The Japanese Society for Apheresis clinical practice guideline for therapeutic apheresis

Most of the diseases for which apheresis therapy is indicated are intractable and rare, and each patient has a different background and treatment course prior to apheresis therapy initiation. Therefore, it is difficult to conduct large-scale randomized controlled trials to secure high-quality evidence. Under such circumstances, the American Society for Apheresis (ASFA) issued its guidelines in 2007, which were repeatedly revised until the latest edition in 2019. The ASFA guidelines are comprehensive. However, in the United States, a centrifugal separation method is mainly used for apheresis, whereas the mainstream procedure in Japan is the membrane separation method. The target diseases and their backgrounds are different from those in Japan. Due to these differences, the direct adoption of the ASFA guidelines in Japanese practice creates various problems. One of the features of apheresis in Japan is the development of treatment methods using hollow-fiber devices such as double filtration plasmapheresis (DFPP) and selective plasma exchange and adsorption-type devices such as polymyxin B-immobilized endotoxin adsorption columns. Specialists in emergency medicine, hematology, collagen diseases/rheumatology, respiratory medicine, cardiovascular medicine, gastroenterology, neurology, nephrology, and dermatology who are familiar with apheresis therapy gathered for this guideline, which covers 86 diseases. In addition, since apheresis therapy involves not only physicians but also clinical engineers, nurses, dieticians, and many other medical professionals, this guideline was prepared in the form of a worksheet so that it can be easily understood at the bedside. Moreover, to the clinical purposes, this guideline is designed to summarize apheresis therapy in Japan and to disseminate and further develop Japanese apheresis technology to the world. As diagnostic and therapeutic techniques are constantly advancing, the guidelines need to be revised every few years. In order to ensure the high quality of apheresis therapy in Japan, both the Japanese Society for Apheresis Registry and the guidelines will be inseparable.

Renal TNFα activates the WNK phosphorylation cascade and contributes to salt-sensitive hypertension in chronic kidney disease

The inappropriate over-activation of the with-no-lysine kinase (WNK)-STE20/SPS1-related proline/alanine-rich kinase (SPAK)-sodium chloride cotransporter (NCC) phosphorylation cascade increases sodium reabsorption in distal kidney nephrons, resulting in salt-sensitive hypertension. Although chronic kidney disease (CKD) is a common cause of salt-sensitive hypertension, the involvement of the WNK phosphorylation cascade is unknown. Moreover, the effect of immune systems on WNK kinases has not been investigated despite the fact that immune systems are important for salt sensitivity. Here we demonstrate that the protein abundance of WNK1, but not of WNK4, was increased at the distal convoluted tubules in the aristolochic acid nephropathy mouse model of CKD. Accordingly, the phosphorylation of both SPAK and NCC was also increased. Moreover, a high-salt diet did not adequately suppress activation of the WNK1-SPAK-NCC phosphorylation cascade in this model, leading to salt-sensitive hypertension. WNK1 also was increased in adenine nephropathy, but not in subtotal nephrectomy, models of CKD. By comparing the transcripts of these three models focusing on immune systems, we hypothesized that tumor necrosis factor (TNF)-α regulates WNK1 protein expression. In fact, TNF-α increased WNK1 protein expression in cultured renal tubular cells by reducing the transcription and protein levels of NEDD4-2 E3-ligase, which degrades WNK1 protein. Furthermore, the TNF-α inhibitor etanercept reversed the reduction of NEDD4-2 expression and upregulation of the WNK1-SPAK-NCC phosphorylation cascade in distal convoluted tubules in vivo in the aristolochic acid nephropathy model. Thus, salt-sensitive hypertension is induced in CKD via activation of the renal WNK1- SPAK-NCC phosphorylation cascade by TNF-α, reflecting a link with the immune system.

Nationwide in-hospital mortality following major fractures among hemodialysis patients and the general population: An observational cohort study

BACKGROUNDS

End-stage kidney disease (ESKD) is associated with increased risk of fracture and subsequent morbidity and mortality. However, fracture site-specific mortality in ESKD patients have yet to be elucidated in comparison with the general population.

METHODS

In this population-based cohort derived from the Diagnosis Procedure Combination database of Japan from 2012 to 2014, we included 9320 ESKD patients undergoing hemodialysis and 547,726 patients without ESKD who were hospitalized for five major fractures, including hip (proximal femur), spine, forearm, upper arm, and leg (distal femur and proximal tibia). Overall and site-specific risks of in-hospital death were determined by logistic regression models.

RESULTS

The age- and sex-adjusted mortality rates were 4.91% (95% confidence interval [CI], 4.46-5.37) and 1.02% (95% CI, 0.99-1.06) in the hemodialysis and general population groups, respectively. The multivariate odds ratio (OR) of death in hemodialysis patients versus the general population was 2.48 (95% CI, 2.25-2.74) for overall fractures, and was particularly high for a subgroup of upper arm fracture (OR 4.82, 95% CI, 3.19-7.28). The site-specific odds of death (95% CI) among hip, spine, forearm, upper arm, and leg (reference) fractures were 1.77 (0.98-3.18), 1.48 (0.79-2.75), 0.19 (0.04-0.86), and 2.01 (1.01-4.01) in hemodialysis patients, and 1.28 (1.13-1.45), 1.00 (0.88-1.14), 0.13 (0.10-0.17), and 0.83 (0.70-0.97) in the general population, respectively.

