Rationale and design of the Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study.

INTRODUCTION: Disease subtyping and monitoring are essential for the management of nephrotic syndrome (NS). Although various biomarkers for NS have been reported, their clinical efficacy has not been comprehensively validated in adult Japanese patients. METHODS: The Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study is a nationwide, multicenter, and prospective cohort study in Japan, enrolling adult (≥18 years) patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN), C3 glomerulopathy (C3G), and lupus nephritis (LN). Baseline clinical information and plasma and urine samples will be collected at the time of immunosuppressive therapy initiation or biopsy. Follow-up data and plasma and urine samples will be collected longitudinally based on the designated protocols. Candidate biomarkers will be measured: CD80, cytotoxic T-lymphocyte antigen 4, and soluble urokinase plasminogen activator receptor for MCD and FSGS; anti-phospholipase A2 receptor and thrombospondin type-1 domain-containing protein 7A antibodies for MN; fragment Ba, C3a, factor I, and properdin for MPGN/C3G; and CD11b, CD16b, and CD163 for LN. Outcomes include complete and partial remission, relapse of proteinuria, a 30% reduction in estimated glomerular filtration rate (eGFR), eGFR decline, and initiation of renal replacement therapy. The diagnostic accuracy and predictive ability for clinical outcomes will be assessed for each biomarker. RESULTS: From April 2019 to April 2023, 365 patients were enrolled: 145, 21, 138, 10, and 51 cases of MCD, FSGS, MN, MPGN/C3G, and LN, respectively. CONCLUSION: This study will provide valuable insights into biomarkers for NS and serve as a biorepository for future studies.

Association of kidney function with cancer incidence and its influence on cancer risk of smoking: The Japan Multi-Institutional Collaborative Cohort Study.

The association between kidney function and cancer incidence is inconsistent among previous reports, and data on the Japanese population are lacking. It is unknown whether kidney function modifies the cancer risk of other factors. We aimed to evaluate the association of estimated glomerular filtration rate (eGFR) with cancer incidence and mortality in 55 242 participants (median age, 57 years; 55% women) from the Japan Multi-Institutional Collaborative Cohort Study. We also investigated differences in cancer risk factors between individuals with and without kidney dysfunction. During a median 9.3-year follow-up period, 4278 (7.7%) subjects developed cancer. Moderately low and high eGFRs were associated with higher cancer incidence; compared with eGFR of 60-74 ml/min/1.73 m2 , the adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) for eGFRs of ≥90, 75-89, 45-59, 30-44 and 10-29 ml/min/1.73 m2 were 1.18 (1.07-1.29), 1.09 (1.01-1.17), 0.93 (0.83-1.04), 1.36 (1.00-1.84) and 1.12 (0.55-2.26), respectively. High eGFR was associated with higher cancer mortality, while low eGFR was not; the adjusted subdistribution HRs (95% CIs) for eGFRs of ≥90 and 75-89 ml/min/1.73 m2 were 1.58 (1.29-1.94) and 1.27 (1.08-1.50), respectively. Subgroup analyses of participants with eGFRs ≥60 and <60 ml/min/1.73 m2 revealed elevated cancer risks of smoking and family history of cancer in those with eGFR <60 ml/min/1.73 m2 , with significant interactions. Our findings suggest that the relationship between eGFR and cancer incidence was U-shaped. Only high eGFR was associated with cancer mortality. Kidney dysfunction enhanced cancer risk from smoking.

Higher hemoglobin levels using darbepoetin alfa and kidney outcomes in advanced chronic kidney disease without diabetes: a prespecified secondary analysis of the PREDICT trial.

BACKGROUND: In the primary analysis of the PREDICT trial, a higher hemoglobin target (11-13 g/dl) with darbepoetin alfa did not improve renal outcomes compared with a lower hemoglobin target (9-11 g/dl) in advanced chronic kidney disease (CKD) without diabetes. Prespecified secondary analyses were performed to further study the effects of targeting higher hemoglobin levels on renal outcomes. METHODS: Patients with an estimated glomerular filtration rate (eGFR) 8-20 ml/min/1.73 m2 without diabetes were randomly assigned 1:1 to the high- and low-hemoglobin groups. The differences between the groups were evaluated for the following endpoints and cohort sets: eGFR and proteinuria slopes, assessed using a mixed-effects model in the full analysis set and the per-protocol set that excluded patients with off-target hemoglobin levels; the primary endpoint of composite renal outcome, evaluated in the per-protocol set using the Cox model. RESULTS: In the full analysis set (high hemoglobin, n = 239; low hemoglobin, n = 240), eGFR and proteinuria slopes were not significantly different between the groups. In the per-protocol set (high hemoglobin, n = 136; low hemoglobin, n = 171), the high-hemoglobin group was associated with reduced composite renal outcome (adjusted hazard ratio: 0.64; 95% confidence interval: 0.43-0.96) and an improved eGFR slope (coefficient: + 1.00 ml/min/1.73 m2/year; 95% confidence interval: 0.38-1.63), while the proteinuria slope did not differ between the groups. CONCLUSIONS: In the per-protocol set, the high-hemoglobin group demonstrated better kidney outcomes than the low-hemoglobin group, suggesting a potential benefit of maintaining higher hemoglobin levels in patients with advanced CKD without diabetes. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov (identifier: NCT01581073).

