Kidney outcomes associated with haematuria and proteinuria trajectories among patients with IgA nephropathy in real-world clinical practice: The Japan Chronic Kidney Disease Database.

AIM: Among patients with Immunoglobulin A (IgA) nephropathy, we aimed to identify trajectory patterns stratified by the magnitude of haematuria and proteinuria using repeated urine dipstick tests, and assess whether the trajectories were associated with kidney events. METHODS: Using a nationwide multicentre chronic kidney disease (CKD) registry, we analysed data from 889 patients with IgA nephropathy (mean age 49.3 years). The primary outcome was a sustained reduction in eGFR of 50% or more from the index date and thereafter. During follow-up (median 49.0 months), we identified four trajectories (low-stable, moderate-decreasing, moderate-stable, and high-stable) in both urine dipstick haematuria and proteinuria measurements, respectively. RESULTS: In haematuria trajectory analyses, compared to the low-stable group, the adjusted hazard ratios (HRs) (95% confidence interval [CI]) for kidney events were 2.59 (95% CI, 1.48-4.51) for the high-stable, 2.31 (95% CI, 1.19-4.50) for the moderate-stable, and 1.43 (95% CI, (0.72-2.82) for the moderate-decreasing groups, respectively. When each proteinuria trajectory group was subcategorized according to haematuria trajectories, the proteinuria group with high-stable and with modest-stable haematuria trajectories had approximately 2-times higher risk for eGFR reduction ≥50% compared to that with low-stable haematuria trajectory. CONCLUSION: Assessments of both haematuria and proteinuria trajectories using urine dipstick could identify high-risk IgA nephropathy patients.

Long-term effectiveness of a primary care practice facilitation program for chronic kidney disease management: an extended follow-up of a cluster-randomized FROM-J study.

BACKGROUND: Practice facilitation program by multidisciplinary care for primary care physicians (PCPs) is expected to improve chronic kidney disease (CKD) outcomes, but there is no clear evidence of its long-term effectiveness. We have previously performed a cluster-randomized controlled trial for 3.5 years (the Frontier of Renal Outcome Modifications in Japan (FROM-J) study) with two arms-group A without the program and group B with the program. We aimed to assess the long-term effectiveness of the practice facilitation program on CKD outcomes via an extended 10-year follow-up of the FROM-J study. METHODS: We enrolled patients who were in the FROM-J study. The primary composite endpoint comprised cardiovascular disease (CVD), renal replacement therapy initiation and a 50% decrease in the estimated glomerular filtration rate (eGFR). The secondary endpoints were survival rate, eGFR decline rate and collaboration rate between PCPs and nephrologists. RESULTS: The occurrence of the primary composite endpoint tended to be lower in group B (group A: 27.1% versus group B: 22.1%, P = 0.051). Furthermore, CVD incidence was remarkably lower in group B (group A: 10.5% versus group B: 6.4%, P = 0.001). Although both mortality and the rate of eGFR decline were identical between both groups, the eGFR decline rate was significantly better in group B than in group A only in patients with stage G3a at enrollment (group A: 2.35 ± 3.87 mL/min/1.73 m2/year versus group B: 1.68 ± 2.98 mL/min/1.73 m2/year, P = 0.02). The collaboration rate was higher in group B. CONCLUSIONS: The CKD practice facilitation program for PCPs reliably decreases CVD events and may reduce the progression of cases to end-stage kidney disease.

A nationwide cross-sectional analysis of biopsy-proven Fabry nephropathy: the Japan Renal Biopsy Registry.

