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Objective: Previous studies reported mixed results on associations between dietary potassium intake and hyperkalemia in patients with chronic kidney disease (CKD). This study investigated the association between potassium intake from different food sources and hyperkalemia in patients with non-dialysis-dependent CKD., Methods: A total of 285 patients were recruited at a university hospital and 2 city hospitals in Tokyo. Dietary potassium intake was estimated by a validated diet history questionnaire. Associations of potassium intake from all foods and individual food groups with serum potassium were examined by multivariable linear regression among potassium binder nonusers. An association between tertile groups of potassium intake and hyperkalemia, defined as serum potassium ≥5.0 mEq/L, was evaluated by multivariable logistic regression., Results: Among 245 potassium binder nonusers, total potassium intake was weakly associated with serum potassium (regression coefficient = 0.147, 95% confidence interval (CI): 0.018-0.277), while an association with hyperkalemia was not observed (first vs third tertile: adjusted odds ratio = 0.98, 95% CI: 0.29-3.26). As for food groups, potassium intakes from potatoes, pulses, and green/yellow vegetables were positively associated with serum potassium. Patients in the highest tertile of potassium intake from potatoes had higher odds of hyperkalemia as compared to those in the lowest tertile (adjusted odds ratio = 4.12, 95% CI: 1.19-14.34)., Conclusion: Total potassium intake was weakly associated with serum potassium, but not with hyperkalemia. Potassium intake from potatoes was associated with hyperkalemia. These findings highlight the importance of considering food sources of potassium in the management of hyperkalemia in CKD., (Copyright © 2024 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: As messenger RNA (mRNA)-based vaccines for coronavirus disease 2019 (COVID-19) have been administered to millions of individuals worldwide, cases of de novo and relapsing glomerulonephritis after mRNA COVID-19 vaccination are increasing in the literature. While most previous publications reported glomerulonephritis after the first or second dose of an mRNA vaccine, few reports of glomerulonephritis occurring after the third dose of an mRNA vaccine currently exist., Case Presentation: We report a case of rapidly progressive glomerulonephritis in a patient following the third dose of an mRNA COVID-19 vaccine. A 77-year-old Japanese man with a history of hypertension and atrial fibrillation was referred to our hospital for evaluation of anorexia, pruritus, and lower extremity edema. One year before referral, he received two mRNA vaccines (BNT162b2) for COVID-19. Three months before the visit, he received a third mRNA vaccine (mRNA-1273) for COVID-19. On admission, the patient presented severe renal failure with a serum creatinine level of 16.29 mg/dL, which had increased from 1.67 mg/dL one month earlier, prompting us to initiate hemodialysis. Urinalysis showed nephrotic-range proteinuria and hematuria. Renal biopsy revealed mild mesangial proliferation and expansion, a lobular appearance, and double contours of the glomerular basement membrane. Renal tubules had severe atrophy. Immunofluorescence microscopy showed strong mesangial staining for IgA, IgM, and C3c. Electron microscopy exhibited mesangial and subendothelial electron-dense deposits, leading to a diagnosis of IgA nephropathy with membranoproliferative glomerulonephritis-like changes. The kidney function remained unchanged after steroid therapy., Conclusions: Although the link between renal lesions and mRNA vaccines remains unclear, a robust immune response induced by mRNA vaccines may play a role in the pathogenesis of glomerulonephritis. Further studies of the immunological effects of mRNA vaccines on the kidney are warranted., (© 2023. The Author(s).)

