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Background Atherosclerosis is often a complication of chronic kidney disease (CKD) because of dyslipidemia and CKD-mineral and bone disorder. High-density lipoproteins (HDLs) are grouped into various subclasses composed of multiple proteins and lipids, and their transformation is altered in CKD. We investigated the roles of lipoprotein subclasses in CKD progression, and atherosclerosis, and the relationships with Klotho and fibroblast growth factor (FGF) 23. Methods Seventy-one CKD patients were enrolled in this prospective cohort study in Japan. The proportions of cholesterol level to total cholesterol level (cholesterol proportion) and lipoprotein particle numbers in 20 lipoprotein fractions were measured by a newly developed high-performance gel permeation chromatography. Results Diabetic nephropathy was observed in 23.9% of the patients. The mean age was 75.0 years and estimated glomerular filtration rate (eGFR) was 17.2 ml/min./1.73m2. The lipoprotein particle numbers in small HDLs were higher in Stage 4 group than in Stage 5 group (p = 0.002). Multivariate regression analysis adjusted for baseline characteristics showed that the cholesterol proportions in very small HDLs were associated with eGFR change rate [F19 β = -17.63, p = 0.036] and ABI [F19 β = 0.047, p = 0.047] in Stage 4 group, and that serum soluble α-Klotho level was associated with the lipoprotein particle numbers in very small HDLs [F19 β = 0.00026, p = 0.012; F20 β = 0.00041, p = 0.036] in Stage 5 group. Conclusions This study showed that HDL subclasses are associated with CKD progression, ABI, and Klotho level in CKD-stage-specific manner.

Hepatitis C virus (HCV) infection is widely prevalent among patients on hemodialysis (HD), but very rarely treated. The aim of our study is to evaluate the burdens of HCV suffered by patients on HD.The Dialysis Outcomes and Practice Patterns Study is an international, prospective, cohort study of patients on HD. We reviewed the HCV status of 76,689 adults enrolled between 1996 and 2015. We compared HCV-positive (HCV+) with HCV-negative (HCV-) patients for risk of mortality, hospitalization, decline in hemoglobin concentration8.5 g/dl, and red blood cell transfusion. We also compared health-related quality of life scores using the Kidney Disease Quality of Life instrument and the Center for Epidemiologic Studies Short Depression Scale. We adjusted for age, sex, race, years on dialysis, 14 comorbid conditions (including hepatitis B infection), and serum albumin, phosphorus, and creatinine concentrations.A total of 7.5% of patients were HCV+ at enrollment. Serum concentrations of alanine aminotransferase and aspartate aminotransferase were not markedly elevated in HCV+ patients on HD; the mean concentrations were only 22.6 and 21.8 U/L, respectively. Median follow-up was 1.4 years. Case-mix adjusted hazard ratios (95% confidence intervals) for HCV+ versus HCV- patients were 1.12 (1.05 to 1.20) for all-cause mortality, 5.90 (3.67 to 9.50) for hepatic-related mortality, 1.09 (1.04 to 1.13) for all-cause hospitalization, and 4.40 (3.14 to 6.15) for hepatic-related hospitalization. Quality of life measures indicated significantly worse scores for physical function, pain, vitality, mental health, depression, pruritus, and anorexia among HCV+ patients. The adjusted hazard ratio for transfusion was 1.36 (95% CI, 1.20 to 1.55) and incidence of hemoglobin concentration8.5 g/dl was 1.12 (95% CI, 1.03 to 1.21). Only 1.5% of HCV+ patients received antiviral medication.HCV infection among patients on HD is associated with higher risk of death, hospitalization, and anemic complications, and worse quality of life scores. Internationally, HCV infection is almost never treated in patients on HD. Our data provide a rationale for more frequent treatment of HCV in this population.

An age-dependent decline has been observed in the association between obesity and type 2 diabetes, a major comorbidity of obesity, although the evidence is limited. Therefore, we investigated the association and the plausible underlying mechanism in a large epidemiological study.We examined the association between the degree of obesity and hyperglycemia in five age groups (20-39, 40-49, 50-59, 60-69, and 70-85 years) in a cross-sectional study of 78,776 apparently healthy Japanese men and women who underwent a checkup in 2012. Hyperglycemia was defined as glycosylated hemoglobin (HbA1c) of ≥5.7% and/or pharmacotherapy for diabetes.The incidence of hyperglycemia was three times higher in the 70-85-year-old group (62%) than in the 20-39-year-old group (20%) in obese individuals (body mass index [BMI] ≥ 27.0 kg/m(2)). However, the incidence was 12 times higher in reference-weight individuals (21.0-22.9 kg/m(2); 48% and 4%, respectively). As age increased, mean BMI and waist circumference approached certain non-obese ranges (22-24 kg/m(2) and 80-86 cm, respectively), even in hyperglycemic subjects. Logistic regression analysis revealed an age-dependent decline in the association between obesity and hyperglycemia, relative to that in reference-weight individuals.Our results confirmed the previously reported age-dependent decline in the association between obesity and hyperglycemia, although hyperglycemia was still prevalent in older obese subjects than in older reference-weight subjects. Therefore, the decline in the association may be accelerated due to an age-dependent increase in the prevalence of hyperglycemia in reference-weight individuals.

Parents of children with cancer are susceptible to psychological distress; however, many parents also report posttraumatic growth (PTG). The objective of this study was to explore the variables associated with PTG in parents of children with cancer who were either on treatment or off treatment.One hundred and nineteen parents (71 mothers and 48 fathers) of children with cancer completed self-report questionnaires, including the PTG Inventory, Center for Epidemiologic Studies Depression Scale, State-Trait Anxiety Inventory, and Impact of Event Scale-Revised. Demographic data and children's medical information were also collected. Multivariate linear regression analyses were conducted to investigate the variables associated with PTG.The mean age of participants was 41.4 years (SD = 6). Higher PTG Inventory scores were associated with parents' lower trait anxiety (P = .028), parents' sex (female; P = .004), treatment status (within 12 months from treatment end compared with on-treatment; P = .048), surgery (P = .007), and late effects (P = .01).Parents' PTG was associated with children's clinical characteristics, parents' sex, and parents' anxiety levels. When dealing with PTG, the parents' psychological characteristics and children's clinical characteristics should be considered. Particularly for parents with high trait anxiety, it is important to reduce anxiety first before addressing PTG.

