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Background: Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are major genetic polycystic kidney diseases that can progress to end-stage kidney disease (ESKD). Longitudinal data on the clinical characteristics associated with clinical outcomes in polycystic kidney disease (PKD), including the development of ESKD and cardiovascular disease (CVD) are lacking in Japan. To address this unmet need the authors are establishing a novel, web-based, Nationwide Cohort Registry Study—the Japanese Registry of PKD (JRP). Methods: The JRP is a prospective cohort study for ADPKD (aim to recruit n = 1000 patients), and both a retrospective and prospective study for ARPKD (aim to recruit n = 100). In the prospective registry, patients will be followed-up for 10 years every 6 months and 12 months for patients with ADPKD and ARPKD, respectively. Data collection will be recorded on Research Electronic Data Capture (REDCap) starting on April 1, 2024, with recruitment ending on March 31, 2029. (jRCT 1030230618). Results: Data to be collected include: baseline data, demographics, diagnostic and genetic information, radiological and laboratory findings, and therapeutic interventions. During follow-up, clinical events such as development of ESKD, hospitalization, occurrence of extra kidney complications including CVD events, and death will be recorded, as well as patient-reported health-related quality of life for patients with ADPKD. Conclusions: The JRP is the first nationwide registry study for patients with ADPKD and ARPKD in Japan, providing researchers with opportunities to advance knowledge and treatments for ADPKD and ARPKD, and to inform disease management and future clinical practice. [ABSTRACT FROM AUTHOR]

Background: Clinical practice guidelines recommend antihypertensive and tolvaptan therapies for patients with autosomal dominant polycystic kidney disease (ADPKD) in Japan. However, tolvaptan therapy may pose an economic burden. The Japanese Ministry of Health, Labour and Welfare supports patients with intractable diseases. This study aimed to confirm the impact of the intractable disease system in Japan on the clinical treatment of ADPKD. Methods: We analyzed the data of 3768 patients with ADPKD having a medical subsidy certificate from the Japanese Ministry of Health, Labour and Welfare in 2015–2016. The following quality indicators were use: the adherence rate to the 2014 clinical practice guideline for polycystic kidney disease (prescription rates of antihypertensive agents and tolvaptan in this cohort) and the number of Japanese patients with ADPKD nationwide started on renal replacement therapy in 2014 and 2020. Results: Compared with new applications from 2015 to 2016, the prescription rates of antihypertensives and tolvaptan for the indicated patients at the 2017 renewal application increased by 2.0% (odds ratio = 1.41, p = 0.008) and 47.4% (odds ratio = 10.1, p > 0.001), respectively. These quality indicators improved with antihypertensive treatment, especially in patients with chronic kidney disease stages 1–2 (odds ratio = 1.79, p = 0.013) and in those aged < 50 years (odds ratio = 1.70, p = 0.003). The number of patients with ADPKD who were started on renal replacement therapy in Japan decreased from 999 in 2014 to 884 in 2020 in the nationwide database (odds ratio = 0.83, p < 0.001). Conclusions: The Japanese public intractable disease support system contributes to improvement of ADPKD treatment. [ABSTRACT FROM AUTHOR]

Background: The prognosis of lupus nephritis (LN) has improved following the introduction of effective immunosuppressive therapy and progress in supportive care. This study examined recent renal and patient prognosis for adults with LN in Japan. Methods: We conducted a nationwide retrospective cohort study of LN patients who received a renal biopsy between 2007 and 2012 that were registered in the Japan Renal Biopsy Registry. Of 623 registered adults with LN from 25 institutions and their affiliated or community hospitals, 489 were eligible for this study. Results: The median age at renal biopsy was 39 years, and 82.2% of patients were female. Renal biopsies were performed in 348 patients with new-onset LN, 106 with relapse LN, and 35 with refractory LN. The distribution of ISN/RPS 2003 Classes was as follows: I 1.6%; II 5.3%; III (± V) 27.0%; IV (± V) 47.0%; V 18.4%; VI 0.6%. During the median observation period of 63.8 months, 36 patients (7.3%) reached a doubling of serum creatinine or end-stage kidney disease (ESKD), and 28 patients (5.7%) died. The 5 year renal and patient survival rates were 93.9% and 94.7%, respectively. Multivariate analysis revealed body mass index (BMI) and estimated glomerular filtration rate (eGFR) were independent risk factors for a doubling of serum creatinine in ESKD. Age and eGFR were independent risk factors for death. Conclusion: Recent prognosis for adults with LN are relatively good in Japan. Risk factors for impaired renal function are BMI and eGFR at renal biopsy, while age and eGFR are risk factors for death. [ABSTRACT FROM AUTHOR]

