Clinical and histological features of lupus nephritis in Japan: A cross-sectional analysis of the Japan Renal Biopsy Registry (J-RBR)

Anti-C1q antibodies in lupus nephritis children with glomerular microthrombosis

AIM

Glomerular microthrombosis (GMT) was a common vascular lesion in patients with lupus nephritis (LN). The objective of this study was to investigate the relationship between serum anti-beta2-glycoprotein I antibodies (a-β2GP1) and anti-complement 1q antibodies (a-C1q) antibodies and to investigate the possible mechanism of GMT in children with LN.

METHODS

The subjects were 191 children with LN diagnosed by renal biopsy in our hospital from January 2017 to January 2020. The patients were divided into GMT group and non-GMT group. The clinical manifestations, laboratory tests, renal pathology, prognosis of the two groups and the relationship between a-β2GP1 and a-C1q antibodies were observed.

RESULTS

In 191 children with LN, 52 cases (27.23%) presented with GMT. The value of C3, haemoglobin (Hb), estimate glomerular filtration rate (eGFR) and anticardiolipin antibody (ACA) in GMT group were lower than that of non-GMT group (p < .05, p < .01). The value of serum creatinine (Scr), 24 h proteinuria (PRO), urine red blood cells (RBC), N-acetyl-β-d-glucosidase (NAG) and retinol-binding protein (RBP), a-C1q, a-β2GP1, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and renal histopathological activity index (AI) score in GMT group were higher than that of non-GMT group (p < .05, p < .01). The positive proportions of serum a-C1q and a-β2GP1 in GMT group were higher than those in non-GMT group (p < .05). According to Spearman correlation analysis, a-C1q was positively correlated with AI score, SLEDAI, a-β2GP1, GMT, LN-III and LN-IV. Hb, eGFR and a-C1q Ab were associated with the formation of GMT in children with LN. The complete proteinuria remission and renal survival in GMT group were significantly lower than those in non-GMT group (p < .05, p < .01).

CONCLUSION

LN children with GMT had more severe clinical manifestations and renal pathologic damages, and poor outcome. Serum a-C1q level was positively correlated with a-β2GP1, and a-β2GP1 may be involved in the formation of GMT in children with LN, which might involve in the activation of complement classical pathway.

Sex differences in systemic lupus erythematosus (SLE): an inception cohort of the Chinese SLE Treatment and Research Group (CSTAR) registry XVII

BACKGROUND

The onset and clinical presentation of systemic lupus erythematosus (SLE) are sex-related. Few studies have investigated the distinctions in clinical characteristics and treatment preferences in male and female SLE patients in the initial cohort. This study aimed to improve the understanding of Chinese SLE patients by characterizing the different sexes of SLE patients in the inception cohort.

METHODS

Based on the initial patient cohort established by the Chinese SLE Treatment and Research Group, a total of 8713 patients (795 men and 7918 women) with newly diagnosed SLE were enrolled between April 2009 and March 2021. Of these, 2900 patients (347 men and 2553 women) were eligible for lupus nephritis (LN). A cross-sectional analysis of the baseline demographic characteristics, clinical manifestations, laboratory parameters, organ damage, initial treatment regimens, and renal pathology classification was performed according to sex.

RESULTS

In the SLE group, as compared to female patients, male patients had a later age of onset (male vs. female: 37.0 ± 15.8 years vs. 35.1 ± 13.7 years, P  = 0.006) and a higher SLE International Collaborative Clinic/American College of Rheumatology damage index score (male vs. female: 0.47 ± 1.13 vs. 0.34 ± 0.81, P  = 0.015), LN (male vs. female: 43.6% vs. 32.2%, P < 0.001), fever (male vs. female: 18.0% vs. 14.6%, P  = 0.010), thrombocytopenia (male vs. female: 21.4% vs. 18.5%, P  = 0.050), serositis (male vs. female: 14.7% vs. 11.7%, P  = 0.013), renal damage (male vs. female: 11.1% vs. 7.4%, P < 0.001), and treatment with cyclophosphamide (CYC) (P < 0.001). The frequency of leukopenia (male vs. female: 20.5% vs. 25.4%, P  = 0.002) and arthritis (male vs. female: 22.0% vs. 29.9%, P < 0.001) was less in male patients with SLE. In LN, no differences were observed in disease duration, SLE Disease Activity Index score, renal biopsy pathological typing, or 24-h urine protein quantification among the sexes. In comparisons with female patients with LN, male patients had later onset ages (P  = 0.026), high serum creatinine (P < 0.001), higher end-stage renal failure rates (P  = 0.002), musculoskeletal damage (P  = 0.023), cardiovascular impairment (P  = 0.009), and CYC use (P  = 0.001); while leukopenia (P  = 0.017), arthritis (P  = 0.014), and mycophenolate usage (P  = 0.013) rates were lower.