BACKGROUND: Fabry disease (FD) is an X-linked inherited disease where renal complications are associated with a poor prognosis. However, little is known about the prevalence of Fabry nephropathy (FN) in patients with chronic kidney disease (CKD). We extracted FN data from the Japan Renal Biopsy Registry, analyzed the prevalence of FN, and examined the correlation between clinical characteristics and renal involvement according to sex differences and hemi- and heterozygosity in patients with FD. METHODS: A total of 38,351 participants who underwent renal biopsy were retrospectively enrolled, and FN was determined. The clinical characteristics of FD patients were examined based on sex differences. RESULTS: Twenty-nine patients (0.076%) (19 males and 10 females, mean age: 43.7 ± 15.5 years old) were diagnosed with FN. Median estimated urinary protein (UP) and mean eGFR levels were 0.9 [interquartile range (IQR) [0.7-1.6] g/gCr and 67.1 ± 36.8 mL/min/1.73 m2, respectively. Mean systolic blood pressure (SBP) was 126.4 ± 17.1 mmHg and diastolic blood pressure was 76.1 ± 12.6 mmHg. An inverse correlation between eGFR and logarithm UP levels was observed (r2 = 0.23, p = 0.02), SBP was positively associated with logarithm UP (r2 = 0.34, p = 0.004) overall and inversely associated with eGFR (r2 = 0.25, p = 0.007) regardless of sex, and SBP was an independent determinant of proteinuria (p = 0.004) and eGFR (p = 0.007). CONCLUSIONS: The prevalence of biopsy-proven FN was 0.076%. Since SBP is associated with eGFR regardless of zygosity, strict SBP control might be necessary to prevent progression to end-stage kidney disease in both male and female patients with FN.

Effects of Agalsidase Alfa Enzyme Replacement Therapy on Left Ventricular Hypertrophy on Electrocardiogram in a Female Patient with Fabry Disease.

Fabry disease is an X-linked lysosomal storage disorder caused by defective enzyme activity of α-galactosidase A and treated with enzyme replacement therapy (ERT) with recombinant α-galactosidase. ERT reduces left ventricular mass assessed by echocardiography or magnetic resonance imaging. However, electrocardiogram changes during ERT have not been fully elucidated. In the present case, ERT with agalsidase alfa for 4 years decreased QRS voltage and negative T depth along with a reduction of left ventricular mass and wall thickness and improvement of symptoms in a female patient with Fabry disease. Long-term observation of electrocardiogram changes might be useful for determining the efficacy of ERT in this case.

Concordance between practice and published evidence in the management of ANCA-associated vasculitis in Japan: A cross-sectional web-questionnaire survey.

OBJECTIVES: We conducted a descriptive study of the physicians' evidence-practice gap for adults covered by the 2017 clinical practice guidelines for the management of antineutrophil cytoplasmic antibody-associated vasculitis in Japan. METHODS: This web-based survey, conducted between January and February 2021, involved physicians who had treated at least five patients in the preceding year at a regional core hospital. The outcome was the physicians' experience in treating patients with microscopic polyangiitis or granulomatosis with polyangiitis [prevalence with 95% confidence intervals (CIs)], defined as treating at least 60% of their patients with the recommended therapy during the year. A modified Poisson regression analysis was performed to explore the factors associated with concordance. RESULTS: The 202 participants included 49 pulmonologists, 65 nephrologists, 61 rheumatologists, and other physicians. The concordance was 31.5% (95% CI, 25.1-38.5) of physicians who used cyclophosphamide or rituximab for the induction of remission. Rheumatology showed the highest concordance with published evidence (risk ratio = 2.4; 95% CI, 1.10-5.22, p = .03). CONCLUSIONS: These results suggest an evidence-practice gap, which varies substantially among subspecialties. Further studies and a new promotional initiative are necessary to close this gap in clinical practice.

Vasohibin-1 has α-tubulin detyrosinating activity in glomerular podocytes.