Efficacy and Safety of Anti-angiogenic Agents for Cancer Patients With Proteinuria or a History of Proteinuria: A Systematic Review.

BACKGROUND/AIM: The safety and efficacy of anti-angiogenic agents in patients with cancer with proteinuria and a history of proteinuria are not well established. This systematic review aimed to answer these questions. MATERIALS AND METHODS: We searched three electronic databases for articles published until June 18, 2021. The main outcomes used were "death", "renal impairment", and "proteinuria impairment". RESULTS: After screening 303 references in the PubMed, Cochrane Library, and ICHUSHI-web databases, this review included five studies on renal cell carcinoma (RCC). In patients with metastatic RCC, the hazard ratio of the presence of (or having) proteinuria (1+ or higher) at baseline was 0.82 (0.23-2.97); thus, proteinuria was not significantly associated with the outcome of death. No significant deterioration in kidney function was observed in patients with proteinuria. Although proteinuria at baseline was a significant risk factor for proteinuria progression during and after treatment, most patients maintained grade 1 or 2 proteinuria and continued treatment without dose reduction or discontinuation. CONCLUSION: While weak evidence suggests that proteinuria at the start of treatment with anti-angiogenic agents might be a risk factor for worsening proteinuria, it was not significantly associated with death or renal impairment.

Relationship between peak aortic jet velocity and progression of aortic stenosis in patients undergoing hemodialysis.

BACKGROUND: The natural history of aortic stenosis (AS) progression, especially before severe AS development, is not well documented. We aimed to investigate the time course of peak aortic jet velocity (Vmax) and AS progression risk according to baseline Vmax, particularly whether there is a Vmax threshold. METHODS: In a retrospective multicenter cohort study of patients on hemodialysis with aortic valve calcification, we investigated the time series of Vmax and the relationship between the baseline Vmax and progression to severe AS by analyzing longitudinal echocardiographic data. RESULTS: Among 758 included patients (mean age, 71 years; 65% male), patients with Vmax <1.5, 1.5-1.9, 2.0-2.4, 2.5-2.9, and 3.0-3.9 m/s were 395 (52%), 216 (29%), 85 (11%), 39 (5.1%), and 23 (3.0%), respectively. The Vmax slope was gradual (mean 0.05-0.07 m/s/year) at Vmax <2 m/s, but steeper (mean 0.13-0.21 m/s/year) at Vmax ≥2 m/s. During a median 3.2-year follow-up, 52 (6.9%) patients developed severe AS. While patients with Vmax <2 m/s rarely developed severe AS, the risk of those with Vmax ≥2 m/s increased remarkably with an increasing baseline Vmax; the adjusted incidence rates in patients with Vmax <1.5, 1.5-1.9, 2.0-2.4, 2.5-2.9, and 3.0-3.9 m/s were 0.59, 0.57, 4.25, 13.8, and 56.1 per 100 person-years, respectively; the adjusted hazard ratio per 0.2 m/s increase in the baseline Vmax was 1.49 (95% confidence interval: 1.32-1.68) when Vmax ≥2 m/s. CONCLUSIONS: The risk of progression to severe AS increased with the baseline Vmax primarily at ≥2 m/s; a Vmax threshold of 2 m/s was observed.

Association of calciprotein particles with serum phosphorus among patients undergoing conventional and extended-hours haemodialysis.

