A case of juvenile-onset fibrillary glomerulonephritis diagnosed by mass spectrometry and immunohistochemistry of DNAJB9.

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease. FGN is characterized by the deposition of randomly arranged, nonbranching microfibrils in the mesangium and glomerular basement membrane. The discovery of DNAJ homolog subfamily B member 9 (DNAJB9) in 2017 was a breakthrough, and DNAJB9 has been proven to be extremely useful for the definitive diagnosis of FGN. While FGN often occurs in middle-aged individuals, this case was diagnosed at a relatively young age of 17. We performed renal biopsy, and light microscopic study revealed mesangial proliferation with expansion and subepithelial deposits. Electron microscopic study showed glomerular deposition of randomly oriented nonbranching fibrils with a mean of 20 nm. However, direct first scarlet stain for amyloidosis was weakly positive. Therefore, we confirmed the diagnosis of FGN and eliminated the presence of amyloidosis with mass spectrometry. This is the first case in Japan in which the complication of amyloidosis was ruled out with mass spectrometry and FGN was diagnosed using immunostaining and mass spectrometry of DNAJB9. We began treatment with cyclosporine A. One and a half years after the start of the treatment, kidney function continues to be normal.

Sex differences in clinical outcomes in Japanese incident dialysis patients: a prospective observational multicenter study.

BACKGROUND: A Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown a one-to-one male-to-female mortality ratio, notwithstanding the statistically longer life expectancy of women in the general population. This finding contrasts with the recent report that Japanese women on dialysis treatment have a more favorable longevity. Accordingly, we further investigated the clinical procedures and outcomes to clarify the sex differences in Japanese patients undergoing dialysis treatment. METHODS: Subjects were incident dialysis patients who participated in a multicenter prospective cohort study from October 2011 to September 2013. The all-cause mortality was analyzed by a Cox proportional hazard regression model and studied separately in women and men with or without cardiovascular disease (CVD) at baseline. RESULTS: Overall, 492 (32.3%) of the 1520 test subjects were women. All-cause mortality was higher in men (28.6%) than in women (19.9%, p < 0.001). Female sex (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.54-0.90) and history of CVD (HR: 1.51, 95% CI: 1.18-1.95) were independent predictors of all-cause mortality. In patients without CVD, female gender was strong independent contributor (HR = 0.46, 95% CI: 0.30-0.70, p < 0.001). In contrast, patients with CVD showed no difference in survival between the sexes (HR: 0.92, 95% CI: 0.67-1.24, p = 0.597). CONCLUSION: Our study demonstrated that women undergoing chronic dialysis therapy had a lower mortality risk than men. However, complication with CVD canceled out the survival advantage in Japanese women on chronic dialysis. We should reevaluate the risk of women with CVD undergoing dialysis and apply the optimal care for CVD.

A Case of Effective Mepolizumab Induction Therapy for Severe Eosinophilic Granulomatosis with Polyangiitis Diagnosed by Eosinophilic Cholecystitis and Interstitial Nephritis.

A 66-year-old man with a history of bronchial asthma and sinusitis was admitted with cholecystitis and peripheral neuropathy. The histopathological findings of the gallbladder revealed necrotic vasculitis and granulomatous inflammation with marked eosinophilic infiltration. Kidney biopsy also showed marked eosinophilic infiltration in the tubulointerstitial area and eosinophilic tubulitis. He was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA) and treated with corticosteroids. However, he showed no response. Therefore, he was administered mepolizumab 300 mg, which resulted in clinical improvement, including normalization of the eosinophil and CRP levels. We herein describe the first case of successful induction therapy of EGPA using mepolizumab.

The effectiveness and safety of computed tomographic peritoneography and video-assisted thoracic surgery for hydrothorax in peritoneal dialysis patients: A retrospective cohort study in Japan.

