Changes in erythropoiesis-stimulating agent responsiveness after transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan

INTRODUCTION

Inadequate dialysis and fluid overload are corrected after starting combined therapy with peritoneal dialysis (PD) and hemodialysis (HD). However, the effects on anemia management has not been elucidated.

METHODS

We conducted a prospective, multicenter, observational cohort study of 40 PD patients (age, 60 ± 10 years; male, 88%; median PD duration, 28 months) starting combined therapy and investigated changes in several clinical parameters, including erythropoiesis-stimulating agent (ESA) resistance index (ERI).

RESULTS

ERI decreased significantly during 6 months after switching to combined therapy (from 11.8 [IQR 8.0-20.4] units/week/kg/(g/dL) to 7.8 [IQR 3.9-18.6] units/week/kg/(g/dL), p = 0.047). Body weight, urinary volume, serum creatinine and the dialysate-to-plasma creatinine ratio (D/P Cr) decreased, whereas hemoglobin and serum albumin increased. In subgroup analysis, the changes in ERI were not affected by cause for starting combined therapy, PD holiday and D/P Cr.

CONCLUSION

Although detailed mechanism was unclear, ESA responsiveness improved after switching from PD alone to combined therapy.

POS0522 ASSOCIATED FACTORS WITH PHYSICAL DYSFUNCTION OF ELDERLY-ONSET RHEUMATOID ARTHRITIS TREATED WITH A TREAT-TO-TARGET STRATEGY

Background

Achievement of normal physical function is an important outcome for older patients. Previous studies of younger cohorts showed that aging, comorbidities, and joint damage influenced the physical function of patients with RA who achieved clinical remission or low disease activity (LDA). We previously demonstrated that a treat-to-target (T2T) strategy for methotrexate (MTX)-naïve elderly-onset RA (EORA) was effective with an acceptable safety profile. It showed that 60.9% of 197 patients achieved HAQ Disability Index (HAQ-DI) ≤0.5 at three years by following the T2T strategy targeting LDA (1).

Objectives

We aimed to evaluate associated factors with HAQ-DI in the T2T strategy targeting LDA for patients with EORA during three-year observational period.

Methods

Treatment was adjusted to target LDA with conventional synthetic disease-modifying antirheumatic drugs (DMARDs), followed by biological DMARDs (bDMARDs) in 197 MTX-naïve EORA patients (mean age 74.9 years) with moderate-to-high disease activity. HAQ-DI was evaluated at week 0, 24, 52, 76, 104, 128, and 156. To evaluate associated factors with SDAI and HAQ-DI over the 36-month follow-up, Bayesian hierarchical logistic regression modeling was applied for 1067 periods from the 197 patients.

Results

At baseline, the enrolled 197 patients with EORA who had normal physical function (HAQ-DI ≤0.5) in 29.4%, HAQ-DI >0.5 and <1.5 in 36.5%, and HAQ-DI ≥1.5 in 33.0%, and the mean age (standard deviation [SD]) in each group was 72.7 (5.9), 74.8 (7.3), and 75.6 (6.7), respectively. Baseline SDAI increased in the group with higher HAQ-DI. The proportions of patients with each comorbidity and estimated creatinine clearance at baseline were not significantly different across the 3 groups.

In the multilevel logistic model, the association of MTX, bDMARDs, and GC use with changes in SDAI in each period was evaluated. Age, sex, and comorbidities (chronic lung disease, cardiovascular disease, history of malignancy, osteoporosis, history of serious infections, and osteoarthritis) were included as inter-individual factors. The model indicated that the use of bDMARDs was associated with a reduction of the SDAI (ΔSDAI: -9.75, SD 0.75, p<0.001), while neither MTX (ΔSDAI: -1.25, SD 1.13, p=0.270) nor GCs (ΔSDAI: -0.78, SD 0.88, p=0.372) was associated with changes in SDAI. Chronic lung diseases (ΔSDAI: 4.64, SD 1.44, p=0.001) and osteoporosis (ΔSDAI: 3.78, SD 1.46, p=0.001) at baseline were associated with the increment of SDAI.

The association of age, sex, the comorbidities, and MTX, bDMARDs, and GC use with physical function in each period was evaluated by the multilevel logistic model. The model indicated that older age (ΔHAQ-DI: 0.03, SD 0.01, p <0.001), chronic lung diseases (ΔHAQ-DI: 0.15, SD 0.10, p=0.001), and osteoporosis (ΔHAQ-DI: 0.30, SD 0.10, p=0.010) at baseline were associated with the increment of HAQ-DI. When the mean SDAI during the observation period was added to the model as an inter-individual factor, the associations of HAQ-DI with the chronic lung diseases and osteoporosis at baseline were not statistically significant.

Conclusion

These data indicate that bDMARDs had a central role in reducing disease activity in the T2T strategy targeting LDA in EORA patients. Chronic lung diseases and osteoporosis at baseline were associated with increase in disease activity and worsening of physical function. However, disease activity had a greater impact on physical function than the comorbidities at baseline.

References

[1]Sugihara T, et al. Rheumatology (Oxford). 2021;60(9):4252-4261

Disclosure of Interests

takahiko sugihara Speakers bureau: TS has received honoraria from Abbvie Japan Co., Ltd., AsahiKASEI Co., Ltd., Astellas Pharma Inc., Ayumi Pharmaceutical, Bristol Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Mitsubishi-Tanabe Pharma Co., Ono Pharmaceutical, Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., and UCB Japan Co. Ltd., Grant/research support from: TS has received research grants from AsahiKASEI Co., Ltd., Daiichi Sankyo., Chugai Pharmaceutical Co., Ltd., and Ono Pharmaceutical., Tatsuro Ishizaki: None declared, Hiroyuki Baba: None declared, Takumi Matsumoto: None declared, Kanae Kubo Speakers bureau: KK has received honoraria from Asahi KASEI, Astellas Pharma, Bristol Myers Squibb, Eisai, AbbVie GK, Boehringer Ingelheim, Daiichi-Sankyo, Chugai Pharmaceutical, Mitsubishi Tanabe Pharma and Nippon Shinyaku., Grant/research support from: KK has received research grants from Asahi KASEI, Mari Kamiya: None declared, Fumio Hirano: None declared, Tadashi Hosoya: None declared, Masayo Kojima Speakers bureau: MK has received speakers bureau from AbbVie, Astellas, Ayumi Pharma, Chugai, Eisai, Eli Lilly, Janssen, Ono Pharmaceutical, Pfizer, Tanabe-Mitsubishi, and Takeda Pharmaceutical Co., Ltd., Nobuyuki Miyasaka: None declared, Masayoshi Harigai Speakers bureau: MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc.,Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Pfizer Japan Inc., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd., Consultant of: MH is a consultant for AbbVie, Boehringer-ingelheim, Bristol Myers Squibb Co., Kissei Pharmaceutical Co.,Ltd. and Teijin Pharma., Grant/research support from: MH has received research grants from AbbVie Japan GK, Asahi Kasei Corp., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Daiichi-Sankyo, Inc.,Eisai Co., Ltd., Kissei Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., Sekiui Medical, Shionogi & Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd.

POS0197 SARS-CoV-2 INFECTION CAUSED THROMBOSIS IN THE LUPUS MODEL WITH ANTIPHOSPHOLIPID ANTIBODY, WHEREAS COVID-19 ASSOCIATED THROMBOSIS WAS IRRELEVANT IN PATIENTS WITH POSITIVE ANTIPHOSPHOLIPID ANTIBODY

Background

Thrombosis is a unique complication in coronavirus disease 2019 (COVID-19). We have reported that elevated ferritin and D-dimer on admission were the risk factors of thromboses by analyzing the patients sequentially admitted to our hospital due to COVID-19 (1). However, we have not analyzed thrombotic complications in the view of the antiphospholipid antibodies (aPLs), which are frequently detected in the COVID-19 patients.

Objectives

To elucidate the thrombogenic effects of aPLs in COVID-19, we analyzed the development of thrombosis in three lupus models after SARS-CoV-2 infection. Additionally, we evaluated the association of thrombotic events and the serum profile of aPLs in Japanese patients with COVID-19.

Methods

Three animal models of lupus (MRL-lpr/lpr, NZBxNZW F1 and NZW×BXSB F1) were evaluated in this study. NZW×BXSB F1 was also considered as a model of antiphospholipid syndrome (APS) since aPLs were detected with a high titer (2). Experimental SARS-CoV-2 infection was induced using mouse-passaged virus strain (3). The incidence of thromboses in the lungs and kidneys were identified by evaluating H&E staining and PTAH staining of paraffin-embedded sections. We have experienced 44 thrombotic events in 34 out of 594 patients admitted to our institute. As a non-thrombotic COVID-19, 68 patients were selected to make a 1 to 2 matched-pair based on the propensity score. In total 102 patients, seven types of aPLs (anti-cardiolipin (CL) IgG/IgM, anti-β2GP1 IgG/IgA/IgM, and anti-phosphatidyl serine/prothrombin complex (PS/PT) IgG/IgM) were measured using specific ELISA kits. The patients’ clinical characteristics and serological profile of aPLs were further evaluated.