Background and hypothesis: Extended-hours haemodialysis (HD) is associated with better clinical outcomes than conventional HD. We investigated whether extended-hours HD and conventional HD have varying effects on blood levels of calciprotein particles (CPPs) and phosphorus, which have been identified as major pathogenic molecules for vascular calcification. Methods: Patients who underwent conventional or extended in-centre daytime HD between January and March 2020 were included. Plasma CPP levels, representing only secondary CPPs (CPP-II), were measured in pre-dialysis samples. Linear and non-linear associations between CPPs and serum phosphorus levels were examined across dialysis modalities. Results: A total of 382 participants (185 undergoing extended-hours HD and 197 undergoing conventional HD) were included in the analysis. The median age of participants was 71 years, 65% of the patients were men and the mean phosphorus level was 5.4 mg/dl. Plasma CPP (CPP-II) levels were lower in the extended-hours HD group than in the conventional HD group [40 018 (arbitrary units) AU versus 75 728 AU; P < .01]. Multivariable linear regression analysis showed that extended-hours HD was associated with lower natural logarithmic plasma CPP (CPP-II) levels: -0.64 (95% confidence interval -0.74 to -0.55). A restricted cubic spline function indicated that extended-hours HD was associated with lower plasma CPP (CPP-II) levels across levels of serum phosphorus, with significant differences observed between groups, especially in hyperphosphataemic conditions (P for interaction <.01). Conclusions: The extended-hours HD group had lower CPP levels than the conventional HD group despite no significant differences in serum phosphorus levels, which may contribute to better clinical outcomes in patients on extended-hours HD.

Association between stopping renin-angiotensin system inhibitors immediately before hemodialysis initiation and subsequent cardiovascular events.

It is controversial whether renin-angiotensin system inhibitors (RASIs) should be stopped in patients with advanced chronic kidney disease (CKD). Recently, it was reported that stopping RASIs in advanced CKD was associated with increased mortality and cardiovascular (CV) events; however, it remains unclear whether stopping RASIs before dialysis initiation affects clinical outcomes after dialysis, which this study aimed to evaluate. In this multicenter prospective cohort study in Japan, we included 717 patients (mean age, 67 years; 68% male) who had a nephrology care duration ≥90 days, initiated hemodialysis, and used RASIs 3 months before hemodialysis initiation. The multivariable adjusted Cox models were used to compare mortality and CV event risk between 650 (91%) patients who continued RASIs until hemodialysis initiation and 67 (9.3%) patients who stopped RASIs. During a median follow-up period of 3.5 years, 170 (24%) patients died and 228 (32%) experienced CV events. Compared with continuing RASIs, stopping RASIs was unassociated with mortality (adjusted hazard ratio [aHR]: 0.82; 95% confidence interval [CI]: 0.50-1.34) but was associated with higher CV events (aHR: 1.59; 95% CI: 1.06-2.38). Subgroup analyses showed that the risk of stopping RASIs for CV events was particularly high in patients aged <75 years, with a significant interaction between stopping RASIs and age. This study revealed that patients who stopped RASIs immediately before dialysis initiation were associated with subsequent higher CV events. Active screening for CV disease may be especially beneficial for these patients.

Relationship between the lower limit of systolic blood pressure target and kidney function decline in advanced chronic kidney disease: an instrumental variable analysis from the REACH-J CKD cohort study.

Intensive antihypertensive treatment decreases cardiovascular disease and mortality risks in chronic kidney disease (CKD), whereas extremely low systolic blood pressure (SBP) is associated with worsening kidney function and poor prognosis. Although the SBP variation is particularly large in patients with CKD, the optimal lower limit of SBP target is unclear. In a nationwide, multicenter cohort study of patients with an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m2, we evaluated the association between the eGFR slopes and the lower limit of SBP target at ≥110 mmHg using a linear mixed-effects model and an instrumental variable method. The instrumental variable was calculated as the facility-level percentage of nephrologists who answered in the survey that their lower limit of SBP target was 110 mmHg or higher. A total of 1320 patients (mean age 70 years; 66% men) were included. The mean eGFR slope ± standard deviation over the four years to baseline was -2.48 ± 2.15 mL/min/1.73 m2/year. The instrumental variable for the lower limit of SBP target at ≥110 mmHg (vs. ≤100 mmHg) was associated with less eGFR decline (coefficient: +1.05 mL/min/1.73 m2/year; 95% confidence interval: 0.33-1.77), while unassociated with a history of cardiovascular disease. The renoprotective effect was particularly larger in the subgroups of the elderly and those with a history of cardiovascular disease. In conclusion, the lower limit of SBP target at 110 mmHg or higher was associated with improved eGFR slope, suggesting the importance of aiming at avoiding excessively low SBP in patients with advanced CKD.

Efficacy of the latest new stimulation patterns of spinal cord stimulation for intractable neuropathic pain compared to conventional stimulation: study protocol for a clinical trial.