CONCLUSION

Hemodialysis patients experienced a 4.8-fold higher mortality rate after fractures than the general population. Mortality after upper arm fracture was specifically high in patients on hemodialysis, likely due to the involvement of vascular access located on the fractured arm.

Encephalopathy Induced by High Plasma and Cerebrospinal Fluid Ceftriaxone Concentrations in a Hemodialysis Patient

Encephalopathy is a rare side effect of cephalosporin treatment. We herein present a case of encephalopathy induced by ceftriaxone, a third-generation cephalosporin, in a patient with renal failure. An 86-year-old woman on maintenance hemodialysis received ceftriaxone for Helicobacter cinaedi bacteremia. Her mental status deteriorated during antibiotic treatment, and an electroencephalogram revealed triphasic waves predominantly in the frontal area. Her consciousness improved after the discontinuation of the antibiotic due to the suspicion of ceftriaxone-induced encephalopathy. This is the first reported case of encephalopathy associated with high plasma and cerebrospinal fluid ceftriaxone concentrations, and provides significant evidence for a causal relationship between the administration of ceftriaxone and the onset of encephalopathy.

Removal Characteristics of Immunoadsorption with the Tryptophan-Immobilized Column Using Conventional and Selective Plasma Separators in the Treatment of Myasthenia Gravis

Autoimmune neurological diseases are often treated by immunoadsorption using a conventional plasma separator and tryptophan-immobilized column (IA). However, there is only one case report on treatment with immunoadsorption using a selective plasma separator and tryptophan-immobilized column (SeIA) in clinical practice. This study aimed to investigate the removal characteristics of antibodies against acetylcholine receptors (AChRAb), immunoglobulin G, fibrinogen, and factor XIII (FXIII) in IA and SeIA in four patients with myasthenia gravis. A total of 19 sessions of immunoadsorption were performed (five sessions of IA and 14 sessions of SeIA) when the processed plasma volume was 2 L. The corresponding reductions were 52.5% ± 6.2% for AChRAb, 58.8% ± 4.2% for fibrinogen, and 36.9% ± 5.5% for FXIII after one session of IA. The corresponding reductions were 45.2% ± 9.9% for AChRAb, 3.5% ± 6.9% for fibrinogen, and -4.6% ± 11.1% for FXIII after one session of SeIA. The removal rates for AChRAb, fibrinogen, and FXIII in IA were significantly higher than those in SeIA. IA could effectively remove AChRAb, and SeIA could retain fibrinogen and FXIII. IA can be combined with SeIA, resulting in both IgG autoantibodies removal by IA and retention of coagulation factors by SeIA.

Failure to sense energy depletion may be a novel therapeutic target in chronic kidney disease

The kidneys consume a large amount of energy to regulate volume status and blood pressure and to excrete uremic toxins. The identification of factors that cause energy mismatch in the setting of chronic kidney disease (CKD) and the development of interventions aimed at improving this mismatch are key research imperatives. Although the critical cellular energy sensor 5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK) is known to be inactivated in CKD, the mechanism of AMPK dysregulation is unknown. In a mouse model of CKD, metabolome analysis confirmed a decrease in AMPK activation in the kidneys despite a high AMP: ATP ratio, suggesting that AMPK did not sense energy depletion. Similar AMPK inactivation was found in heart and skeletal muscle in CKD mice. Several uremic factors were shown to inactivate AMPK in vitro and in ex vivo preparations of kidney tissue. The specific AMPK activator A-769662, which bypasses the AMP sensing mechanism, ameliorated fibrosis and improved energy status in the kidneys of CKD mice, whereas an AMP analog did not. We further demonstrated that a low-protein diet activated AMPK independent of the AMP sensing mechanism, leading to improvement in energy metabolism and kidney fibrosis. These results suggest that a failure to sense AMP is the key mechanism underlying the vicious cycle of energy depletion and CKD progression and direct AMPK activation may be a novel therapeutic approach in CKD.

Oral and maxillofacial surgery in patients undergoing dialysis for advanced renal disease: report of five cases

BACKGROUND

Perioperativemanagement of hemodialysis patients involves many difficulties. High mortality rate and circulatory or respiratory complications in these patients were reported. However, in such reports, there is no concrete information of perioperative management in hemodialysis patients to prevent surgical complications and successful outcomes.