Results

We identified the development of thromboses in the lungs or kidneys in 6 out of 12 (50%) NZW×BXSB F1 mice after the SARS-CoV-2 infection, whereas no thrombosis was observed in non-infected mice. Further, there was no thrombosis in the other lupus models (0%) after the infection. These findings might suggest the pathogenic role of aPLs under the SARS-CoV-2 infection.

Among our COVID-19 patients, 39 out of 102 (38%) were tested positive for one or more aPLs. The positive ratios of any aPLs were statistically indifferent between the patients with or without thrombosis; anti-CL IgG (8.8% vs 5.9%)/IgM (0% vs 5.9%), anti-β2GP1 IgG (21% vs 12%)/IgA (8.8% vs 15%)/IgM (0% vs 1.5%), and anti-PS/PT IgG (0% vs 2.9%)/IgM (12% vs 13%), respectively. In addition, their titers were relatively lower than those observed in APS patients. The patients’ characteristics and the prognosis of COVID-19 were comparable regardless of the detection of any aPLs. These findings suggested that COVID-19 associated aPLs were irrelevant to thrombotic complications.

Conclusion

Thromboses were induced after the infection of SARS-CoV-2 only in the APS model. However, aPLs detected in COVID-19 patients have little impact on the development of thrombosis. SARS-CoV-2 infection might have a high risk of thrombosis, especially in APS patients, as shown in the case report (4). The discrepancy of its thrombogenic effects of aPLs might be explained by the low titer of the antibody or the diversity of antibody epitope. Further analyses are required to clarify the mechanisms of aPLs production and the development of thrombosis in COVID-19.

References

[1]Oba S, et al. Arterial and Venous Thrombosis Complicated in COVID-19: A Retrospective Single-Center Analysis in Japan. Front Cardiovasc Med. 2021 Nov 19;8:767074.

[2]Hashimoto Y, et al. Anticardiolipin antibodies in NZW x BXSB F1 mice. A model of antiphospholipid syndrome. J Immunol. 1992 Aug 1;149(3):1063-8.

[3]Iwata-Yoshikawa N, et al. A lethal mouse model for evaluating vaccine-associated enhanced respiratory disease during SARS-CoV-2 infection. Sci Adv. 2022 Jan 7;8(1):eabh3827.

[4]Chidharla A, et al. A Case Report of COVID-Associated Catastrophic Antiphospholipid Syndrome Successfully Treated with Eculizumab. J Blood Med. 2021 Oct 30;12:929-933.

Disclosure of Interests

Seiya Oba: None declared, Tadashi Hosoya Speakers bureau: Janssen Pharmaceutical K.K.

Daiichi Sankyo Company, limited

Asahi Kasei Corporation

Ono pharmaceuticals

Eisai

Eli Lilly, Daisuke Kawata: None declared, Wenshi Lee: None declared, Mari Kamiya: None declared, Yoji Komiya: None declared, Hideyuki Iwai: None declared, Yuko Nukui: None declared, Shuji Tohda: None declared, Shinsuke Yasuda Speakers bureau: Abbvie,

Asahi Kasei Pharma,

Chugai Pharmaceutical,

Eisai, Eli Lilly,

GlaxoSmithKline,

Mitsubishi Tanabe Pharma,

Ono pharmaceutical,

Pfizer., Consultant of: ImmunoForge, Grant/research support from: Abbvie,

Asahi Kasei Pharma,

Chugai Pharmaceutical,

CSL Behring,

Eisai,

ImmunoForge,

Mitsubishi Tanabe Pharma,

Ono pharmaceutical

Clinical feasibility of transfer to combined therapy with peritoneal dialysis and hemodialysis for patients on peritoneal dialysis: A prospective multicenter study in Japan

INTRODUCTION

Although combined therapy with peritoneal dialysis (PD) and hemodialysis (HD) is widespread in Japan, its clinical utility has been reported only in retrospective or before-and-after test lacking a control group.

METHODS

We conducted a prospective, multicenter, observational cohort study of 176 incident PD patients and compared patient survival and changes in clinical parameters between patients on different dialysis modalities.

RESULTS

During a median follow-up of 41 months, 47 patients transferred to combined therapy and 35 patients transferred directly to HD. Patients transferred to combined therapy had a significantly better survival than those transferred directly to HD. However, we could not establish this difference in a multivariate analysis because only six patients died among these groups. The decreases in urea nitrogen and serum creatinine were more prominent among patients directly transferred to HD.

CONCLUSION

This is the first report revealing clinical feasibility of transfer to combined therapy for PD patients.

A review of Hyphodiscaceae

In a recently published classification scheme for Leotiomycetes, the new family Hyphodiscaceae was erected; unfortunately, this study was rife with phylogenetic misinterpretations and hampered by a poor understanding of this group of fungi. This manifested in the form of an undiagnostic familial description, an erroneous familial circumscription, and the redescription of the type species of an included genus as a new species in a different genus. The present work corrects these errors by incorporating new molecular data from this group into phylogenetic analyses and examining the morphological features of the included taxa. An emended description of Hyphodiscaceae is provided, notes and descriptions of the included genera are supplied, and keys to genera and species in Hyphodiscaceae are supplied. Microscypha cajaniensis is combined in Hyphodiscus, and Scolecolachnum nigricans is a taxonomic synonym of Fuscolachnum pteridis. Future work in this family should focus on increasing phylogenetic sampling outside of Eurasia and better characterising described species to help resolve outstanding issues.

Uric acid-lowering effect of dotinurad, a novel selective urate reabsorption inhibitor, in hypertensive patients with gout or asymptomatic hyperuricemia: a pooled analysis of individual participant data in phase II and III trials

Background: Hyperuricemia is a risk factor for the development of hypertension and is comorbid in many hypertensive patients. According to Japanese hypertension management guidelines published in 2019, a target serum uric acid level of ≤6.0 mg/dL is recommended in hypertensive patients with gout or asymptomatic hyperuricemia. Dotinurad is a novel uric acid-lowering drug classified as a selective urate reabsorption inhibitor. A pooled analysis was performed on the uric acid-lowering effect of dotinurad in 222 hypertensive patients with gout or asymptomatic hyperuricemia in four clinical trials (NCT02344862, NCT02416167, NCT03100318, NCT03372200). Moreover, we analyzed the long-term uric acid-lowering effect of dotinurad in 154 hypertensive patients with gout or asymptomatic hyperuricemia (NCT03006445).Results: In the pooled analysis, the percent change in the decrease of serum uric acid with the use of dotinurad was 42.17 ± 12.42% at a dose of 2 mg and 60.42 ± 8.03% at a dose of 4 mg; the percentage of patients who achieved a serum uric acid level of ≤6.0 mg/dL was 82.8% and 100.0%. The long-term uric acid-lowering effect of dotinurad showed almost the same results. In this study, the concomitant use of diuretics or angiotensin II receptor blockers affected the uric acid-lowering effect of dotinurad at only a dose of 2 mg in the pooled analysis.Conclusions: In the pooled analysis, dotinurad lowered serum uric acid levels. Dotinurad has an achievement rate of over 80% for serum uric acid level of ≤6.0 mg/dL in both analyses, and will be clinically useful for the management of hyperuricemic states in hypertensive patients.

Comparative study of a novel selective urate reabsorption inhibitor "dotinurad" among patient groups with different stages of renal dysfunction

BACKGROUND

Dotinurad is a selective urate reabsorption inhibitor (SURI), which selectively inhibits URAT1 to lower serum uric acid levels in patients with hyperuricemia. Herein, the effects of dotinurad were compared among patient groups with different stages of renal dysfunction.

METHODS

Patient data from four clinical trials were pooled and divided into four groups according to the stage of renal dysfunction to compare the effects of dotinurad at different stages. The grouping (stages G1-G3b) was based on the estimated glomerular filtration rate (eGFR) of the patients. In addition, patient data from a long-term study (34 or 58 weeks) were evaluated in the same manner.