We report a case of membranous nephropathy (MN) in a patient with tuberculosis infection and lung adenocarcinoma. A 50-year-old Filipino woman underwent a renal biopsy for the evaluation of proteinuria and hematuria. Immunofluorescence analysis revealed positive staining of IgG in the glomerular basement membrane and mesangial matrices, while electron microscopy demonstrated the presence of sub-epithelial deposits, suggesting MN. To screen for secondary causes of MN, we conducted a computed tomography (CT) scan of the chest and abdomen, which revealed a ground-glass opacity in the middle lobe of the right lung and an enlarged paraaortic lymph node. A T-SPOT test was positive, suggesting the possibility of a latent tuberculosis infection, as she was asymptomatic. A follow-up chest CT scan showed persistent presence of the ground-glass opacities, suggesting a non-infectious cause. Video-assisted thoracoscopic resection of the middle right lobe and partial resection of the lower right lobe were performed because the possibility of lung cancer could not be excluded. Notably, pathological analysis of the lung revealed adenocarcinoma in the middle lobe and epithelioid granuloma in the lower lobe, suggesting an active tuberculosis infection. One month after surgery, anti-tuberculosis treatment was initiated. Thereafter, her proteinuria, which had increased to 6 g/gCre preoperatively, began to decrease. Five months after surgery, the patient achieved complete remission. The speed of remission suggests that tuberculosis likely played a primary role in the etiology of MN. Our case underscores the importance of screening tests for infections and malignancies in patients with MN, even if suggestive symptoms are absent., (© 2021. Japanese Society of Nephrology.)

We report a case of acute ischemic nephropathy in a patient with severe renal artery stenosis and bradycardia due to sick sinus syndrome. An 83-year-old Japanese woman with a history of hypertension was diagnosed with sick sinus syndrome and scheduled for pacemaker implantation. Four days prior to admission for the procedure, she experienced sudden-onset severe right flank pain that persisted for 1 day. On the day of admission, her serum creatinine level increased from 1.35 mg/dL, measured 2 weeks earlier, to 7.04 mg/dL. Laboratory examinations showed elevated C-reactive protein and lactate dehydrogenase levels. A computed tomography scan showed a severely atrophied left kidney, suggesting that it was non-functioning. Doppler ultrasonography of the right renal artery showed an extended acceleration time, suggesting proximal stenosis. Magnetic resonance imaging showed no enhancement in the proximal portions of the right renal artery, consistent with severe stenosis or occlusion. The patient developed severe bradycardia with lightheadedness; as a result, pacemaker implantation was performed on post-admission day 7. On day 10, digital subtraction angiography revealed diffuse severe stenosis of the right renal artery; intravascular ultrasonography suggested plaque rupture. Percutaneous transluminal renal angioplasty (PTRA) was performed and a drug-eluting stent was placed. On day 11, hemodialysis was performed owing to deteriorating renal function. The patient's renal function dramatically improved shortly thereafter. This case highlights the importance of PTRA for select patients, as it can potentially save some patients from chronic dialysis, and outlines the possible implications of bradycardia in the pathogenesis of ischemic nephropathy., (© 2021. Japanese Society of Nephrology.)

We report a case of immunotactoid glomerulonephritis (ITG) in a patient with cold agglutinins. An 86-year-old Japanese male with a history of hypertension, dyslipidemia, and gastric malignancy presented to our hospital for the evaluation of proteinuria and hematuria. He had an elevated blood pressure of 200/77 mmHg and edema of the lower extremities. Initial blood test results revealed an impaired renal function (creatinine, 1.37 mg/dL) and hypoalbuminemia (albumin, 2.6 g/dL). His estimated daily urinary protein was 5.89 g/g creatinine, meeting the diagnostic criteria for nephrotic syndrome. The selectivity index for proteinuria indicated low selectivity (0.329). We conducted a renal biopsy to identify the cause of nephrotic syndrome. Immunofluorescence microscopy demonstrated positive staining of IgM, C4, and C1q. Electron microscopy exhibited mesangial expansion with inflammatory cells and a lobular structure, suggesting membranoproliferative glomerulonephritis. Subendothelial deposits containing microtubular structures with a diameter of approximately 30-200 nm were found, concurrent with the criteria for the diagnosis of ITG. Screening for lymphoproliferative diseases and immunological abnormalities revealed a positive direct Coombs test result and the presence of cold agglutinins. Paraproteinemia was absent. The similarities between cold agglutinin disease and ITG, including the production of autoantibodies and involvement of complement pathways, raise the possibility that cold agglutinins played a role in the development of ITG; however, we were unable to prove it due to difficulties in detecting cold agglutinins on renal histology. We discuss the possible implications for pathogenesis considering prior reports on nephrotic syndrome being potentially associated with cold agglutinins., (© 2021. Japanese Society of Nephrology.)

