平井 啓之

INTRODUCTION: Clinical studies on differences among changes in cerebral and hepatic oxygenation during hemodialysis (HD) in patients with and without intradialytic hypotension (IDH) are limited. We investigated changes in intradialytic cerebral and hepatic oxygenation before systolic blood pressure (SBP) reached the nadir during HD and compared these differences between patients with and without symptomatic IDH. METHODS: We analyzed data from 109 patients with (n = 23) and without (n = 86) symptomatic IDH who were treated with HD. Cerebral and hepatic regional oxygen saturation (rSO2), as a marker of tissue oxygenation and circulation, was monitored during HD using an INVOS 5100c oxygen saturation monitor. Changes in cerebral or hepatic rSO2 when SBP reached the nadir during HD were compared between the groups of patients. RESULTS: The cerebral rSO2 before HD in patients with and without symptomatic IDH was 49.7 ± 11.2% and 51.3 ± 9.1% (p = 0.491). %Changes in cerebral rSO2 did not significantly differ between the two groups from 60 min before the SBP nadir during HD. Hepatic rSO2 before HD in patients with and without symptomatic IDH was 58.5 ± 15.4% and 57.8 ± 15.9% (p = 0.869). The %changes in hepatic rSO2 were significantly lower in patients with symptomatic IDH than in those without throughout the observational period (p < 0.001). We calculated the area under the receiver operating characteristic curve (AUC) and estimated cutoff values for changes in hepatic rSO2 as a symptomatic IDH predictor. The predictive ability at 5 and 40 min before symptomatic IDH onset was excellent, with AUCs and cutoff values of 0.847 and 0.841, and -10.9% and -5.0%, respectively. CONCLUSIONS: Hepatic oxygenation significantly decreased more in patients with symptomatic IDH before its onset, than in those without symptomatic IDH, whereas changes in cerebral oxygenation did not differ. Evaluating changes in hepatic oxygenation during HD might help to predict symptomatic IDH.

Only a few cases of renal vein thrombosis (RVT) occurring in patients with vasculitis have been reported. RVT associated with vasculitis and hemolytic anemia has not been reported yet. We describe here a patient with RVT complicated by pulmonary embolism, autoimmune hemolytic anemia, and eosinophilic granulomatous polyangiitis. A 69-year-old Japanese man who had been treated with corticosteroids was referred to our department for severe proteinuria (4.32 g/gCr). Abdominal ultrasonography showed bilateral RVT, and contrast-enhanced computed tomography showed bilateral pulmonary embolism. Therefore, the patient was diagnosed with RVT complicated by pulmonary embolism. Anticoagulation therapy with heparin followed by apixaban was started. Thereafter, the D-dimer concentration decreased from 8.3 to 1.2 μg/mL, and urinary protein excretion improved to 0.62 g/gCr. Renal function was unchanged with an estimated glomerular filtration rate of 68.8 mL/minute/1.73 m2. The thrombi in both renal veins and pulmonary arteries gradually regressed. Clinicians should be aware of this complication when worsening proteinuria is observed during steroid therapy in patients with autoimmune hemolytic anemia and eosinophilic granulomatous polyangiitis.

BACKGROUND: We investigated factors associated with the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antibody titer after the second dose of the BNT162b2 messenger RNA coronavirus disease 2019 (COVID-19) vaccine in Japanese patients undergoing hemodialysis. METHODS: Overall, 75 patients (41 men, 34 women; mean age 71.4 ± 12.2 years) with a hemodialysis duration of 5.7 ± 6.1 [interquartile range, 1.0-8.5] years were enrolled in this single-center, prospective, cross-sectional study. We used multiple linear regression analysis to determine the relationships of the anti-SARS-CoV-2 spike antibody titer with patient demographic and clinical parameters. We also compared the anti-SARS-CoV-2 spike antibody titer between hemodialysis patients and 22 healthcare workers (10 men, 12 women; mean age 48.5 ± 14.4 years). RESULTS: Autoimmune disease presence (standard coefficient [β] =  - 0.290, p = 0.018), lymphocyte counts (β = 0.261, p = 0.015), hemoglobin levels (β = 0.290, p = 0.009), and blood urea nitrogen concentrations (β = 0.254, p = 0.033) were significantly and independently correlated with the log-anti-SARS-CoV-2 spike antibody titer. The anti-SARS-CoV-2 spike antibody titer was significantly lower in hemodialysis patients than in healthcare workers (3589 ± 3921 [813-4468] vs. 12,634 ± 18,804 [3472-10,257] AU/mL; p < 0.002). CONCLUSIONS: Autoimmune disease presence, lymphocyte counts, hemoglobin levels, and blood urea nitrogen concentrations were associated with the anti-SARS-CoV-2 spike antibody titer after the second dose of the BNT162b2 messenger RNA COVID-19 vaccine in Japanese patients undergoing hemodialysis.