RESULTS

In the pooled analysis, the percentage of patients achieving a serum uric acid level of ≤ 6.0 mg/dL was 64.7-100.0% at a dose of 2 or 4 mg. In the long-term analysis, the percentage of patients achieving a serum uric acid level of ≤ 6.0 mg/dL was 60.0-100.0% at a dose of 2 or 4 mg. Although the outcomes in stage G3b were worse due to higher baseline serum uric acid levels, satisfactory outcomes were observed in all stages. Even in stages G3a and G3b, when renal function declined, the eGFR remained constant throughout the dose period.

CONCLUSION

The efficacy of dotinurad was confirmed in hyperuricemic patients with normal renal function (stage G1) and mild to moderate renal dysfunction (stage G2-G3b). Dotinurad was found to be effective in the treatment of hyperuricemia in patients with mild to moderate renal dysfunction.

Association Between Kidney Function Decline and Baseline TNFR Levels or Change Ratio in TNFR by Febuxostat Chiefly in Non-diabetic CKD Patients With Asymptomatic Hyperuricemia

Background: The levels of circulating tumor necrosis factor receptor (TNFR) 1 and 2 help predict the future decline of estimated glomerular filtration rate (eGFR) chiefly in patients with diabetes. It has been recently reported that the change ratio in TNFR1 by SGLT2 inhibitor treatment is also related with future GFR decline in patients with diabetes. The aims of this study are to investigate the association between baseline TNFR levels and early change in TNFR levels by the non-purine selective xanthine oxidase inhibitor, febuxostat, and future eGFR decline chiefly in chronic kidney disease (CKD) patients without diabetes.

Methods: We conducted a post-hoc analysis of the FEATHER study on patients with asymptomatic hyperuricemia and CKD stage 3, who were randomly assigned febuxostat 40 mg/day or matched placebo. This analysis included 426 patients in whom baseline stored samples were available. Serum TNFR levels at baseline were measured using enzyme-linked immunosorbent assay. Those levels were also measured using 12-week stored samples from 197 randomly selected patients.

Results: Compared with placebo, short-term febuxostat treatment significantly decreased the median percent change from baseline in serum uric acid (−45.05, 95% CI −48.90 to −41.24 mg/dL), TNFR1 (1.10, 95% CI−2.25 to 4.40), and TNFR2 (1.66, 95% CI −1.72 to 4.93), but not TNFR levels. Over a median follow-up of 105 weeks, 30 patients (7.0%) experienced 30% eGFR decline from baseline. In the Cox multivariate model, high levels of baseline TNFR predicted a 30% eGFR decline, even after adjusting for age, sex, systolic blood pressure, high sensitivity C-reactive protein, uric acid, and presence or absence of febuxostat treatment and diabetes, in addition to baseline albumin to creatinine ratio and eGFR.

Conclusion: Early change in circulating TNFR levels failed to predict future eGFR decline; however, regardless of febuxostat treatment, the elevated baseline level of TNFR was a strong predictor of 30% eGFR decline even in chiefly non-diabetic CKD patients with asymptomatic hyperuricemia.

Dotinurad: a novel selective urate reabsorption inhibitor for the treatment of hyperuricemia and gout

INTRODUCTION

Gout is an inflammatory disease triggered by deposition of urate crystals secondary to longstanding hyperuricemia, and its management implies both the treatment of flares and management of hyperuricemia. Dotinurad is a selective urate reabsorption inhibitor (SURI), potently inhibits urate transporter 1 in the apical surface of renal proximal tubular cells, and has been approved for the treatment of gout and hyperuricemia in Japan.

AREAS COVERED

This overview of dotinurad covers nonclinical and clinical pharmacology studies in special populations and its efficacy and safety in Japanese hyperuricemic patients with and without gout.

EXPERT OPINION

Dotinurad, as an SURI, is expected to inhibit urate reabsorption more effectively than conventional urate-lowering agents. It is noninferior to benzbromarone or febuxostat in reducing serum urate levels in hyperuricemic patients with or without gout. Its efficacy is not attenuated in patients with mild to moderate renal impairment or with hepatic impairment. At a maintenance dose of 2 or 4 mg once daily, most patients achieved the target serum urate level of ≤6 mg/dL in a long-term study. No findings that raised safety concerns, including liver injury, were identified. Dotinurad is expected to be a new therapeutic option in hyperuricemic patients with and without gout.

Therapeutics potentiating microglial p21-Nrf2 axis can rescue neurodegeneration caused by neuroinflammation

Neurodegenerative disorders are caused by progressive neuronal loss, and there is no complete treatment available yet. Neuroinflammation is a common feature across neurodegenerative disorders and implicated in the progression of neurodegeneration. Dysregulated activation of microglia causes neuroinflammation and has been highlighted as a treatment target in therapeutic strategies. Here, we identified novel therapeutic candidate ALGERNON2 (altered generation of neurons 2) and demonstrate that ALGERNON2 suppressed the production of proinflammatory cytokines and rescued neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease model. ALGERNON2 stabilized cyclinD1/p21 complex, leading to up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), which contributes to antioxidative and anti-inflammatory responses. Notably, ALGERNON2 enhanced neuronal survival in other neuroinflammatory conditions such as the transplantation of induced pluripotent stem cell-derived dopaminergic neurons into murine brains. In conclusion, we present that the microglial potentiation of the p21-Nrf2 pathway can contribute to neuronal survival and provide novel therapeutic potential for neuroinflammation-triggered neurodegeneration.

Differences in Corrective Mode for Divalent Ions and Parathyroid Hormone between Standard- and Low-Calcium Dialysate in Patients on Continuous Ambulatory Peritoneal Dialysis—Result of a Nationwide Survey in Japan

⋄ Background

In patients on continuous ambulatory peritoneal dialysis (CAPD), dialysate calcium concentration has a strong influence on correction of serum calcium, phosphorus, and parathyroid hormone (PTH); however, the optimal concentration of Ca in PD solution is still uncertain. The aim of the survey reported here was to evaluate the prevalence of patients treated with standard- [SCD (approximately 3.25 – 4.0 mEq/L)] or low-calcium [LCD (approximately 1.8 – 2.5 mEq/L)] dialysate and differences in the clinical effects for correction of abnormalities in divalent ions and PTH.

⋄ Materials and Methods

We used a questionnaire to survey 333 peritoneal dialysis facilities nationwide in Japan. Then, we analyzed serum Ca, P, and PTH levels and the prescription rates for CaCO3 as a P binder and for vitamin D (VitD) analogs.

⋄ Results

The 2384 CAPD patients enrolled in this analysis had a mean age of 60.5 ± 14.2 years and a mean duration of CAPD of 44.1 ± 39.2 months. The prevalences of SCD, LCD, and combination of SCD and LCD were, respectively, 49%, 50%, and 1% at initiation, and 40%, 38%, and 22% at the time of the survey. In 735 and 876 patients respectively, LCD and SCD had been prescribed from initiation to the time of the survey. In these two groups, we observed no difference in initiation and current serum levels of Ca and P. But prescription rates for CaCO3 and VitD analogs were higher in the LCD group than in the SCD group, and PTH levels were higher in the LCD group than in the SCD group.

⋄ Conclusions

A beneficial effect of LCD was revealed in the increased doses of CaCO3 and VitD analogs seen in that group without the occurrence of hypercalcemia; however, PTH levels in that group were not maintained within an acceptable range. The survey suggests that more serious attention should be paid to the Ca concentration in peritoneal dialysate so as to lessen mineral and PTH disorders in CAPD.

Subtype-specific gout susceptibility loci and enrichment of selection pressure on ABCG2 and ALDH2 identified by subtype genome-wide meta-analyses of clinically defined gout patients

Objectives

Genome-wide meta-analyses of clinically defined gout were performed to identify subtype-specific susceptibility loci. Evaluation using selection pressure analysis with these loci was also conducted to investigate genetic risks characteristic of the Japanese population over the last 2000–3000 years.

Methods

Two genome-wide association studies (GWASs) of 3053 clinically defined gout cases and 4554 controls from Japanese males were performed using the Japonica Array and Illumina Array platforms. About 7.2 million single-nucleotide polymorphisms were meta-analysed after imputation. Patients were then divided into four clinical subtypes (the renal underexcretion type, renal overload type, combined type and normal type), and meta-analyses were conducted in the same manner. Selection pressure analyses using singleton density score were also performed on each subtype.

Results

In addition to the eight loci we reported previously, two novel loci, PIBF1 and ACSM2B, were identified at a genome-wide significance level (p<5.0×10^–8) from a GWAS meta-analysis of all gout patients, and other two novel intergenic loci, CD2-PTGFRN and SLC28A3-NTRK2, from normal type gout patients. Subtype-dependent patterns of Manhattan plots were observed with subtype GWASs of gout patients, indicating that these subtype-specific loci suggest differences in pathophysiology along patients’ gout subtypes. Selection pressure analysis revealed significant enrichment of selection pressure on ABCG2 in addition to ALDH2 loci for all subtypes except for normal type gout.