Autosomal recessive polycystic kidney disease ht Diagnostic criteria for ADPKD as an intractable disease A patient must fulfil either of the following criteria to be diagnosed with ADPKD: Red area of the CKD severity classification heat map. In 2020, the Research for Intractable Renal Diseases of the Ministry of Health, Labour and Welfare of Japan established the Committee of Guideline for Polycystic Kidney Disease, which published (A Digest from Evidence-Based Clinical Practice Guideline for Polycystic Kidney Disease 2020) on the website (jin-shogai.jp/policy/index.html). However, the effect of valvular disease therapy on the prognosis of patients with ADPKD with valvular disease remains unknown. B Prediction of eGFR in patients with class 1 ADPKD Prevalence and prognosis The results of a 1994 epidemiological survey yielded an estimated 31,000 (diagnosed and undiagnosed) patients with ADPKD in Japan, with one in 4033 Japanese citizens estimated to have the disease. [Extracted from the article]

This document is a correction notice for an article titled "Public support for patients with intractable diseases in Japan: impact on clinical indicators from nationwide registries in patients with autosomal dominant polycystic kidney disease." The correction states that the third author, Tomonori Kimura, was inadvertently left out of the original publication. The corrected article includes the author's affiliation details. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. The article is authored by multiple individuals and covers various aspects of the topic. [Extracted from the article]

Background: Practice patterns and bleeding complications of percutaneous native kidney biopsy (PNKB) have not recently been investigated and the Japanese Society of Nephrology performed a nationwide questionnaire survey in 2018. Methods: The survey consisted of nine sections about PNKB: (1) general indications; (2) indications for high-risk patients; (3) informed consent; (4) pre-biopsy evaluation; (5) procedures; (6) sedation; (7) post-biopsy hemostasis, bed rest, and examinations; (8) bleeding complications; and (9) specimen processing. A supplementary survey examined bleeding requiring transcatheter arterial embolization (TAE). Results: Overall, 220 directors of facilities (nephrology facility [NF], 168; pediatric nephrology facility [PF], 52) completed the survey. Indications, procedures, and monitoring protocols varied across facilities. Median lengths of hospital stay were 5 days in NFs and 6 days in PFs. Gauge 14, 16, 18 needles were used in 5%, 56%, 33% in NFs and 0%, 63%, 64% in PFs. Mean limits of needle passes were 5 in NFs and 4 in PFs. The bed rest period was 16–24 h in 60% of NFs and 65% of PFs. Based on 17,342 PNKBs, incidence rates of macroscopic hematuria, erythrocyte transfusion, and TAE were 3.1% (NF, 2.8%; PF, 6.2%), 0.7% (NF, 0.8%; PF, 0%), and 0.2% (NF, 0.2%; PF, 0.06%), respectively. Forty-six percent of facilities processed specimens all for light microscopy, immunofluorescence, and electron microscopy, and 21% processed for light microscopy only. Timing of bleeding requiring TAE varied among PNKB cases. Conclusion: Wide variations in practice patterns of PNKB existed among facilities, while PNKBs were performed as safely as previously reported. [ABSTRACT FROM AUTHOR]