A 68-year-old man received hemodialysis (HD) for the treatment of end-stage renal failure for 6 years. Five years prior to carotid artery stenting (CAS), a neck ultrasound performed to screen for carotid atherosclerosis revealed an asymptomatic right internal carotid artery stenosis. One month prior, the stenotic lesion progressed to 74% by cerebral angiography; therefore, CAS was performed. To evaluate the influence of right internal carotid artery stenosis on the intradialytic cerebral circulation and oxygenation, cerebral regional oxygen saturation (rSO2) at bilateral forehead was measured using the INVOS 5100c oxygen saturation monitor (Covidien Japan, Japan) during HD before and after CAS. Before CAS, right cerebral rSO2 was maintained during HD, whereas left cerebral rSO2 gradually increased from the initiation to end of HD. However, the differences of intradialytic cerebral rSO2 changes between bilateral sides disappeared after CAS. In the present case, before CAS, the intradialytic increase in left cerebral rSO2 might reflect the increase in the left cerebral blood flow to compensate for the ultrafiltration-associated decreases in the right cerebral blood flow and perfusion pressure. Furthermore, the preserved right cerebral rSO2 before CAS might reflect the mechanism maintaining the right cerebral blood flow from the collateralized circle of Willis during HD. Throughout our experience, cerebral oxygenation monitoring during HD might disclose intradialytic changes in cerebral blood flow distribution between the ipsilateral and contralateral side in HD patients with carotid artery stenosis.

Background: Carnitine supplementation improves various dialysis-related symptoms including erythropoietin-resistant anemia in patients who are undergoing hemodialysis. However, the utility of carnitine supplementation in patients who are undergoing peritoneal dialysis (PD) is not fully understood. Methods: Thirteen patients undergoing PD [mean age: 54.2 ± 14.8 years, males: 9/13 (69%)] administered oral carnitine supplementation (mean dose: 9.1 ± 3.3 mg/kg/day) for 4–6 months were retrospectively investigated. Changes in serum carnitine levels and other clinical variables including the erythropoietin resistance index (ERI) were analyzed after carnitine supplementation. Results: Carnitine supplementation increased serum total carnitine (48.5 ± 10.2 vs. 130.1 ± 37.2 μmol/L, P &lt 0.01), free carnitine (31.1 ± 8.3 vs. 83.1 ± 24.6 μmol/L, P &lt 0.01), and acyl carnitine (17.4 ± 2.8 vs. 46.9 ± 13.8, P &lt 0.01) levels. The acyl carnitine/free carnitine ratio was not affected (0.6 ± 0.1 vs. 0.6 ± 0.1, P = 0.75). Although the mean ERI was not affected by carnitine supplementation [13.7 ± 4.7 vs. 11.6 ± 3.4 IU/kg/(g/dL)/week, P = 0.28], the ERI change rate was significantly decreased (1.00 ± 0.00 vs. 0.87 ± 0.11, P &lt 0.01). Conclusion: Carnitine supplementation may improve erythropoietin resistance in patients who are undergoing PD.

The microRNAs (miRNAs) that can regulate diabetic kidney disease (DKD) have not been fully characterized. The aim of this study was to identify the miRNAs that affect DKD and could be used as specific biomarkers or therapeutic agents. First, kidney tissues from two DKD mouse models and control mice were screened for differences in miRNA expression by microarray analysis followed by quantitative real-time reverse transcription-PCR. Six miRNAs were differentially expressed from controls in both DKD mouse models. Among them, miRNA-125b-5p and miRNA-181b-5p were exclusively downregulated in the DKD mouse model. Next, we administered miRNA-181b-5p-mimic to DKD mice, which reduced the albuminuria and abnormal mesangial expansion. Pathway analysis and database research revealed that overexpression of miRNA-181b-5p significantly altered the expression of seven mRNAs in six known signaling pathways in the kidneys of DKD mice. Furthermore, the serum level of miRNA-125b-5p was significantly higher in patients with DKD (1.89±0.40-fold, P&lt 0.05) compared with patients with other kidney diseases (0.94±0.13-fold) and healthy subjects (1.00±0.19-fold). Serum levels of miRNA-181b-5p were lower in patients with DKD (0.30±0.06-fold, P&lt 0.05) compared with patients with other kidney diseases (1.06±0.20-fold) and healthy subjects (1.00±0.16-fold). These results suggest that miRNA-125b-5p and miRNA-181b-5p may represent novel diagnostic biomarkers and that miRNA-181b-5p may represent a therapeutic target for DKD.