CONCLUSIONS

Male SLE patients had more severe organ damage and a higher LN incidence compared with female SLE patients; therefore, they may require more aggressive initial treatment compared to female patients.

MOONLIGHT study: the design of a comparative study of the effectiveness of belimumab in patients with a history of lupus nephritis from the post-Marketed effectiveness of belimumab cOhOrt and JapaN Lupus NatIonwide reGistry (LUNA) coHorT

Introduction

Lupus nephritis (LN) is more prevalent in patients with SLE of Asian ethnicity than in Caucasian patients. Belimumab became available in Japan in 2017 to treat patients with SLE, including those with LN. In the BLISS-LN trial (NCT01639339), belimumab showed a favourable effect on renal outcomes when combined with standard therapy (ST) starting at the induction treatment phase for active LN, but real-world effectiveness of belimumab in LN has not been extensively studied. Here we describe the protocol for the MOONLIGHT (post-Marketed effectiveness of belimumab cOhOrt and JapaN Lupus NatIonwide ReGistry (LUNA) coHorT) study, which will use data from a Japan postmarketing surveillance study and the Lupus Registry of Nationwide Institutions (LUNA) to evaluate the real-world effectiveness of belimumab plus ST versus ST alone in patients with a history of active LN who are not in the induction phase.

Methods and analysis

This multicentre, retrospective, observational study (GSK Study 214710) will enrol adults with SLE and a history of active LN, holding ≥3 years of complete follow-up data from the initiation of belimumab (no continuous treatment required). Data for patients with belimumab plus ST treatment (postmarketing registry data, belimumab cohort) will be compared with those for patients with ST only treatment (LUNA data, comparison cohort). Patients who discontinue/initiate belimumab after the start of the follow-up may be included in the comparison/belimumab cohort, respectively. The primary endpoint will be the occurrence of renal flares, for which belimumab’s effectiveness will be estimated using a marginal structural model to consider time-dependent treatment and confounding factors. Secondary endpoints will include change in corticosteroid dose, renal disease activity, extrarenal disease activity, disease severity/activity biomarkers, LN class changes, end-stage kidney disease events and hospitalisations.

Ethics and dissemination

This study will be conducted according to the Declaration of Helsinki and the local ethical guidelines. Findings will be submitted to peer-reviewed journals and presented at scientific meetings.

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.

Evaluation of a newly proposed renal risk score for Japanese patients with ANCA-associated glomerulonephritis

BACKGROUND

We determined the usefulness and prognostic ability of the renal risk score (RRS), proposed in Europe, for Japanese patients with antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (AAGN) and high myeloperoxidase (MPO)-ANCA positivity; these aspects remain to be verified.

METHODS

This retrospective study was conducted on 86 Japanese patients with new, biopsy-confirmed AAGN. We calculated the RRS and analyzed the relationship between this classification, and clinicopathological features and prognosis. We also compared the predictive values between RRS for endpoints including renal death and conventional prognostic tools for patients with AAGN.

RESULTS

There were 33, 37, and 16 patients in the low-, medium-, and high-risk groups, respectively. All patients were MPO-ANCA positive. The median follow-up period was 33 months; 16 (18.6%) patients progressed to end-stage renal disease (ESRD). In the high-risk group, 9/16 (56.3%) patients progressed to ESRD, and renal prognosis was significantly poorer than that in other groups (low-risk group, P < 0.001; medium-risk group, P = 0.004). In Cox multivariate regression analysis, RRS was an independent, poor renal prognostic factor (hazard ratio 5.22; 95% confidence interval 2.20-12.40; P < 0.001). The receiver-operating characteristic curves of the RRS for each endpoint were comparable with those of the 2010 histological classification and those of the severity classification of Japanese rapidly progressive glomerulonephritis.

CONCLUSIONS

This is the first study to report the usefulness of the RRS for predicting renal outcomes among Japanese patients with AAGN. Our predictive value of the RRS was comparable with that of conventional prognostic tools.