Anti-centromere antibody (ACA), a typical autoantibody of systemic sclerosis, is also detected in primary biliary cirrhosis (PBC). However, its pathogenic role is not fully understood. The aim of this study was to determine the association between ACA and kidney function in PBC.A cohort of 37 patients diagnosed as having PBC from July 2001 to November 2011 at Yokosuka Kyosai Hospital was retrospectively analyzed for a follow-up period of 12 months. The annual rate of estimated glomerular filtration rate (eGFR) decline within 1 year after the diagnosis was evaluated. The factors associated with eGFR decline were evaluated by linear regression analysis and logistic regression analysis.Overall, 37 PBC patients were included, of whom 12 (32%) had ACA. The patients with ACA had a lower eGFR (65.9 ± 19.9 vs. 80.3 ± 12.1 mL/min/1.73 m(2), P = 0.01), a higher likelihood of chronic kidney disease (CKD) (58 vs. 4%, P = 0.0005), and a higher rate of annual eGFR decline (-4.3 ± 5.1 vs. 0.2 ± 4.6 mL/min/year, P = 0.01) than those without ACA. Univariate regression analysis and multivariate regression analysis adjusted for potential cofounders including age, eGFR, sex, diabetes mellitus, and hypertension showed that ACA was associated with eGFR decline (P = 0.011 and 0.017, respectively). Multivariate logistic regression analysis adjusted for these cofounders showed that ACA was associated with eGFR decline less than -4 mL/min/year (odds ratio 7.21, 95% confidence interval 0.93-56.1, P = 0.059).ACA is an independent risk factor for CKD in PBC. Evaluation of ACA and kidney function is necessary to prevent CKD progression in PBC patients.

Medical Evidence Report Form CMS-2728 data is frequently used to study US dialysis patients, but the validity of these data have been called into question. We compared predialysis erythropoietin use as recorded on Form CMS-2728 with claims data as part of an assessment of quality of care among hemodialysis patients. Medicare claims were linked to Form CMS-2728 data for 18,870 patients. Dialysis patients, 67 years old or older, who started dialysis from 1 June 2005 to 31 May 2007 were eligible. Logistic and multivariate regressions were used to compare the use of either Form CMS-2728 or the corresponding claims data to predict mortality and the probability of meeting target hemoglobin levels. The sensitivity, specificity, and kappa coefficient for the predialysis erythropoietin indicator were 58.0%, 78.4%, and 0.36, respectively. Patients with a predialysis erythropoietin claim were less likely to die compared with patients without a claim (odds ratio = 0.80 and 95% confidence interval = 0.74-0.87), but there was no relationship observed between predialysis care and death using only Form CMS-2728 predictors. At the facility level, a predialysis erythropoietin claim was associated with a 0.085 increase in the rate of meeting target hemoglobin levels compared with patients without a claim (p = 0.041), but no statistically significant relationship was observed when using the Form CMS-2728 indicators. The agreement between Form CMS-2728 and claims data is poor and discordant results are observed when comparing the use of these data sources to predict health outcomes. Facilities with higher agreement between the two data sources may provide greater quality of care.

Background: We examined the independent contribution of pre-ESRD (end-stage renal disease) care and care after starting hemodialysis (post-HD) with facility-specific mortality among incident patients. Methods: We studied 6,217 incident patients treated at 311 dialysis facilities. A pre-ESRD care score was assessed as the sum of quality measures met on the Centers for Medicare and Medicaid Services Form 2728, including predialysis nephrology and dietary care, having a fistula, hemoglobin and serum albumin. A post-HD care score was evaluated by the sum of quality targets attained, including HD adequacy, anemia, serum albumin and hemoglobin measured on an annual quality survey. A fifth post-HD care measure was having obtained an influenza vaccination during the current year. Results: Individual patient mortality was associated with both pre-ESRD (p < 0.001) and post-HD (p < 0.001) care scores. Linear regression models including both pre-ESRD and post-HD care scores showed that a 1-point increase in the pre-ESRD care score resulted in a 0.30 (95% CI: –0.47, –0.12) decreased facility standardized mortality ratio; no association for post-HD care score was noted (–0.11; 95% CI: –0.26, 0.04). Conclusion: Pre-ESRD and post-HD care are both strongly associated with individual patient mortality. In contrast, only pre-ESRD care is associated with facility mortality, suggesting that early mortality reflects differences in pre-ESRD care in the community.

In patients with chronic kidney disease (CKD), low body mass index (BMI) is associated with high mortality. This relationship in emergently hospitalized CKD patients is unknown. We investigated the association between obesity and short-term mortality in emergently admitted patients with dialysis-independent CKD (DI-CKD) with and without infection. This retrospective cohort study examined Diagnosis Procedure Combination data of 26103 emergently hospitalized DI-CKD patients. Patients were divided into 8 groups according to their BMI and the presence of infectious diseases. The primary outcome was in-hospital death within 100 days. Cox proportional hazards models adjusted for baseline characteristics showed that low BMI was associated with the outcome both in infected and in non-infected patients (reference group as non-infected and medium BMI [24-26 kg/m2] group): infected and the lowest BMI (≤20 kg/m2) group, hazard ratio (HR) 1.82 (95% confidence interval 1.51, 2.19); non-infected and the lowest BMI group, 1.39 (1.16, 1.67). When patients were stratified according to presence of diabetes mellitus (DM), patients with DM showed that low BMI was associated with the outcome both in infected and in non-infected patients, whereas in non-DM patients, this relationship was attenuated in the non-infected group. For emergently hospitalized CKD patients with infection, high BMI was associated with lower mortality irrespective of the DM status. For non-infected patients, the effects of obesity for in-hospital mortality were modified by the DM status.

Trafficking of water channel aquaporin-2 (AQP2) to the apical membrane and its vasopressin and protein kinase A (PKA)–dependent regulation in renal collecting ducts is critical for body water homeostasis. We previously identified an AQP2 binding protein complex including actin and tropomyosin-5b (TM5b). We show that dynamic interactions between AQP2 and the actin cytoskeleton are critical for initiating AQP2 apical targeting. Specific binding of AQP2 to G-actin in reconstituted liposomes is negatively regulated by PKA phosphorylation. Dual color fluorescence cross-correlation spectroscopy reveals local AQP2 interaction with G-actin in live epithelial cells at single-molecule resolution. Cyclic adenosine monophosphate signaling and AQP2 phosphorylation release AQP2 from G-actin. In turn, AQP2 phosphorylation increases its affinity to TM5b, resulting in reduction of TM5b bound to F-actin, subsequently inducing F-actin destabilization. RNA interference–mediated knockdown and overexpression of TM5b confirm its inhibitory role in apical trafficking of AQP2. These findings indicate a novel mechanism of channel protein trafficking, in which the channel protein itself critically regulates local actin reorganization to initiate its movement.