Background: Although cerebral regional oxygen saturation (rSO2) is significantly lower in hemodialysis (HD) patients than that in healthy controls, investigations on cerebral oxygenation in peritoneal dialysis (PD) patients are limited. We aimed to confirm the cerebral oxygenation status and identify the factors affecting cerebral rSO2 in PD patients. Methods: Thirty-six PD patients (21 men and 15 women mean age, 62.8 ± 12.7 years) were recruited. In addition, 27 healthy volunteers (17 men and 10 women mean age, 43.5 ± 18.8 years) were recruited as a control group. Cerebral rSO2 was monitored at the forehead using an INVOS 5100c oxygen saturation monitor. Results: Cerebral rSO2 was significantly lower in PD patients than that in healthy controls (57.0 ± 7.3% vs 68.9 ± 8.6%, p &lt 0.001) moreover, cerebral rSO2 was significantly correlated with natural logarithm (Ln)-PD duration (r = −0.389, p = 0.019) and serum albumin concentration (r = 0.370, p = 0.026) in a simple linear regression analysis. Multivariable linear regression analysis was performed using variables that showed a significant correlation and p &lt 0.20 (serum creatinine, serum sodium, Ln-C-reactive protein, and dosage of erythropoiesis-stimulating agent) with the cerebral rSO2. Cerebral rSO2 was independently associated with Ln-PD duration (standardized coefficient: −0.339) and serum albumin concentration (standardized coefficient: 0.316). Conclusions: Cerebral rSO2 was significantly affected by the PD duration and serum albumin concentration. Further prospective studies are needed to clarify whether preventing a decrease in serum albumin concentration leads to the maintenance of cerebral oxygenation in patients undergoing PD.

PURPOSE: We compared the efficacy of teneligliptin versus linagliptin for glycemic control and renoprotection in patients with advanced-stage diabetic kidney disease. PATIENTS AND METHODS: Changes in the glycated hemoglobin (HbA1c), fasting blood glucose concentration, urine albumin-to-creatinine ratio (UACR), and estimated glomerular filtration rate (eGFR) during a 12-month period were retrospectively analyzed after switching from linagliptin to teneligliptin in 13 patients with advanced-stage diabetic kidney disease (teneligliptin group). Thirteen propensity score-matched patients who were treated with linagliptin alone served as controls (linagliptin group). RESULTS: The HbA1c, fasting blood glucose concentration, and UACR did not change during the 12-month study period in either group. The annual change rate in the eGFR did not differ between before and after baseline in either group. CONCLUSION: Switching from linagliptin to teneligliptin may not improve glycemic control, reduce urinary protein excretion, or ameliorate the rate of renal function decline in patients with advanced-stage diabetic kidney disease. These results suggest that teneligliptin may not be more advantageous for glycemic control and renoprotection compared with linagliptin in patients with advanced-stage diabetic kidney disease.

Vascular access is necessary for hemodialysis, and in some cases where it is difficult to establish an arteriovenous fistula or arteriovenous graft, a permanent hemodialysis catheter may be used. However, serious catheter-related complications, such as central vein stenosis or thrombosis, can occur. We herein present a case of complete brachiocephalic vein obstruction in a patient with lupus nephritis receiving hemodialysis using a tunneled hemodialysis catheter. A 64-year-old patient underwent maintenance hemodialysis while taking an anticoagulant, with a tunneled hemodialysis catheter in the right internal jugular vein, because of arteriovenous fistula failure when hemodialysis was introduced. However, the catheter was removed because of a catheter-related bloodstream infection. Following the administration of antibiotics, an arteriovenous graft was implanted between the brachial artery and axillary vein in the right arm. Surprisingly, arteriovenous graft failure and complete obstruction of the right brachiocephalic vein were observed 3 days after arteriovenous graft creation. In conclusion, we report the case of tunneled hemodialysis catheter-related complete obstruction of the right brachiocephalic vein in a lupus nephritis patient undergoing hemodialysis. Clinicians should be aware of this potential complication when tunneled hemodialysis catheters are used and consider the next vascular access type before a tunneled hemodialysis catheter has been indwelled for the long term.

Background Few studies have assessed the relationship between serum total carbon dioxide (CO2) and bicarbonate ion (HCO3 -) concentration in patients undergoing peritoneal dialysis. We determined the agreement between serum total CO2 and HCO3 - concentration and the diagnostic accuracy of serum total CO2 for the prediction of low (HCO3 - <24 mEq/L) and high (HCO3 - ≥24 mEq/L) bicarbonate concentrations in patients on peritoneal dialysis. Methods We collected 245 samples of venous blood from 51 patients on peritoneal dialysis. Independent factors that correlated with the HCO3 - concentration were analyzed using multiple linear regression analysis. The diagnostic accuracy of serum total CO2 was evaluated by receiver operating characteristic (ROC) curve analysis and a 2×2 table. Agreement between serum total CO2 and HCO3 - concentration was assessed by Bland-Altman analysis. Results Serum total CO2 was independently correlated with HCO3 - concentration (β = 0.354, p < 0.001). The area under the curve of serum total CO2 for the identification of low and high bicarbonate concentrations was 0.909. The diagnostic accuracy of serum total CO2 for the prediction of low and high bicarbonate concentrations was: sensitivity, 91.5%; specificity, 74.7%; positive predictive value, 53.5%; negative predictive value, 96.5%; and accuracy, 78.8%. Bland-Altman analysis showed a moderate agreement between serum total CO2 and HCO3 - concentration. Conclusion Serum total CO2 correlated closely with the HCO3 - concentration in patients undergoing peritoneal dialysis. Serum total CO2 might be useful for predicting low and high bicarbonate in peritoneal dialysis patients.