CASE PRESENTATION

We retrospectively reviewed the cases of 5 hemodialysis patients who underwent oral surgery under general anesthesia between January 2005 and December 2017. Primary disease was oral squamous cell carcinoma (SCC) in 4 patients and mandibular ameloblastoma in 1 patient. Partial resection was performed in 2 cases, neck dissection in 1 case. Two cases underwent surgery including vascularized reconstruction. The patients were dialyzed the day before and after surgery for the control of fluid and electrolyte status. Patients received intraoperative and postoperative intravenous infusion of potassium-free solution at 20-40 mL/h. Erythropoiesis-stimulating agents (ESAs) were used on the day of hemodialysis during hospitalization. Nafamostat mesilate as an anticoagulant during hemodialysis were used from postoperative day (POD)1 to 7. From POD 1 to 10, cephalosporin as prophylactic antibiotics is adjusted to quarter from half the initial dose. The resuming time of oral intake was similar to that of other oral surgery patients without kidney disease. The daily intake limits of protein, salt and liquid were managed during hospitalization and no cases suffered from malnutrition. No cardiorespiratory complications occurred during the perioperative period. In a case of vascularized osteocutaneous scapular flap reconstruction, grafted scapular bone survived and scapular cutaneous flap necrotized. Necrotic tissue was debrided and split thickness skin was successfully used to cover the grafted scapular bone.

CONCLUSIONS

Postoperative better result could be achieved if adequate perioperative management specific to hemodialysis patients is carried out. Vascularized flap reconstruction at oral and maxillofacial region in hemodialysis patients is beneficial treatment. Even if the first flap has wound complication secondary flap reconstruction is success and aesthetically better results could be achieved by the strict wound management and debridement.

Metformin increases urinary sodium excretion by reducing phosphorylation of the sodium-chloride cotransporter

OBJECTIVE

Metformin is an antidiabetic drug that is widely used to treat patients with diabetes mellitus. Recent studies have reported that treatment with metformin not only improved blood glucose levels but also reduced blood pressure. However, it remains unclear how metformin reduces blood pressure. We hypothesized that metformin affects sodium reabsorption in the kidneys.

METHODS

Urinary sodium excretion and expression of renal sodium transporters were examined in 8-week-old male C57BL/6 mice with acute and chronic treatment of metformin. In addition, we examined metformin effects using ex vivo preparations of mice kidney slices.

RESULTS

In this study, we demonstrated that metformin increased urinary sodium excretion by reducing phosphorylation of the thiazide-sensitive Na-Cl cotransporter (NCC) in acute and chronic metformin administration. We also confirmed reduction of phosphorylated NCC in an ex vivo study. The activity of other renal sodium transporters, such as NKCC2, ENaC, and NHE3 did not show significant changes. WNK-OSR1/SPAK kinase signals were not involved in this inactivation effect of metformin on NCC.

CONCLUSION

Metformin increased urinary sodium excretion by reducing phosphorylation of NCC, suggesting its role in improving hypertension.

Decreased KLHL3 expression is involved in the pathogenesis of pseudohypoaldosteronism type II caused by cullin 3 mutation in vivo

BACKGROUND

Pseudohypoaldosteronism type II (PHAII) is a hereditary hypertensive disease caused by mutations in four genes: WNK1, WNK4, Kelch-like3 (KLHL3), and cullin3 (CUL3). Recently, it was revealed that CUL3-KLHL3 E3 ligase complex ubiquitinates WNK1 and WNK4, leading to their degradation, and that a common pathogenesis of PHAII is defective WNK degradation due to CUL3-KLHL3 E3 ligase complex impairment. PHAII-causing CUL3 mutations mediate exon9 skipping, producing a CUL3 protein with a 57-amino acid deletion (Δ403-459). However, the pathogenic effects of KLHL3, an adaptor protein that links WNKs with CUL3, in PHAII caused by CUL3 mutation remain unclear.

METHODS

To clarify detailed pathophysiological mechanisms underlying PHAII caused by CUL3 mutation in vivo, we generated and analyzed knock-in mice carrying the same CUL3 exon9 deletion (CUL3^WT/Δex9) as that reported in PHAII patients.

RESULTS

CUL3^WT/Δex9 mice exhibited a PHAII-like phenotype. Interestingly, we confirmed markedly decreased KLHL3 expression in CUL3^WT/Δex9 mice by confirming the true KLHL3 band in vivo. However, the expression of other KLHL family proteins, such as KLHL2, was comparable between WT and mutant mice.

CONCLUSION

KLHL3 expression was decreased in CUL3^WT/Δex9 mice. However, expression levels of other KLHL family proteins were comparable between the wild-type and mutant mice. These findings indicate that the decreased abundance of KLHL3 is a specific phenomenon caused by mutant CUL3 (Δexon9). Our findings would improve our understanding of the pathogenesis of PHAII caused by CUL3 mutation in vivo.

Removal Dynamics of Autoantibodies, Immunoglobulins, and Coagulation Factors by Selective Plasma Exchange on Three Consecutive Days

Selective plasma exchange has been shown to be effective in various diseases, but no studies have assessed the benefits of daily treatment. We aimed to investigate the removal dynamics of immunoglobulins, fibrinogen, and factor XIII on three consecutive days in three patients. For mean processed plasma volumes of 1.06 × plasma volume, reductions of 79.6%, 49.3%, and 8.6% were seen for immunoglobulins G, A, and M, respectively. The reductions for fibrinogen and factor XIII were 18.4% and 13.0%, respectively. Removal dynamics were similar for immunoglobulin G-related autoantibodies and immunoglobulin G when using daily selective plasma exchange. Moreover, daily use effectively removed the immunoglobulin G while retaining the coagulation factors. When disease-specific autoantibodies are limited to immunoglobulin G, daily selective plasma exchange may be a useful and safe method of intensive induction treatment for plasmapheresis. However, further study is required in larger cohorts to confirm these findings.