Conclusions

Our findings on subtype GWAS meta-analyses and selection pressure analysis of gout will assist elucidation of the subtype-dependent molecular targets and evolutionary involvement among genotype, phenotype and subtype-specific tailor-made medicine/prevention of gout and hyperuricaemia.

Effects of mild and moderate renal dysfunction on pharmacokinetics, pharmacodynamics, and safety of dotinurad: a novel selective urate reabsorption inhibitor

BACKGROUND

Dotinurad, a novel selective urate reabsorption inhibitor, exerts a serum uric acid-lowering effect by selectively inhibiting urate transporter 1 (URAT1) in patients with hyperuricemia. It is generally known that the progression of renal dysfunction is associated with a reduction in the serum uric acid-lowering effects of uricosuric drugs. We, therefore, investigated the pharmacokinetics (PK), pharmacodynamics (PD), and safety of dotinurad in subjects with renal dysfunction.

METHODS

This was a parallel-group, open-label, single-dose clinical pharmacology study. Dotinurad (1 mg) was administered once, orally to subjects with mild (estimated glomerular filtration rate [eGFR], ≥ 60 to < 90 mL/min/1.73 m2) or moderate (eGFR, ≥ 30 to < 60 mL/min/1.73 m2) renal dysfunction or normal (eGFR, ≥ 90 mL/min/1.73 m2) renal function.

RESULTS

The time-course of mean plasma concentration of dotinurad had similar profiles across the groups. Regarding PK, there was no significant difference between the renal dysfunction groups and normal renal function group. Regarding PD, the maximum reduction rate in serum uric acid levels and the fractional uric acid excretion (FE) ratio (FE0-24/FE-24-0) were significantly lower in the moderate renal dysfunction group than in the normal renal function group. However, other PD parameters were not significantly different among the groups. No notable adverse events or adverse drug reactions were observed in this study.

CONCLUSION

These results suggested that no dose adjustment might be necessary when administering dotinurad to patients with mild-to-moderate renal dysfunction. ClinicalTrials.gov Identifier: NCT02347046.

A clinical pharmacology study of the novel, selective urate reabsorption inhibitor dotinurad in outpatients

BACKGROUND

Dotinurad is a novel, selective urate reabsorption inhibitor (SURI), which reduces serum uric acid levels by selective inhibition of the urate transporter 1 (URAT1). The Japanese guideline for the management of hyperuricemia and gout recommends that drug selection should be based on classification of hyperuricemia as a fundamental principle. However, there may be some cases where this principle is not observed. We investigated the pharmacodynamics and safety of dotinurad in outpatients with uric acid overproduction or uric acid underexcretion type.

METHODS

This was a multicenter, open-label, forced titration study. Patients were classified as uric acid overproduction or underexcretion type. Study treatment was initiated at 0.5 mg/day, followed by dose titration to the estimated maximum dose of 4 mg/day over 14 weeks. The primary endpoint was urinary uric acid excretion at each 24-h urine collection.

RESULTS

A total of 26 hyperuricemic patients with or without gout were enrolled in the study and assigned to the uric acid overproduction group (overproduction group) or the uric acid underexcretion group (underexcretion group). Although urinary uric acid excretion, the primary endpoint, tended to be slightly greater in the overproduction group, no notable difference was noted between the two hyperuricemic types. Neither type had noteworthy safety concerns associated with dotinurad.

CONCLUSION

The results of the study demonstrated no relevant differences between the hyperuricemic types in terms of pharmacodynamic action and safety of dotinurad.

Is Encapsulating Peritoneal Sclerosis a Threatening Issue in Continuous Ambulatory Peritoneal Dialysis? The Japanese Experience

Encapsulating peritoneal sclerosis (EPS) is undoubtedly the most serious complication of continuous ambulatory peritoneal dialysis treatment in Japan, with a mortality rate ranging from about 39% to 49% in reported series. Cases of EPS have been linked to long-term peritoneal dialysis, and limitations on renal transplantation in Japan mean that most Japanese patients have to accept long-term dialysis therapy, which is a critical problem. Treatment alternatives for EPS include total parenteral nutrition, prednisolone administration, and surgical approaches, all of which have varying success rates. Additional therapeutic and new preventive measures have to be established for EPS.

Tranexamic Acid Increases Peritoneal Ultrafiltration Volume in Patients on Capd

Objective

The preservation of ultrafiltration (UF) capacity is crucial to maintaining long-term continuous ambulatory peritoneal dialysis (CAPD). The aim of the present study was to investigate whether the antiplasmin agent tranexamic acid (TNA) increases UF volume in CAPD patients.

Patients and Methods

Fifteen patients on CAPD, 5 with UF loss and 10 without UF loss, were recruited for the study. The effect of TNA was evaluated with respect to changes in UF volume, peritoneal permeability, peritoneal clearance, bradykinin (BK), and tissue plasminogen activator (tPA) concentration.

Setting

Dialysis unit of the Saiseikai Central Hospital.

Results

In patients with UF loss, 2 weeks of treatment with oral TNA produced a significant increase in UF volume in all subjects (5/5). TNA also produced a significant increase in peritoneal clearances of urea and creatinine (Cr). However, the peritoneal equilibration test (PET) revealed that TNA had no effect on dialysate/plasma (D/P) Cr, Kt/V, or the protein catabolic rate (PCR). TNA also had no effect on net glucose reabsorption. In contrast, significant decreases in BK and blood tPA concentrations in response to TNA treatment were noted. BK concentration in drainage fluid was also reduced. In the case of patients without UF loss, TNA produced an increase in UF volume in 70% (7/10). However, no differences were found in blood and drainage BK and tPA concentrations between the TNA treatment and nontreatment periods in these patients. A comparison of basal BK and tPA concentration showed that there were no differences in these parameters between patients with UF loss and those without loss of UF. Furthermore, TNA given intraperitoneally to a patient also produced a marked increase in UF volume.

Conclusion

The present study suggests that TNA enhances UF volume in patients both with and without UF loss. Since TNA did not affect peritoneal permeability and glucose reabsorption, the mechanism by which TNA exerts an enhancing action on UF is largely unknown. We speculate that it may be associated with suppression of the BK and/or tPA system, at least in patients with UF loss.

Suppression of Nε-(Carboxymethyl)Lysine Generation by the Antioxidant N-Acetylcysteine

Objective

Accumulated evidence suggests that Nε-(carboxymethyl)lysine (CML), which is a dominant antigen of advanced glycation end-products (AGEs), is generated in the peritoneal cavity of patients undergoing continuous ambulatory peritoneal dialysis (CAPD), and that this process may be involved in the pathophysiology of the peritoneal injury found with CAPD treatment. Since CML is a sequential product of glycation and oxidation processes, CML generation could be suppressed by antioxidants. The aim of this in vitro study was to clarify the effect of N-acetylcysteine (NAC), an antioxidant, on CML generation from proteins under high glucose settings mimicking peritoneal dialysis solutions.

Design

Test proteins (bovine serum albumin/type I collagen) were incubated continuously for 16 weeks in glucose solutions (200 mmol/L) with or without NAC (2 mmol/L), and the generation time courses (8 and 16 weeks) of CML and furosine (the biomarker of the glycation products of the early Maillard reaction) were determined.

Results

In both proteins, furosine and CML were progressively generated in accordance with the duration of the incubation period. No apparent differences were found between solutions with and without NAC in furosine levels at the 8th and 16th weeks. However, the generation of CML was lower in the solution with NAC throughout the test periods.

Conclusion

The results showed that NAC could suppress the generation of CML. This indicates the therapeutic potential of antioxidants for the glycoxidative stress-related peritoneal injury occurring during CAPD.

Transluminal Replacement of Displaced Peritoneal Catheter Using a Special “Alpha-Replacer” Guidewire: Effectiveness and Limitations

Background

Transluminal replacement of a displaced peritoneal catheter (TRC) using a metal guidewire is a noninvasive treatment of catheter displacement with acute malfunction. The “alpha-replacer” is a special guidewire developed specifically for TRC. This wire is usually flexible but becomes harder if coiled in the hand. Application of this unique guidewire might improve the effectiveness of TRC.

Methods

TRC using an alpha-replacer was performed in 10 cases for urgent correction of peritoneal catheter displacement. All patients had received a double cuffed, straight-end swan-neck catheter.

Results

The primary success rate of TRC using the alpha-replacer was 90% (9 of 10 cases). No patients developed complications such as injury of the peritoneum or abdominal organs. Relapse of catheter displacement was observed in 2 cases (20%) within 1 week, requiring surgical intervention to prevent relapse.