RATIONALE: Herein, we report 3 hemodialysis patients with idiopathic hypereosinophilic syndrome who were successfully treated using corticosteroid therapy. PATIENT CONCERNS: Case 1 was a 63-year-old man who was undergoing hemodialysis because of bilateral nephrectomy and developed hypereosinophilia with digestive symptoms, myocardial injury, and intradialytic hypotension. Case 2 was an 83-year-old man who was undergoing hemodialysis because of nephrosclerosis and developed hypereosinophilia with pruritus, myocardial injury, and intradialytic hypotension. Case 3 was a 59-year-old man who was undergoing hemodialysis because of diabetic nephropathy and developed hypereosinophilia with pruritus, myocardial injury, and intradialytic hypotension. DIAGNOSES: All 3 patients presented with hypereosinophilia (eosinophil count ≥1500 /μL for more than 1 month) and multiple-organ involvement (intradialytic hypotension, cardiac injury, digestive symptoms, and allergic dermatitis). A specific cause for the hypereosinophilia was not identified by systemic computed tomography, electrocardiography, echocardiography, bone marrow examination, or blood tests. Furthermore, Case 2 and 3 had not recently started taking any new drugs and drug-induced lymphocyte stimulation tests were negative in Case 1. Therefore, they were diagnosed with idiopathic hypereosinophilic syndrome. INTERVENTIONS: All 3 patients received corticosteroid therapy with prednisolone at a dose of 40 mg/d, 30 mg/d, and 60 mg/d in Case 1, 2, and 3, respectively. OUTCOMES: Their digestive symptoms, pruritus, intradialytic hypotension, and serum troponin I concentrations were immediately improved alongside reductions in their eosinophil counts. LESSONS: There have been few case reports of idiopathic hypereosinophilic syndrome in patients undergoing hemodialysis. We believe that recording of the clinical findings and treatments of such patients is mandatory to establish the optimal management of idiopathic hypereosinophilic syndrome.

INTRODUCTION: The prevalence of cognitive impairment in patients undergoing hemodialysis (HD) is higher than that in healthy controls. To date, studies on the association between cognitive function and cerebral oxygenation in these patients are limited. Therefore, in this study, we aimed to cross-sectionally investigate the association between cognitive assessment scores and clinical factors, including cerebral oxygenation, in patients undergoing HD. METHODS: In this observational study, 193 HD patients were included. Cerebral regional oxygen saturation (rSO2) was monitored using an INVOS 5,100c oxygen saturation monitor. Poor cognition was defined as a Mini-Mental State Examination (MMSE) score ≤23. We analyzed the association between MMSE score and clinical factors, including cerebral rSO2. RESULTS: MMSE score in HD patients included in this study was 26.8 ± 3.3. There were 164 patients (85%) with MMSE score ≥24 and 29 patients (15%) with an MMSE score ≤23. In the patients with MMSE score ≥24, cerebral rSO2 (53.8% ± 8.3%) was significantly higher than that in patients with MMSE score ≤23 (49.5% ± 9.8%; p = 0.013). Multivariable linear regression analysis was performed using the following confounding factors: age, mean blood pressure, cerebral rSO2, HD duration, ultrafiltration rate, hemoglobin, serum Cr, serum calcium, serum phosphate, total cholesterol, high-density lipoprotein cholesterol levels, serum albumin, presence of diabetes mellitus or chronic glomerulonephritis, history of comorbid cardiovascular or cerebrovascular disease, and use of renin-angiotensin-aldosterone system inhibitors or vitamin D analogs. MMSE score was independently and significantly associated with age (standardized coefficient: -0.244) and cerebral rSO2 (standardized coefficient: 0.180). CONCLUSIONS: MMSE score was independently associated with age (negative effect) and cerebral rSO2 (positive effect) in this cross-sectional study. Further prospective studies are needed to clarify whether maintaining cerebral oxygenation prevents the deterioration of cognitive function in patients undergoing HD.