Dialysis Case Volume Associated With In-Hospital Mortality in Maintenance Dialysis Patients

Introduction

Accumulating evidence suggests that a large hospital volume (HV) is associated with favorable outcomes in various diseases or surgical procedures. The aim of this study is to clarify the correlation of HV and dialysis case volume (DCV) with in-hospital death in patients on maintenance dialysis.

Methods

The study cohort was derived from the Diagnosis Procedure Combination database, a national inpatient database in Japan, from 2012 to 2014. We included 382,689 admissions of maintenance dialysis patients over the age of 20 years in the analysis. HV was defined as the mean number of daily hospitalized patients, and DCV was defined as the mean number of annually hospitalized patients on maintenance dialysis. The primary outcome was in-hospital all-cause mortality, evaluated using multivariable logistic regression models across the respective quartiles of HV and DCV.

Results

The mean age of participants was 69 ± 12 years; 94% were receiving hemodialysis, and 21,182 patients (5.5%) died after hospitalization. In unadjusted models, larger HV and DCV were both associated with lower in-hospital mortality. However, this association remained significant only for DCV after adjustment for potential confounders, with multivariable-adjusted odds ratios of 0.82 (95% confidence interval [CI], 0.79–0.85), 0.76 (95% CI, 0.73–0.80), and 0.68 (95% CI, 0.65–0.72) for DCV 249 to 432, 433 to 713, and ≥714 (vs. ≤ 248) admissions per year, respectively. Multivariable subgroup analyses determined that this association was independent of age, sex, dialysis modality, Charlson Comorbidity Index, and emergency admission.

Conclusion

Selective admission to hospitals with a large DCV may improve outcomes of dialysis patients.

Kidney enlargement and multiple liver cyst formation implicate mutations in PKD1/2 in adult sporadic polycystic kidney disease

Distinguishing autosomal-dominant polycystic kidney disease (ADPKD) from other inherited renal cystic diseases in patients with adult polycystic kidney disease and no family history is critical for correct treatment and appropriate genetic counseling. However, for patients with no family history, there are no definitive imaging findings that provide an unequivocal ADPKD diagnosis. We analyzed 53 adult polycystic kidney disease patients with no family history. Comprehensive genetic testing was performed using capture-based next-generation sequencing for 69 genes currently known to cause hereditary renal cystic diseases including ADPKD. Through our analysis, 32 patients had PKD1 or PKD2 mutations. Additionally, 3 patients with disease-causing mutations in NPHP4, PKHD1, and OFD1 were diagnosed with an inherited renal cystic disease other than ADPKD. In patients with PKD1 or PKD2 mutations, the prevalence of polycystic liver disease, defined as more than 20 liver cysts, was significantly higher (71.9% vs 33.3%, P = .006), total kidney volume was significantly increased (median, 1580.7 mL vs 791.0 mL, P = .027) and mean arterial pressure was significantly higher (median, 98 mm Hg vs 91 mm Hg, P = .012). The genetic screening approach and clinical features described here are potentially beneficial for optimal management of adult sporadic polycystic kidney disease patients.

Loop diuretics are associated with greater risk of sarcopenia in patients with non-dialysis-dependent chronic kidney disease

Introduction

Sarcopenia, the age-related loss of muscle mass and function, frequently accompanies chronic kidney disease. The aim of this study was to clarify the prevalence and the risk factors for sarcopenia among patients with non-dialysis-dependent chronic kidney disease (NDD-CKD), focusing on the use of drugs.

Methods

We conducted a cross-sectional analysis on a cohort of 260 patients with NDD-CKD in a university hospital, recruited between June 2016 and March 2017. We extracted data on patient gender, age, cause of chronic kidney disease, use of drugs, and comorbidities that could potentially affect the prevalence of sarcopenia. Sarcopenia was diagnosed using the criteria of the Asian Working Group for Sarcopenia. Logistic regression analysis was performed to analyze the association of each factor on the prevalence of sarcopenia.

Results

25.0% of our study subjects had sarcopenia. Multivariable analysis revealed that an increased risk of sarcopenia was significantly associated with age, male gender, body mass index, diabetes mellitus, and loop diuretic use (odds ratio, 4.59: 95% confidence interval, 1.81–11.61: P-value 0.001).

Conclusions

In our cohort, the prevalence of sarcopenia in patients with NDD-CKD was high, and diuretics use, particularly loop diuretic use, was suggested to be a risk factor of sarcopenia. Although loop diuretics are commonly used in patients with CKD, careful consideration of the risk of sarcopenia may be necessary.

Prognosis of chronic kidney disease with normal-range proteinuria: The CKD-ROUTE study

BACKGROUND

Although lower estimated glomerular filtration rate (eGFR) and higher proteinuria are high risks for mortality and kidney outcomes, the prognosis of chronic kidney disease (CKD) in patients with normal-range proteinuria remains unclear.

METHODS

In this prospective cohort study, 1138 newly visiting stage G2-G5 CKD patients were stratified into normal-range and abnormal-range proteinuria groups. Study endpoints were CKD progression (>50% eGFR loss or initiation of dialysis), cardiovascular events, and all-cause death.