INTRODUCTION: Albeit uncommon, hydrothorax is an important complication of peritoneal dialysis (PD). Due to paucity of evidence for optimal treatment, this study aimed to evaluate the effectiveness and safety of computed tomographic (CT) peritoneography and surgical intervention involving video-assisted thoracic surgery (VATS) for hydrothorax in a retrospective cohort of patients who underwent PD in Japan. METHODS: Of the 982 patients who underwent PD from six centers in Japan between 2007 and 2019, 25 (2.5%) with diagnosed hydrothorax were enrolled in this study. PD withdrawal rates were compared between patients who underwent VATS for diaphragm repair (surgical group) and those who did not (non-surgical group) using the Kaplan-Meier method and log-rank test. RESULTS: The surgical and non-surgical groups comprised a total of 11 (44%) and 14 (56%) patients, respectively. Following hydrothorax diagnosis by thoracentesis and detection of penetrated sites on the diaphragm using CT peritoneography, VATS was performed at a median time of 31 days (interquartile range [IQR], 20-96 days). During follow-up (median, 26 months; IQR, 10-51 months), 9 (64.3%) and 2 (18.2%) patients in the non-surgical and surgical groups, respectively, withdrew from PD (P = 0.021). There were no surgery-related complications or hydrothorax relapse in the surgical group. CONCLUSIONS: This study demonstrated the effectiveness and safety of CT peritoneography and VATS for hydrothorax. This approach may be useful in hydrothorax cases to avoid early drop out of PD and continue PD in the long term. Further studies are warranted to confirm these results.

Aichi cohort study of the prognosis in patients newly initiated into dialysis (AICOPP): baseline characteristics and trends observed in diabetic nephropathy.

BACKGROUND: Over 300,000 patients receive maintenance dialysis in Japan; managing these patients is extremely important. This study aimed to report on prior management of chronic kidney diseases and prognostication after dialysis initiation. PATIENTS AND METHODS: Seventeen institutions participated in the Aichi cohort study of prognosis in patients newly initiated into dialysis and recruited patients over a period of 2 years. Exclusion criteria were (1) patients under 20 years; (2) patients who died before hospital discharge; and (3) patients who could not provide consent. RESULT: Here, we showed data on dialysis initiation time. Of 1524 patients with mean age of 67.5 ± 13.0 years, 659 patients were put on dialysis following diabetic nephropathy diagnosis. At dialysis initiation time, creatinine and estimated glomerular filtration rate levels were 8.97 ± 3.21 mg/dl and 5.45 ± 2.22 ml/min/1.73 m2, respectively. Medications taken were angiotensin II receptor blockers in 866; angiotensin-converting enzyme inhibitors in 135; calcium antagonist in 1202; and diuretics, alone or in combination, in 1059. Among patients with diabetic nephropathy, many had increased body weight and systolic blood pressure and were taking loop and thiazide diuretics at dialysis initiation time. Many patients with diabetic nephropathy had coronary artery disease and percutaneous coronary intervention. CONCLUSION: Many patients with diabetic nephropathy who registered for this study had coronary artery disease and problems with excess body fluid. Further analyses may clarify how underlying conditions and disease management before and after dialysis initiation affect prognosis.

Risk Score to Predict 1-Year Mortality after Haemodialysis Initiation in Patients with Stage 5 Chronic Kidney Disease under Predialysis Nephrology Care.

