Advances in dialysis therapy and population aging have increased both the age at dialysis initiation and the duration of treatment. This has resulted in a growing population of elderly patients undergoing peritoneal dialysis (PD). PD is often considered a suitable home-based kidney replacement therapy for older adults. However, elderly patients undergoing PD frequently experience complex clinical conditions, including frailty, sarcopenia, nutritional impairment, and chronic inflammation. These conditions are associated with reduced quality of life (QOL), functional decline, and adverse outcomes, such as hospitalization, cardiovascular events, and mortality. Therefore, nutritional impairment is an important yet often overlooked clinical problem in this population. This review summarizes the current evidence on the characteristics, assessment, and management of nutritional impairment in elderly patients receiving PD. We discuss available screening and assessment tools, including serum biomarkers, composite nutritional indices, body composition analysis, and the Global Leadership Initiative on Malnutrition (GLIM) criteria. We also highlight their clinical applicability and limitations in elderly PD populations. Additionally, we review evidence regarding energy and protein requirements, dietary patterns, oral nutritional supplementation, protein supplementation, and combined nutritional and exercise interventions, paying particular attention to sarcopenia and frailty. Although high-quality data specific to elderly and frail PD patients remain limited, emerging evidence suggests that early screening, long-term individualized nutritional interventions, and preservation of residual kidney function may support nutritional and functional management. We propose a practical, stepwise approach to nutritional management based on multidisciplinary care that emphasizes patient-centered outcomes and QOL rather than life prolongation alone. Further prospective and randomized studies are needed to establish optimal strategies for this growing population.

Reports of glomerulonephritis associated with lymphoproliferative disorders are common, but reports of minimal change disease (MCD) accompanying non-Hodgkin’s lymphoma are rare. Here, we present a case of a 45-year-old woman diagnosed with primary Waldenström’s macroglobulinemia (WM) during MCD treatment. Her kidney biopsy revealed endothelial cell injury in parts of the MCD. Subsequently, she developed steroid-resistant nephrotic syndrome and temporary acute kidney injury, requiring dialysis. Remission of the nephrotic syndrome was achieved after initiating combination therapy with bendamustine and rituximab for WM. The renal histological findings and treatment course suggest a causal relationship between MCD and WM in this case. The pathogenesis of MCD associated with WM may involve the release of glomerular permeability factors derived from B lymphocytes. Although mild WM is often managed with observation, steroid-resistant nephrotic syndrome associated with WM should raise suspicion of a paraneoplastic syndrome, necessitating active chemotherapy targeting WM as a critical treatment approach.

Patients with ifosfamide-induced renal damage present with Fanconi syndrome. Karyomegalic nephropathy/interstitial nephritis (KNIN) is a rare form of chronic tubulo-interstitial nephritis that was initially considered a type of familial nephropathy. However, several reports of drug-induced KNIN, i.e., KNIN-like nephropathy, have been reported in recent years. We present the case of an 18-year-old man who presented with Fanconi syndrome and progressive renal dysfunction after receiving chemotherapy including ifosfamide and cisplatin for right femoral osteosarcoma. Renal biopsy revealed numerous atrophied tubular epithelial cells with large, polymorphic nuclei, and the definitive diagnosis was KNIN. Most patients with KNIN-like nephropathy who receive ifosfamide are concomitantly treated with cisplatin, indicating that ifosfamide and cisplatin might act synergistically to increase the risk for KNIN-like nephropathy. Further investigation in case series is warranted to reveal potential treatment approaches and to evaluate prognosis.

A 57-year-old man was diagnosed with peritoneal dialysis (PD)-associated peritonitis 2 months after surgery for tunnel infection (TI) caused by Mycobacteroides abscessus (M. abscessus). The patient was treated with multiple antibiotics, and the cell count in the PD effluent decreased. However, the patient experienced abdominal pain and developed hiccups. Computed tomography revealed an encapsulated fluid collection, indicating intra-abdominal abscess (IAA) formation. Percutaneous drainage was performed to treat IAA, and the catheter was removed. This case suggests that PD-associated peritonitis caused by M. abscessus can lead to IAA formation. If symptoms persist even after a favorable course of peritonitis, IAA should be suspected.

Amyloid light-chain amyloidosis is a rare multiorgan disorder characterized by amyloid deposits in various organs and extracellular tissues. If untreated, it can have progressive and irreversible consequences, ultimately leading to death. When amyloid protein is deposited in the perivascular tissues and the vessels become fragile, the skin shows purpuric changes due to vascular collapse. The “raccoon eyes” appearance can be the first manifestation of amyloid light-chain amyloidosis and should not be overlooked.

Background: This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications. Methods: Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest. Results: Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27–0.70) and straight type catheter (HR 2.14; 95% CI 1.24–3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30–5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines. Conclusion: PD catheter placement in Japan was proven to be safe and appropriate.