BACKGROUND: Spinal cord stimulation (SCS) is one of the neuromodulation therapies for chronic neuropathic pain. The conventional paresthesia-based SCS involves the application of tonic stimulation that induces a sense of paresthesia. Recently, new SCS stimulation patterns without paresthesia have been developed. Differential target multiplexed (DTM) stimulation and fast-acting subperception therapy (FAST) stimulation are the latest paresthesia-free SCS patterns. METHODS: A single-center, open-label, crossover, randomized clinical trial to investigate the superiority of SCS using the latest new stimulation patterns over conventional tonic stimulation for neuropathic pain is planned. This study consists of two steps: SCS trial (first step) and SCS system implantation (second step). In the SCS trial, participants will be randomly assigned to 4 groups receiving stimulation, including tonic, DTM, and FAST. Each stimulation will then be performed for 2 days, and a visual analog scale (VAS) for pain will be evaluated before and after each stimulation pattern. A stimulation-off period for 1 day is set between each stimulation pattern to wash out the residual previous stimulation effects. Pain improvement is defined as more than 33% reduction in the pain VAS. The primary analysis will compare pain improvement between the new stimulation patterns and the conventional tonic stimulation pattern in the SCS trial. The secondary outcomes will be evaluated as follows: (1) the relationships between causative disease and improvement rate by each stimulation pattern; (2) comparison of pain improvement between the DTM and FAST stimulation patterns in all cases and by causative disease; (3) changes in assessment items preoperatively to 24 months after the implantation; (4) preoperative factors associated with long-term effects defined as continuing for more than 12 months; and (5) adverse events related to this study 3 months after the implantation. DISCUSSION: This study aims to clarify the effectiveness of the latest new stimulation patterns compared to the conventional tonic stimulation. In addition, which stimulation pattern is most effective for which kind of causative disease will be clarified. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT) 1,042,220,094. Registered on 21 November 2022, and last modified on 6 January 2023. jRCT is an approved member of the Primary Registry Network of WHO ICTRP.

Number of calcified aortic valve leaflets: natural history and prognostic value in patients undergoing haemodialysis.

AIMS: Aortic valve calcification in aortic sclerosis, a precursor of aortic stenosis (AS), is not always present in all three leaflets; how calcification develops in each leaflet is unknown. We aimed to investigate the natural history of calcification development in each aortic valve leaflet and the prognostic value of the number of calcified leaflets. METHODS AND RESULTS: In a retrospective multicentre cohort study of patients undergoing haemodialysis without AS, we observed calcification development in each aortic valve leaflet using echocardiography. We investigated the association between the number of calcified leaflets and AS development and mortality using time-to-event analysis. Among the 1507 patients (mean age, 66 years; 66% male) included in the longitudinal echocardiography analysis, 709 (47%) had aortic sclerosis at baseline: one-leaflet calcified, 370 (52%); two-leaflet calcified, 215 (30%); and three-leaflet calcified, 124 (17%). The median time for one calcified leaflet increase was 3-4 years, and 251 (17%) patients developed AS during a median 3.2-year follow-up. The increased number of calcified aortic valve leaflets was associated with developing AS; compared with that of one-leaflet calcified, the adjusted hazard ratios (aHRs) [95% confidence intervals (CIs)] of two- and three-leaflet calcified were 2.12 (1.49-3.00) and 4.43 (3.01-6.52), respectively; the aHR (95% CI) per one calcified leaflet increase was 2.24 (1.96-2.55). It was also associated with all-cause mortality; the aHR (95% CI) per one calcified leaflet increase was 1.18 (1.08-1.27). CONCLUSION: The number of calcified aortic valve leaflets strongly predicted AS development and even mortality in patients undergoing haemodialysis, suggesting the usefulness of assessing calcification for each valve leaflet separately using echocardiography.

Differential target multiplexed spinal cord stimulation using a paddle-type lead placed at the appropriate site for neuropathic pain after spinal cord injury in patients with past spinal surgical histories: study protocol for an exploratory clinical trial.

