration and thereby increased PTH levels, resulting in the improvement of markers of bone turnover. The administration of sevelamer is of therapeutic benefit for the improvement of bone remodeling activity even in hemodialysis patients with diabetes.

Remission of IgA nephropathy after allogeneic peripheral blood stem cell transplantation followed by immunosuppression for acute lymphocytic leukemia

We report a case with immunoglobulin A (IgA) nephropathy, showing IgA deposition which disappeared after peripheral blood stem cell transplantation (PBSCT) for acute lymphocytic leukemia (ALL). In 1996, a 28-year-old man was diagnosed with IgA nephropathy by renal biopsy. Steroid therapy improved proteinuria from 3 g/day to 1 g/day. In 2003, he received PBSCT following the initial therapy for ALL. After complete remission, urinary protein and hematuria remained at between (-) and (+/-). In 2004, the second renal biopsy specimen revealed no deposit of IgA or C3. These findings suggested that immune reconstruction with PBSCT following immunosuppression therapy was of benefit to IgA nephropathy.

The outcome and a new ISN/RPS 2003 classification of lupus nephritis in Japanese

BACKGROUND

A considerable diversity in prognosis is seen with lupus glomerulonephritis (LGN). Hence, the clinical usefulness of a recent International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 classification to judge the long-term outcome of human LGN has been investigated.

METHODS

We studied retrospectively 60 subjects with LGN (7 males, 53 females, mean age of 33 years old) who underwent renal biopsies and were followed from 1 to 366 months, with a mean of 187 months. We diagnosed renal pathology as classes, active and sclerosing lesions, according to the new and WHO1995 classification of LGN, and analyzed the clinicopathologic factors affecting to the prognosis of LGN.

RESULTS

New classification got much higher consensus in the judgment of classes (98% vs. 83%, P = 0.0084). The group of Class IV-S (N = 6) or IV-G (N = 17) at initial biopsies showed higher rate of end-stage renal failure (ESRF) compared with that of Class I, II, III or V (40.9% vs. 2.6%, P < 0.001). The mean 50% renal survival time of Class IV was 189 +/- 29 months, and patients with Class IV-S tended to have a poorer prognosis (95 +/- 22 months for IV-S vs. 214 +/- 35 months for IV-G, P = 0.1495). Class IV was also selected as the most significant risk factor for ESRF by stepwise model (P = 0.002). In subanalysis for ESRF in Class IV (-S or -G), treatment including methylprednisolone pulse therapy was only selected as a significant improving factor for primary outcome (P = 0.034). In addition, activity index was the significant risk factor of death and/or ESRF after initial renal biopsies (P = 0.043). As for actuarial patient death during all follow-up periods, complications with anti-phospholipid syndrome or nephrotic syndrome were significant risk factors (P = 0.013, P = 0.041, respectively).

CONCLUSION

New ISN/RPS 2003 classification provided beneficial pathologic information relevant to the long-term renal outcome and the optimal therapy preventing ESRF and/or death in patients with LGN.

Malignant gastrointestinal stromal tumor originating in the lesser omentum, complicated by rapidly progressive glomerulonephritis and gastric carcinoma

A 69-year-old man was admitted with a large elastic mass in the upper abdomen. Computed tomography revealed a massive tumor in contact with the liver and gastrointestinal endoscopy revealed a gastric adenocarcinoma. He developed acute renal failure with massive proteinuria and died with a marked enlargement of the tumor. Autopsy revealed a tumor located in the lesser omentum. The tumor was considered to be a Gastrointestinal Stromal Tumor (GIST) because it was positive for c-kit. In addition, crescent formations and immune complexes in glomeruli were observed. We report the first case of GIST complicated by rapidly progressive glomerulonephritis and gastric carcinoma.

Dietary sodium restriction restores nocturnal reduction of blood pressure in patients with primary aldosteronism

The purpose of this study was to elucidate the effects of dietary sodium restriction on diurnal blood pressure (BP) variation in primary aldosteronism. We studied the diurnal variation in the systemic hemodynamic indices and in baroreflex sensitivity (BRS). In 13 subjects with aldosterone-producing adenomas (2 males; mean age, 39+/-2 years), intra-arterial pressure was monitored telemetrically on a normal salt diet (NaCl 10-12 g/day). Non-dippers were defined as those with a nocturnal reduction in systolic BP (SBP) of less than 10% of daytime SBP. Ten subjects showed a non-dipper pattern. Six of these "non-dippers" underwent repetitive hemodynamic studies on the last day of a 1-week low salt diet regimen (NaCl 2-4 g/day). Stroke volume was determined using Wesseling's pulse contour method, calibrated with indocyanine green dilution. BRS was calculated every 30 min as delta pulse interval/delta SBP on spontaneous variations. Nocturnal reduction of SBP was 4.1% on the normal salt diet. With sodium restriction, urinary sodium excretion decreased from 187+/-8 to 46+/-8 mmol/day, and body weight decreased from 57.9+/-2.1 to 56.6+/-1.9 kg. Night-time BP significantly decreased with dietary modification from 154+/-7/88+/-4 to 140+/-6/78+/-4 mmHg, whereas daytime BP was unaltered. With sodium restriction, cardiac index and stroke index decreased throughout the day. No significant difference was seen in either daytime or nighttime BRS between the two diets. We conclude that the non-dipper pattern is common in patients with an aldosterone-producing adenoma on a normal salt intake, and under such conditions, volume expansion appears to play a major role in the impairment of nocturnal BP reduction.

Quantitative HPLC analysis of cardiac glycosides in Digitalis purpurea leaves

An analytical method for the determination of cardiac glycosides in Digitalis purpurea leaves by hplc was developed. Quantitation was carried out by the incorporation of lanatoside A as an internal standard. The present method is sufficiently precise and relatively simple.