Conclusion

TRC using the alpha-replacer as described herein offers effective and safe treatment of peritoneal catheter displacement.

Dotinurad versus benzbromarone in Japanese hyperuricemic patient with or without gout: a randomized, double-blind, parallel-group, phase 3 study

Background

Dotinurad is a novel selective urate reabsorption inhibitor that reduces serum urate levels in hyperuricemic patients with or without gout by selectively inhibiting urate transporter 1. This study was conducted to compare the efficacy and safety of dotinurad with those of benzbromarone.

Methods

In this 14-week, randomized, multicenter, double-blind, parallel-group, dose escalation, benzbromarone-controlled, phase 3 study, hyperuricemic patients with or without gout were randomized to two groups that received either dotinurad 2 mg or benzbromarone 50 mg. Dotinurad or benzbromarone was administered once a day for 14 weeks. The primary endpoint was the percent change in serum uric acid level from the baseline to the final visit.

Results

A total of 201 Japanese hyperuricemic patients with or without gout (dotinurad: 102, benzbromarone: 99) received at least one dose of the study drug. The mean percent change in serum uric acid level from the baseline to the final visit in the dotinurad and benzbromarone groups was 45.9% and 43.8%, respectively. Non-inferiority of dotinurad 2 mg to benzbromarone 50 mg in lowering serum uric acid was verified by the predefined non-inferiority margin (95% CI − 1.27 to 5.37%). The incidence of adverse events and adverse drug reactions was comparable between the two groups.

Conclusion

Dotinurad 2 mg was verified to have a non-inferior serum uric acid lowering effect compared with benzbromarone 50 mg, in Japanese hyperuricemic patients with or without gout.

ClinicalTrials.gov Identifier

NCT03100318.

A non-inferiority study of the novel selective urate reabsorption inhibitor dotinurad versus febuxostat in hyperuricemic patients with or without gout

Background

Dotinurad is a novel, selective urate reabsorption inhibitor, which reduces serum uric acid levels by selective inhibition of the urate transporter 1. We evaluated the efficacy and safety of dotinurad versus febuxostat, a widely used drug in Japan, in hyperuricemic Japanese patients with or without gout.

Methods

This was a multicenter, randomized, double-blind, active-controlled, parallel-group, forced-titration study in hyperuricemic patients. Study treatment in the dotinurad and febuxostat groups was initiated at 0.5 and 10 mg/day, followed by dose titration to 2 and 40 mg/day, respectively, over 14 weeks. The primary endpoint was the percent change in serum uric acid level from the baseline to the final visit.

Results

A total of 203 hyperuricemic patients with or without gout were enrolled in the study and randomized to receive dotinurad or febuxostat. The percent change in serum uric acid level from the baseline to the final visit was 41.82% in the dotinurad group and 44.00% in the febuxostat group. The mean difference was − 2.17% (two-sided 95% confidence interval − 5.26% to 0.92%). The lower limit of the interval was above the non-inferiority margin (− 10%), demonstrating the non-inferiority of dotinurad to febuxostat. The profiles of adverse events and adverse drug reactions raised no noteworthy safety concerns in either group.

Conclusion

The non-inferiority of dotinurad to febuxostat in terms of serum uric acid lowering effect was confirmed. No noteworthy safety concerns arose.

Clinical efficacy and safety of dotinurad, a novel selective urate reabsorption inhibitor, in Japanese hyperuricemic patients with or without gout: randomized, multicenter, double-blind, placebo-controlled, parallel-group, confirmatory phase 2 study

BACKGROUND

Dotinurad, a novel selective urate reabsorption inhibitor (SURI), reduces serum uric acid levels by selectively inhibiting urate transporter 1 (URAT1) for the treatment of hyperuricemia with or without gout. We confirmed the serum uric acid lowering effect and safety of dotinurad.

METHODS

This was a confirmatory, 12-week, randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose escalation, late phase 2 study. The study arms were dotinurad 0.5, 1, 2, or 4 mg and placebo. The primary endpoint was the percent change in serum uric acid level from the baseline to the final visit. The secondary endpoint was the percentage of patients achieving a serum uric acid level ≤ 6.0 mg/dL at the final visit.

RESULTS

The study drugs were administered to 200 Japanese hyperuricemic patients with or without gout. The mean percent change in serum uric acid level from the baseline to the final visit in the dotinurad 0.5, 1, 2, and 4 mg groups and the placebo group was 21.81%, 33.77%, 42.66%, 61.09%, and - 2.83%, respectively. The percentage of patients achieving a serum uric acid level ≤ 6.0 mg/dL at the final visit in each group was 23.1%, 65.9%, 74.4%, 100%, and none, respectively. Regarding safety, the incidence of adverse events did not increase with dose escalation in the dotinurad groups. No significant differences were observed in the incidence of gouty arthritis in each group.

CONCLUSION

The serum uric acid lowering effect and safety of dotinurad were confirmed in hyperuricemic patients with or without gout. CLINICALTRIALS.

GOV IDENTIFIER

NCT02416167.

Genome-wide association study revealed novel loci which aggravate asymptomatic hyperuricaemia into gout

Objective

The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout.

Methods

We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia).

Results

This new approach enabled us to identify two novel gout loci (rs7927466 of CNTN5 and rs9952962 of MIR302F) and one suggestive locus (rs12980365 of ZNF724) at the genome-wide significance level (p<5.0×10^–8). The present study also identified the loci of ABCG2, ALDH2 and SLC2A9. One of them, rs671 of ALDH2, was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three ‘gout vs AHUA GWAS’-specific loci (CNTN5, MIR302F and ZNF724) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level.

Conclusions

This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals.

Multicenter, Open-Label Study of Long-Term Topiroxostat (FYX-051) Administration in Japanese Hyperuricemic Patients with or Without Gout

Background and Objectives

Topiroxostat—a novel selective xanthine oxidoreductase inhibitor—has been reported to reduce serum urate levels. The purpose of this study was to assess the efficacy and safety of long-term topiroxostat administration in Japanese hyperuricemic patients with or without gout.

Methods

This multicenter, open-label study evaluated the efficacy and safety of long-term twice-daily oral topiroxostat administration in patients with or  without gout. The initial topiroxostat dosage was 40–80 mg/day, and the maintenance dosage was 120 mg/day, which was increased to 240 mg/day at 40 mg increments if the serum urate level exceeded 6.0 mg/dL.

Results

Serum urate level, which was the primary endpoint, decreased stably over time and showed significant reduction on the final visit (38.44% ± 13.34%) compared with that at the baseline. Both urinary albumin/creatinine ratio and mean blood pressure significantly improved. The overall incidence rate of adverse drug reactions to topiroxostat was 67.8%; on the final visit, the rate of adverse drug reactions was 66.7% with 120 mg/day, 72.2% with 160 mg/day, 53.8% with ≥ 200 mg/day, and 100% with the other dosages. On the final visit, the incidence of gouty arthritis, for which a causal relationship with topiroxostat could not be ruled out, was 4.1% overall, 4.8% with 120 mg/day, 0% with 160 mg/day, and 7.7% with ≥ 200 mg/day.

Conclusions

We verified the efficacy and safety of 58-week oral topiroxostat administration at stepwise increments to up to 240 mg/day.

Study Registration

JAPIC CTI-101068.

Effect of Oral Alfacalcidol on Clinical Outcomes in Patients Without Secondary Hyperparathyroidism Receiving Maintenance Hemodialysis: The J-DAVID Randomized Clinical Trial

IMPORTANCE

Patients with chronic kidney disease have impaired vitamin D activation and elevated cardiovascular risk. Observational studies in patients treated with hemodialysis showed that the use of active vitamin D sterols was associated with lower risk of all-cause mortality, regardless of parathyroid hormone levels.

OBJECTIVE

To determine whether vitamin D receptor activators reduce cardiovascular events and mortality in patients without secondary hyperparathyroidism undergoing hemodialysis.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, open-label, blinded end point multicenter study of 1289 patients in 207 dialysis centers in Japan. The study included 976 patients receiving maintenance hemodialysis with serum intact parathyroid hormone levels less than or equal to 180 pg/mL. The first and last participants were enrolled on August 18, 2008, and January 26, 2011, respectively. The final date of follow-up was April 4, 2015.

INTERVENTIONS

Treatment with 0.5 μg of oral alfacalcidol per day (intervention group; n = 495) vs treatment without vitamin D receptor activators (control group; n = 481).

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite measure of fatal and nonfatal cardiovascular events, including myocardial infarctions, hospitalizations for congestive heart failure, stroke, aortic dissection/rupture, amputation of lower limb due to ischemia, and cardiac sudden death; coronary revascularization; and leg artery revascularization during 48 months of follow-up. The secondary outcome was all-cause death.