The management of prosthetic dialysis arteriovenous graft infection comprises antibiotic treatment and total or partial excision of infected grafts for infectious source control. Partial excision with graft bypass is an important graft preservation strategy for localized infection but carries a higher reinfection risk. Here, we report a case of prosthetic graft infection that was successfully treated with partial excision, a graft bypass procedure, and a portable negative pressure wound therapy system, PICO, applied to the open wound postoperatively. The combined approach may be a useful strategy that decreases reinfection risk, shortens the length of hospital stay, and preserves graft patency.

We report a case of nail-patella syndrome (NPS) with unusual thinning of the glomerular basement membrane (GBM) associated with a novel heterozygous variant in the LMX1B gene. A 43-year-old female patient with a previous diagnosis of NPS, referred to our hospital for persistent proteinuria, underwent a renal biopsy, which revealed minor glomerular abnormalities. She underwent a second renal biopsy at the age of 56 owing to the presence of persistent proteinuria and decline in serum albumin, meeting the diagnostic criteria for nephrotic syndrome. Light microscopy demonstrated glomerulosclerosis and cystic dilatation of the renal tubules. Notably, electron microscopy revealed unusual thinning of the GBM, which is quite different from typical biopsy findings observed in patients with NPS, characterized by thick GBM with fibrillary material and electron-lucent structures. Comprehensive genetic screening for 168 known genes responsible for inherited kidney diseases using a next-generation sequencing panel identified a novel heterozygous in-frame deletion-insertion (c.723_729delinsCAAC: p.[Ser242_Lys243delinsAsn]) in exon 4 of the LMX1B gene, which may account for the disrupted GBM structure. Further studies are warranted to elucidate the complex genotype-phenotype relationship between LMX1B and proper GBM morphogenesis., (© 2021 S. Karger AG, Basel.)

Background: Delirium is an independent predictor of death in patients undergoing dialysis for end-stage renal disease (ESRD). However, it is unknown whether delirium during hospitalization at the start of hemodialysis (HD) in elderly populations is associated with early mortality., Methods: We conducted a retrospective cohort study to investigate the association between delirium and early mortality in the elderly after starting HD. The cohort consisted of patients ≥ 75 years who started dialysis for ESRD at the National Center for Global Health and Medicine from 2010 to 2017 and at Yokosuka Kyosai Hospital from 2007 to 2011. Delirium was defined as patients who showed new symptoms of transient confused thinking and reduced awareness of their environment and were prescribed antipsychotic medications. The primary outcome was death within 1 year. Data were analyzed using Cox proportional hazard models with adjustments for baseline characteristics. A multinomial logistic regression was used to identify the determinants of patients developing delirium., Results: We enrolled 259 patients (males, 60%); 33 patients were diagnosed with delirium. The primary outcome was observed in 19 patients with delirium (58%) and 24 patients without delirium (11%) (p < 0.01). Delirium was independently associated with all-cause mortality within 1 year after starting HD (hazard ratio 7.82, 95% confidence interval 4.26-14.3; adjusted hazard ratio 7.16, 95% confidence interval 3.49-14.7). Delirium was positively correlated with "cognitive impairment" as well as "the use of steroids.", Conclusion: Delirium is independently associated with early mortality in the elderly after starting HD.