Background: Hyperuricemia is a known risk factor for end-stage renal disease. Although xanthine oxidase (XO) inhibitors are expected to protect the kidney function, evidence to this end is insufficient at present. Methods: This study was a multi-center, open-labeled, randomized study conducted in Mie Prefecture in Japan. Patients were included if they were between 20 and 80 years old and had a serum uric acid (sUA) level ≥ 7.0 mg/dl with or without gout, estimated glomerular filtration rate (eGFR) of 15–60 ml/min/1.73 m2, and urinary protein creatinine ratio (uPCR) of 0.15–3.5 g/gCr. Patients were randomly assigned to a Topiroxostat or Febuxostat group, and the treatment target for the sUA level was < 6.0 mg/dl. The primary outcome was the change in the uPCR after 24 weeks. Results: The change in the median uPCR after 24 weeks was not statistically significant after treatment in the Topiroxostat or Febuxostat group (0.05 g/gCr and − 0.04 g/gCr, respectively). However, the sUA levels decreased significantly in both groups (Topiroxostat group: 8.6 ± 1.1 at baseline to 6.0 ± 1.1 mg/dl at 24 weeks, Febuxostat group: 8.4 ± 1.1 mg/dl at baseline to 5.9 ± 1.3 mg/dl at 24 weeks). No significant change in the eGFR after 24 weeks was noted in either the Topiroxostat or Febuxostat group (− 0.04 ± 4.59 ml/min/1.73 m2 and 0.31 ± 4.70 ml/min/1.73 m2, respectively). Conclusions: In this study, XO inhibitors did not significantly reduce the uPCR in chronic kidney disease stage 3 and 4 patients with hyperuricemia. [ABSTRACT FROM AUTHOR]

Background: We encountered a case of bromism that was found to be due to pseudohyperchloremia. Hyperchloremia is known to be able to reveal existing bromism, but the fact that bromine (Br) influences chloride (Cl) in assays that use ion electrode machines is not widely known. Methods: We assayed samples by an ion electrode method, using four types of machines. Different amounts of Cl or Br were added to each sample. Results: With the addition of Cl to the samples, the assayed Cl concentrations were proportional to the amount of added Cl. With the addition of Br to the samples, the assayed Cl concentrations, as measured by all machines, were increased, but the amounts of the increase differed significantly, and were not proportional to the amount of Br added. In particular, in the machine most markedly influenced by additional Br, the Cl concentrations increased from 94.9 to 139.6 mEq/l with the addition of 10 mEq/l of Br. Conversely, in the least influenced machine, Cl values increased from 95.0 to 103.0 mEq/l with the addition of 10 mEq/l of Br. Conclusion: The influence on the Cl assay of the addition of Br varied significantly between different ion electrode machines. Clinical nephrologists therefore need to be able to recognize the characteristics of the specific machines used in their hospitals. [ABSTRACT FROM AUTHOR]

No consensus exists on the amount of bed rest required after renal biopsy. Moreover, forced prolonged bed rest can be uncomfortable in patients undergoing renal biopsy. To evaluate whether the length of strict bed rest affects the incidence of pain and other complications after renal biopsy. This single-center retrospective observational study was conducted in 94 consecutive patients undergoing biopsy of a native kidney between November 2005 and December 2006 at Mie University Hospital. The control group was composed of 317 patients who underwent biopsy of a native kidney between January 2001 and October 2005. The incidence of biopsy-related complications was compared between two periods of strict bed rest: 2 h of strict bed rest with no abdominal bandage (November 2005 to December 2006) and 7 h of strict bed rest with an abdominal bandage (January 2001 to October 2005). The primary outcome was the incidence of back pain requiring analgesics. The secondary outcomes were: need for transfusion or hemostatic intervention, decrease of ≥10% in hemoglobin (Hb) after biopsy, macroscopic hematuria, infection possibly related to biopsy, need for single or indwelling bladder catheterization, and other biopsy-related complications. The incidence of back pain requiring analgesics decreased with a shorter period of strict bed rest [7.5% versus 21.1%, odds ratio (OR) 0.30, 95% confidence interval (95% CI) 0.12–0.64, p = 0.004]. Even after adjustment for age, sex, perinephric hematoma size, and number of biopsy punctures, the incidence of back pain decreased significantly (OR 0.34, 95% CI 0.14–0.73, p = 0.01). With a shorter period of strict bed rest, there were no significant differences in bleeding complications (need for transfusion or other hemostatic intervention), decrease of ≥10% in Hb or macroscopic hematuria. However, the need for indwelling bladder catheterization decreased significantly (36.2% versus 50.5%, OR 0.55, 95% CI 0.34–0.88, p = 0.013). Shortening the period of strict bed rest after renal biopsy from 7 h to 2 h decreased the incidence of back pain, but there was no increase in bleeding or other biopsy-related complications. Our findings suggest that a shorter period of strict bed rest can safely reduce discomfort in renal biopsy patients. [ABSTRACT FROM AUTHOR]