Podocytes are highly specialized epithelial cells in glomeruli, with a complex morphology composed of a cell body, primary processes, and foot processes, which maintain barrier function in glomerular filtration. The microtubule-based cytoskeleton is necessary for podocyte morphology. Microtubule structure and function can be affected by post-translational modification of tubulin, including detyrosination. Recent studies have shown that vasohibin-1 (VASH1), an antiangiogenic factor, has tubulin carboxypeptidase activity that causes detyrosination of α-tubulin. We aimed to examine the role of VASH1 in regulating α-tubulin detyrosination in podocytes and the potential involvement of VASH1 deficiency in renal morphology. In normal mouse kidneys, detyrosinated α-tubulin was mainly identified in glomeruli, especially in podocytes; meanwhile, in cultured immortalized podocytes, α-tubulin detyrosination was promoted with cell differentiation. Notably, α-tubulin detyrosination in glomeruli was diminished in Vash1 homozygous knockout (Vash1-/-) mice, and knockdown of VASH1 in cultured podocytes prevented α-tubulin detyrosination. Although VASH1 deficiency-induced downregulation of detyrosination caused no remarkable glomerular lesions, urinary albuminuria excretion and glomerular volume were significantly higher in Vash1-/- mice than in wild-type mice. Furthermore, decreased glomerular nephrin expression and narrower slit diaphragms width were observed in Vash1-/- mice. Taken together, we demonstrated that α-tubulin detyrosination in podocytes was mainly regulated by VASH1 and that VASH1 deficiency-mediated decreases in α-tubulin detyrosination led to minor alterations in podocyte morphology and predisposition to albuminuria. VASH1 expression and α-tubulin detyrosination may be novel targets for maintaining glomerular filtration barrier integrity.

Development of Urinary Diagnostic Biomarker for IgA Nephropathy by Lectin Microarray.

INTRODUCTION: The pathogenic roles of aberrantly glycosylated IgA1 have been reported. However, it is unexplored whether the profiling of urinary glycans contributes to the diagnosis of IgAN. METHODS: We conducted a retrospective study enrolling 493 patients who underwent renal biopsy at Okayama University Hospital between December 2010 and September 2017. We performed lectin microarray in urine samples and investigated whether c-statistics of the reference standard diagnosis model employing hematuria, proteinuria, and serum IgA were improved by adding the urinary glycan intensity. RESULTS: Among 45 lectins, 3 lectins showed a significant improvement of the models: Amaranthus caudatus lectin (ACA) with the difference of c-statistics 0.038 (95% CI: 0.019-0.058, p < 0.001), Agaricus bisporus lectin (ABA) 0.035 (95% CI: 0.015-0.055, p < 0.001), and Maackia amurensis lectin (MAH) 0.035 (95% CI: 0.015-0.054, p < 0.001). In 3 lectins, each signal plus reference standard showed good reclassification (category-free NRI and relative IDI) and good model fitting associated with the improvement of AIC and BIC. Stratified by eGFR, the discriminatory ability of ACA plus reference standard was maintained, suggesting the robust renal function-independent diagnostic performance of ACA. By decision curve analysis, there was a 3.45% net benefit by adding urinary glycan intensity of ACA to the reference standard at the predefined threshold probability of 40%. CONCLUSIONS: The reduction of Gal(ß1-3)GalNAc (T-antigen), Sia(α2-3)Gal(ß1-3)GalNAc (Sialyl T), and Sia(α2-3)Gal(ß1-3)Sia(α2-6)GalNAc (disialyl-T) was suggested by binding specificities of 3 lectins. C1GALT1 and COSMC were responsible for the biosynthesis of these glycans, and they were known to be downregulated in IgAN. The urinary glycan analysis by ACA is a useful and robust noninvasive strategy for the diagnosis of IgAN.

Focal segmental glomerulosclerosis histologic variants and renal outcomes based on nephrotic syndrome, immunosuppression and proteinuria remission.