Uremic toxins (UTs) generally accumulate in patients developing end-stage renal disease (ESRD). Although some kinds of UTs cause early death after starting hemodialysis (HD), it remains unknown whether the degree of excessive accumulation of various UTs is associated with worsening of prognosis. We retrospectively conducted this cohort study consisting of adult patients developing ESRD who initiated HD at the National Center for Global Health and Medicine from 2010 to 2019. We created a new uremic score, which was defined as the aggregate score of the following variables reflecting uremic state: elevated blood urea nitrogen, β2-microglobulin, and anion gap before starting HD. The primary outcome was early mortality within 1-year after HD commencement. The hazard ratio (HR) and 95% confidence interval (CI) for a one-point increase in uremic score was calculated with Cox proportional hazard models adjusted by baseline conditions. We included 230 participants, 16 of whom experienced the primary outcome of early mortality after HD commencement. Uremic score was significantly associated with the primary outcome (crude HR: 1.91, 95% CI 1.16-3.14; adjusted HR: 4.19, 95% CI 1.79-9.78). Our novel uremic score, reflecting accumulation of specific UTs, more precisely predicts early mortality after HD commencement.

Background: Serum anion gap (AG) has recently been proven to represent a biomarker for predicting prognosis in patients with end-stage renal disease (ESRD). However, whether change in AG (ΔAG) at the time of starting hemodialysis predicts mortality after starting hemodialysis in elderly patients with ESRD remains unknown., Methods: This retrospective cohort investigated the association between ΔAG and mortality after starting hemodialysis in the elderly. The cohort comprised patients ≥ 75 years old who started hemodialysis for ESRD at National Center for Global Health and Medicine between 2010 and 2017 and at Yokosuka Kyosai Hospital between 2007 and 2011. Patients were stratified into three groups (G1-3) based on ΔAG, calculated according to the equation: ΔAG = sodium - (chloride + bicarbonate) - 12. The primary outcome was death within 1 year of starting hemodialysis. Data were analyzed using Cox proportional hazard models with adjustments for baseline characteristics., Results: We enrolled 254 patients (59% male). Median ΔAG was 2.6 (G1: > 3, n = 111; G2: 0-3, n = 103; G3: < 0, n = 40). The primary outcome was observed in 43 patients. Hazard ratios (HRs) were significantly higher for G1 and G3 than for G2 (G1: HR 2.47, 95% confidence interval 1.13-5.37; G3: HR 3.86, 95% confidence interval 1.62-9.16). Adjusted HRs (aHRs) were significantly higher for G1 and G3 than for G2 (G1: aHR 3.06, 95% confidence interval 1.23-7.62; G3: aHR 3.12, 95% confidence interval 1.10-8.78)., Conclusions: A J-curve phenomenon is evident between ΔAG and early mortality after starting hemodialysis in the elderly.

Immersion pulmonary edema (IPE) is a rare condition observed in divers. We report a case of a 66-year-old man on maintenance dialysis who developed acute dyspnea and blood-tinged sputum after scuba diving. Vital signs on admission were significant for elevated blood pressure at 209/63 mmHg and hypoxia with an oxygen requirement of 6 L/min. Physical examination was remarkable for bilateral coarse crackles and systolic ejection murmur. Chest radiography revealed bilateral pulmonary edema. Echocardiography showed aortic stenosis and diffuse hypokinesis of left ventricular wall motion. We started bilevel positive airway pressure and administered nitroglycerin and nicardipine to maintain adequate oxygenation and reduce blood pressure. We started hemodialysis and extracorporeal ultrafiltration to remove excess fluid. His dyspnea subsided and oxygen was no longer required on Day 3. His long-standing hypertension, increased afterload due to vasoconstriction induced by cold water, increased capillary pressure due to impaired left ventricular motion and increased preload caused by exertion, and aortic stenosis probably contributed to pulmonary congestion. We propose maintenance dialysis as a novel risk factor for IPE due to its tendency to induce volume overload, increase pulmonary capillary pressure, and increase aortic stenosis risk. Patients on hemodialysis should refrain from diving to prevent this life-threatening condition., (© 2020 Wiley Periodicals, Inc.)