The hepato-splanchnic circulation directly influences oxygenation of the abdominal organs and plays an important role in compensating for the blood volume reduction that occurs in the central circulation during hemodialysis (HD) with ultrafiltration. However, the hepato-splanchnic circulation and oxygenation cannot be easily evaluated in the clinical setting of HD therapy. We included 185 HD patients and 15 healthy volunteers as the control group in this study. Before HD, hepatic regional oxygen saturation (rSO2), a marker of hepatic oxygenation reflecting the hepato-splanchnic circulation and oxygenation, was monitored using an INVOS 5100c oxygen saturation monitor. Hepatic rSO2 was significantly lower in patients undergoing HD than in healthy controls (56.4 ± 14.9% vs. 76.2 ± 9.6%, p < 0.001). Multivariable regression analysis showed that hepatic rSO2 was independently associated with body mass index (BMI; standardized coefficient: 0.294), hemoglobin (Hb) level (standardized coefficient: 0.294), a history of cardiovascular disease (standardized coefficient: -0.157), mean blood pressure (BP; standardized coefficient: 0.154), and serum albumin concentration (standardized coefficient: 0.150) in Model 1 via a simple linear regression analysis. In Model 2 using the colloid osmotic pressure (COP) in place of serum albumin concentration, the COP (standardized coefficient: 0.134) was also identified as affecting hepatic rSO2. Basal hepatic oxygenation before HD might be affected by BMI, Hb levels, a history of cardiovascular disease, mean BP, serum albumin concentration, and the COP. Further prospective studies are needed to clarify whether changes in these parameters, including during HD, affect the hepato-splanchnic circulation and oxygenation in HD patients.

Background: We investigated the effects of roxadustat on the anemia, iron metabolism, peritoneal membrane function, and residual renal function; and determined the factors associated with the administration of roxadustat in patients who were undergoing peritoneal dialysis. Methods: We retrospectively analyzed the changes in hemoglobin, serum ferritin, transferrin saturation (TSAT), 4-h dialysate/plasma creatinine, and renal weekly urea clearance over the 24 weeks following the change from an erythropoiesis-stimulating agent (ESA) to roxadustat in 16 patients who were undergoing peritoneal dialysis and had anemia (Roxadustat group). Twenty-three peritoneal dialysis patients who had anemia and continued ESA served as a control group (ESA group). Results: There were no significant differences in hemoglobin, serum ferritin, TSAT, 4-h dialysate/plasma creatinine, or renal weekly urea clearance between the two groups at baseline. The hemoglobin concentration was significantly higher in the Roxadustat group than in the ESA group after 24 weeks (11.6 ± 1.0 g/dL vs. 10.3 ± 1.1 g/dL, p < 0.05), whereas the ferritin concentration and TSAT were significantly lower (139.5 ± 102.0 ng/mL vs. 209.2 ± 113.1 ng/mL, p < 0.05; and 28.1 ± 11.5% vs. 44.8 ± 10.4%, p < 0.05, respectively). The changes in 4-h dialysate/plasma creatinine and renal weekly urea clearance did not differ between the two groups. Linear regression analysis revealed that the serum potassium concentration correlated with the dose of roxadustat at 24 weeks (standard coefficient = 0.580, p = 0.019). Conclusion: Roxadustat may improve the anemia and reduce the serum ferritin and TSAT of the peritoneal dialysis patients after they were switched from an ESA, without association with peritoneal membrane function or residual renal function.

OBJECTIVE: The aim of this study was to investigate the effects of elobixibat on constipation and lipid metabolism; and determine the factors associated with the effect of elobixibat on constipation in patients with moderate to end-stage chronic kidney disease (CKD). METHODS: Stool frequency and serum lipid parameters were retrospectively analyzed before and after 4 weeks of elobixibat administration in 42 patients (CKD stage G3, 6; stage G4, 9; stage G5, 9; stage G5D, 18). Relationships between the change in stool frequency after initiation of elobixibat and various clinical parameters were analyzed by using linear regression analysis. RESULTS: Elobixibat increased stool frequency from 0.5 ± 0.4 per day to 1.1 ± 0.6 per day (p < 0.001) regardless of whether patients were undergoing dialysis, on concomitant laxatives, or were administered elobixibat before or after breakfast. Elobixibat reduced low-density lipoprotein cholesterol concentration (from 90.9 ± 37.2 mg/dL to 77.5 ± 34.8 mg/dL, p < 0.05) and increased high-density lipoprotein cholesterol concentration (from 44.9 ± 14.3 mg/dL to 57.0 ± 25.8 mg/dL, p < 0.05), but did not change triglyceride concentration. Adverse effects were observed in two patients (nausea and diarrhea). Only phosphate concentration was correlated with the change in stool frequency after initiation of elobixibat (standard coefficient = 0.321, p = 0.043). CONCLUSIONS: Elobixibat improved constipation and lipid metabolism in patients with moderate to end-stage CKD, without serious adverse events.