BACKGROUND: The associations of focal segmental glomerulosclerosis (FSGS) histological variants with renal outcomes have rarely been investigated comprehensively by clinically relevant subgroups in this modern age. METHODS: Data on 304 (173 nephrotic and 131 non-nephrotic) patients with biopsy-confirmed FSGS from 2010 to 2013 were analyzed using the Japanese nationwide renal biopsy registry. The primary outcome was a composite of a 30% decline in estimated glomerular filtration rate or progression to end-stage kidney disease 5 years from the biopsy. We compared outcomes of FSGS variants according to the Columbia classification using survival analyses. Subgroup analyses were performed based on nephrotic syndrome (NS), immunosuppression and proteinuria remission (PR; proteinuria <0.3 g/day) during follow-up. Additionally, associations of NS, immunosuppression and PR with outcomes were examined for each variant. RESULTS: The distribution of variants was 48% (n = 145) FSGS not otherwise specified, 19% (n = 57) tip, 15% (n = 47) perihilar, 13% (n = 40) cellular and 5% (n = 15) collapsing. The outcome event occurred in 87 patients (29%). No significant differences in the outcome were found among the variants. Subgroup analyses yielded similar results. However, there was a trend toward improved outcome in patients with PR irrespective of variants [hazard ratio adjusted for histological variant and potential confounders (adjusted HR) 0.19 (95% confidence interval 0.10-0.34)]. NS was marginally associated with better outcome compared with non-NS [adjusted HR 0.50 (95% confidence interval 0.25-1.01)]. CONCLUSIONS: FSGS variants alone might not have significant impacts on the renal outcome after 5 years, while PR could be predictive of improved renal prognosis for any variant. Specific strategies and interventions to achieve PR for each variant should be implemented for better renal outcomes.

Clinical and pathological characteristics of patients with acute kidney injury in Japan in whom kidney biopsy was performed: a cross-sectional analysis of the Japan Renal Biopsy Registry (J­RBR).

INTRODUCTION: Acute kidney injury (AKI) is a worldwide concern and it leads to a poor prognosis or end-stage kidney disease. The purpose of this study was to clarify the characteristics of patients with AKI in whom kidney biopsy was performed using data of the Japan Renal Biopsy Registry (J-RBR). METHODS: We screened 38,351 cases that were registered in the J-RBR from 2007 to 2018. We obtained data for 383 patients with AKI based on clinical diagnosis for analysis 1 and data for 714 patients with acute interstitial nephritis (AIN) or acute tubular necrosis (ATN) based on pathological diagnosis for analysis 2. RESULTS: Of the cases screened, 383 patients with AKI (1.0%) were included in analysis 1. The main pathological diagnoses of AKI were AIN, ATN, chronic interstitial nephritis, nephro-sclerosis and crescentic glomerulonephritis. Of the cases screened, 589 patients with AIN (1.5%) and 110 patients with ATN (0.3%) were included in analysis 2. The main clinical diagnoses of AIN were AKI, rapidly progressive glomerulonephritis (RPGN), chronic nephritic syndrome (CNS) and drug-induced nephropathy (DIN), whereas those of ATN were AKI, RPGN, DIN and CNS. ATN patients had a higher serum creatinine level than that of AIN patients. CONCLUSION: Our results revealed that cases in the J-RBR included 1.0% of AKI cases based on clinical diagnosis and 1.5% and 0.3% of AIN and ATN cases, respectively, based on pathological diagnosis. In patients with suspected intrinsic AKI, kidney biopsy should be performed for diagnosis of the precise etiology and selection of appropriate treatment.

Epidemiology and temporal changes in the prognosis of rapidly progressive glomerulonephritis in Japan: a nationwide 1989-2015 survey.