Background: Clinical studies on the effects of thalidomide-induced damage on thalidomide victims as they age have only recently started to be conducted, but no studies have examined socioeconomic differences in terms of healthcare and social status between thalidomiders and the age-matched general population in Japan. Therefore, we carried out a nationwide survey focusing on the life situations of thalidomiders., Method: Questionnaires were sent to 274 thalidomiders in Japan. The questionnaire items basically matched those of the Comprehensive Survey of Living Conditions (CSLC) in the general population conducted by the Japanese Government. The results were compared with those of the CSLC for individuals aged 55-59 years, which was the cohort most similar in age to the average thalidomider living in Japan., Results: More thalidomiders rated their health condition as relatively bad or bad compared with the general population (20.2% vs. 13.3%, respectively). A much higher percentage of thalidomiders reported having some health or physical problem caused by a disease or injury (68.8% vs. 32.6%, respectively), and thalidomiders reported visiting medical and healthcare-related facilities more frequently. A higher proportion of thalidomiders (9.2%) were unemployed, and thalidomiders tended to feel higher levels of worry and stress, especially in terms of the future., Conclusions: The results of this nationwide survey of the life situations of thalidomiders in Japan clarified their health conditions and the related associations with socioeconomic status. These findings could be expected to help improve the provision of medical and healthcare, welfare measures, and financial support for thalidomiders in the near future., (© 2019 The Authors. Birth Defects Research published by Wiley Periodicals, Inc.)

Aims: This retrospective cohort study compared the results of vascularised and non-vascularised anterior sliding tibial grafts for the treatment of osteoarthritis (OA)of the ankle secondary to osteonecrosis of the talus., Patients and Methods: We reviewed the clinical and radiological outcomes of 27 patients who underwent arthrodesis with either vascularised or non-vascularised (conventional) grafts, comparing the outcomes (clinical scores, proportion with successful union and time to union) between the two groups. The clinical outcome was assessed using the Mazur and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores. The mean follow-up was 35 months (24 to 68)., Results: The mean outcome scores increased significantly in both groups. In the vascularised graft group, the mean Mazur score improved from 36.9 to 74.6 and the mean AOFAS scale improved from 49.6 to 80.1. In the conventional arthrodesis group, the mean Mazur score improved from 35.5 to 65 and the mean AOFAS scale from 49.2 to 67.6. Complete fusion was achieved in 13 patients (76%) in the vascularised group, but only four (40%) in the conventional group. The clinical outcomes and proportion achieving union were significantly better in the vascularised group compared with the conventional arthrodesis group, although time to union was similar in the two groups., Take Home Message: Vascularised sliding tibial grafts may be used to achieve arthrodesis in patients with OA of the ankle secondary to osteonecrosis of the talus., (©2016 The British Editorial Society of Bone & Joint Surgery.)

Purpose: Articular cartilage homeostasis involves modulation of chondrocyte matrix synthesis in response to mechanical stress (MS). We studied extracellular and intracellular mechanotransduction pathways mediating this response., Methods: We first confirmed rapid up-regulation of the putative chondro-protective cytokine, interleukin (IL)-4, as an immediate response to MS. We then studied the role of IL-4 by investigating responses to exogenous IL-4 or a specific IL-4 inhibitor, combined with MS. Next we investigated the intracellular second messengers. Since chondrocyte phenotype alters according to the extracellular environment, we characterized the response to mechanotransduction in 3-dimensionally embedded chondrocytes., Results: Expression of aggrecan and type II collagen was significantly up-regulated by exogenous IL-4 whereas MS-induced matrix synthesis was inhibited by an IL-4 blocker. Further, MS-induced matrix synthesis was completely blocked by a p38 MAPK inhibitor, while it was only partially blocked by inhibitors of other putative second messengers., Conclusion: IL-4 mediates an extracellular pathway of mechanotransduction, perhaps via an autocrine/paracrine loop, while p38 mediates an intracellular pathway prevalent only in a 3-dimensional environment.