Background and Aims Hypokalemia is one of the most common problems in the emergency department (ED). Severe hypokalemia, defined as a serum potassium level <= 2.5 mEq/L, is a relatively uncommon electrolyte disorder, and few studies have reported its prevalence, etiology, symptoms, and management in the ED. Therefore, we aimed to investigate them in this study. Methods This retrospective single-center study included adult patients whose serum potassium levels were measured in the ED between 2012 and 2019. Data including age, sex, serum potassium levels, and serum creatinine levels were collected from the electronic medical records. Results The serum potassium levels of 21,616 adult patients were measured. The median age of these patients was 73 years (range: 57-83 years), and 38% were men. The prevalence of severe hypokalemia was 0.4%. The most common symptom of symptomatic severe hypokalemia was weakness (p = 0.001). Malnutrition, use of Japanese herbal medicine, and use of diuretics were the main causes of severe hypokalemia. Sixty-one patients (70%) underwent electrocardiography. Fifty-nine patients (68%) received treatment for severe hypokalemia within one day of the visit. Conclusion The management of severe hypokalemia in the ED may be suboptimal. Emergency physicians should be vigilant to avoid missing hypokalemia.

BACKGROUND:Cytotoxic T lymphocyte antigen-4 (CTLA-4) is an essential inhibitory regulator of immune activation. CTLA-4 haploinsufficiency is known to be associated with dysregulation of FOXP3+ regulatory T cells, hyperactivation of effector T cells, and lymphocytic infiltration of multiple organs. However, there have only been a few reports of renal involvement with CTLA-4. Herein, we present a case of acute granulomatous tubulointerstitial nephritis (TIN) in a patient with CTLA-4 haploinsufficiency.CASE PRESENTATION:A 44-year-old man presented with a 3-week history of fever and malaise, and subsequently developed acute kidney injury (AKI) a few days after treatment with levofloxacin (LVFX). A kidney biopsy and immunohistochemical staining revealed granulomatous TIN with dominantly infiltrating CD4+ T cells. General symptoms and renal impairment showed improvement after discontinuation of LVFX and initiation of oral steroids. However, they worsened following steroid tapering. Further, a colon biopsy analysis showed similar findings to the renal tissue analysis. We suspected that granulomatous TIN was possibly associated with CTLA-4 haploinsufficiency. Therefore, the patient was transferred to another hospital for further treatment of CTLA-4 haploinsufficiency using immunosuppressive agents.CONCLUSIONS:There have been few reports regarding renal involvement of CTLA-4 haploinsufficiency. In the present case, granulomatous TIN could have arisen due to instability of immune regulatory functions, such as CTLA-4 haploinsufficiency, and treatment with LVFX could have triggered immunologic activation and severe inflammation as well as renal dysfunction.

Background: Hyperkalemia is an electrolyte disorder frequently encountered in the emergency department. There are few studies on seasonal variation in the prevalence of hyperkalemia. The aim of this study was to investigate the seasonal changes in the prevalence of hyperkalemia in the emergency department. Materials and Methods: We retrospectively reviewed a total of 24,085 patients presented to the emergency department between January 2012 and December 2020. Age, gender, serum potassium level, and serum creatinine level were recorded. The definition used for hyperkalemia was a serum potassium level of ≥ 5.5 mEq/L. Renal function was divided into two categories: preserved (eGFR ≥ 60 mL/min/1.73 m2) or reduced (eGFR < 60 mL/min/1.73 m2). Results: The prevalence of hyperkalemia was 2.1% in patients with preserved renal function and was 11.9% in patients with reduced renal function (p < 0.001). The prevalence of hyperkalemia was highest in winter, followed by spring, autumn, and summer in patients with preserved renal function (p < 0.001) and those with reduced renal function (p < 0.001). There was a linear correlation between monthly weather temperature and the prevalence of hyperkalemia in patients with preserved renal function (r = −0.392; p < 0.001) and those with reduced renal function (r = −0.487; p < 0.001). Conclusions: we found that the prevalence of hyperkalemia was significantly higher in winter for both patients with preserved renal function and those with reduced renal function.