BACKGROUND: Rapidly progressive glomerulonephritis (RPGN) can progress to end-stage kidney disease within a short period. This study is a continuation of the chronological nationwide survey conducted by the Japan-RPGN working group. METHODS: We examined a total of 2793 RPGN cases registered during four periods (1989-1998, 1999-2001, 2002-2008, 2009-2011) plus 1386 cases in 2012-2015. As potential prognostic determinants, we investigated the onset period, the clinical severity (CS) grade [classified according to age, serum creatinine (sCr) and C-reactive protein levels, and presence/absence of lung lesions], and causative disease. RESULTS: The cumulative overall RPGN patient survival at 24 months kept improving over the five periods (72.0%, 72.9%, 77.7%, 83.0%, 84.9%, p < 0.001 for trend). The cumulative renal survival also improved in the latest period (68.7%, 75.4%, 76.7%, 73.4%, 78.2%, p < 0.001 for trend). The CS grade was well stratified to predict both life and renal prognoses. Anti-glomerular basement membrane disease (aGBMD)-RPGN had a poorer renal prognosis than other diseases. In anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV-RPGN, accounting for > 70% of the overall RPGN), the prognostic results were similar to that for overall RPGN. There was a much better renal prognosis for the latest period under the condition of sCr < 3 mg/dL (the 24-month cumulative renal survival: 97.9%), but not for sCr ≥ 3 mg/dL (61.5%). CONCLUSIONS: In overall RPGN as well as AAV-RPGN, both life and renal prognoses tended to improve, but the favorable renal result was substantially limited to mild cases. There was no improvement of the renal prognosis in aGBMD-RPGN.

Clinicopathological discordance in biopsy-proven nephrosclerosis: a nationwide cross-sectional study of the Japan Renal Biopsy Registry (J-RBR).

BACKGROUND: Patients with nephrosclerosis display heterogenous clinical phenotypes, often leading to a clinical diagnosis discordant with pathological nephrosclerosis diagnosis. However, little is known about clinical factors associated with clinicopathological discordance of biopsy-proven nephrosclerosis. METHODS: In a cross-sectional study of 891 patients with biopsy-proven nephrosclerosis registered in the Japan Renal Biopsy Registry (J-RBR) between July 2007 and June 2016, we examined clinical characteristics associated with a pre-biopsy clinical diagnosis discordant with pathological nephrosclerosis diagnosis using multivariable logistic regression with adjustment for relevant clinical characteristics. RESULTS: Overall, the mean (SD) age was 58.6 (13.7) years; 67.6% of patients were male; and 63.2% were on antihypertensive drugs. The median estimated glomerular filtration rate (eGFR) was 43.8 mL/min/1.73 m2 and the median proteinuria was 0.5 g/day. Of the 891 patients, 497 (55.8%) had a clinical diagnosis discordant with pathological nephrosclerosis diagnosis, with chronic nephritic syndrome being the most common (> 75%) discordant clinical diagnosis. After multivariable adjustment, age (odds ratio 1.34, [95% confidence interval, 1.16-1.55], per 10 years increase), eGFR (1.10 [1.00-1.21], per 10 mL/min/1.73 m2 increase), and proteinuria (1.20 [1.03-2.16], per 1 g/day decrease) were found to be significantly associated with the clinicopathological discordance. CONCLUSIONS: Patients with older age, higher eGFR, and lower proteinuria had significantly higher likelihood of being clinically diagnosed with other glomerular disease in patients with biopsy-proven nephrosclerosis. Our findings highlight the heterogeneous clinical phenotypes of nephrosclerosis and suggest the need for continuous improvement of clinical diagnostic accuracy as well as for wider kidney biopsy indications for nephrosclerosis.

A nationwide analysis of renal and patient outcomes for adults with lupus nephritis in Japan.

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.

Deep learning analysis of clinical course of primary nephrotic syndrome: Japan Nephrotic Syndrome Cohort Study (JNSCS).