Near-infrared spectroscopy (NIRS) has recently been applied as a tool to measure regional oxygen saturation (rSO2), a marker of tissue oxygenation, in clinical settings including cardiovascular and brain surgery, neonatal monitoring and prehospital medicine. The NIRS monitoring devices are real-time and noninvasive, and have mainly been used for evaluating cerebral oxygenation in critically ill patients during an operation or intensive care. Thus far, the use of NIRS monitoring in patients with chronic kidney disease (CKD) including hemodialysis (HD) has been limited therefore, we investigated rSO2 values in some organs during HD. We monitored rSO2 values using a NIRS device transmitting near-infrared light at 2 wavelengths of attachment. The HD patients were placed in a supine position, with rSO2 measurement sensors attached to the foreheads, the right hypochondrium and the lower legs to evaluate rSO2 in the brain, liver and lower leg muscles, respectively. NIRS monitoring could be a new approach to clarify changes in organ oxygenation during HD or factors affecting tissue oxygenation in CKD patients. This article describes a protocol to measure tissue oxygenation represented by rSO2 as applied in HD patients.

Background: Zinc deficiency is common and is associated with erythropoietin resistant anemia, dysgeusia, and hypogonadism in patients undergoing hemodialysis. However, the prevalence and clinical effects of zinc deficiency in patients undergoing peritoneal dialysis (PD) have not been determined. Methods: This was a retrospective, cross-sectional study. The prevalence of serum zinc deficiency and the clinical factors related to serum zinc concentration were determined in 49 patients undergoing PD [mean age 59.5 years (±14.8 years), 38/49 were men (78.6%), median PD period 24.0 months (12.5–45.0 months)]. A serum zinc concentration &lt 60 μg/dL was defined as serum zinc deficiency, and a serum zinc concentration between 60 and 80 μg/dL as possible serum zinc deficiency. Results: Serum zinc deficiency was present in 51% (25/49) of the patients, and possible serum zinc deficiency was present in 45% (22/49) of patients undergoing PD. Multivariate analysis showed that serum zinc concentration significantly correlated with serum ferritin concentration (β = 0.357, P &lt 0.01). Conclusions: The prevalences of serum zinc deficiency and possible serum deficiency are high and serum zinc concentration correlates with serum ferritin concentration in patients undergoing PD.

MicroRNAs (miRNAs) are involved in various disease states and are effective biomarkers for the early diagnosis of diseases and treatment in mice. However, standard protocols for the purification of miRNAs and detection of their expression in the kidneys of acute kidney injury (AKI) mice have not been well established. This study developed an effective and simple protocol to purify and quantify miRNAs in the kidneys of an AKI mouse model induced by renal ischemia-reperfusion using quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). This protocol comprises five steps: 1) induction of AKI by renal ischemia-reperfusion, 2) harvesting of kidneys, 3) purification of total RNA, including miRNAs, from kidneys, 4) cDNA synthesis by reverse transcription of miRNA, and 5) qRT-PCR to detect miRNA expression. Using this protocol, the renal ischemia-reperfusion injury model can be generated with mild to severe forms of AKI. Additionally, if the procedure is followed properly, a consistent AKI model with minimal individual differences can be obtained. This qRT-PCR assay shows a very wide dynamic range and enables the discrimination of mature miRNAs, which can be accurately quantified with high specificity. This protocol can be used to study the miRNA expression profile in AKI kidneys.

Hemoglobin (Hb) is associated with cerebral oxygenation status owing to its important role of carrying oxygen to systemic tissues. However, data concerning the associations between Hb levels and cerebral regional oxygen saturation (rSO2) of hemodialysis (HD) patients is limited. We aimed to identify these associations to consider a target Hb level for renal anemia management. This study included 375 HD patients. Cerebral rSO2 before HD was monitored using the INVOS 5100c oxygen saturation monitor. Multivariable linear regression analysis showed that cerebral rSO2 was independently associated with natural logarithm (Ln)-HD duration (standardized coefficient: -0.36), mean blood pressure (standardized coefficient: 0.13), pH (standardized coefficient: -0.10), serum albumin (standardized coefficient: 0.14), presence of diabetes mellitus (standardized coefficient: -0.20), and Hb level (standardized coefficient: 0.29). Furthermore, a generalized linear model with restricted cubic spline function was used to investigate the non-linear association between cerebral rSO2 and Hb levels. In the multivariable analysis for the adjustment with Ln-HD duration, mean blood pressure, pH, serum albumin, and presence of diabetes mellitus, a linear relationship was demonstrated between the two variables (p for linearity = 0.79). Hb levels revealed the positive and significant association with cerebral rSO2 in this study. Moreover, the relationship between cerebral rSO2 and Hb level was proven to be linear. Therefore, the target Hb level in renal anemia management would be considered to be the upper limits for the appropriate management of renal anemia by previous guidelines and position statement from the viewpoint of maintaining cerebral oxygenation in HD patients.