We report a case of pneumatosis intestinalis in a diabetic patient with minimal change nephrotic syndrome, receiving immunosuppressive drugs and an alpha-glucosidase inhibitor. The patient was a 72-year-old female, who suffered from right lower abdominal pain. Abdominal CT showed massive air in the intestinal wall, compatible with pneumatosis intestinalis. Her general condition rapidly deteriorated with systemic inflammatory response syndrome. The patient had received respiratory support for a week, along with antimicrobial therapy and continuous hemofiltration, and then recovered. Even though pneumatosis intestinalis is generally recognized as a mild disease, careful attention is necessary when it follows a serious condition.

Background: Details about the progression of chronic kidney disease (CKD) have yet to be clarified in Asia. We investigated the progression rate of CKD in Japanese patients treated with combination therapy.Methods: This study was conducted with patients with non-diabetic CKD. Their dietary protein intake (DPI) was 0.6 to 0.9 g/kg/day. Angiotensin-converting-enzyme inhibitors or angiotension-II-receptor blockades were regularly prescribed. The rate of loss of kidney function was defined as the decline in creatinine clearance (CCr) per month. Factors correlating with the rate of loss of kidney function and CCr were analyzed by regression analysis, and CCr prediction formulae were then developed by multiple logistic regression analysis.Results: Thirty-eight patients were enrolled in this study (male 19, female 19) and observed for 71.0 months. Their average age was 57.7 years old. The average CCr and the rate of loss of kidney function were 38.2 ml/min/1.73 m2 and 0.410 ml/min/1.73 m2/month, respectively. The loss of kidney function was accelerated by urinary proteine excretion and hypoalbuminemia. Values for the CCr prediction formulae were calculated using serum creatinine concentration, weight, and age, and the formulae showed that the rate of loss of kidney function in younger males was faster than that in the elderly or females. The differences among the formulae in the loss of kidney function were greatest in the younger males.Conclusions: We found that the loss of kidney function varies according to patients' age and background. To slow the progression of CKD, future strategies should take the different characteristics of each age group into account.

Electrolyte abnormalities, particularly dysnatremia, are independent predictors of adverse outcome in individuals with and without renal failure. However, the association of serum chloride level (Cl−) with mortality or risk of cardiovascular (CV) events in chronic kidney disease (CKD) remains unclear. This prospective cohort study included 923 pre-dialysis CKD G2–G5 patients among the participants of the CKD Research of Outcomes in Treatment and Epidemiology (CKD-ROUTE) study, who newly visited 16 nephrology centers. The primary outcome was a composite of overall death and CV events, and the secondary outcome was overall death. Data were analyzed using the Cox hazards model with adjustment for potential confounders. Median Cl− was 106.0 mEq/L at enrollment [quartile (Q) 1: ≤103.9, n = 207; Q2: 104.0–105.9, n = 207; Q3: 106.0–108.0, n = 289; Q4: ≥108.1, n = 220]. During a median follow-up of 33 months, there were 98 CV events, 66 deaths, and 154 composite outcomes. The hazard ratio (HR) for the composite outcome was higher for Q1 than Q3 [HR 1.72; 95 % confidence interval (CI) 1.08–2.72; P = 0.022]. As a continuous variable in a subset of patients whose Cl− was ≤106.0 mEq/L, higher Cl− was associated with lower risk of the composite outcome (HR 0.93; 95 % CI 0.87–0.99; P = 0.023). HR for all-cause mortality was also higher for Q1 than Q3 (HR 2.48; 95 % CI 1.22–5.03; P = 0.012). Low Cl− was associated with increased mortality and risk of CV events in pre-dialysis CKD patients. Cl− may be an additional prognostic indicator in CKD.

As a result of the advances in computers, data collection has become easy. The huge amount of data now available through computers is called big data. The characteristics of big data are represented by three Vs: (1) volume, (2) variety, and (3) velocity. Volume, variety, and velocity refer to the amount of data, the range of data types and sources, and the speed and frequency of the acquisition of responses from users, respectively. The steps in the analysis of big data include (1) the review of data, (2) the construction of a model, and (3) the interpretation of results. Big data has mainly been analyzed by methods based on correlation analysis. The analytical method mainly based on the correlations found in big data is useful in predicting the prognosis from the analytical results. However, the factors useful for predicting the prognosis are not always useful in the treatment of patients. In medicine, the results of correlating events alone cannot be applied to clinical practice because the causal relationship between causes and the onset of diseases is important. To use big data in medicine, the results obtained from the analysis of big data should be validated by clinical studies.

Low urine pH, a plausible predictor for chronic kidney disease and metabolic disorders, is often observed in obese individuals. However, the association between low urine pH and low body weight is equivocal. We examined clinical parameters including urine pH and body mass index (BMI) in a cross-sectional study of 3629 apparently healthy Japanese adults aged 25-80 years who underwent a health-screening check-up. Urine pH was lower and the prevalence of proteinuria was significantly higher in subjects with BMI of ≥ 27.0 kg/m(2) compared with those with BMI of 21.0-22.9 kg/m(2). By contrast, hematuria was more prevalent in subjects with BMI of ≤ 20.9 kg/m(2). Logistic regression analysis showed that BMI of ≥ 27.0 kg/m(2) was significantly associated with low urine pH (≤ 5.5), which remained significant after adjustment for relevant confounders including age, sex, proteinuria, estimated glomerular filtration rate, urine density, hematuria, smoking status, and daily alcohol drinking. However, the association disappeared after further adjustment for serum uric acid. In contrast, the association between low urine pH and BMI of ≤ 19.0 kg/m(2) was significant after adjustment for age and sex and rather strengthened by the further adjustment for serum uric acid. In conclusion, low urine pH may be independently associated with low BMI. However, the underlying mechanisms of low urine pH in low body weight may differ from those in high body weight.