BACKGROUND: Neuropathic pain after spinal cord injury (SCI), both traumatic and non-traumatic, is refractory to various treatments. Spinal cord stimulation (SCS) is one of the neuromodulation therapies for neuropathic pain, although SCS has insufficient efficacy for neuropathic pain after SCI. The reasons are presumed to be inappropriate locations of SCS leads and conventional tonic stimulation itself does not have a sufficient analgesic effect for the pain. In patients with past spinal surgical histories, the cylinder-type leads are likely to be placed on the caudal side of the SCI because of surgical adhesions. Differential target multiplexed (DTM) stimulation is one of the latest new stimulation patterns that is superior to conventional stimulation. METHODS: A single-center, open-label, randomized, two-way crossover trial is planned to investigate the efficacy of SCS using DTM stimulation placing a paddle lead at the appropriate site for neuropathic pain after SCI in patients with spinal surgical histories. The paddle-type lead delivers energy more efficiently than a cylinder-type lead. This study consists of two steps: SCS trial (first step) and SCS system implantation (second step). The primary outcome is rates of achieving pain improvement with more than 33% reduction 3 months after SCS system implantation. The secondary outcomes are to be evaluated as follows: (1) effectiveness of DTM and tonic stimulations during the SCS trial; (2) changes of assessment items from 1 to 24 months; (3) relationships between the result of the SCS trial and the effects 3 months after SCS system implantation; (4) preoperative factors associated with a long-term effect, defined as continuing for more than 12 months; and (5) whether gait function improves from 1 to 24 months. DISCUSSION: A paddle-type lead placed on the rostral side of SCI and using DTM stimulation may provide significant pain relief for patients with intractable neuropathic pain after SCI in patients with past spinal surgical histories. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT) jRCT 1042220093. Registered on 21 November 2022, and last modified on 6 January 2023. jRCT is approved as a member of the Primary Registry Network of WHO ICTRP.

All-cause and cardiovascular mortality in patients undergoing hemodialysis with aortic sclerosis and mild-to-moderate aortic stenosis: A cohort study.

BACKGROUND AND AIMS: Mild-to-moderate aortic stenosis (AS) and aortic sclerosis, a precursor of AS, are associated with mortality in the general population; however, their association in patients undergoing hemodialysis with higher morbidity of AS is unknown. Thus, we investigated the mortality of aortic sclerosis and mild-to-moderate AS in patients undergoing hemodialysis. METHODS: This was a retrospective multicenter cohort study of consecutive patients undergoing hemodialysis at nine dialysis facilities who underwent screening echocardiography between January 2008 and December 2019. We investigated the mortality of patients with aortic sclerosis or mild-to-moderate AS using multivariable Cox proportional hazards regression. RESULTS: Among 1,878 patients undergoing hemodialysis, those with normal aortic valves, aortic sclerosis, mild AS, moderate AS, severe AS, and prosthetic aortic valves were 844 (45%), 793 (42%), 161 (8.6%), 38 (2.0%), 11 (0.6%), and 31 (1.7%), respectively. After excluding patients with severe AS and prosthetic aortic valves, we performed comparative analysis on 1,836 patients (mean age, 67 years; 66% male). In a median follow-up of 3.6 years, crude death rates (per 100 person-years) were 5.2, 10.6, and 13.0 in patients with normal aortic valves, aortic sclerosis, and mild-to-moderate AS, respectively. Compared with normal aortic valves, both aortic sclerosis and mild-to-moderate AS were associated with all-cause and cardiovascular death: adjusted hazard ratios (95% confidence intervals) were 1.36 (1.13-1.65) and 1.36 (1.02-1.80) for all-cause death; and 1.52 (1.06-2.17) and 1.74 (1.04-2.92) for cardiovascular death, respectively. CONCLUSIONS: Aortic sclerosis and mild-to-moderate AS were independent risk factors for all-cause and cardiovascular death in patients undergoing hemodialysis.

Impact of old age on the association between in-center extended-hours hemodialysis and mortality in patients on incident hemodialysis.

With the global problem of aging, it has become more difficult to improve the prognosis of older dialysis patients. Extended-hours hemodialysis offers longer treatment time compared to conventional hemodialysis regimen and provides favorable metabolic status, hemodynamic stability, and increased dietary intake. Despite prior studies reporting that in-center extended-hours hemodialysis can reduce the mortality rate, the treatment impact on elderly patients remains unclear. Therefore, we examined the association between extended-hours hemodialysis compared to conventional hemodialysis and all-cause mortality. Survival analyses using Cox proportional hazard model with multivariable adjustments and propensity-score based method were performed to compare mortality risk between 198 consecutive patients who started in-center extended-hours hemodialysis (Extended-HD) and 1407 consecutive patients who initiated conventional hemodialysis. The median age was 67.1 years in the Extended-HD group and 70.7 years in the conventional hemodialysis group. Extended-HD was associated with lower all-cause mortality in overall patients and the subgroup >70 years (adjusted hazard ratios of 0.60 [95% CI, 0.39-0.91] and 0.35 [95% CI, 0.18-0.69], respectively). There was a significant interaction between age >70 years and Extended-HD. In conclusion, extended-hours hemodialysis was associated with a lower mortality rate, especially in elderly patients.