RESULTS

Among 976 patients who were randomized from 108 dialysis centers, 964 patients were included in the intention-to-treat analysis (median age, 65 years; 386 women [40.0%]), and 944 (97.9%) completed the trial. During follow-up (median, 4.0 years), the primary composite outcome of cardiovascular events occurred in 103 of 488 patients (21.1%) in the intervention group and 85 of 476 patients (17.9%) in the control group (absolute difference, 3.25% [95% CI, -1.75% to 8.24%]; hazard ratio, 1.25 [95% CI, 0.94-1.67]; P = .13). There was no significant difference in the secondary outcome of all-cause mortality between the groups (18.2% vs 16.8%, respectively; hazard ratio, 1.12 [95% CI, 0.83-1.52]; P = .46). Of the 488 participants in the intervention group, 199 (40.8%) experienced serious adverse events that were classified as cardiovascular, 64 (13.1%) experienced adverse events classified as infection, and 22 (4.5%) experienced malignancy-related serious adverse events. Of 476 participants in the control group, 191 (40.1%) experienced cardiovascular-related serious adverse events, 63 (13.2%) experienced infection-related serious adverse events, and 21 (4.4%) experienced malignancy-related adverse events.

CONCLUSIONS AND RELEVANCE

Among patients without secondary hyperparathyroidism undergoing maintenance hemodialysis, oral alfacalcidol compared with usual care did not reduce the risk of a composite measure of select cardiovascular events. These findings do not support the use of vitamin D receptor activators for patients such as these.

TRIAL REGISTRATION

UMIN-CTR Identifier: UMIN000001194.

Febuxostat Therapy for Patients With Stage 3 CKD and Asymptomatic Hyperuricemia: A Randomized Trial

RATIONALE & OBJECTIVE

Epidemiologic and clinical studies have suggested that urate-lowering therapy may slow the progression of chronic kidney disease (CKD). However, definitive evidence is lacking.

STUDY DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING & PARTICIPANTS

467 patients with stage 3 CKD and asymptomatic hyperuricemia at 55 medical institutions in Japan.

INTERVENTION

Participants were randomly assigned in a 1:1 ratio to receive febuxostat or placebo for 108 weeks.

OUTCOMES

The primary end point was the slope (in mL/min/1.73m² per year) of estimated glomerular filtration rate (eGFR). Secondary end points included changes in eGFRs and serum uric acid levels at 24, 48, 72, and 108 weeks of follow-up and the event of doubling of serum creatinine level or initiation of dialysis therapy.

RESULTS

Of 443 patients who were randomly assigned, 219 and 222 assigned to febuxostat and placebo, respectively, were included in the analysis. There was no significant difference in mean eGFR slope between the febuxostat (0.23±5.26mL/min/1.73m² per year) and placebo (-0.47±4.48mL/min/1.73m² per year) groups (difference, 0.70; 95% CI, -0.21 to 1.62; P=0.1). Subgroup analysis demonstrated a significant benefit from febuxostat in patients without proteinuria (P=0.005) and for whom serum creatinine concentration was lower than the median (P=0.009). The incidence of gouty arthritis was significantly lower (P=0.007) in the febuxostat group (0.91%) than in the placebo group (5.86%). Adverse events specific to febuxostat were not observed.

LIMITATIONS

GFR was estimated rather than measured, and patients with stages 4 and 5 CKD were excluded.

CONCLUSIONS

Compared to placebo, febuxostat did not mitigate the decline in kidney function among patients with stage 3 CKD and asymptomatic hyperuricemia.

FUNDING

Funded by Teijin Pharma Limited.

TRIAL REGISTRATION

Registered at the UMIN (University Hospital Medical Information Network) Clinical Trials Registry with study number UMIN000008343.

Uric acid-lowering and renoprotective effects of topiroxostat, a selective xanthine oxidoreductase inhibitor, in patients with diabetic nephropathy and hyperuricemia: a randomized, double-blind, placebo-controlled, parallel-group study (UPWARD study)

BACKGROUND

Hyperuricemia is supposed to be an independent risk factor for kidney dysfunction in diabetic patients. We attempted to examine the uric acid-lowering effect and the renoprotective effect of topiroxostat, a selective xanthine oxidoreductase inhibitor, in patients with diabetic nephropathy and hyperuricemia in this pilot study.

METHODS

The study design was randomized, double-blind, placebo-controlled, parallel-group study. A total of 65 patients with hyperuricemia and diabetic nephropathy with microalbuminuria were enrolled and assigned to either the topiroxostat group or the placebo group. Topiroxostat (stepwise dosing from 40 to 160 mg/day) or matching placebo was administered BID for 28 weeks. The primary endpoint was a change in the urinary albumin-to-creatinine ratio in the first-morning-void urine sample. Secondary endpoints were changes in the estimated glomerular filtration rate and the serum uric acid level.

RESULTS

At 28 weeks, there was no significant difference in the percent change from baseline in the urinary albumin-to-creatinine ratio between the two groups (topiroxostat: 0 vs. placebo: 17%, p = 0.3206), but the changes in the estimated glomerular filtration rate (- 0.2 vs. - 4.0 mL/min/1.73 m², p = 0.0303) and the serum uric acid level (- 2.94 vs. - 0.20 mg/dL, p < 0.0001) were significantly different between the topiroxostat and placebo groups. Gouty arthritis occurred in 1 patient in the placebo group and no patients in the topiroxostat group.

CONCLUSION

These findings support that diabetic nephropathy combined with hyperuricemia may be associated with kidney dysfunctions. Topiroxostat provides strict control of the serum uric acid level preventing decline of eGFR in these patients.

Multiple common and rare variants of ABCG2 cause gout

Objective

Previous studies have suggested an association between gout susceptibility and common dysfunctional variants in ATP-binding cassette transporter subfamily G member 2/breast cancer resistance protein (ABCG2/BCRP), including rs72552713 (Q126X) and rs2231142 (Q141K). However, the association of rare ABCG2 variants with gout is unknown. Therefore, we investigated the effects of rare ABCG2 variants on gout susceptibility in this study.

Methods

We sequenced the exons of ABCG2 in 480 patients with gout and 480 healthy controls (Japanese males). We also performed functional analyses of non-synonymous variants of ABCG2 and analysed the correlation between urate transport function and scores from the protein prediction algorithms (Sorting Intolerant from Tolerant (SIFT) and Polymorphism Phenotyping v2 (PolyPhen-2)). Stratified association analyses and multivariate logistic regression analysis were performed to evaluate the effects of rare and common ABCG2 variants on gout susceptibility.

Results

We identified 3 common and 19 rare non-synonymous variants of ABCG2. SIFT scores were significantly correlated with the urate transport function, although some ABCG2 variants showed inconsistent scores. When the effects of common variants were removed by stratified association analysis, the rare variants of ABCG2 were associated with a significantly increased risk of gout (OR=3.2, p=6.4×10⁻³). Multivariate logistic regression analysis revealed that the size effect of these rare ABCG2 variants (OR=2.7, p=3.0×10⁻³) was similar to that of the common variants, Q126X (OR=3.4, p=3.2×10⁻⁶) and Q141K (OR=2.3, p=2.7×10⁻¹⁶).

Conclusions

This study revealed that multiple common and rare variants of ABCG2 are independently associated with gout. These results could support both the ‘Common Disease, Common Variant’ and ‘Common Disease, Multiple Rare Variant’ hypotheses for the association between ABCG2 and gout susceptibility.

Schizophrenia-like phenotypes in mice with NMDA receptor ablation in intralaminar thalamic nucleus cells and gene therapy-based reversal in adults

In understanding the mechanism of schizophrenia pathogenesis, a significant finding is that drug abuse of phencyclidine or its analog ketamine causes symptoms similar to schizophrenia. Such drug effects are triggered even by administration at post-adolescent stages. Both drugs are N-methyl-d-aspartate receptor (NMDAR) antagonists, leading to a major hypothesis that glutamate hypofunction underlies schizophrenia pathogenesis. The precise region that depends on NMDAR function, however, is unclear. Here, we developed a mouse strain in which NMDARs in the intralaminar thalamic nuclei (ILN) were selectively disrupted. The mutant mice exhibited various schizophrenia-like phenotypes, including deficits in working memory, long-term spatial memory, and attention, as well as impulsivity, impaired prepulse inhibition, hyperlocomotion and hyperarousal. The electroencephalography analysis revealed that the mutant mice had a significantly reduced power in a wide range of frequencies including the alpha, beta and gamma bands, both during wake and rapid eye movement (REM) sleep, and a modest decrease of gamma power during non-REM sleep. Notably, restoring NMDARs in the adult ILN rescued some of the behavioral abnormalities. These findings suggest that NMDAR dysfunction in the ILN contributes to the pathophysiology of schizophrenia-related disorders. Furthermore, the reversal of inherent schizophrenia-like phenotypes in the adult mutant mice supports that ILN is a potential target site for a therapeutic strategy.