High serum sodium (sNa) concentrations may be associated with hypertension, which deteriorates kidney function. However, it is equivocal whether high sNa concentrations are associated with impaired kidney function independently of blood pressure (BP) or serum chloride (sCl). Therefore, we addressed this issue in an apparently healthy population.Clinical variables including estimated glomerular filtration rate (eGFR) were examined in 3603 men and women (aged 25-75 years) who underwent health-screening check-ups. sNa concentrations were classified into five categories.Most parameters, including age and BP, increased with increasing sNa, whereas eGFR decreased. Logistic regression analysis showed that, compared with low-normal sNa (≤ 140 mEq/l), high sNa (≥ 144 mEq/l) was significantly associated with elevated BP (≥ 130/85 mmHg) even after adjustment for blood hematocrit, eGFR, serum potassium (sK) concentration and sCl. The highest sNa category was significantly associated with reduced eGFR (60 ml/min/1.73 m(2)) independently of elevated BP. Unlike adjustment for sK, adjustment for sCl strengthened the association between high sNa and elevated BP but attenuated the association between high sNa and reduced eGFR.These results suggest that high sNa concentrations, even within the normal range, are independently associated with elevated BP and impaired kidney function. These associations may be substantially modified by sCl.

Vitamin D analogs have generally been recommended for treatment of mineral bone disease in chronic kidney disease (CKD). However, the association between this treatment and CKD progression has not yet been established. We designed a post hoc propensity score-matched cohort analysis derived from 3-year follow-up data of a prospective cohort. Adult participants with pre-dialysis CKD stages 4–5 who had newly been prescribed active vitamin D analogs during the observation period were eligible as matched cases. Then, matched controls were extracted from participants who had never been prescribed active vitamin D analogs. The primary outcome was a composite of end-stage renal disease or a 50 % reduction in estimated glomerular filtration rate (eGFR). A Cox proportional hazards model evaluated the association between the use of vitamin D analogs and the primary outcome. We enrolled 240 patients (males, 65 %). The number of matched cases and controls was 30 and 210, respectively. The primary outcome was observed in 94 patients, whereas 25 patients died. The mean ± standard deviation age and eGFR were 69 ± 12 years and 17 ± 5.7 ml/min/1.73 m2, respectively. In a Cox proportional hazard model, the use of vitamin D analogs was independently associated with a lower risk of the primary outcome (crude hazard ratio 0.41; 95 % confidence interval 0.19, 0.89; adjusted hazard ratio 0.38; 95 % confidence interval 0.17, 0.88). The use of vitamin D analogs is independently associated with the preservation of renal function in patients with pre-dialysis CKD stages 4–5.

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.

A 77-year-old man with a 13-year history of systemic sclerosis (SSc) was admitted to our hospital with fever, appetite loss, and disorientation. The patient was well 2 days prior to the admission and had been taking a low dose of a steroid and vasodilators over the previous 10 years. In regular clinic visits, his blood pressure was normotensive and serum creatinine (Cr) was within the normal range. On admission, hypertension (blood pressure 214/105 mmHg), proteinuria, and hypercreatinemia (3.6 mg/dL) led to the diagnosis of sclerotic renal crisis (SRC). Thrombocytopenia (5.4 × 10(4)/μL), erythrocyte fragmentation, and elevated lactate dehydrogenase were suggestive of thrombotic microangiopathy (TMA). The immediate initiation of angiotensin-converting enzyme inhibitor therapy and plasma exchange (PE) rapidly improved the disorientation and thrombocytopenia. It is notable that SRC might occur in patients with a 13-year history of SSc. PE should be considered as a treatment option for SRC complicated by TMA.

Background The relationship between hyperuricemia and chronic kidney disease (CKD) has been found in various observational studies. Although hypouricemia is associated with cardiovascular events, it has not been established as a risk factor for CKD. We investigated the relationship between serum uric acid level and the loss of kidney function and incident CKD in healthy people. Materials and Methods Healthy people were enrolled in this community-based prospective cohort study, the Saitama Cardiometabolic Disease and Organ Impairment Study, Japan. The analysis was conducted on 4188 subjects followed up for at least 3 years, 3102 for 6 years and 1052 for 9 years. Their data including glomerular filtration rate (eGFR) decline were examined every three years. The outcome event was incident CKD or the decrease in eGFR by more than 25% in three years. Multivariate statistical models were adjusted for the baseline characteristics. Results The following data was obtained: mean±SD age, male, 39.6±10.4 years, female 38.4±10.8 years; eGFR, male, 81.9±16.4 ml/min/1.73m2, female, 82.1±17.5 ml/min/1.73m2; serum uric acid level, male, 5.8±1.2 mg/dl, female, 4.1±0.9 mg/dl. Both low and high serum uric acid levels were associated with the outcome and eGFR decline in males (multivariate logistic additional additive models, linear p = 0.0001, spline p = 0.043; generalized additive models, linear p = 0.0001, spline p = 0.012). In subjects with low serum uric acid levels (male

近年開発されたマキサカルシトール (OCT) はカルシトリオールに比し, 高Ca血症をきたしにくいビタミンD製剤であり, 静注投与が一般的であるが, 副甲状腺への局注療法も有効とされている. しかし, 静注投与では血清Ca値の上昇をきたすために投与量が制限され, 充分な副甲状腺ホルモンの抑制が得られない例があり, また局注療法は集中的に連日ないしは隔日投与が必要とされ, 通院患者への適用は困難である. われわれはOCTの静注にもかかわらず, 副甲状腺ホルモンの充分な改善が得られず, 高Ca血症などのためにOCTの増量が困難であり, エコー上, 副甲状腺の腫大を認めた維持透析患者12名 (男5人, 女7人) に対し, OCTの静注療法は継続したまま, 副甲状腺内にOCTを間欠的に局注し, その併用効果を検討した. 12人の平均年齢は59.8±1.8歳, 平均透析歴は159.4±24.5か月, 血液透析11名, 血液・腹膜併用透析1名, 血清intact PTH値は555±78pg/mL, 平均腫大腺数は1.6腺で容積は1.3±0.4cm3であった. これらの症例に対し, エコーガイド下, 腫大副甲状腺内にOCT 10μgを局注した. 半年間のPIT回数は平均2.3 (1-6)回/症例であった. 全例で経過中, 12mg/dLを超える高度な血清Ca上昇はなく, 反回神経麻痺等の重篤な副作用もみられなかった. 12人中, 11人では一時的または永続的な副甲状腺ホルモンの低下がみられ, 初回局注より半年の時点で40%以上のintact PTH値の低下が得られたのは5例であったが, 他の症例に比し, 有意な臨床的相違はみられなかった. 1例は局注にても副甲状腺ホルモンの低下がみられず, 副甲状腺摘出術に至った. 以上からOCTの静注に副甲状腺内局注を併用する治療は透析患者の二次性副甲状腺機能亢進症に対し, 治療選択肢のひとつになりえると考えられた.

