Hyporesponsiveness to erythropoiesis-stimulating agent in non-dialysis-dependent CKD patients: The BRIGHTEN study.

Among non-dialysis-dependent chronic kidney disease (ND-CKD) patients, a low hematopoietic response to erythropoiesis-stimulating agents (ESAs) is a predictor for poor renal and cardiovascular outcome. To assess the method for evaluating hyporesponsiveness to ESA in patients with ND-CKD, a multicenter, prospective, observational study of 1,980 adult patients with ND-CKD with renal anemia was conducted. Darbepoetin alfa (DA) and iron supplement administrations were provided according to the recommendation of the attached document and the guidelines of JSDT (Japanese Society of Dialysis and Transplantation). The primary outcomes were progression of renal dysfunction and major adverse cardiovascular events. ESA responsiveness was assessed using pre-defined candidate formulae. During the mean follow-up period of 96 weeks, renal and cardiovascular disease (CVD) events occurred in 683 (39.6%) and 174 (10.1%) of 1,724 patients, respectively. Among pre-set candidate formulae, the one expressed by dividing the dose of DA by Hb level at the 12-week DA treatment was statistically significant in predicting renal (hazard ratio [HR], 1.449; 95% confidence interval [CI], 1.231-1.705; P<0.0001) and CVD events (HR, 1.719; 95% CI, 1.239-2.386; P = 0.0010). The optimum cut-off values for both events were close to 5.2. In conclusion, hyporesponsiveness to ESA in ND-CKD cases, which is associated with a risk for renal and CVD events, may be evaluated practicably as the dose of DA divided by the Hb level at the 12-week DA treatment, and the cut-off value of this index is 5.2. A search for the causes of poor response and measures for them should be recommended in such patients. Trial registration: ClinicalTrials. gov Identifier: NCT02136563; UMIN Clinical Trial Registry Identifier: UMIN000013464.

Mood Disorder in Systemic Lupus Erythematosus Induced by Antiribosomal P Protein Antibodies Associated with Decreased Serum and Brain Tryptophan.

Antiribosomal P protein (anti-P) autoantibodies commonly develop in patients with systemic lupus erythematosus. We have previously established hybridoma clones producing anti-P mAbs. In this study, we explored the pathogenesis of behavioral disorders induced by anti-P Abs using these mAbs. New Zealand Black × New Zealand White F1, New Zealand White, C57BL/6, and BALB/c mice were treated with 1 mg of anti-P Abs once every 2 wk. The behavioral disorder was evaluated by the tail suspension test, forced swim test, and open field test. Following administration of anti-P Abs, New Zealand Black × New Zealand White F1 and C57BL/6 mice developed depressive behavior and showed increased anxiety with elevated serum TNF-α and IL-6 levels. Anti-P Abs were not deposited in the affected brain tissue; instead, this mood disorder was associated with lower serum and brain tryptophan concentrations. Tryptophan supplementation recovered serum tryptophan levels and prevented the behavioral disorder. TNF-α and IL-6 were essential for the decreased serum tryptophan and disease development, which were ameliorated by treatment with anti-TNF-α neutralizing Abs or dexamethasone. Peritoneal macrophages from C57BL/6 mice produced TNF-α, IL-6, and IDO-1 via interaction with anti-P Abs through activating FcγRs, which were required for disease development. IVIg, which has an immunosuppressive effect partly through the regulation of FcγR expression, also prevented the decrease in serum tryptophan and disease development. Furthermore, serum tryptophan concentrations were decreased in the sera of systemic lupus erythematosus patients with anti-P Abs, and lower tryptophan levels correlated with disease activity. Our study revealed some of the molecular mechanisms of mood disorder induced by anti-P Abs.

Initial responsiveness to darbepoetin alfa and its contributing factors in non-dialysis chronic kidney disease patients in Japan.