BACKGROUND: Prognosis of nephrotic syndrome has been evaluated based on pathological diagnosis, whereas its clinical course is monitored using objective items and the treatment strategy is largely the same. We examined whether the entire natural history of nephrotic syndrome could be evaluated using objective common clinical items. METHODS: Machine learning clustering was performed on 205 cases from the Japan Nephrotic Syndrome Cohort Study, whose clinical parameters, serum creatinine, serum albumin, dipstick hematuria, and proteinuria were traceable after kidney biopsy at 5 measured points up to 2 years. The clinical patterns of time-series data were learned using long short-term memory (LSTM)-encoder-decoder architecture, an unsupervised machine learning classifier. Clinical clusters were defined as Gaussian mixture distributions in a two-dimensional scatter plot based on the highest log-likelihood. RESULTS: Time-series data of nephrotic syndrome were classified into four clusters. Patients in the fourth cluster showed the increase in serum creatinine in the later part of the follow-up period. Patients in both the third and fourth clusters were initially high in both hematuria and proteinuria, whereas a lack of decline in the urinary protein level preceded the worsening of kidney function in fourth cluster. The original diseases of fourth cluster included all the disease studied in this cohort. CONCLUSIONS: Four kinds of clinical courses were identified in nephrotic syndrome. This classified clinical course may help objectively grasp the actual condition or treatment resistance of individual patients with nephrotic syndrome.

The Beneficial Effect of Personalized Lifestyle Intervention in Chronic Kidney Disease Follow-Up Project for National Health Insurance Specific Health Checkup: A Five-Year Community-Based Cohort Study.

Background and Objectives: Mimasaka city is a relatively small city with a population of 28,381, and an aging rate (≥65 years old) of 38.9%, where only one nephrology clinic is available. Since 2013, the city has conducted its own unique lifestyle intervention for the participants of the National Health Insurance specific medical health checkup, aiming to prevent the progression of chronic kidney disease (CKD) severity. Materials and Methods: The persons in National Health Insurance specific medical health checkup (40−74 years old) conducted in Mimasaka city in 2013, with eGFR less than 50 mL/min/1.73 m² or 50−90 mL/min/1.73 m² with urine dipstick protein 1+ or more, were registered for the CKD follow-up project, as high-risk subjects for advanced renal dysfunction. Municipal workers directly visited the subjects' homes to provide individual health guidance and encourage medical consultation. We aimed to examine the effect of home-visit intervention on the changes of renal function and related factors until 2017. Results: The number of the high-risk subjects who continuously received the health checkup until 2017 was 63, and only 23 (36.5%) visited a medical institution in the first year. The eGFR decreased by only 0.4 mL/min/1.73 m²/year, and the subjects with urinary protein 1+ or higher decreased significantly from 20 (31.7%) to 9 (14.3%) (p = 0.034) in the high-risk subjects. The changes in eGFR and urinary protein was almost in the same fashion regardless of their medical institution visits. Next, we examined the effects of various factors on ΔeGFR, the changes of eGFR from 2013 to 2017, by multivariate linear regression analysis. The effects of medical institution visit were not significant, and the degree of urinary protein (coefficient B: 4.503, ß: 0.705, p < 0.001), age (coefficient B: 4.753, ß: 0.341, p = 0.004), and smoking (coefficient B: 5.878, ß: 0.295, p = 0.031) had independent significant effects, indicating that they were the factors exacerbating the decrease in eGFR from the baseline. Conclusions: The personalized lifestyle intervention by home-visit in CKD follow-up project showed the possibility of beneficial effects on the deterioration of renal function. This may be an efficient method to change behavior in a small community with limited medical resources.

Plasma Globotriaosylsphingosine and α-Galactosidase A Activity as a Combined Screening Biomarker for Fabry Disease in a Large Japanese Cohort.