RESULTS

In total, 927 patients who were followed for >6 months were included in the analysis. The mean age was 67 years, and 70.2% were male. During a median follow-up of 35 months, CKD progression, cardiovascular events, and mortality were observed in 223, 110, and 55 patients, respectively. Patients with normal-range proteinuria had a significantly lower risk for CKD progression (hazard ratio, 0.20; 95% confidence interval, 0.10-0.38) than those with abnormal-proteinuria by multivariate Cox proportional hazard analysis. We also analyzed patients with normal-range proteinuria (n = 351). Nephrosclerosis was the most frequent cause of CKD among all patients with normal-range proteinuria (59.7%). During a median follow-up of 36 months, CKD progression, cardiovascular events, and mortality were observed in 10, 28, and 18 patients, respectively. The Kaplan-Meyer analysis demonstrated that the risks of CKD progression and cardiovascular events were not significantly different among CKD stages, whereas the risk of death was significantly higher in patients with advanced-stage CKD. Multivariate Cox proportional hazard analysis showed that the risk of three endpoints did not significantly differ among CKD stages.

CONCLUSION

Newly visiting CKD patients with normal-range proteinuria, who tend to be overlooked during health checkups did not exhibit a decrease in kidney function even in advanced CKD stages under specialized nephrology care.

Anaemia management and mortality risk in newly visiting patients with chronic kidney disease in Japan: The CKD-ROUTE study

AIM

To investigate the association between iron deficiency anaemia and mortality risk and assess the changes in anaemia and iron status after primary management by a nephrologist.

METHODS

In this prospective cohort study, we stratified 951 non-dialysis chronic kidney disease (CKD) G2-G5 patients newly visiting 16 nephrology centres into four groups according to the presence of anaemia with or without iron deficiency. All-cause mortality, cardiovascular (CV)-related mortality, and a change in anaemia and iron status after specialized primary care were the endpoints evaluated.

RESULTS

During a median follow-up time of 19 months, the number of all-cause deaths and CV-related deaths were 56 and 26, respectively. Compared with the control group, the groups with isolated anaemia and iron deficiency anaemia had significantly higher all-cause mortalities (isolated anaemia: hazard ratio (HR), 3.37; 95% confidence intervals (CI), 1.76-6.44; iron deficiency anaemia: HR, 3.11; 95% CI, 1.21-8.01) and CV-related mortalities (isolated anaemia: HR, 3.64; 95% CI, 1.36-9.73; iron deficiency anaemia: HR, 3.86; 95% CI, 1.11-13.41). In the isolated anaemia group, erythropoietin-stimulating agent (ESA) prescriptions significantly increased to approximately 70%. However, in patients with both anaemia and iron deficiency, iron prescriptions only increased to 48.1%.

CONCLUSIONS

Iron deficiency anaemia and isolated anaemia were associated with all-cause and CV-related mortality. The absence of relative increase in iron prescriptions suggests that iron deficiency should be accurately assessed and iron supplementation should be appropriately used to manage anaemia in non-dialysis patients with CKD.

A novel heterozygous mutation in the ATP6V0A4 gene encoding the V-ATPase a4 subunit in an adult patient with incomplete distal renal tubular acidosis

A 40-year-old Japanese man who had a medical history of hypokalemic periodic paralysis 4 months prior was hospitalized to undergo a cholecystectomy. Hypokalemia, nephrocalcinosis and alkaluria suggesting distal renal tubular acidosis (dRTA) were detected, but metabolic acidosis was not evident. An ammonium chloride/furosemide–fludrocortisone/bicarbonate loading test demonstrated a remarkable disability in urinary H⁺ excretion. A novel heterozygous mutation in the ATP6V0A4 gene encoding the vacuolar H⁺-ATPase (V-ATPase) a4 subunit p.S544L was detected. Among cases of V-ATPase a4 mutations, this is the first case in which a heterozygous mutation developed to an incomplete or latent form of dRTA.

Comprehensive genetic testing approach for major inherited kidney diseases, using next-generation sequencing with a custom panel

BACKGROUND

Gene identification of hereditary kidney diseases by DNA sequencing is important for precise diagnosis, treatment, and genetic consultations. However, the conventional Sanger sequencing is now practically powerless in the face of ever increasing numbers of reported causative genes of various hereditary diseases. The advent of next-generation sequencing technology has enabled large-scale, genome-wide, simultaneous sequence analyses of multiple candidate genes.

METHODS

We designed and verified a comprehensive diagnosis panel for approximately 100 major inherited kidney diseases, including 127 known genes. The panel was named Simple, sPEedy and Efficient Diagnosis of Inherited KIdney Diseases (SPEEDI-KID). We applied the panel to 73 individuals, clinically diagnosed with an inherited kidney disease, from 56 families.

RESULTS

The panel efficiently covered the candidate genes and allowed a prompt and accurate genetic diagnosis. Moreover, 18 unreported mutations suspected as the disease causes were detected. All these mutations were validated by Sanger sequencing, with 100 % concordance.