BACKGROUND: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is associated with cardiovascular events and poor renal outcome in patients with chronic kidney disease (CKD). This study aimed to investigate the initial responsiveness to darbepoetin alfa (DA) and its contributing factors using the data from the BRIGHTEN. METHODS: Of 1980 patients enrolled at 168 facilities, 1695 were included in this analysis [285 patients were excluded mainly due to lack of hemoglobin (Hb) values]. The initial ESA response index (iEResI) was defined as a ratio of Hb changes over 12 weeks after DA administration per weight-adjusted total DA dose and contributing factors to iEResI were analyzed. RESULTS: The mean age was 70 ± 12 years (male 58.8%; diabetic nephropathy 27.6%). The median creatinine and mean Hb levels at DA initiation were 2.62 mg/dL and 9.8 g/dL, respectively. The most frequent number of DA administration during 12 weeks was 3 times (41.1%), followed by 4 (15.6%) times with a wide distribution of the total DA dose (15-900 µg). Remarkably, 225 patients (13.3%) did not respond to DA. Multivariate analysis showed that male gender, hypoglycemic agent use, iron supplementation, high eGFR, low Hb, low CRP, low NT-proBNP, and low urinary protein-creatinine ratio were independently associated with better initial response to DA (P = < 0.0001, 0.0108, < 0.0001, 0.0476, < 0.0001, 0.0004, 0.0435, and 0.0009, respectively). CONCLUSIONS: Non-responder to DA accounted for 13.3% of patients with non-dialysis CKD. Iron supplementation, low CRP, low NT-proBNP, and less proteinuria were predictive and modifiable factors associated with better initial response to DA.

Anemia and iron deficiency among chronic kidney disease Stages 3-5ND patients in the Chronic Kidney Disease Outcomes and Practice Patterns Study: often unmeasured, variably treated.

BACKGROUND: International variation in anemia assessment and management practices in chronic kidney disease (CKD) is poorly understood. METHODS: We performed a cross-sectional analysis of anemia laboratory monitoring, prevalence and management in the prospective Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps). A total of 6766 participants with CKD Stages 3a-5ND from nephrology clinics in Brazil, France, Germany and the USA were included. RESULTS: Among patients with anemia (hemoglobin <12 g/dL), 36-58% in Brazil, the USA and Germany had repeat hemoglobin measured and 40-61% had iron indices measured within 3 months of the index hemoglobin measurement. Anemia was more common in the USA and Brazil than in France and Germany across CKD stages. Higher ferritin and lower iron saturation (TSAT) levels were observed with lower hemoglobin levels, and higher ferritin with more advanced CKD. The proportion of anemic patients with ferritin <100 ng/mL or TSAT <20% ranged from 42% in Brazil to 53% in France and Germany, and of these patients, over 40% in Brazil, Germany and the USA, compared with 27% in France, were treated with oral or intravenous iron within 3 months after hemoglobin measurement. The proportion of patients with hemoglobin <10 g/dL treated with erythropoiesis-stimulating agents ranged from 28% in the USA to 57% in Germany. CONCLUSIONS: Hemoglobin and iron stores are measured less frequently than per guidelines. Among all regions, there was a substantial proportion of anemic patients with iron deficiency who were not treated with iron, highlighting an area for practice improvement in CKD care.

Effect of ferric citrate hydrate on FGF23 and PTH levels in patients with non-dialysis-dependent chronic kidney disease with normophosphatemia and iron deficiency.

BACKGROUND: In patients with normophosphatemia with chronic kidney disease (CKD), fibroblast growth factor 23 (FGF23) and parathyroid hormone (PTH) increase urinary phosphate excretion while maintaining serum phosphate within the normal range. Recent reports have shown that, in this stage, phosphate binders do not decrease serum FGF23 and PTH levels. Iron deficiency promotes transcription of FGF23 and iron-supplementation for iron deficiency decreases serum FGF23 levels. We hypothesized that ferric citrate hydrate, an iron-based phosphate binder, will decrease serum FGF23 levels in patients with non-dialysis-dependent CKD with normophosphatemia and iron deficiency. METHODS: This was a single-center, randomized, open-label interventional study. The inclusion criteria were as follows: (1) eGFR < 45 mL/min/1.73 m2, (2) normophosphatemia, (3) iron deficiency. Patients were assigned to the following groups: ferric citrate hydrate (FCH)-group, sodium ferrous citrate (SFC)-group, and control-group. After 12 weeks of intervention, we evaluated serum FGF23 levels and CKD-mineral bone disorder markers. RESULTS: There were 17 patients in the FCH-group, 14 in the SFC-group, and 9 in the control-group. The serum ferritin levels increased in the FCH-group and SFC-group compared with baseline. Serum FGF23 levels were unchanged; the change in the FCH-group was from 52.91 RU/mL (42.48-72.91) to 40.00 RU/mL (30.30-58.13) (P = 0.1764). However, in the FCH-group, serum PTH levels significantly decreased compared with baseline, from 68.00 pg/mL (49.00-141.00) to 60.00 pg/mL (44.00-144.00) (P = 0.0101). CONCLUSION: Iron-based phosphate binder did not decrease serum FGF23 levels, but decreased serum PTH levels.