Fabry disease is an X-linked disorder of α-galactosidase A (GLA) deficiency. Our previous interim analysis (1 July 2014 to 31 December 2015) revealed plasma globotriaosylsphingosine as a promising primary screening biomarker for Fabry disease probands. Herein, we report the final results, including patients enrolled from 1 January to 31 December 2016 for evaluating the potential of plasma globotriaosylsphingosine and GLA activity as a combined screening marker. We screened 5691 patients (3439 males) referred from 237 Japanese specialty clinics based on clinical findings suggestive of Fabry disease using plasma globotriaosylsphingosine and GLA activity as primary screening markers, and GLA variant status as a secondary screening marker. Of the 14 males who tested positive in the globotriaosylsphingosine screen (≥2.0 ng/mL), 11 with low GLA activity (<4.0 nmol/h/mL) displayed GLA variants (four classic, seven late-onset) and one with normal GLA activity and no pathogenic variant displayed lamellar bodies in affected organs, indicating late-onset biopsy-proven Fabry disease. Of the 19 females who tested positive in the globotriaosylsphingosine screen, eight with low GLA activity displayed GLA variants (six classic, two late-onset) and five with normal GLA activity displayed a GLA variant (one classic) and no pathogenic variant (four late-onset biopsy-proven). The combination of plasma globotriaosylsphingosine and GLA activity can be a primary screening biomarker for classic, late-onset, and late-onset biopsy-proven Fabry disease probands.

Clinical impact of urinary CD11b and CD163 on the renal outcomes of anti-neutrophil cytoplasmic antibody-associated glomerulonephritis.

BACKGROUND: The detection of leukocyte-derived CD11b (α subunit of integrin Mac-1) and CD163 (scavenger receptor) in urine may reflect renal inflammation in antineutrophil cytoplasmic antibody-associated glomerulonephritis (ANCA-GN). The objective of this study was to evaluate the clinical significance of urinary CD11b (U-CD11b) and CD163 (U-CD163) in ANCA-GN. METHODS: U-CD11b and U-CD163 were examined using enzyme-linked immunosorbent assay in ANCA-GN urine samples from our institutional cohort (n = 88) and a nationwide cohort (n = 138), and their association with renal histology was subsequently analyzed. Logistic regression analyses were performed on a nationwide ANCA cohort to determine the associations of the two urinary molecules with renal remission failure at 6 months or with yearly estimated glomerular filtration rate (eGFR) slope over a 24-month observation period. RESULTS: U-CD11b and U-CD163 were significantly associated with cellular crescent formation and leukocyte accumulation in glomerular crescents. With regard to interstitial inflammation, both levels of U-CD11b and U-CD163 at diagnosis remarkably increased in ANCA-GN compared with the levels observed in nonglomerular kidney disorders including nephrosclerosis, immunoglobulin G4-related disease and tubulointerstitial nephritis; however, the presence of U-CD11b alone was significantly correlated with tubulointerstitial leukocyte infiltrates. Although neither U-CD11b nor U-CD163 at diagnosis was associated with remission failure at 6 months, multivariate analysis demonstrated that the baseline U-CD11b levels were significantly associated with the increase in eGFR following immunosuppressive therapy. CONCLUSIONS: Although both U-CD11b and U-CD163 reflect renal leukocyte accumulation, U-CD11b at diagnosis provides additional clinical value by predicting the recovery rate after the treatment of ANCA-GN.

Clinical and histological features in pediatric and adolescent/young adult patients with renal disease: a cross-sectional analysis of the Japan Renal Biopsy Registry (J-RBR).

BACKGROUND: Only a few studies have investigated epidemiological and clinicopathological information regarding pediatric and adolescent and young adult (AYA) patients with renal disease. The purpose of this study was to clarify the differences and relationship of clinicopathological findings between pediatric and AYA patients using the Japan Renal Biopsy Registry (J-RBR). METHODS: This cross-sectional study analyzed data from patients registered in the J-RBR between 2007 and 2017. Clinicopathological findings at diagnosis were analyzed for 3,463 pediatric (age < 15 years) and 6,532 AYA (age 15-30 years) patients. RESULTS: Although chronic nephritic syndrome was the most common clinical diagnosis at age > 5 years, nephrotic syndrome was the most frequent diagnosis at age < 4 years. The most common pathological diagnosis as classified by pathogenesis in pediatric patients was primary glomerular disease (except IgA nephropathy), whereas IgA nephropathy was increased in AYA patients. Mesangial proliferative glomerulonephritis was the most common pathological diagnosis as classified by histopathology in both pediatric and AYA patients. Minor glomerular abnormalities were the most frequent histopathologic diagnoses of nephrotic syndrome in childhood, but their frequency decreased with age. CONCLUSION: To the best of our knowledge, this is the first report of clinicopathological features of pediatric and AYA patients in a large nationwide registry of renal biopsy. There were differences of clinical, pathological and histopathologic findings between pediatric and AYA patients.