Hemodialysis is rarely terminated by events associated with anticoagulants. A 69-year-old woman on hemodialysis due to chronic renal failure (CRF) developed an anaphylactoid reaction with hypereosinophilia. On the basis of clinical and laboratory findings, we concluded that the causes of this anaphylactoid reaction were low-molecular-weight heparin and heparin. Our patient also showed high levels of soluble interleukin-2 receptor (sIL-2R) and eosinophil cationic protein (ECP), which decreased after the cessation of hemo-dialysis. To date, there has been no report of high levels of cytokines induced by hemodialysis-associated anaphylactoid reaction. In this report, we discuss the mechanism underlying drug-induced anaphylactoid reaction, particularly that involving eosinophilia and cytokines.

Adhesion of hematopoietic cells, mainly through alpha4beta1 and alpha5beta1 integrins, to the bone marrow microenvironment may play important roles in regulation of hematopoiesis. However, the mechanisms for signaling, outside-in signaling, have largely remained to be established. We demonstrate here that cross-linking of alpha4beta1 by anti-alpha4 antibody induces tyrosine phosphorylation of Pyk2, Shc, and Cbl as well as binding of the adaptor protein CrkL with Cbl in a murine hematopoietic cell line, 32D/EpoR-Wt. Furthermore, cross-linking of alpha4beta1 induced activation of the Rho family small GTPase Rac, which was enhanced by induced overexpression of CrkL and was inhibited by the phosphatidylinositol 3(')-kinase (PI3K) inhibitor LY294002. In addition, adhesion of 32D/EpoR-Wt cells to immobilized H-296, a recombinant fibronectin peptide specific for alpha4beta1, induced tyrosine phosphorylation of Jak2, the erythropoietin receptor (EpoR), and the IL-3 receptor beta subunit as well as Pyk2, Shc, and Cbl. Tyrosine phosphorylation of Jak2 and EpoR was also induced in a human leukemic cell line, UT-7, by adhesion to immobilized H-296. However, adhesion of 32D/EpoR-PM4 cells, expressing the W282R mutant EpoR defective in coupling with Jak2, to immobilized H-296 failed to induce tyrosine phosphorylation of the mutant EpoR. These results implicate CrkL in PI3K-dependent activation of Rac by outside-in signaling from alpha4beta1 and suggest that adhesion through alpha4beta1 further activates cytokine receptor-associated Jak2 to induce phosphorylation of these receptors.

Hearing loss leads to impaired social functioning and quality of life. Hearing loss is also associated with sleeping disorders and cardiometabolic risk factors. Here, we determined whether subclinical hearing loss is associated with sleep duration and cardiometabolic risk factors in a cross-sectional and longitudinal study of healthy Japanese general population. 48,091 men and women aged 20–79 years who underwent medical checkups were included in a cross-sectional study, and 6,674 were included in an 8-year longitudinal study. The prevalence of audiometrically determined hearing loss (>25 dB) at 4000 and 1000 Hz increased significantly with increasing sleep duration in any age strata. Logistic regression analysis showed that compared with reference sleep duration (6 h) longer sleep duration (≥8 h) was significantly associated with hearing loss, even after adjusting for potential confounding factors. Simultaneously, hearing loss was significantly associated with male sex, diabetes, and no habitual exercise. In the longitudinal study, the risk of longer sleep duration (≥8 h) after 8 years was significantly greater in subjects with hearing loss at 4000 Hz at baseline. In conclusion, current results suggest a potential association of subclinical hearing loss with longer sleep duration and cardiometabolic risk factors in a Japanese general population.

Tumor necrosis factor alpha (TNFalpha) activates various signal transduction pathways including those involving phosphatidylinositol 3-kinase (PI3K), extracellular signal-regulated kinases (Erk), c-Jun N-terminal protein kinases (JNK), and p38 kinases. Using the Rac binding domain of PAK (PAK-RBD) as an activation-specific probe, here we demonstrate that TNFalpha very rapidly and transiently activates the Rho family GTPase Rac in L929 cells. The PI3K inhibitor LY294002 significantly inhibited TNFalpha activation of Rac as well as Erk and abolished that of the PI3K target Akt, without showing any inhibitory effects on JNK and p38 activation. Furthermore, TNFalpha activation of Erk was abolished by a dominant negative Rac mutant, Rac17N, or by an activated Rac mutant, Rac12V. These findings suggest that Rac is activated by a mechanism that is at least partly dependent on PI3K in TNFalpha stimulated cells and plays a critical role in activation of the Erk signaling pathway.

The CrkL adaptor protein is involved in signaling from the receptor for erythropoietin (Epo) as well as interleukin (IL)-3 and activates beta(1) integrin-mediated hematopoietic cell adhesion through its interaction with C3G, a guanine nucleotide exchange factor for Rap1. We demonstrate here that Epo as well as IL-3 activates Rap1 in an IL-3-dependent hematopoietic cell line, 32D, expressing the Epo receptor. The cytokine-induced activation of Rap1 was augmented in cells that inducibly overexpress CrkL or C3G. The CrkL-mediated enhancement of cell adhesion was inhibited by expression of a dominant negative mutant of Rap1, Rap1A-17N, whereas an activated mutant of Rap1, Rap1A-63E, activated beta(1) integrin-dependent adhesion of hematopoietic cells. In 32D cells, Rap1 was also activated by phorbol 12-myristate 13-acetate and ionomycin, which also enhanced cell adhesion to fibronectin, whereas, an inhibitor of phospholipase C, inhibited both cytokine-induced activation of Rap1 and cell adhesion. It was also demonstrated that Rap1 as well as CrkL is involved in signaling from the EpoR endogenously expressed in a human leukemic cell line, UT-7. These results suggest that Epo and IL-3 activate Rap1 at least partly through the CrkL-C3G complex as well as through additional pathways most likely involving phospholipase Cgamma and strongly implicate Rap1 in regulation of beta(1) integrin-mediated hematopoietic cell adhesion.

We treated a female patient suffering from immunoglobulin A (IgA) nephropathy and congenital deficiency of the ninth component of the complement system (C9). She was admitted with hematuria and proteinuria, and the C9 deficiency was diagnosed based on the low hemolytic activity of 50 % of the hemolytic unit of the complements (CH50) and the normal C3 level in the plasma. Renal biopsy revealed mild mesangial proliferation, and immunofluorescence examination revealed mild mesangial deposits of IgA and C3 with the same distribution. We discuss the pathogenesis of IgA nephropathy and the role of the complements in its progression.

