The predictive value of crescents in the disease progression of lupus nephritis based on the 2018 International Society of Nephrology/Renal Pathology Society Revision System: a large cohort study from China

A nomogram predicting the histologic activity of lupus nephritis from clinical parameters

BACKGROUND

The 2021 clinical guidelines of the Kidney Disease: Improving Global Outcomes emphasize the importance of the histological activity index (AI) in the management of lupus nephritis (LN). Patients with LN and a high AI have poor renal outcomes and high rates of nephritic relapse. In this study we constructed prediction models for the AI in LN.

METHODS

The study population comprised 337 patients diagnosed with LN using kidney biopsy. The participants were randomly divided into training and testing cohorts. They were further divided into high-activity (AI >2) and low-activity (AI ≤2) groups. This study developed two clinical prediction models using logistic regression and least absolute shrinkage and selection operator (LASSO) analyses with laboratory test results collected at the time of kidney biopsy. The performance of models was assessed using 5-fold cross-validation and validated in the testing cohort. A nomogram for individual assessment was constructed based on the preferable model.

RESULTS

Multivariate analysis showed that higher mean arterial pressure, lower estimated glomerular filtration rate, lower complement 3 level, higher urinary erythrocytes count and anti-double-stranded DNA seropositivity were independent risk factors for high histologic activity in LN. Both models performed well in the testing cohort regarding the discriminatory ability to identify patients with an AI >2. The average area under the curve of 5-fold cross-validation was 0.855 in the logistic model and 0.896 in the LASSO model. A webtool based on the LASSO model was created for clinicians to enter baseline clinical parameters to produce a probability score of an AI >2.

CONCLUSIONS

The established nomogram provides a quantitative auxiliary tool for distinguishing LN patients with a high AI and helps physicians make clinical decisions in their comprehensive assessment.

Urine proteomic signatures of histological class, activity, chronicity, and treatment response in lupus nephritis

Lupus nephritis (LN) is a pathologically heterogenous autoimmune disease linked to end-stage kidney disease and mortality. Better therapeutic strategies are needed as only 30%-40% of patients completely respond to treatment. Noninvasive biomarkers of intrarenal inflammation may guide more precise approaches. Because urine collects the byproducts of kidney inflammation, we studied the urine proteomic profiles of 225 patients with LN (573 samples) in the longitudinal Accelerating Medicines Partnership in RA/SLE cohort. Urinary biomarkers of monocyte/neutrophil degranulation (i.e., PR3, S100A8, azurocidin, catalase, cathepsins, MMP8), macrophage activation (i.e., CD163, CD206, galectin-1), wound healing/matrix degradation (i.e., nidogen-1, decorin), and IL-16 characterized the aggressive proliferative LN classes and significantly correlated with histological activity. A decline of these biomarkers after 3 months of treatment predicted the 1-year response more robustly than proteinuria, the standard of care (AUC: CD206 0.91, EGFR 0.9, CD163 0.89, proteinuria 0.8). Candidate biomarkers were validated and provide potentially treatable targets. We propose these biomarkers of intrarenal immunological activity as noninvasive tools to diagnose LN and guide treatment and as surrogate endpoints for clinical trials. These findings provide insights into the processes involved in LN activity. This data set is a public resource to generate and test hypotheses and validate biomarkers.

Renal Histopathology Associated With Kidney Failure and Mortality in Patients With Lupus Nephritis: A Long-Term Real-World Data Study

OBJECTIVE

Lupus nephritis (LN), a common manifestation of systemic lupus erythematosus, is associated with a higher risk of kidney failure and death. The renal pathology of LN helps elucidate the severity of inflammation and the extent of irreversible damage. We aimed to identify histologic variables that correlate with risks of kidney failure and mortality.

METHODS

Between 2006 and 2019, a total of 526 patients with LN were enrolled. Renal pathology was classified according to the International Society of Nephrology/Renal Pathology Society classification. Components of activity and chronicity indices were analyzed to determine which variables correlated with an increased risk of kidney failure and death, with the adjustment of potential confounders.

RESULTS

During the follow-up period (median 7.5, IQR 3.5-10.7 years), 58 patients progressed to kidney failure and 64 died. In the multivariate Cox regression analysis, tubular atrophy (hazard ratio [HR] 2.28, 95% CI 1.66-3.14) and tubulointerstitial inflammation (HR 3.13, 95% CI 1.34-7.33) predicted kidney failure. The renal outcome was even worse if tubular atrophy and tubulointerstitial inflammation coexisted (10-year kidney survival rate: 63.22%). The presence of cellular crescents was associated with an increased risk of death in male patients with LN (HR 1.91, 95% CI 1.02-3.57), whereas the presence of fibrous crescents predicted death in female patients with LN (HR 5.70, 95% CI 1.61-20.25).

CONCLUSION

Histologic variables of renal biopsy in LN could be regarded as prognostic indicators for kidney failure and mortality.

Association between glomerular mTORC1 activation and crescents formation in lupus nephritis patients

OBJECTIVE

This study aims to explore the association between glomerular mammalian target of rapamycin complex 1 (mTORC1) pathway activation and crescents' degree in lupus nephritis (LN) patients.

METHODS

A total of 159 biopsy-proven LN patients were enrolled in this retrospective study. The clinical and pathological data of them were collected at the time of renal biopsy. mTORC1 pathway activation was measured by immunohistochemistry, expressed by the mean optical density (MOD) of p-RPS6 (ser235/236), and multiplexed immunofluorescence. The association of mTORC1 pathway activation with clinico-pathological features especially renal crescentic lesions, and the composite outcomes in LN patients was further analyzed.