CONCLUSION

In conclusion, we developed a powerful diagnostic method, focusing on inherited kidney diseases, using a custom panel, SPEEDI-KID, allowing a fast, easy, and comprehensive diagnosis regardless of the disease type.

Bence-Jones Protein λ-type Multiple Myeloma Patient Withdrawn from Maintenance Hemodialysis after Long-term Bortezomib and Dexamethasone Therapy

The effectiveness of bortezomib treatment for multiple myeloma (MM) is well established. However, the protocol by which maintenance therapy using bortezomib should be continued for myeloma patients requiring regular hemodialysis remains to be established. We herein report a case of MM with severe renal insufficiency requiring hemodialysis for nearly 30 months which was finally withdrawn from renal replacement therapy during monthly maintenance treatment with bortezomib and dexamethasone for two years. The details of this case are essential for establishing clinical guidelines for applying intermittent low-frequency bortezomib therapy in dialysis-dependent myeloma patients.

Removal kinetics of antibodies against glutamic acid decarboxylase by various plasmapheresis modalities in the treatment of neurological disorders

Plasmapheresis is one of the acute treatment modalities for neurological disorders associated with antibodies against glutamic acid decarboxylase (anti-GAD). However, there is little information about the removal kinetics of anti-GAD by various plasmapheresis modalities. Here, we investigated the removal rate of anti-GAD and fibrinogen (Fib) by immunoadsorption (IA), plasma exchange using a conventional plasma separator (OP-PE), and plasma exchange using a high cut-off selective membrane plasma separator (EC-PE) in two cases of anti-GAD-associated neurological diseases. In case 1, IA and OP-PE were used, and the percent reductions were as follows: anti-GAD: 38.2% and 69.1% and Fib: 67.7% and 68.2%, respectively. In case 2, OP-PE and EC-PE were used, and the percent reductions were as follows: anti-GAD: 65.8% and 48.5% and Fib: 68.5% and 19.8%, respectively. OP-PE could remove anti-GAD more efficiently than IA. Further, EC-PE could maintain coagulation factors such as Fib better than IA and OP-PE. It is important to select the appropriate plasmapheresis modality on the basis of the removal kinetics.

Two Cases of Hemodialysis-associated Chronic Portal-systemic Shunt Encephalopathy (CPSE) with Opposite Changes in the Blood Ammonia Concentrations during Hemodialysis: A Case Report and Literature Review

The onset of hyperammonemia due to the flow of ammonia-rich portal vein blood through a portal-systemic shunt causes a type of encephalopathy known as chronic portal-systemic shunt encephalopathy (CPSE). We herein report two cases of CPSE that presented with opposite changes in the blood ammonia concentrations during hemodialysis. It is curious that the encephalopathy was ameliorated by hemodialysis in case 1, but not case 2. Therefore, it is necessary to recognize CPSE and assess the blood ammonia concentrations in dialysis patients who develop a disturbance of consciousness, even if the serum transaminase level is normal.

Successful recovery from an acute kidney injury due to amniotic fluid embolism

A 33-year-old Japanese woman at 40 weeks gestation visited the maternity hospital after imminent labor had begun. After the delivery, persistent bleeding developed resulting in hemorrhagic shock. Although the hemorrhage was eventually controlled, hepatic and renal dysfunction occurred, leading to acute kidney injury (AKI). The patient's clinical presentation was suggestive of amniotic fluid embolism (AFE). We subsequently initiated continuous renal replacement therapy (RRT) for AKI. The patient's condition improved, she discontinued RRT, and her renal function recovered. We herein report a patient who successfully recovered from AKI caused by AFE.

Fibronectin glomerulopathy

Fibronectin glomerulopathy occurs between the second and fifth decades of life in most patients, and it is known to be slowly progressive with mild proteinuria leading to kidney failure. The case of a 78-year-old woman with a rapid course of nephrotic syndrome due to fibronectin glomerulopathy is reported. She had proteinuria that rapidly increased to 6.8 g/day in a month and microscopic haematuria. A renal biopsy specimen showed lobular glomerulopathy and membranoproliferative glomerulonephritis-like lesions on light microscopy. There was scanty staining for immunoglobulins and complement. Electron microscopy revealed granular deposits with fibril formation. Immunohistochemistry of the fibronectin showed intense staining in the mesangium and peripheral loop. Therefore, this case was diagnosed as fibronectin glomerulopathy. The kidney function was rapidly decreasing, necessitating haemodialysis 2 months after renal biopsy. It is important to consider fibronectin glomerulopathy in the differential diagnosis of nephrotic syndrome in older people.

Baseline characteristics and prevalence of cardiovascular disease in newly visiting or referred chronic kidney disease patients to nephrology centers in Japan: a prospective cohort study

BACKGROUND

About 39,000 patients were newly prescribed renal replacement therapy in Japan in 2011, resulting in a total of more than 300,000 patients being treated with dialysis. This high prevalence of treated end stage kidney disease (ESKD) patients is an emergent problem that requires immediate attention. We launched a prospective cohort study to evaluate population specific characteristics of the progression of chronic kidney disease (CKD). In this report, we describe the baseline characteristics and risk factors for cardiovascular disease (CVD) prevalence among this cohort.