BACKGROUND: Few risk scores are available for predicting mortality in chronic kidney disease (CKD) patients undergoing predialysis nephrology care. Here, we developed a risk score using predialysis nephrology practice data to predict 1-year mortality following the initiation of haemodialysis (HD) for CKD patients. METHODS: This was a multicenter cohort study involving CKD patients who started HD between April 2006 and March 2011 at 21 institutions with nephrology care services. Patients who had not received predialysis nephrology care at an estimated glomerular filtration rate (eGFR) of approximately 10 mL/min per 1.73 m2 were excluded. Twenty-nine candidate predictors were selected, and the final model for 1-year mortality was developed via multivariate logistic regression and was internally validated by a bootstrapping technique. RESULTS: A total of 688 patients were enrolled, and 62 (9.0%) patients died within one year of HD initiation. The following variables were retained in the final model: eGFR, serum albumin, calcium, Charlson Comorbidity Index excluding diabetes and renal disease (modified CCI), performance status (PS), and usage of erythropoiesis-stimulating agent (ESA). Their ß-coefficients were transformed into integer scores: three points were assigned to modified CCI≥3 and PS 3-4; two to calcium>8.5 mg/dL, modified CCI 1-2, and no use of ESA; and one to albumin<3.5 g/dL, eGFR>7 mL/min per 1.73 m2, and PS 1-2. Predicted 1-year mortality risk was 2.5% (score 0-4), 5.5% (score 5-6), 15.2% (score 7-8), and 28.9% (score 9-12). The area under the receiver operating characteristic curve was 0.83 (95% confidence interval, 0.79-0.89). CONCLUSIONS: We developed a simple 6-item risk score predicting 1-year mortality after the initiation of HD that might help nephrologists make a shared decision with patients and families regarding the initiation of HD.

Two brothers with collagenofibrotic glomerulopathy.

Collagenofibrotic glomerulopathy is a rare glomerular disease characterized by extensive accumulation of atypical type III collagen fibers within the mesangial matrix and subendothelial space. Laboratory evaluation of this disease shows a marked increase in serum procollagen III peptide (P III P) levels. Here, we report the case of two brothers with collagenofibrotic glomerulopathy confirmed by histology. Patient 1 presented with proteinuria and hypertension and patient 2 presented with nephrotic-range proteinuria. Immunohistochemistry revealed strong staining for antibodies to type III collagen in the widened subendothelial spaces in both patients. Electron microscopy revealed numerous collagenous fibers in the mesangium and subendothelial space. P III P levels were elevated in both patients. Most reported cases of collagenofibrotic glomerulopathy, including the adult-onset type, have been sporadic. Within the limits of our literature search, this is only the third report of adult siblings with collagenofibrotic glomerulopathy confirmed by histology. This report indicates that it may be beneficial to measure serum P III P levels in the siblings of patients diagnosed with adult-onset collagenofibrotic glomerulopathy.

Successful treatment of refractory gout using combined therapy consisting of febuxostat and allopurinol in a patient with chronic renal failure.

Gouty arthritis is a metabolic disorder associated with hyperuricemia. Despite the development of novel pharmacotherapies, some hyperuricemia patients are drug refractory and develop gout. A 74-year-old man with frequent gouty attacks and chronic renal failure presented with asymmetrical polyarthritis affecting multiple joints. The diagnosis of gout was confirmed based on the presence of monosodium urate crystals in the patient's right wrist. The administration of systemic corticosteroids relieved the joint inflammation and pain; however, the urate level increased to 28 mg/dL and the gout attacks recurred. Combined allopurinol, febuxostat, and benzbromarone therapy reduced the urate level to <6 mg/dL, and the attacks gradually declined. This is the first report of two xanthine oxidase inhibitors being used to treat refractory gout.

A novel GDNF-inducible gene, BMZF3, encodes a transcriptional repressor associated with KAP-1.

The Krüppel-associated box (KRAB)-containing zinc finger proteins (ZFPs) comprise the largest family of zinc finger transcription factors that function as transcriptional repressors. In the study of glial cell line-derived neurotrophic factor (GDNF)-RET signaling, we have identified bone marrow zinc finger 3 (BMZF3), encoding a KRAB-ZFP, as a GDNF-inducible gene by differential display analysis. The expression of BMZF3 transcripts in the human neuroblastoma cell line TGW increased 1h after GDNF stimulation, as determined by Northern blotting and quantitative reverse-transcriptase polymerase chain reaction. The BMZF3 possesses transcriptional repressor activity in the KRAB domain. BMZF3 interacts with a co-repressor protein, KRAB-associated protein 1 (KAP-1), through the KRAB domain and siRNA-mediated knockdown of KAP-1 abolished the transcriptional repressor activity of BMZF3, indicating that KAP-1 is necessary for BMZF3 function. Furthermore, siRNA-mediated silencing of BMZF3 inhibited cell proliferation. These findings suggest that BMZF3 is a transcriptional repressor induced by GDNF that plays a role in cell proliferation.