Impaired mobility at the onset of dialysis is considered one of the most important risk factors for short-term mortality after initiation of dialysis in elderly patients. However, whether a decline in mobility after starting dialysis also affects mortality is unclear.A total of 202 patients (age,75 years; mean, 80.4 ± 4.3) were enrolled in this retrospective cohort study in Yokosuka, Japan. They were divided into three subgroups by mobility: independent mobility at onset of dialysis and preservation of mobility after starting dialysis (group 1, n = 104); independent mobility at onset of dialysis and decline in mobility after starting dialysis (group 2, n = 48); and impaired mobility at onset of dialysis (group 3, n = 50). They were followed for 6 months after starting dialysis. A Cox proportional hazards model was used to evaluate the association between mobility and mortality.A total of 24.8% of patients had impaired mobility at the start of dialysis, and 68.9% declined in mobility after starting dialysis. In multivariate Cox proportional hazards analysis, the adjusted hazard ratios of groups 2 and 3 compared with group 1 were 3.80 (95% confidence interval, 1.02-14.10) and 4.94 (95% confidence interval, 1.42-17.10), respectively.Not only impaired mobility at the start of dialysis but also a decline in mobility after starting dialysis is associated with short-term mortality after initiation of dialysis.

Sleep disorder and poor sleep quality are common in chronic hemodialysis (HD) patients. They have been claimed as a cause of morbidity and mortality. The relationship between the degree of sleepiness and survival has not been studied. We studied the degree of sleepiness in 1,252 adult HD patients (age ≥20 years) recruited into the Dialysis Outcomes Practice Pattern Study in Japan (J-DOPPS III), using the Japanese version of the Epworth Sleepiness Scale (JESS) questionnaire. Demographic data were presented for three subgroups: low, intermediate, and high JESS score. Cox proportional hazard regression analysis was performed to estimate the independent effect of several variables on survival. The hazard ratio for mortality was 2.312 (95% CI 1.267-4.220; p = 0.006) for those with a high JESS score (vs. those with a low JESS score) after adjusting for age, vintage (length of time on HD), sex, diabetes, body mass index, cardiovascular disease, HD treatment regimen (time, frequency, and single-pool Kt/V), laboratory data (serum albumin, creatinine, and total cholesterol), and medication (antihypertensive drugs, erythropoietin, vitamin D, and phosphate binders). Patients ≥70 years of age with comorbid conditions (congestive heart failure, stroke, and diabetes) showed a significantly higher JESS score (≥16). The JESS score did not show interaction by age. Results showed that the degree of sleepiness is related to survival in Japanese HD patients, particularly in elderly patients.

Background Because of the absorption of glucose in peritoneal dialysis (PD) solution, PD patients show an atherogenic lipid profile, which is predictive of poor survival in PD patients. Lipoprotein subclasses consist of a continuous spectrum of particles of different sizes and densities (fraction). In this study, we investigated the lipoprotein fractions in PD patients with controlled serum low-density lipoprotein (LDL) cholesterol level, and evaluated the effects of icodextrin on lipid metabolism. Methods Forty-nine PD patients were enrolled in this cross-sectional study in Japan. The proportions of cholesterol levels to total cholesterol level (cholesterol proportion) in 20 lipoprotein fractions were measured using an improved method of high-performance gel permeation chromatography (HPGPC). Results Twenty-six patients used icodextrin. Although no significant differences in cholesterol levels in LDL and high-density lipoprotein (HDL) were observed between the patients using icodextrin (icodextrin group) and control groups, HPGPC showed that the icodextrin group had significantly lower cholesterol proportions in the small LDL (t-test, p=0.053) and very small LDL (p=0.019), and significantly higher cholesterol proportions in the very large HDL and large HDL than the control group (p=0.037; p=0.066, respectively). Multivariate analysis adjusted for patient characteristics and statin use showed that icodextrin use was negatively associated with the cholesterol proportions in the small LDL (p=0.037) and very small LDL (p=0.026), and positively with those in the very large HDL (p=0.040), large HDL (p=0.047), and medium HDL (p=0.009). Conclusions HPGPC showed the relationship between icodextrin use and the cholesterol proportions in lipoprotein fractions in PD patients. These results suggest that icodextrin may improve atherogenic lipid profiles in a manner different from statin.

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.

A 59-year-old-woman received related non-myeloablative allogeneic peripheral blood stem cell transplantation (PBSCT) subsequent to autologous PBSCT in our hospital five years after she was diagnosed as oligo-secretory myeloma. She was admitted to our hospital because of vomiting and grayish diarrhea 4 months after non-myeloablative allogeneic PBSCT (mini-alloPBSCT). Although her initial symptoms improved after admission, she gradually showed thrombocytopenia, anemia, and oliguria during the 2 weeks after admission. Our diagnosis was thrombotic thrombocytopenic purpura (TTP) and acute renal failure (ARF) secondary to mini-alloPBSCT. After cessation of cyclosporine administration, we began to treat her with plasma exchange (PE) and hemodialysis. During the three and a half months after we started PE, the TTP gradually improved. Although PE had been reported to be ineffective for TTP post bone marrow transplantation, we could finally discontinue PE. In contrast, since her anuria continued, she was managed with hemodialysis. One month after PE was started, her activity of von Willebrand factor-cleaving protease was 41% (normal range, >50%) and the ultrasonographic investigation of both kidneys was normal. She could be discharged after four and a half months hospitalization and lived well as an outpatient for a further two months. She died shortly after readmission from multiple organ failure without the relapse of TTP. The patient's clinical course would suggest that TTP post mini-alloPBSCT could be treated with PE in some cases, despite the development of dialysis-requiring severe ARF being a poor prognostic factor.

Background Obesity is associated with diabetes mellitus and cardiovascular diseases. However, it has been reported that weight loss is associated with incident chronic kidney disease (CKD) in healthy males. The purpose of this prospective cohort study is to investigate the effects of weight loss on kidney function in healthy people in terms of body mass index (BMI) and gender. Methods A total of 8447 nondiabetic healthy people were enrolled in the Saitama Cardiometabolic Disease and Organ Impairment Study, Japan. Relationships between estimated glomerular filtration rate (eGFR) change, BMI, and BMI change were evaluated using 3D-scatter plots with spline and generalized additive models (GAMs) adjusted for baseline characteristics. Results The subjects were stratified into four groups according to BMI. The mean±standard deviations for males and females were, respectively, 40.11±9.49, and 40.3±9.71 years for age and 76.39±17.72 and 71.49±18.4 ml/min/1.73m2 for eGFR. GAMs showed that a decreasing BMI change (