An 88-year-old man with congenital hemophilia A developed end-stage renal disease due to microscopic polyangiitis. He was at risk for catheter-related infection because he was taking immunosuppressive agents for the treatment of polyangiitis. He was also unable to manipulate the peritoneal dialysis device. Therefore, hemodialysis using an arteriovenous fistula was induced for renal replacement therapy. Recombinant coagulation factor VIII (1000 IU) was administered via the venous chamber of the hemodialysis circuit 10 min before the end of each hemodialysis session, and nafamostat mesylate (25 mg/h) was employed as an anticoagulant during hemodialysis. His clotting factor VIII activity level increased to &gt  50% and activated partial thromboplastin time decreased to 50 s at the end of each hemodialysis session. This method allowed him to achieve hemostasis at the puncture site of the arteriovenous fistula and undergo stable hemodialysis with no complications, including bleeding. This case suggests that hemodialysis using an arteriovenous fistula with coagulation factor replacement and nafamostat mesylate in each hemodialysis session is a therapeutic option for end-stage renal disease in patients of advanced age with hemophilia at high risk of bleeding.

Immunoglobulin A (IgA) nephropathy is a type of primary glomerulonephritis characterized by the abnormal deposition of IgA, leading to the end-stage renal failure. In recent years, the involvement of microRNAs (miRNAs) has been reported in the pathogenesis of IgA nephropathy. However, there is no established method for profiling miRNAs in IgA nephropathy using small animal models. Therefore, we developed a reliable method for analyzing miRNA in the kidney of an IgA mouse model (HIGA mouse). The goal of this protocol is to detect the altered expression levels of miRNAs in the kidneys of HIGA mice when compared with the levels in kidneys of control mice. In brief, this method consists of four steps: 1) obtaining kidney samples from HIGA mice 2) purifying total RNA from kidney samples 3) synthesizing complementary DNA from total RNA and 4) quantitative reverse transcription polymerase chain reaction (qRT-PCR) of miRNAs. Using this method, we successfully detected the expression levels of several miRNAs (miR-155-5p, miR-146a-5p, and miR-21-5p) in the kidneys of HIGA mice. This new method can be applied to other studies profiling miRNAs in IgA nephropathy.

A 49-year-old woman developed eosinophilic peritonitis 2 months after starting continuous ambulatory peritoneal dialysis because of congenital right kidney hypoplasia and chronic glomerulonephritis. This was shown to have been induced by sucroferric oxyhydroxide, an iron-based phosphate binder, using a drug-induced lymphocyte stimulation test. Her eosinophilic peritonitis was improved after stopping the administration of sucroferric oxyhydroxide without providing any immunosuppressive agents.

INTRODUCTION: The use of warfarin in patients undergoing hemodialysis is associated with decreased bone mineral density and an increased incidence of bone fracture. However, no studies to date have directly estimated bone quality with bone histomorphometry in patients with bone abnormalities who are taking warfarin and undergoing hemodialysis. PATIENT CONCERNS: A 47-year-old female with Noonan syndrome presented with progressive bilateral lower extremity pain on walking, and skin sclerosis. She had been undergoing maintenance hemodialysis for 25 years following 2 years of peritoneal dialysis for chronic glomerulonephritis. She had been taking warfarin as an anticoagulant agent for 13 years after she underwent an aortic valve replacement. DIAGNOSIS: Warfarin-induced impairment of bone material quality. INTERVENTIONS AND OUTCOMES: Histomorphometric analysis of the bone biopsy specimens showed impairment in bone calcification processes, a high turnover of bone remodeling, low bone volume, and mild fibrosis. The bone abnormality could not be categorized into any type of representative bone disease classification such as osteitis fibrosa, osteomalacia, adynamic bone disease, uremic osteodystrophy, or hyperparathyroidism, but was consistent with warfarin-induced impairment of bone material quality. CONCLUSION: Warfarin can induce impairment of bone material quality in a patient undergoing hemodialysis.

A 76-year-old woman on hemodialysis (HD) for diabetic nephropathy was admitted to our hospital with occasional intradialytic hypotension (IDH). We continuously monitored the regional oxygen saturation (rSO2) in the brain, liver, and lower limb muscle during HD. The time course of changes in rSO2 ratios in each region was evaluated throughout HD. The rSO2 ratio was defined as the ratio of rSO2 value at t (min) during HD to the rSO2 value before HD. During the early phase of HD, blood pressure (BP) gradually decreased and both hepatic and lower limb muscle rSO2 ratios decreased with changes in BP, whereas the cerebral rSO2 ratio was relatively maintained. At around 90 min after HD initiation, the BP decreased to 71/46 mmHg (mean BP, 54 mmHg) and the previously maintained cerebral rSO2 ratio also suddenly decreased. Soon after the onset of IDH, ultrafiltration was stopped, normal saline was infused, and intravenous noradrenaline infusion was started. After the BP recovered, cerebral and hepatic rSO2 ratios improved, but the lower limb muscle rSO2 ratio remained low. After restarting ultrafiltration, improvement in the lower limb muscle rSO2 ratio was delayed, although cerebral and hepatic oxygenation were maintained. This observation aids in our understanding of the effect of IDH on regional tissue oxygenation.