Oral pharmacological chaperone migalastat compared with enzyme replacement therapy in Fabry disease: 18-month results from the randomised phase III ATTRACT study.

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder caused by GLA mutations, resulting in α-galactosidase (α-Gal) deficiency and accumulation of lysosomal substrates. Migalastat, an oral pharmacological chaperone being developed as an alternative to intravenous enzyme replacement therapy (ERT), stabilises specific mutant (amenable) forms of α-Gal to facilitate normal lysosomal trafficking. METHODS: The main objective of the 18-month, randomised, active-controlled ATTRACT study was to assess the effects of migalastat on renal function in patients with Fabry disease previously treated with ERT. Effects on heart, disease substrate, patient-reported outcomes (PROs) and safety were also assessed. RESULTS: Fifty-seven adults (56% female) receiving ERT (88% had multiorgan disease) were randomised (1.5:1), based on a preliminary cell-based assay of responsiveness to migalastat, to receive 18 months open-label migalastat or remain on ERT. Four patients had non-amenable mutant forms of α-Gal based on the validated cell-based assay conducted after treatment initiation and were excluded from primary efficacy analyses only. Migalastat and ERT had similar effects on renal function. Left ventricular mass index decreased significantly with migalastat treatment (-6.6 g/m2 (-11.0 to -2.2)); there was no significant change with ERT. Predefined renal, cardiac or cerebrovascular events occurred in 29% and 44% of patients in the migalastat and ERT groups, respectively. Plasma globotriaosylsphingosine remained low and stable following the switch from ERT to migalastat. PROs were comparable between groups. Migalastat was generally safe and well tolerated. CONCLUSIONS: Migalastat offers promise as a first-in-class oral monotherapy alternative treatment to intravenous ERT for patients with Fabry disease and amenable mutations. TRIAL REGISTRATION NUMBER: NCT00925301; Pre-results.

Nephrotoxicity of cisplatin combination chemotherapy in thoracic malignancy patients with CKD risk factors.

BACKGROUND: Nephrotoxicity is the major side effect that limits the dose of cisplatin that can be safely administered, and it is a clinical problem in cancer patients who received cisplatin combination chemotherapy. Recent evidence has demonstrated that patients with chronic kidney disease (CKD) have an increased risk of developing acute kidney injury (AKI). The present study was conducted to evaluate the prevalence of CKD risk factors in patients who received cisplatin and to assess the correlation between CKD risk factors and cisplatin-induced AKI. METHODS: We retrospectively analyzed 84 patients treated with cisplatin combination chemotherapy for thoracic malignancies. AKI was defined as a decrease in the estimated glomerular filtration rate (eGFR) > 25% from base line, an increase in the serum creatinine (sCre) level of > 0.3 mg/dl or ≥ 1.5 times the baseline level. RESULTS: Eighty of the 84 patients (95.2%) had at least one risk factor for CKD. All enrolled patients received cisplatin with hydration, magnesium supplementation and mannitol. Cisplatin-induced AKI was observed in 18 patients (21.4%). Univariate analysis revealed that cardiac disease and use of non-steroidal anti-inflammatory drugs (NSAIDs) were associated with cisplatin-induced nephrotoxicity (odds ratios [OR] 6 and 3.56, 95% confidence intervals [CI] 1.21-29.87 and 1.11-11.39, p = 0.04 and p = 0.04, respectively). Multivariate analysis revealed that cisplatin nephrotoxicity occurred significantly more often in patients with both risk factors (OR 13.64, 95% CI 1.11-326.83, p = 0.04). Patients with more risk factors for CKD tended to have a greater risk of developing cisplatin-induced AKI. CONCLUSIONS: We should consider avoiding administration of cisplatin to patients with CKD risk factors, particularly cardiac disease and NSAID use.

Administration of Ferric Citrate Hydrate Decreases Circulating FGF23 Levels Independently of Serum Phosphate Levels in Hemodialysis Patients with Iron Deficiency.