Nucleolin modulates the subcellular localization of GDNF-inducible zinc finger protein 1 and its roles in transcription and cell proliferation.

GZF1 is a zinc finger protein induced by glial cell-line-derived neurotrophic factor (GDNF). It is a sequence-specific transcriptional repressor with a BTB/POZ (Broad complex, Tramtrack, Bric a brac/Poxvirus and zinc finger) domain and ten zinc finger motifs. In the present study, we used immunoprecipitation and mass spectrometry to identify nucleolin as a GZF1-binding protein. Deletion analysis revealed that zinc finger motifs 1-4 of GZF1 mediate its association with nucleolin. When zinc fingers 1-4 were deleted from GZF1 or nucleolin expression was knocked down by short interference RNA (siRNA), nuclear localization of GZF1 was impaired. These results suggest that nucleolin is involved in the proper subcellular distribution of GZF1. In addition, overexpression of nucleolin moderately inhibited the transcriptional repressive activity of GZF1 whereas knockdown of nucleolin expression by siRNA enhanced its activity. Thus, the repressive activity of GZF1 is modulated by the level at which nucleolin is expressed. Finally, we found that knockdown of GZF1 and nucleolin expression markedly impaired cell proliferation. These findings suggest that the physiological functions of GZF1 may be regulated by the protein's association with nucleolin.

GDNF-inducible zinc finger protein 1 is a sequence-specific transcriptional repressor that binds to the HOXA10 gene regulatory region.

The RET tyrosine kinase receptor and its ligand, glial cell line-derived neurotrophic factor (GDNF) are critical regulators of renal and neural development. It has been demonstrated that RET activates a variety of downstream signaling cascades, including the RAS/mitogen-activated protein kinase and phosphatidylinositol-3-kinase(PI3-K)/AKT pathways. However, nuclear targets specific to RET-triggered signaling still remain elusive. We have previously identified a novel zinc finger protein, GZF1, whose expression is induced during GDNF/RET signaling and may play a role in renal branching morphogenesis. Here, we report the DNA binding property of GZF1 and its potential target gene. Using the cyclic amplification and selection of targets technique, the consensus DNA sequence to which GZF1 binds was determined. This sequence was found in the 5' regulatory region of the HOXA10 gene. Electrophoretic mobility shift assay revealed that GZF1 specifically binds to the determined consensus sequence and suppresses transcription of the luciferase gene from the HOXA10 gene regulatory element. These findings thus suggest that GZF1 may regulate the spatial and temporal expression of the HOXA10 gene which plays a role in morphogenesis.

Identification of a novel glial cell line-derived neurotrophic factor-inducible gene required for renal branching morphogenesis.

In the developing kidney, activation of the rearrangement during transfection tyrosine kinase by glial cell line-derived neurotrophic factor (GDNF) is required for normal branching of the ureteric bud epithelium [corrected]. By differential display analysis we identified a novel GDNF-inducible gene (named GZF1) with a BTB/POZ (broad complex, tramtrack, and bric-a-brac)/(poxvirus and zinc finger) domain and 10 tandemly repeated zinc finger motifs. The up-regulation of the GZF1 gene showed two peaks at 1 h and 24-48 h after GDNF stimulation by Northern blotting. The late induction was also found at protein levels by Western blotting with anti-GZF1 antibody. As observed for other proteins with the BTB/POZ domain, the GZF1 protein had strong transcriptional repressive activity. Intriguingly, its expression was detected at high levels in branching ureteric buds and collecting ducts of mouse metanephric kidney in which RET was also expressed. Antisense phosphorothioated oligodeoxynucleotides of the GZF1 gene markedly impaired the ureteric bud branching in the metanephric organ culture, suggesting that the induction of GZF1 expression via the GDNF/RET signaling system is required for renal branching morphogenesis.