Background Although lifestyle is associated with metabolic syndrome and cardiovascular diseases, there has been no sufficient evidence of lifestyles on incident chronic kidney disease (CKD). The purpose of this prospective cohort study is to investigate the effects of lifestyles on kidney function in healthy people. Methods A total of 7473 healthy people were enrolled in this Saitama Cardiometabolic Disease and Organ Impairment Study, Japan. Data on alcohol consumption, exercise frequency, and sleep duration were collected. The outcome event was incident CKD or decrease in estimated glomerular filtration rate (eGFR) by >25% in 3 years. Results Subjects were classified into four groups according to body mass index and gender. Mean ± standard deviation of age was 38.8±10.5 years; eGFR, 78.1±15.2 ml/min/1.73m2. In the male groups, multivariate logistic regression models showed that the outcome events were associated with a small amount of alcohol consumed (20 to 140g of alcohol/week) (ref. more than 140g of alcohol/week); non-obese male, adjusted odds ratio 1.366 (95% confidence interval, 1.086, 1.718); obese male (body mass index ≥25), 1.634 (1.160, 2.302); and with frequent exercise (twice a week or more) (ref. no exercise); non-obese male, 1.417 (1.144, 1.754); obese male, 1.842 (1.317, 2.577). Sleep duration was not associated with the outcome events. Conclusion These findings suggest that, regardless of obesity, a small amount of alcohol consumed and high exercise frequency were associated with the increased risk of loss of kidney function in the male groups.

Background For hemodialysis (HD) patients, many risk factors for death are associated with each other intricately. However, they are often considered separately in clinical settings. We evaluated the maintenance HD patients’ risk of death within one year from multiple risk factors simultaneously considering their interrelationships using a novel index (survival index, SI) for HD patients in the United States developed using data from the Dialysis Outcomes and Practice Patterns Study (DOPPS). Methods We analyzed data from 3899 and 3765 patients to develop and validate SI, respectively. To predict death within one year, candidate models were developed using logistic regression models. The final model was determined by comparing the accuracy among the models for the prediction of deaths. Results The model included age; body mass index; serum creatinine, albumin, total cholesterol and phosphorus levels; history of cardiovascular diseases; and arteriovenous fistula use. SI showed a higher accuracy in predicting death (c-statistic, 0.739) than geriatric nutritional risk index (0.647) and serum albumin level (0.637). The probability of death predicted on the basis of SI matched the observed number of deaths. Cox proportional hazard models for time-dependent SI showed that patients with low SI had a higher risk of death than patients with high SI [reference, Group 4 (26.1≤SI)]; Group 1 (SI

According to recent reports, deformity and size of mesothelial cells reflect mesothelial condition. We applied flow cytometry (FCM) to the analyzation of mesothelial cells in peritoneal dialysis effluent (PDE) and the relationship between the period of peritoneal dialysis (PD) and peritoneal function. Eighteen patients treated for two to 89 months by PD were selected. Their dialysate: plasma creatinine ratio (D/P creatinine)was 0.67 +/- 0.086 (0.53 to 0.87). Overnight PDE was drained and centrifuged. The cell population of peritoneal cells identified by anti-cytokeratin, CD14 and 45 antibodies was studied by FCM. Cytokeratin positive cells were identified as mesothelial cells, distinct from macrophages, granulocytes or lymphocytes. The forward scatter (FSC) of cytokeratin positive cells, fluorescence intensity of cytokeratin and percentage of cytokeratin-positive cells in PDE were 395.6 +/- 55.5 (298.31 to 527.72), 333.9 +/- 272.9 (67.55 to 1,071.95), and 6.75 +/- 6.1% (0.44 to 21.14), respectively. There was a positive correlation between D/P creatinine and FSC, and a negative correlation between D/P creatinine and cytokeratin fluorescence intensity or the percentage of cytokeratin positive cells. However, there was no correlation between the period of PD and FSC, cytokeratin fluorescence intensity or the percentage of cytokeratin-positive cells. It was suggested that the alteration of mesothelial cells is not necessarily influenced by the period of PD, but influences peritoneal function. It was found that the analysis of cell population by FCM reflects the morphological and functional changes in the peritoneum of patients on PD.

We report a case of tuberous sclerosis (TSC) associated with renal cell carcinoma and angiomyolipoma in a patient, who developed endstage renal failure that required hemodialysis after nephrectomy. A 37-year-old woman with TSC was admitted for further investigation of bilateral renal masses detected by computed tomography (CT). Angiography revealed a tumor stain (4 cm in diameter) in the medial portion of the right kidney. Because renal cell carcinoma (RCC) was strongly suspected, right nephrectomy was performed. Her serum creatinine level was already increased, moderately, at 2.4 mg/dl, before the right nephrectomy. Her renal function deteriorated quickly (in 1(1/2) years) after the right nephrectomy, and hemodialysis was introduced the next year. The histological findings of the resected right kidney revealed marked intimal thickening of the intralobular arteries. These findings suggested that the renal function loss was not only caused by the nephron mass reduction due to the nephrectomy but was also caused by nephrosclerosis. Though most patients with TSC die before developing endstage renal failure, this patient is currently receiving maintenance hemodialysis and has been followed for 3 years with no recurrence of RCC in the left kidney.

Malaria remains one of the world's major health problems, particularly in developing tropical countries. Imported malaria is reportedly increasing in Western countries. Acute renal failure (ARF) is the most common cause of death in severe malaria. We report the case of a 63-year-old female patient with a history of travel to a rural area in South Africa who was in coma and had a high fever on admission. Thirty percent of her erythrocytes were infected with Plasmodium falciparum. She had cerebral malaria, malarial nephropathy, anemia, hepatic dysfunction, and disseminated intravenous coagulation (DIC). Quinine and artesunate treatment decreased the number of parasites in the blood. To manage renal failure, hemodialysis was performed for 11 days. A relationship between ARF and hepatic dysfunction was suggested. This relationship is an indication of the clinical course of the disease. In this article, we discuss the mechanism underlying the development of malarial nephropathy and its management, particularly the usefulness of hemodialysis.