RATIONALE:Adult-onset hepatitis B virus-associated membranoproliferative glomerulonephritis (HBV-MPGN) is generally refractory, and an effective treatment for this condition has not been established. The indications for steroids in HBV-MPGN are an important clinical concern. PATIENT CONCERNS:A 28-year-old woman with a chronic hepatitis B virus infection developed nephrotic syndrome in her second month of pregnancy, with urinary protein levels of 3 to 10 g/d that continued into her postpartum period. She was a carrier of HBV with HBeAg seroconversion. As her renal impairment could have been a result of pregnancy, we observed her for 10 months postpartum without any intervention. However, spontaneous remission after childbirth was not achieved and urine protein levels were sustained at 1 to 3 g/d. About 10 months after delivery, elevated serum liver enzyme levels were observed. DIAGNOSIS:Biopsies showed MPGN, with deposition of hepatitis B antigen in the glomeruli, and chronic B-type hepatitis with a severity grade of A1F0. She was diagnosed with HBV-MPGN. INTERVENTIONS:The patient was started on entecavir 0.5 mg/d in March 2008. Within 1 month, serum HBV DNA became undetectable; within 3 months, her alanine aminotransferase levels normalized. However, urinary protein excretion did not decrease to <2 g/d. On a second renal biopsy, performed 7 months after entecavir treatment, proliferative lesions of the glomeruli were observed; therefore, prednisolone was started at an initial dose of 30 mg/d. OUTCOMES:Her proteinuria improved immediately and prednisolone was tapered over 10 months. A third renal biopsy showed a remarkable resolution of HBV-MPGN, with a significant decrease in mesangial proliferation and immune complex deposition. HBV reactivation was not observed during the prednisolone treatment. LESSONS:Additional prednisolone therapy in combination with antiviral therapy should be considered for refractory HBV-MPGN, with sufficient care taken regarding HBV reactivation.

Minimal change nephrotic syndrome (MCNS) responds well to steroids, but some patients show frequent relapses. Long-term steroid administration leads to various adverse effects. We previously reported the effectiveness in refractory nephrosis patients of administrating microemulsified CyA (ME-CyA) once before meals and setting the target value of the CyA blood concentration at 2 h after ME-CyA administration (C2) to 600–1200 ng/ml. On this trial we evaluate the effectiveness and safety of ME-CyA for suppressing relapse of adult new-onset MCNS patients using C2 monitoring.

Vascular access intervention therapy (VAIVT) has been positioned as the first choice of treatment for stenosis lesions frequently observed in arteriovenous fistula (AVF) for hemodialysis patients in Japan. Furthermore, increased blood flow can provide a stable dialysis. In contrast, it has been reported that excess blood flow of AVF causes high-output heart failure. Although VAIVT is used to increase blood flow of AVF, the impact of VAIVT on cardiac load has been rarely reported. We examined the factors associated with cardiac load in hemodialysis patients undergoing VAIVT by measuring levels of human atrial natriuretic polypeptide (hANP) and brain natriuretic peptide (BNP) before and after VAIVT. Data were extracted on hemodialysis patients who underwent measurements of hANP and BNP in before and after VAIVT at our facility and related facilities between February 2014 and December 2014. Nineteeen patients (median age, 73.0 [66.5-80.5] years; male, 52.6%; 36.8% with diabetes; median duration of dialysis treatment, 50.0 [21-109] months) were enrolled in this study. Flow volume of AVF was higher after VAIVT than that before VAIVT (442.0 vs. 758.0 mL/minute, P<0.001). Moreover, resistance index (RI) of AVF after VAIVT was lower than that before VAIVT (0.61 vs. 0.53, P<0.01). Although hANP did not change before and after VAIVT (55.6 vs. 54.9 pg/mL, P=0.099), BNP after VAIVT was significantly higher than that before VAIVT (145.2 vs. 175.0 pg/mL, P<0.05). Factors correlated with the increase in BNP were flow volume of AVF before VAIVT (r=-0.458, P=0.049) and levels of BNP before VAIVT (r=0.472, P=0.041). There was no significant correlation between the increase in hANP with flow volume of AVF before VAIVT, levels of hANP before VAIVT. Patients with high levels of BNP and low flow volume of AVF before VAIVT were considered to have a high risk of developing heart failure after VAIVT.

Chloride (Cl)-depletion alkalosis (CDA) develops due to the loss of Cl-rich body fluid, i.e., vomiting or diuretics use, and is typically treated with a chloride-rich solution such as normal saline (NS). Although NS is one of the most utilized Cl-rich solutions, high cation-gap amino acid (HCG-AA) predominantly comprises Cl and less sodium, making HCG-AA more efficient in correcting CDA. We herein report a case of CDA with chronic hyponatremia after frequent vomiting, which was successfully treated with HCG-AA without overcorrecting hyponatremia or causing hypervolemia. HCG-AA may be more beneficial than NS for treating hyponatremic or hypervolemic metabolic alkalosis.

Treatment with telaprevir (TVR) entails adverse side‐effects including anaemia and elevation of serum creatinine (SCr) level. Our purpose was to evaluate the effects of treatment with TVR on renal function in adults with chronic hepatitis C.

To improve outcomes in patients with chronic kidney disease (CKD), it is important to identify prognostic factors for end-stage renal disease (ESRD) as well as cardiovascular disease (CVD). This study assessed urinary concentrations of albumin, N-acetyl-β-D-glucosaminidase (NAG), and liver-type fatty acid-binding protein (L-FABP), as predictors of ESRD and CVD.