Sarcopenia, which is characterized by the loss of skeletal muscle, has been reported to contribute to development of physical disabilities, various illnesses, and increasing mortality. MicroRNAs (miRNAs) are small non-coding RNAs that inhibit translation of target messenger RNAs. Previous studies have shown that miRNAs play pivotal roles in the development of sarcopenia. Therefore, this systematic review focuses on miRNAs that regulate sarcopenia.

Carnitine deficiency contributes to developing various pathological conditions, such as cardiac dysfunction, muscle weakness, and erythropoietin-resistant anemia in patients undergoing hemodialysis. However, a conclusion has not been reached concerning the prevalence and the effect of carnitine deficiency in patients undergoing peritoneal dialysis (PD). In this study, the prevalence of carnitine deficiency and the clinical factors associated with carnitine deficiency were investigated in 60 patients undergoing PD. The median age of the patients was 62.5 years (52.5–72.5 years), the proportion of male sex was 44/60 (73.3%), and the median PD period was 24 months (12–45 months). Carnitine deficiency (acyl carnitine/free carnitine ratio &gt 0.4) was detected in 56/60 (93%) patients. Multiple regression analysis showed that the erythropoietin resistance index was independently associated with carnitine deficiency (β = 0.283, p = 0.04). These results suggest that carnitine plays pivotal roles in hematogenesis in patients undergoing PD.

Background: Proteinase 3-antineutrophil cytoplasmic antibody has been reported to be positive in 5-10% of cases of renal injury complicated by infective endocarditis however, histological findings have rarely been reported for these cases. Case presentation: A 71-year-old Japanese man with a history of aortic valve replacement developed rapidly progressive renal dysfunction with gross hematuria and proteinuria. Blood analysis showed a high proteinase 3-antineutrophil cytoplasmic antibody (163 IU/ml) titer. Streptococcus species was detected from two separate blood culture bottles. Transesophageal echocardiography detected mitral valve vegetation. Histological evaluation of renal biopsy specimens showed necrosis and cellular crescents in glomeruli without immune complex deposition. The patient met the modified Duke criteria for definitive infective endocarditis. On the basis of these findings, the patient was diagnosed with proteinase 3-antineutrophil cytoplasmic antibody-positive necrotizing crescentic glomerulonephritis complicated by Streptococcus infective endocarditis. His renal disease improved, and his proteinase 3-antineutrophil cytoplasmic antibody titer normalized with antibiotic monotherapy. Conclusion: Few case reports have described histological findings of proteinase 3-antineutrophil cytoplasmic antibody-positive renal injury complicated with infective endocarditis. We believe that an accumulation of histological findings and treatments is mandatory for establishment of optimal management for proteinase 3-antineutrophil cytoplasmic antibody-positive renal injury complicated with infective endocarditis.

Hemodialysis (HD) patients frequently experience severe anemia, requiring intradialytic blood transfusion. Severe anemia leads to deterioration of systemic tissue oxygenation. However, few reports have examined the effect of intradialytic blood transfusion on tissue oxygenation changes. This study aimed to (i) monitor the differences in tissue oxygenation in the brain and liver during intradialytic blood transfusion, and (ii) elucidate the clinical factors affecting cerebral and hepatic oxygenation. Thirty-eight HD patients with severe anemia requiring intradialytic blood transfusion were included (27 men, 11 women mean age, 70.2 ± 1.6 years). Cerebral and hepatic regional oxygen saturation (rSO2) values were monitored using near-infrared spectroscopy (INVOS 5100c oxygen saturation monitor). Cerebral and hepatic rSO2 were significantly higher after than before blood transfusion (p &lt 0.001, both). Furthermore, hepatic rSO2 was significantly higher than cerebral rSO2 after transfusion (p = 0.004). In multivariable linear regression analysis, cerebral rSO2 changes were independently associated with the natural logarithm of hemoglobin (Hb) ratio (Hb after/before transfusion) (standardized coefficient: 0.367, p = 0.023), whereas hepatic rSO2 changes were independently associated with the natural logarithm of [Hb ratio/colloid osmotic pressure ratio (colloid osmotic pressure after/before transfusion)] (standardized coefficient: 0.378, p = 0.019). In conclusion, throughout intradialytic blood transfusion, brain and liver tissue oxygenation improved. Hepatic rSO2 was significantly higher than cerebral rSO2 at the end of HD. Furthermore, cerebral oxygenation changes were associated with only transfusion-induced Hb increase, whereas hepatic oxygenation changes were associated with both transfusion-induced Hb increase (positive changes) and ultrafiltration-induced colloid osmotic pressure increase (negative changes).