Clinical manifestations of focal segmental glomerulosclerosis in Japan from the Japan Renal Biopsy Registry: age stratification and comparison with minimal change disease

Focal segmental glomerulosclerosis (FSGS) is a serious condition leading to kidney failure. We aimed to investigate the clinical characteristics of FSGS and its differences compared with minimal change disease (MCD) using cross-sectional data from the Japan Renal Biopsy Registry. In Analysis 1, primary FSGS (n = 996) were stratified by age into three groups: pediatric (< 18 years), adult (18–64 years), and elderly (≥ 65 years), and clinical characteristics were compared. Clinical diagnosis of nephrotic syndrome (NS) was given to 73.5% (97/132) of the pediatric, 41.2% (256/622) of the adult, and 65.7% (159/242) of the elderly group. In Analysis 2, primary FSGS (n = 306) and MCD (n = 1303) whose clinical diagnosis was nephrotic syndrome (NS) and laboratory data were consistent with NS, were enrolled. Logistic regression analysis was conducted to elucidate the variables which can distinguish FSGS from MCD. On multivariable analysis, higher systolic blood pressure, higher serum albumin, lower eGFR, and presence of hematuria associated with FSGS. In Japanese nationwide registry, primary FSGS patients aged 18–64 years showed lower rate of NS than those in other ages. Among primary nephrotic cases, FSGS showed distinct clinical features from MCD.

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.

Electronic supplementary material

The online version of this article (10.1007/s10157-020-01932-6) contains supplementary material, which is available to authorized users.

Analysis of clinical and laboratory characteristics and pathology of lupus nephritis-based on 710 renal biopsies in China

OBJECTIVES

This study aimed to analyse the clinical and laboratory characteristics of different pathologic classifications of lupus nephritis (LN) patients in terms of age at systemic lupus erythematosus (SLE) diagnosis and nephritis onset.

METHOD

Clinical, laboratory, and pathological data of 710 LN patients diagnosed by renal biopsy at our institution between 2000 and 2018 were retrospectively analysed. Patients were divided into the different pathological classification groups; childhood-, adult- and elderly-onset SLE groups and early- and late-onset LN groups.

RESULTS

Class IV occurred most frequently and had the lowest complement C3 level. There was an obvious increase in active index in class IV and class V + IV. Patients with class VI showed some clinical characteristics similar to end-stage renal disease. Patients with proliferative nephritis were younger at SLE diagnosis and had higher blood pressure, higher frequency of proteinuria and urinary erythrocyte and lower haemoglobin and complement C3. Pathologic classification between childhood-, adult- and elderly-onset SLE patients or between early- and late-onset LN patients was not significantly different. Elderly-onset SLE patients had the highest chronic index (CI), IgA, IgG and Sjögren's syndrome A antibodies and Sjögren's syndrome B antibodies rates, whereas late-onset LN patients showed significantly higher CI, haemoglobin, complement C3 and C4 but lower uric acid, IgM and IgG.

CONCLUSIONS

LN patients present with different clinical and laboratory characteristics according to pathological classification, age at SLE diagnosis and nephritis onset. These results might be valuable for estimating the pathology and guiding treatment and prognosis. Key Points • Patients with proliferative nephritis have more severe immune disorders, worse renal function and stronger inflammatory state. • The elderly-onset SLE patients showed a poorer condition. • The late-onset LN patients might have a more stable status.

Clinical features and pathogenesis of membranoproliferative glomerulonephritis: a nationwide analysis of the Japan renal biopsy registry from 2007 to 2015

BACKGROUND

The incidence and age distribution of membranoproliferative glomerulonephritis (MPGN) vary throughout the world by race and ethnicity. We sought to evaluate the clinical features, pathogenesis, and age distribution of MPGN among a large nationwide data from the Japan Renal Biopsy Registry (J-RBR).

METHODS

A cross-sectional survey of 593 patients with MPGN (types I and III) registered in the J-RBR between 2007 and 2015 was conducted. Clinical parameters, and laboratory findings at diagnosis were compared between children (< 20 years), adults (20-64 years), and elderly patients (≥ 65 years).

RESULTS

The median age of the patients was 59.0 years and mean proteinuria was 3.7 g/day. The rate of nephrotic syndrome was significantly higher in adults (40.4%) and elderly patients (54.0%) than in children (14.9%), whereas the rate of chronic glomerulonephritis was significantly higher in children (66.2%) than in adults (34.4%) and elderly patients (31.2%). According to the CGA risk classification, high-risk (red zone) cases accounted for 3.4% of children, 52.5% of adults and 84.1% of elderly patients with MPGN. As for pathogenesis, primary MPGN was most frequent (56.0%). Lupus nephritis was the most common disease among adult patients with secondary MPGN, whereas infectious disease was more common in elderly patients. Multiple regression analysis revealed that high systolic blood pressure and high proteinuria were independent factors associated with decreased estimated glomerular filtration rate (eGFR) in adults and elderly patients with MPGN.

CONCLUSIONS

In Japan, adults and elderly patients with MPGN had a lower eGFR and severer proteinuria than children.