Renal biopsy is essential for the diagnosis of kidney diseases, but complications, particularly bleeding incidents, remain problematic. To evaluate the frequency of renal biopsy complications, and to reveal clinical and laboratory factors associated with overt bleeding complications, focusing on those available at hospital ward, we conducted a retrospective observational study for the period between 2001 and 2005 at Mie University Hospital in patients who underwent percutaneous renal biopsy of a native kidney. Of a total of 323 patients, 317 met the inclusion criteria. Only one patient (0.3%) required blood transfusion or intervention to stop bleeding. The mean decrease in hemoglobin (Hb) after biopsy was 0.43 ± 0.7 g/dL. Hb decreased ≥1.0 g/dL in 66 patients (20.8%) and ≥10% in 32 patients (10.1%). On ultrasonography, perirenal hematoma was detected immediately after biopsy in 273 patients (86.1%), and 41 patients (12.9%) showed hematoma ≥2 cm in width. Analgesics were required for back pain in 67 patients (21.1%). Vasovagal response developed in 31 patients (9.8%). Macrohematuria occurred in 12 patients (3.8%). Urinary catheter was used in 161 patients (50.8%). For Hb decrease ≥10% after biopsy, multivariate analysis revealed perirenal hematoma (≥2 cm) as a significant factor. Other significant factors were prolonged international normalized ratio of prothrombin time, elevated blood pressure on hospital admission, older age, increased serum creatinine level, and steroid use. Perirenal hematoma ≥2 cm on ultrasonography immediately after biopsy might well represent a predictive factor for bleeding complications. [ABSTRACT FROM AUTHOR]

A 69-year-old woman presented with unusual electron microscopic findings. The patient was admitted to ascertain the cause of her persistent proteinuria, and kidney biopsy was performed. While light microscopic findings and immunofluorescence study suggested membranous nephropathy, electron microscopic study showed microspheric particles aggregated in the subepithelial space where electron-dense deposits should have existed. While the microspheric particles could have been unusual and rough deposits, detailed study suggested that the particles could be parts of glomerular podocytes, for example foot processes. This unusual finding was considered as being in a unique clinical course of membranous nephropathy, but a variant of glomerulopathy associated with podocytic infolding, proposed by Joh et al. (J Nephrol 49:61–67, ), could not be excluded. [ABSTRACT FROM AUTHOR]

In the original publication, some errors have been found in the alignment of Table 9. The corrected table is given below [ABSTRACT FROM AUTHOR]

The corrected text is given below: According to the questionnaire survey results that were performed for the publication of this book, among 15,657 kidney biopsy cases that were performed in Japan, gross hematuria after kidney biopsy was found in 431 patients (2.8%), bladder wash was in 56 cases (0.4%), red blood cell transfusion was in 121 cases (0.8%), renal arterial embolization was in 31 cases (0.2%), and death occurred in one case (0.006%). Correction to: Clinical and Experimental Nephrology (2021) 25:325-364 https://doi.org/10.1007... In the original publication of the article, the author found errors in the values under the title "Chapter 7: Complications". [Extracted from the article]