Presence of decoy cells for 6 months on urine cytology efficiently predicts BK virus nephropathy in renal transplant recipients.

OBJECTIVES: To investigate the association between duration of consecutive presence of decoy cells on urine cytology and BK virus nephropathy after kidney transplantation. METHODS: In total, 121 kidney transplant recipients were retrospectively evaluated. The best duration of consecutive presence of decoy cells that could be used to predict BK virus nephropathy was analyzed using the area under the curve for each duration, and recipients were divided into two groups based on the best predictive performance. The effectiveness of SV40 immunostaining on urinary cytology was also analyzed. RESULTS: In total, 2534 urine specimens as well as SV40 immunostaining in 2241 urine specimens were analyzed. Six consecutive months of decoy cell positivity had the best predictive performance for BK virus nephropathy (area under the curve = 0.832). The incidence of BK virus nephropathy in recipients with positive decoy cells for 6 months or more consecutive months (5/44) was significantly higher than in those who had positive decoy cells for less than 6 months (0/77; P = 0.005). Decoy cell positivity had a sensitivity, specificity, positive predictive value, and negative predictive value for BK virus nephropathy of 100%, 66%, 11%, and 100% respectively. SV40 immunostaining provided slightly better specificity (68%) and positive predictive value (12%). CONCLUSIONS: The detection of decoy cells at 6 months or more on urine cytology had high predictive value for BK virus nephropathy in kidney transplant recipients. SV40 immunostaining on urine cytology added minimal diagnostic accuracy.

Correction to: Temporal change in life and renal prognosis of rapidly progressive glomerulonephritis in Japan via nationwide questionnaire survey.

In the Original publication of the article, the text in the horizontal axis in Fig. 1a and b appears incorrectly as "Time from treatment start (Months)".

The revised version 2018 of the nationwide web-based registry system for kidney diseases in Japan: Japan Renal Biopsy Registry and Japan Kidney Disease Registry.

BACKGROUND: The Japan Renal Biopsy Registry (J-RBR), the first nation-wide registry of renal biopsies in Japan, was established in 2007, and expanded to include non-biopsy cases as the Japan Kidney Disease Registry (J-KDR) in 2009. The J-RBR/J-KDR is one of the biggest registries for kidney diseases. It has revealed the prevalence and distribution of kidney diseases in Japan. This registry system was meant to be revised after 10 years. METHODS: In 2017, the Committees of the Japanese Society of Nephrology started a project for the revision of the J-RBR/J-KDR. The revised system was designed in such a way that the diagnoses of the patients could be selected from the Diagnosis Panel, a list covering almost all known kidney diseases, and focusing on their pathogenesis rather than morphological classification. The Diagnosis Panel consists of 22 categories (18 glomerular, 1 tubulointerstitial, 1 congenital/genetical, 1 transplant related, and 1 other) and includes 123 diagnostic names. The items for clinical diagnosis and laboratory data were also renewed, with the addition of the information on immunosuppressive treatment. RESULTS: The revised version of J-RBR/J-KDR came into use in January 2018. The number of cases registered under the revised system was 2748 in the first year. The total number of cases has reached to 43,813 since 2007. CONCLUSION: The revised version 2018 J-RBR/J-KDR system attempts to cover all kidney diseases by focusing on their pathogenesis. It will be a new platform for the standardized registration of kidney biopsy cases that provides more systemized data of higher quality.