GWAS of clinically defined gout and subtypes identifies multiple susceptibility loci that include urate transporter genes

Objective

A genome-wide association study (GWAS) of gout and its subtypes was performed to identify novel gout loci, including those that are subtype-specific.

Methods

Putative causal association signals from a GWAS of 945 clinically defined gout cases and 1213 controls from Japanese males were replicated with 1396 cases and 1268 controls using a custom chip of 1961 single nucleotide polymorphisms (SNPs). We also first conducted GWASs of gout subtypes. Replication with Caucasian and New Zealand Polynesian samples was done to further validate the loci identified in this study.

Results

In addition to the five loci we reported previously, further susceptibility loci were identified at a genome-wide significance level (p<5.0×10⁻⁸): urate transporter genes (SLC22A12 and SLC17A1) and HIST1H2BF-HIST1H4E for all gout cases, and NIPAL1 and FAM35A for the renal underexcretion gout subtype. While NIPAL1 encodes a magnesium transporter, functional analysis did not detect urate transport via NIPAL1, suggesting an indirect association with urate handling. Localisation analysis in the human kidney revealed expression of NIPAL1 and FAM35A mainly in the distal tubules, which suggests the involvement of the distal nephron in urate handling in humans. Clinically ascertained male patients with gout and controls of Caucasian and Polynesian ancestries were also genotyped, and FAM35A was associated with gout in all cases. A meta-analysis of the three populations revealed FAM35A to be associated with gout at a genome-wide level of significance (p_meta=3.58×10⁻⁸).

Conclusions

Our findings including novel gout risk loci provide further understanding of the molecular pathogenesis of gout and lead to a novel concept for the therapeutic target of gout/hyperuricaemia.

Clinical efficacy and safety of topiroxostat in Japanese hyperuricemic patients with or without gout: a randomized, double-blinded, controlled phase 2b study

Topiroxostat, a selective xanthine oxidoreductase inhibitor, is used in Japan for the treatment of hyperuricemic patients with or without gout. In terms of the effectiveness of topiroxostat in lowering serum urate levels, the dose-response relationship has been evaluated; however, it remains to be verified. A randomized, multi-center, double-blinded study of topiroxostat was performed for Japanese hyperuricemic patients with or without gout. During the 16-week study, 157 Japanese hyperuricemic patients with or without gout were randomly assigned to receive a placebo, topiroxostat at 120 or 160 mg/day, or allopurinol at 200 mg/day. The primary endpoint of this study was to determine the lowering rate of serum uric acid levels compared to those of baseline at the end of administration. A dose-response relationship (regarding decreases in the serum urate levels) was confirmed for the placebo and topiroxostat at 120 and at 160 mg/day. Moreover, at the end of administration, the lowering rate of serum urate levels was determined to be -44.8% in the topiroxostat 160-mg/day group. No significant difference in the incidence of adverse events was observed among all groups, including the allopurinol group. The serum urate-lowering effect of topiroxostat was found to have a dose-response relationship in Japanese hyperuricemic patients with or without gout.

Comparison of topiroxostat and allopurinol in Japanese hyperuricemic patients with or without gout: a phase 3, multicentre, randomized, double-blind, double-dummy, active-controlled, parallel-group study

WHAT IS KNOWN AND OBJECTIVE

There are no clinical reports that have compared topiroxostat, a selective xanthine oxidase inhibitor, with allopurinol in serum urate-lowering efficacy. The aim of this study was to compare the efficacy and safety of topiroxostat and allopurinol in Japanese hyperuricemic patients with or without gout.

METHODS

A phase 3, multicentre, randomized, double-blind, double-dummy, active-controlled, parallel-group study conducted in Japan. Patients who had inadequate serum urate levels (a gout patient: serum urate level ≥416·4 μmol/L; an asymptomatic hyperuricemic patient with specific complications (urinary lithiasis, hypertension, hyperlipidemia and/or diabetes): serum urate level ≥475·8 μmol/L; and an asymptomatic hyperuricemic patient with no specific complications: serum urate level ≥535·3 μmol/L) were randomized to topiroxostat 120 mg/day or allopurinol 200 mg/day, with an equal allocation ratio, for 16 weeks. To prevent the onset of gouty arthritis by rapid serum urate reduction, these doses were increased in a stepwise manner. The primary efficacy endpoint was the per cent change in serum urate level from baseline to the final visit.

RESULTS AND DISCUSSION

Overall, 206 patients were randomly assigned to topiroxostat and allopurinol. Two hundred and three patients (allopurinol: n = 105, topiroxostat: n = 98) received at least one dose of the study drug and had their serum urate level assessed at least once. The baseline characteristics were comparable between groups. The mean age of patients was 53·0 ± 11·4 years and 99% of patients were male. The primary efficacy endpoint was -34·3 ± 11·1% in the allopurinol group (n = 105) and -36·3 ± 12·7% in the topiroxostat group (n = 98). Non-inferiority of the serum urate-lowering efficacy of topiroxostat to allopurinol was proved by the predefined non-inferiority margin (95% confidence interval, -5·3 to 1·3%). The overall incidences of adverse events and adverse drug reactions were similar between both groups.

WHAT IS NEW AND CONCLUSION

Topiroxostat 120 mg/day provides non-inferior serum urate reduction compared with allopurinol 200 mg/day and is well tolerated in Japanese hyperuricemic patients with or without gout.

Clinical efficacy and safety of topiroxostat in Japanese male hyperuricemic patients with or without gout: an exploratory, phase 2a, multicentre, randomized, double-blind, placebo-controlled study

WHAT IS KNOWN AND OBJECTIVE

In Japan, although topiroxostat, a selective xanthine oxidoreductase inhibitor, has been used for the treatment of patients with hyperuricemia including gout, no published randomized controlled studies evaluating the dose-dependent relationship with respect to the serum urate-lowering efficacy have been reported. The aim of this study was to evaluate the dose-dependent relationship with serum urate-lowering efficacy and safety of topiroxostat in Japanese hyperuricemic patients including gout.

METHODS

We conducted an exploratory, phase 2a, multicentre, randomized, double-blind, 8-week, placebo-controlled study in Japanese hyperuricemic patients with or without gout. The study arms were placebo and topiroxostat 40, 60, 80 or 120 mg/day. The primary efficacy endpoint was the per cent change in serum urate level from baseline to the final visit.

RESULTS AND DISCUSSION

One hundred and eighty-seven eligible patients were randomized and 186 received at least one dose of the study drug. The study results demonstrated a dose-dependent serum urate reduction effect ranging from 40 to 120 mg/day (P < 0·001, Jonckheere-Terpstra test). The mean per cent change in serum urate level from baseline at the final visit was -30·8% in the 120-mg group and 1·6% with placebo, with a between-group difference of -32·4% ([95% confidence interval, -38·9% to -25·9%]; P < 0·001). Incidences of overall adverse events (AEs) in the topiroxostat groups were comparable to those in the placebo group; however, the incidence of AEs in the 120-mg group was statistically lower than that in the placebo group. The incidences of gouty arthritis were not statistically but numerically higher in the topiroxostat 80- and 120-mg groups.

WHAT IS NEW AND CONCLUSIONS

A dose-dependent serum urate-lowering efficacy of topiroxostat was observed in Japanese hyperuricemic male patients with or without gout. Further clinical studies aimed at evaluating the long-term safety and clinical efficacy are warranted.

Revision of the Massarineae (Pleosporales, Dothideomycetes)

We here taxonomically revise the suborder Massarineae (Pleosporales, Dothideomycetes, Ascomycota). Sequences of SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) are newly obtained from 106 Massarineae taxa that are phylogenetically analysed along with published sequences of 131 taxa in this suborder retrieved from GenBank. We recognise 12 families and five unknown lineages in the Massarineae. Among the nine families previously known, the monophyletic status of the Dictyosporiaceae, Didymosphaeriaceae, Latoruaceae, Macrodiplodiopsidaceae, Massarinaceae, Morosphaeriaceae, and Trematosphaeriaceae was strongly supported with bootstrap support values above 96 %, while the clades of the Bambusicolaceae and the Lentitheciaceae are moderately supported. Two new families, Parabambusicolaceae and Sulcatisporaceae, are proposed. The Parabambusicolaceae is erected to accommodate Aquastroma and Parabambusicola genera nova, as well as two unnamed Monodictys species. The Parabambusicolaceae is characterised by depressed globose to hemispherical ascomata with or without surrounding stromatic tissue, and multi-septate, clavate to fusiform, hyaline ascospores. The Sulcatisporaceae is established for Magnicamarosporium and Sulcatispora genera nova and Neobambusicola. The Sulcatisporaceae is characterised by subglobose ascomata with a short ostiolar neck, trabeculate pseudoparaphyses, clavate asci, broadly fusiform ascospores, and ellipsoid to subglobose conidia with or without striate ornamentation. The genus Periconia and its relatives are segregated from the Massarinaceae and placed in a resurrected family, the Periconiaceae. We have summarised the morphological and ecological features, and clarified the accepted members of each family. Ten new genera, 22 new species, and seven new combinations are described and illustrated. The complete ITS sequences of nrDNA are also provided for all new taxa for use as barcode markers.