BACKGROUND/AIM: Dietary phosphate intake and vitamin D receptor activator (VDRA) regulate fibroblast growth factor 23 (FGF23); iron may modulate FGF23 metabolism. We aimed to determine whether oral iron supplementation influences serum FGF23 concentration in hemodialysis (HD) patients, while excluding the effect of dietary phosphate intake. METHODS: This prospective study enrolled 27 maintenance HD patients with iron deficiency and hyperphosphatemia treated with sevelamer-HCl. The phosphate binder was changed from sevelamer-HCl to ferric citrate hydrate (FCH) to maintain constant phosphate levels. VDRA, other phosphate binders, and cinacalcet HCl were not changed. Serum intact FGF23, C-terminal FGF23 (C-term FGF23), intact parathyroid hormone (PTH), 1,25(OH)2D and other parameters were monitored for 12 weeks. RESULTS: Serum phosphate levels (5.89 ± 1.45 mg/dl at baseline, 5.54 ± 1.35 mg/dl at 12 weeks) and 1,25(OH)2D levels were unchanged. Serum ferritin levels increased from 25.6 ± 24.3 ng/ml at baseline to 55.8 ± 33.5 ng/ml at 12 weeks with FCH administration. Serum intact FGF23 and C-term FGF23 levels significantly decreased at 12 weeks compared with baseline (2,000 (1,300.0-3,471.4) to 1,771.4 (1,142.9-2,342.9) pg/ml, p = 0.01, and 1,608.7 (634.8-2,308.7) to 1,165.2 (626.1-1,547.8) RU/ml, p = 0.007, respectively); serum intact PTH levels significantly increased (96 (65-125) to 173 (114-283) pg/ml, p < 0.001). CONCLUSIONS: Oral FCH administration decreased serum intact FGF23 and C-term FGF23 levels and increased intact PTH levels; phosphate and 1,25(OH)2D levels were unchanged. Oral FCH administration to treat iron deficiency is a possible strategy for reducing serum FGF23 levels independent of phosphate and VDRA.

Atherosclerosis following renal injury is ameliorated by pioglitazone and losartan via macrophage phenotype.

OBJECTIVE: Chronic kidney disease (CKD) amplifies atherosclerosis, which involves renin-angiotensin system (RAS) regulation of macrophages. RAS influences peroxisome proliferator-activated receptor-γ (PPARγ), a modulator of atherogenic functions of macrophages, however, little is known about its effects in CKD. We examined the impact of combined therapy with a PPARγ agonist and angiotensin receptor blocker on atherogenesis in a murine uninephrectomy model. METHODS: Apolipoprotein E knockout mice underwent uninephrectomy (UNx) and treatment with pioglitazone (UNx + Pio), losartan (UNx + Los), or both (UNx + Pio/Los) for 10 weeks. Extent and characteristics of atherosclerotic lesions and macrophage phenotypes were assessed; RAW264.7 and primary peritoneal mouse cells were used to examine pioglitazone and losartan effects on macrophage phenotype and inflammatory response. RESULTS: UNx significantly increased atherosclerosis. Pioglitazone and losartan each significantly reduced the atherosclerotic burden by 29.6% and 33.5%, respectively; although the benefit was dramatically augmented by combination treatment which lessened atherosclerosis by 55.7%. Assessment of plaques revealed significantly greater macrophage area in UNx + Pio/Los (80.7 ± 11.4% vs. 50.3 ± 4.2% in UNx + Pio and 57.2 ± 6.5% in UNx + Los) with more apoptotic cells. The expanded macrophage-rich lesions of UNx + Pio/Los had more alternatively activated, Ym-1 and arginine 1-positive M2 phenotypes (Ym-1: 33.6 ± 8.2%, p < 0.05 vs. 12.0 ± 1.1% in UNx; arginase 1: 27.8 ± 0.9%, p < 0.05 vs. 11.8 ± 1.3% in UNx). In vitro, pioglitazone alone and together with losartan was more effective than losartan alone in dampening lipopolysaccharide-induced cytokine production, suppressing M1 phenotypic change while enhancing M2 phenotypic change. CONCLUSION: Combination of pioglitazone and losartan is more effective in reducing renal injury-induced atherosclerosis than either treatment alone. This benefit reflects mitigation in macrophage cytokine production, enhanced apoptosis, and a shift toward an anti-inflammatory phenotype.