Background: We ask patients' doctors and nurses to answer the questionnaires after intervention for self-assessment and mutual assessment. Purpose: We analyze the questionnaires and assess intervention by our team. Patients and Method: The questionnaire included; had their requests been resolved? (Q1), had patients and their family looked changed? (Q2), had doctors looked changed? (Q3), had nurses looked changed? (Q4), and we asked them to write down detail of the change concretely. We analyzed 35 questionnaires of patients with malignant tumors whom we had intervened in from 2012 to 2013. Results: The characteristics of the 35 cases were as follows: male, 20; female, 15; mean age, 66 years; range, 40-82 years; location, digestive organ, 12, hematopoietic organ, 10, urinary tract, 5, head and neck, 4, lung, 3, uterine adnexa, 1. 9 patients were under intensive treatment and 26 were in terminal stage. Aims were as follows: pain control, 27, relief of symptoms except pain, 13, mental support, 21, introduction of hospice or home care, 4, family support, 9. Mean interventional period was 21 days; range, 2-83 days, and mean interventional time was 7; range, 2-17. Doctors and nurses assessed their requests had been resolved in 19 (54%) and 14 (40%) cases, respectively (Q1), and answered yes in 26 (74%) and 29 (82%) (Q2), 22 (62%) and 11 (31%) (Q3), and 10 (28%) and 28 (80%) (Q4), respectively. Almost all changes were favorable. Each answer of doctors and nurses had agreed in 20 (57%) (Q1), 27 (77%) (Q2), 20 (57%) (Q3), and 14 cases (40%) (Q4). Conclusion: Our intervention brought favorable changes for most patients and their families, although requests had resolved in not a lot of cases. We should work on doctors and nurses to hold their information in common to correct the discrepancy in their assessment.

Previous studies have shown that hematopoietic cytokines, including erythropoietin (Epo) and interleukin (IL)-3, activate the Ras GTPase and the downstream Raf/Erk/Elk-1 signaling pathway. Here we report that Epo or IL-3 rapidly and transiently activates Rac, a Rho family GTPase, in hematopoietic cell lines, 32D/EpoR-Wt and UT-7. The cytokine-induced activation of Rac was augmented in a 32D/EpoR-Wt clone that inducibly overexpresses the adaptor protein CrkL or the Ras guanine nucleotide exchange factor C3G, which forms a complex with CrkL. Furthermore, the Rac activation was enhanced or inhibited in cells inducibly expressing an activated Ras mutant, H-Ras61L, or a dominant negative Ras mutant, H-Ras17N, respectively. In addition, the cytokine-induced Rac activation was inhibited by a phosphatidyl-inositol 3'-kinase (PI3K) inhibitor, LY294002, which also inhibited the Erk activation. A dominant negative Rac mutant, Rac17N, also inhibited the cytokine-induced activation of Erk as well as Elk-1. On the other hand, activation of Akt downstream of PI3K was found to play an inhibitory role in cytokine activation of Erk/Elk-1. Together, these results indicate that Rac is activated by Epo or IL-3 at downstream of the Ras/PI3K pathway in parallel with Akt and plays a role in activation of the Erk/Elk-1 signaling pathway in hematopoietic cells.

The erythropoietin (Epo) receptor transduces its signals by activating physically associated tyrosine kinases, mainly Jak2 and Lyn, and thereby inducing tyrosine phosphorylation of various substrates including the Epo receptor (EpoR) itself. We previously demonstrated that, in Epo-stimulated cells, an adapter protein, CrkL, becomes tyrosine-phosphorylated, physically associates with Shc, SHP-2, and Cbl, and plays a role in activation of the Ras/Erk signaling pathway. Here, we demonstrate that Epo induces binding of CrkL to the tyrosine-phosphorylated EpoR and SHIP1 in 32D/EpoR-Wt cells overexpressing CrkL. In vitro binding studies showed that the CrkL SH2 domain directly mediates the EpoR binding, which was specifically inhibited by a synthetic phosphopeptide corresponding to the amino acid sequences at Tyr(460) in the cytoplasmic domain of EpoR. The CrkL SH2 domain was also required for tyrosine phosphorylation of CrkL in Epo-stimulated cells. Overexpression of Lyn induced constitutive phosphorylation of CrkL and activation of Erk, whereas that of a Lyn mutant lacking the tyrosine kinase domain attenuated the Epo-induced phosphorylation of CrkL and activation of Erk. Furthermore, Lyn, but not Jak2, phosphorylated CrkL on tyrosine in in vitro kinase assays. Together, the present study suggests that, upon Epo stimulation, CrkL is recruited to the EpoR through interaction between the CrkL SH2 domain and phosphorylated Tyr(460) in the EpoR cytoplasmic domain and undergoes tyrosine phosphorylation by receptor-associated Lyn to activate the downstream signaling pathway leading to the activation of Erk and Elk-1.

Background Elderly patients with chronic kidney disease (CKD) are usually at a high risk of fractures due to both osteoporosis and CKD-mineral bone disease (MBD). A new marker is needed to prevent fractures and control CKD-MBD from the early to advanced stages of CKD. In the early stage of CKD, fibroblast growth factor 23 (FGF23) level increases before parathyroid hormone (PTH) and phosphate levels increase, and steadily increases with the progression of kidney disease. It has been reported that FGF23 is related to the overall fracture risk. We investigated the usefulness of FGF23 as a marker for evaluating the risk of vertebral fracture and CKD-MBD in elderly CKD patients. Methods One hundred and five elderly predialysis CKD patients who had never been treated for osteoporosis and had never used calcium supplements, vitamin D supplements, or phosphate binders were enrolled in this cross-sectional study in Tokyo, Japan. We investigated the prevalence of vertebral fracture and measured serum calcium, phosphate, 1,25(OH)2 vitamin D [1,25(OH)2D], intact PTH, FGF23, alkaline phosphatase, and urinary N-terminal telopeptide levels. Then, we examined the relationship between the level of FGF23 and those of bone-metabolism-related markers and identified markers associated with vertebral fractures in elderly CKD patients. Results The background features of the patients were as follows: female, 32.4%; diabetes mellitus, 39.0%; average age (standard deviation), 73.2 (7.7) years; and estimated glomerular filtration rate (eGFR), 45.7 (24.1) ml/min/1.73 m2. Adjusted multivariate regression analysis showed that the natural logarithm value of FGF23 level [ln(FGF23)] was positively associated with body mass index (p = 0.002), serum phosphate level (p = 0.0001), and negatively with eGFR (p = 0.0006). Multivariate logistic regression analysis showed that vertebral fracture was independently associated with ln(FGF23) (adjusted odds ratio, 4.44; 95% confidence interval, 1.13-17.46). A receiver-operating-characteristic curve of ln(FGF23) showed that the optimal cutoff level of FGF23 indicative of vertebral fracture was 56.8 pg/ml (sensitivity, 0.82; specificity, 0.63). Conclusions FGF23 level was independently associated with the levels of bone-metabolism-related markers and vertebral fracture. FGF23 is a new candidate marker for detecting abnormalities of bone metabolism and vertebral fracture in elderly CKD patients.