Hereditary renal amyloidosis caused by a heterozygous G654A gelsolin mutation: a report of two cases

Finnish-type familial amyloidosis (FAF) is a rare hereditary systemic amyloidosis that mainly exhibits cranial neuropathy. We describe a Japanese family with FAF manifested predominantly as renal amyloidosis. The proband was a 42-year-old woman with a 21-year history of proteinuria due to renal amyloidosis. Her mother was subsequently diagnosed with a similar disorder. After the first renal biopsy, both patients were followed up routinely for a period of 14 years. Genetic analysis of DNA samples revealed a heterozygous G654A gelsolin mutation. Severe renal involvement has not been reported previously in patients with FAF bearing a heterozygous gelsolin mutation.

ABCG2 dysfunction increases the risk of renal overload hyperuricemia

ATP-binding cassette transporter, sub-family G, member 2 (ABCG2/BCRP) is identified as a high-capacity urate exporter, and its dysfunction has an association with serum uric acid levels and gout/hyperuricemia risk. Generally, hyperuricemia has been classified into urate "overproduction type," "underexcretion type," and "combined type" based on only renal urate excretion, without considering an extra-renal pathway such as gut excretion. In this study, we investigated the effects of ABCG2 dysfunction on human urate handling and the mechanism of hyperuricemia. Clinical parameters for urate handling including urinary urate excretion (UUE) were examined in 644 Japanese male outpatients with hyperuricemia. The severity of their ABCG2 dysfunction was estimated by genotype combination of two common ABCG2 variants, nonfunctional Q126X (rs72552713) and half-functional Q141K (rs2231142). Contrary to the general understanding that ABCG2 dysfunction leads to decreased renal urate excretion, UUE was significantly increased by ABCG2 dysfunction (P=3.60×10(-10)). Mild, moderate, and severe ABCG2 dysfunctions significantly raised the risk of "overproduction" hyperuricemia including overproduction type and combined type, conferring risk ratios of 1.36, 1.66, and 2.35, respectively. The present results suggest that common dysfunctional variants of ABCG2 decrease extra-renal urate excretion including gut excretion and cause hyperuricemia. Thus, "overproduction type" in the current concept of hyperuricemia should be renamed "renal overload type," which is caused by two different mechanisms, "extra-renal urate underexcretion" and genuine "urate overproduction." Our new concept will lead to a more accurate diagnosis and more effective therapeutic strategy for hyperuricemia and gout.

Genome-wide association study of clinically defined gout identifies multiple risk loci and its association with clinical subtypes

OBJECTIVE

Gout, caused by hyperuricaemia, is a multifactorial disease. Although genome-wide association studies (GWASs) of gout have been reported, they included self-reported gout cases in which clinical information was insufficient. Therefore, the relationship between genetic variation and clinical subtypes of gout remains unclear. Here, we first performed a GWAS of clinically defined gout cases only.

METHODS

A GWAS was conducted with 945 patients with clinically defined gout and 1213 controls in a Japanese male population, followed by replication study of 1048 clinically defined cases and 1334 controls.

RESULTS

Five gout susceptibility loci were identified at the genome-wide significance level (p<5.0×10(-8)), which contained well-known urate transporter genes (ABCG2 and SLC2A9) and additional genes: rs1260326 (p=1.9×10(-12); OR=1.36) of GCKR (a gene for glucose and lipid metabolism), rs2188380 (p=1.6×10(-23); OR=1.75) of MYL2-CUX2 (genes associated with cholesterol and diabetes mellitus) and rs4073582 (p=6.4×10(-9); OR=1.66) of CNIH-2 (a gene for regulation of glutamate signalling). The latter two are identified as novel gout loci. Furthermore, among the identified single-nucleotide polymorphisms (SNPs), we demonstrated that the SNPs of ABCG2 and SLC2A9 were differentially associated with types of gout and clinical parameters underlying specific subtypes (renal underexcretion type and renal overload type). The effect of the risk allele of each SNP on clinical parameters showed significant linear relationships with the ratio of the case-control ORs for two distinct types of gout (r=0.96 [p=4.8×10(-4)] for urate clearance and r=0.96 [p=5.0×10(-4)] for urinary urate excretion).

CONCLUSIONS

Our findings provide clues to better understand the pathogenesis of gout and will be useful for development of companion diagnostics.

Mechanistic view of renal protective action of calcium channel blockade

Calcium channel blockers are one of the most useful antihypertensive agents because of their definite blood pressure lowering action. Although the antihypertensive effect of calcium channel blockers is attributed predominantly to the blockade of L-type calcium channels, recent studies demonstrate that the blockade of other subtypes of calcium channels, including T-type and N-type calcium channels, offers renal protective action because of their beneficial action on glomerular capillary pressure, renal fibrotic process, sympathetic nerve activity and aldosterone synthesis. It requires more extensive studies to clarify whether the ostensibly beneficial actions of these calcium channel blockers are available in a clinical setting.

Combined therapy with peritoneal dialysis and hemodialysis: a multicenter retrospective observational cohort study in Japan

BACKGROUND/AIMS

Combining peritoneal dialysis (PD) and hemodialysis (HD) has been common treatment option in Japan.

METHODS

In this retrospective, multicenter, observational study, the clinical characteristics and outcomes of 104 patients (57 ± 11 years, males 72%) who had switched from PD alone to combined therapy with PD and HD were studied. Clinical parameters were measured at baseline and after 3 months of combined therapy.

RESULTS

At baseline, urine volume, dialysate-to-plasma ratio of creatinine (D/P Cr), and total Kt/V were 150 ml/day (range: 0-2,000 ml/day), 0.67 ± 0.11, and 1.8 ± 0.4, respectively. During the first 3 months of combined therapy, body weight, urine volume, serum creatinine level, and D/P Cr decreased, whereas hemoglobin levels increased.

CONCLUSIONS

In patients where PD does not result in acceptable outcomes, combined therapy with PD and HD may have potential benefits in terms of dialysis adequacy and hydration status. Video Journal Club “Cappuccino with Claudio Ronco” at http://www.karger.com/?doi=368389

TRPM8 has a key role in experimental colitis-induced visceral hyperalgesia in mice

BACKGROUND

Transient receptor potential channel melastatin 8 (TRPM8) is activated by cold temperatures and cooling agents (menthol and icilin). Recent studies showed TRPM8 is expressed in visceral organs and peripheral sensory pathways. However, the role of TRPM8 in visceral hyperalgesia is poorly understood in pathological states such as inflammatory bowel disease. Hence, we investigated the distribution of TRPM8 and its involvement in visceral hyperalgesia in experimental colitis mice.

METHODS

TRPM8 immunoreactivity was detected using immunohistochemical staining with fluorescein-conjugated tyramide amplification. Visceral hyperalgesia was measured by the intracolonic administration of TRPM8 agonist, WS-12, in control and dextran sodium sulfate (DSS)-induced colitis mice.

KEY RESULTS

TRPM8 immunoreactivity in the distal colon was much higher than in the transverse and proximal colon under physiological conditions. TRPM8 immunoreactivity markedly increased in the distal colon mucosa of DSS-induced colitis mice compared with control mice. The number of TRPM8 nerve fibers in mucosa of DSS- or 2,4,6-trinitrobenzene sulfonic acid-induced colitis model mice drastically increased compared with control mice. TRPM8 immunoreactivities colocalized with the calcitonin gene-related peptide- and substance P-immunoreactive nerve fibers in the mucosa. Intracolonic administration of WS-12 induced behavioral visceral pain-like responses. The numbers of these responses in the colitis model mice were 3 times higher than in control mice, and were decreased by pretreatment with the TRPM8 channel blocker AMTB.

CONCLUSIONS & INFERENCES

Increased expression of TRPM8 may contribute to the visceral hyperalgesia of experimental colitis.