METHODS

New patients from 16 nephrology centers who were older than 20 years of age and who visited or were referred for the treatment of CKD stage 2-5, but were not on dialysis therapy, were recruited in this study. At enrollment, medical history, lifestyle behaviors, functional status and current medications were recorded, and blood and urine samples were collected. Estimated glomerular filtration rate (eGFR) was calculated by a modified three-variable equation.

RESULTS

We enrolled 1138 patients, 69.6% of whom were male, with a mean age of 68 years. Compared with Western cohorts, patients in this study had a lower body mass index (BMI) and higher proteinuria. The prevalence of CVD was 26.8%, which was lower than that in Western cohorts but higher than that in the general Japanese population. Multivariate analysis demonstrated the following association with CVD prevalence: hypertension (adjusted odds ratio (aOR) 3.57; 95% confidence interval (CI) 1.82-7.02); diabetes (aOR 2.45; 95% CI 1.86-3.23); hemoglobin level less than 11 g/dl (aOR 1.61; 95% CI 1.21-2.15); receiving anti-hypertensive agents (aOR 3.54; 95% CI 2.27-5.53); and statin therapy (aOR 2.73; 95% CI 2.04-3.66). The combination of decreased eGFR and increased proteinuria was also associated with a higher prevalence of CVD.

CONCLUSIONS

The participants in this cohort had a lower BMI, higher proteinuria and lower prevalence of CVD compared with Western cohorts. Lower eGFR and high proteinuria were associated with CVD prevalence. Prospective follow up of these study patients will contribute to establishment of individual population-based treatment of CKD.

Development of minimal-change glomerular disease and Hashimoto's thyroiditis during the treatment of sarcoidosis

Minimal-change glomerular disease, sarcoidosis and autoimmune thyroid disease rarely occur in the same patient. We herein report a patient in which minimal-change glomerular disease and Hashimoto's thyroiditis developed during the treatment of sarcoidosis with steroids. A 66-year-old female was admitted to our hospital with symptoms of nephrotic syndrome. Nine months before admission, she was diagnosed as having ocular and pulmonary sarcoidosis, for which prednisolone at an initial dose of 40 mg/day was started. When the dose of prednisolone was tapered to 20 mg/day, she noticed swelling of the lower extremities. Examination confirmed the simultaneous occurrence of minimal-change glomerular disease and Hashimoto's thyroiditis, which were diagnosed based on kidney histology, ultrasonography of the thyroid gland and positive antithyroglobulin antibodies. We used intravenous methylprednisolone pulse therapy followed by 40 mg/day oral prednisolone. The patient achieved complete remission of nephrotic syndrome and steroids were tapered without relapse.

Severe hyperparathyroidism in a pre-dialysis chronic kidney disease patient treated with a very low protein diet

The present report describes a case of a 64-year-old pre-dialysis woman with chronic kidney disease (CKD) stage 5, who developed severe hyperparathyroidism. This patient had been on a very low protein diet (VLPD) to delay the progression of CKD and the need for renal replacement therapy (RRT). Her serum calcium levels were high-normal to slightly high during this time. However, her serum intact parathyroid hormone (PTH) levels increased from 400 to 1160 pg/ml rapidly over a period of 3 months. Serum 1,25-(OH)2D levels were low, and ultrasound of the neck showed three markedly enlarged parathyroid glands exceeding 2 cm. Parathyroidectomy was performed, and all glands showed nodular hyperplasia, which indicated severe secondary hyperparathyroidism leading to tertiary. Severe secondary hyperparathyroidism requiring surgical intervention is usually observed in patients with long-term RRT and is relatively rare in the pre-dialysis patient. In this case, extension of the pre-dialysis period by VLPD may have predisposed this patient to develop severe secondary hyperparathyroidism. Thus, careful monitoring of calcium, phosphorus, and PTH may be necessary in patients treated with VLPD even before renal replacement therapy. Furthermore, initiation of dialysis should not be excessively delayed by strict protein restriction dietary therapy.

Brachial-ankle pulse wave velocity predicts increase in blood pressure and onset of hypertension

BACKGROUND

The present study was designed to test the hypothesis that brachial-ankle pulse wave velocity (baPWV) predicts longitudinal increases in blood pressure (BP) and new onset of hypertension in individuals with normal BP.

METHODS

baPWV was measured using a semiautomated device in 2,496 participants (27-84 years) without hypertension who visited our hospital for a yearly health check-up. They were followed up for 4 years with the endpoint being development of hypertension.

RESULTS

During the follow-up period (median, 733 days; actual follow-up, 5,215 person-years), hypertension developed in 698 participants (133.8/1,000 person-years). Kaplan-Meier analysis revealed that risk for hypertension was increased across the tertiles of baseline baPWV. The hazard ratio (first tertile as reference) was 2.02 (95% confidence interval (CI) 1.55-2.64) and 3.49 (95% CI 2.66-4.57) in the second and third tertiles, respectively, after adjustment for possible risk factors. Multivariate Cox proportional hazard regression analysis adjusted for known risk factors, where baPWV was used as a continuous variable, also indicated that the baseline value of baPWV independently predicted new onset of hypertension (P < 0.001). Furthermore, baseline baPWV was significantly associated with a longitudinal increase in BP after adjustment for known risk factors in multiple regression analysis (P < 0.001).

CONCLUSION

This study provides the first evidence that baPWV is an independent predictor of longitudinal increases in BP as well as of new onset of hypertension.

Generation and analyses of R8L barttin knockin mouse

Barttin, a gene product of BSND, is one of four genes responsible for Bartter syndrome. Coexpression of barttin with ClC-K chloride channels dramatically induces the expression of ClC-K current via insertion of ClC-K-barttin complexes into plasma membranes. We previously showed that stably expressed R8L barttin, a disease-causing missense mutant, is retained in the endoplasmic reticulum (ER) of Madin-Darby canine kidney (MDCK) cells, with the barttin β-subunit remaining bound to ClC-K α-subunits (Hayama A, Rai T, Sasaki S, Uchida S. Histochem Cell Biol 119: 485-493, 2003). However, transient expression of R8L barttin in MDCK cells was reported to impair ClC-K channel function without affecting its subcellular localization. To investigate the pathogenesis in vivo, we generated a knockin mouse model of Bartter syndrome that carries the R8L mutation. These mice display disease-like phenotypes (hypokalemia, metabolic alkalosis, and decreased NaCl reabsorption in distal tubules) under a low-salt diet. Immunofluorescence and immunoelectron microscopy revealed that the plasma membrane localization of both R8L barttin and the ClC-K channel was impaired in these mice, and transepithelial chloride transport in the thin ascending limb of Henle's loop (tAL) as well as thiazide-sensitive chloride clearance were significantly reduced. This reduction in transepithelial chloride transport in tAL, which is totally dependent on ClC-K1/barttin, correlated well with the reduction in the amount of R8L barttin localized to plasma membranes. These results suggest that the major cause of Bartter syndrome type IV caused by R8L barttin mutation is its aberrant intracellular localization.

Calcium-alkali syndrome-like symptoms manifested by daily alphacalcidol and thiazide

A 73-year-old man was admitted with complaints of a 2-month history of generalized weakness and numbness. Laboratory examination revealed hypercalcemia, metabolic alkalosis, and kidney injury, similar to the traditional milk-alkali syndrome. The clinical history and the response to therapy indicated that alphacalcidol and thiazide taken daily were the cause. Recently, it has been recommended the term "milk-alkali syndrome" be replaced by "calcium-alkali syndrome", which broadens the definition of the condition. This case suggests that the calcium-alkali syndrome can occur without calcium and alkali, but rather with alphacalcidol and a thiazide diuretic.

Aldosterone-stimulated SGK1 activity mediates profibrotic signaling in the mesangium

Several recent reports support the hypothesis that aldosterone contributes to the progression of renal injury. Mineralocorticoids increase the expression of serum- and glucocorticoid-inducible protein kinase 1 (SGK1), which is upregulated in several fibrotic diseases. It was hypothesized that SGK1 may mediate the effects of aldosterone on glomerular fibrosis and inflammation. In primary cultures of rat mesangial cells, aldosterone stimulated the expression, phosphorylation, and kinase activity of SGK1, as well as SGK1-dependent NF-kappaB activity. Furthermore, aldosterone augmented the promoter activity and protein expression of intercellular adhesion molecule-1 (ICAM-1), which modulates the inflammatory response, and the profibrotic cytokine connective tissue growth factor (CTGF) in an SGK1- and NF-kappaB-dependent manner. Similar to the in vitro results, uninephrectomized rats that were treated with aldosterone demonstrated increased glomerular expression of SGK1, ICAM-1, and CTGF proteins than untreated rats; these changes were accompanied by hypertension, glomerulosclerosis, and inflammation. In conclusion, these findings suggest that aldosterone stimulates ICAM-1 and CTGF transcription via the activation of SGK1 and NF-kappaB, effects that may contribute to the progression of aldosterone-induced mesangial fibrosis and inflammation.

Important role of apoptosis signal-regulating kinase 1 in ischemic acute kidney injury

We investigated the role of apoptosis signal-regulating kinase 1 (ASK1) in ischemia/reperfusion (I/R)-induced acute kidney injury (AKI). Blood urea nitrogen (BUN) and serum creatinine were significantly higher in ASK1+/+ mice than in ASK1-/- mice after I/R injury. Renal histology of ASK1+/+ mice showed significantly greater tubular necrosis and degradation. In ASK1-/- mice, phosphorylation of ASK1, JNK, and p38K, and the number of TUNEL-positive cells and infiltrated leukocytes decreased after I/R injury. Apoptotic changes were significantly decreased in cultured renal tubular epithelial cells (TECs) from ASK1-/- mice under hypoxic condition. Transfection with dominant-active ASK1 induced apoptosis in TECs. Protein expression of monocyte chemoattractant protein-1 (MCP-1) was significantly weaker in ASK1-/- mice after I/R injury. Transfection with dominant negative-ASK1 significantly decreased MCP-1 production in TECs. These results demonstrated that ASK1 is activated in I/R-induced AKI, and blockage of ASK1 attenuates renal tubular apoptosis, MCP-1 expression, and renal function.