RESULTS

mTORC1 pathway activation could be detected in the crescentic lesions and was positively correlated with the percentage of crescents (r = 0.479, P < 0.001) in LN patients. Subgroup analysis showed mTORC1 pathway was more activated in patients with cellular or fibrocellular crescentic lesions (P < 0.001), but not fibrous crescentic lesions (P = 0.270). The optimal cutoff value of the MOD of p-RPS6 (ser235/236) was 0.0111299 for predicting the presence of cellular-fibrocellular crescents in >7.39% of the glomeruli by the receiver operating characteristic curve. Cox regression survival analysis showed that mTORC1 pathway activation was an independent risk factor for the worse outcome (defined by composite endpoints of death, end-stage renal disease and a decrease of >30% in eGFR from baseline).

CONCLUSION

Activation of mTORC1 pathway was closely associated with the cellular-fibrocellular crescentic lesions and could be a prognostic marker in LN patients.

Outcomes and risk factors in patients with crescentic glomerulonephritis: a multicenter cohort study

BACKGROUND

Patients with crescentic glomerulonephritis have a poor prognosis despite immunosuppressive therapy. This study investigated the clinicopathologic features, outcomes, and risk factors in Chinese patients with crescentic glomerulonephritis.

METHODS

The multicenter cohort study included consecutive individuals with crescentic glomerulonephritis and a minimum follow-up of 1 year after biopsy, observed from January 2013 to December 2020. Primary outcome was the occurrence of death or end stage kidney disease (ESKD) for surviving patients. Multivariable adjusted Cox proportional hazards model was applied.

RESULTS

Of 109 patients enrolled, 73 (67%) suffered primary outcomes, including 39 deaths, and 34 ESKDs among the 70 surviving patients, with a mean follow-up of 26 months. All 26 patients with over 90% glomeruli with crescents reached a primary outcome. Patients with type III crescentic glomerulonephritis had the worst prognosis for primary outcomes (HR, 95% CI for type I vs. type III: 0.29, 0.14-0.58; type II vs. type III: 0.44, 0.22-0.91) and a significantly faster rate of eGFR decline after adjusting for baseline variables. In patients with 75%-100% glomeruli with crescents, the risk of a primary outcome increased nearly fourfold (HR 3.96; 95% CI 2.17-7.23) compared with patients with 50-75% glomeruli with crescents after adjusting for baseline variables. Type of crescentic glomerulonephritis and percentage of cellular and total glomeruli with crescents were independent risk factors for early primary outcomes (within 6 months).

CONCLUSIONS

This study provides new insights into crescentic glomerulonephritis, including a description of the worst outcomes occurring in patients with type III crescentic glomerulonephritis, and suggests that the quantification of the percentage of crescents may be of use for guiding therapeutic decisions, due to their role in identifying the risk of primary outcomes.

Glomerulonephritis associated with systemic sclerosis: a case report

BACKGROUND

Systemic sclerosis is a multiorgan autoimmune disease that can overlap with other rheumatologic disorders; however, co-occurrence with antineutrophil cytoplasmic antibody-associated vasculitis is rare.

CASE PRESENTATION

A 39-year-old Persian female patient with systemic sclerosis according to American College of Rheumatology/European League Against Rheumatism 2013 criteria with a disease duration of 6 years was admitted to the hospital due to a rise in creatinine level in July 2021. She had complaints of nasal speech and feeling of nasal perforation. The first symptoms of antineutrophil cytoplasmic antibody-associated vasculitis had started 5 years earlier with palpable purpura in the lower limbs, hemoptysis, and positive perinuclear (p)-antibody-associated vasculitis level (> 300 AU/mL). Still, the diagnosis was not achieved due to the patient's reluctance to undergo a biopsy. She was treated with azathioprine (150 mg/day) and prednisolone (10 mg/day) during the 5-year follow-up. Her renal biopsy results showed cortical renal tissue with a cellular crescent in more than 50% of the specimen, rupture of the Bowman capsule and the glomerular basement membrane, peri-glomerular inflammation, and mild tubular atrophy in microscopic examinations. The immunofluorescence study resulted in a granular pattern of immune deposits along the glomerular basement membrane, mesangial tissue, and tubular basement membranes.

CONCLUSION

We reported a rare case of comorbid systemic sclerosis and antineutrophil cytoplasmic antibody-associated vasculitis with nasal perforation. Her renal biopsy showed immune deposits along the glomerular basement membrane, mesangial tissue, and tubular basement membranes. Overlapping with other collagen vascular diseases can occur in rheumatology patients with uncommon manifestations. In systemic sclerosis, renal involvement in the form of glomerulonephritis is infrequent, and comorbid systemic lupus erythematosus or antineutrophil cytoplasmic antibody-associated vasculitis should be considered.

Role of crescents for lupus nephritis in clinical, pathological and prognosis: a single-center retrospective cohort study

BACKGROUND

Referring to the International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2018 pathological classification, we aim to reveal the significance of cellular/fibrocellular crescents in lupus nephritis (LN) patients.

METHODS

Patients with LN proven by renal biopsy at the First Affiliated Hospital of Wenzhou Medical University from December 2001 to November 2017 were identified, and eligible cases were divided into two groups according to the presence or absence of cellular/fibrocellular crescents in renal biopsy tissues.

RESULTS

A total of 401 LN patients were identified from our follow-up database, and 296 eligible LN patients were enrolled in the study. Of these patients, 146 patients in the group without cellular/fibrocellular crescents (non-crescent group) and 150 patients in the group with cellular/fibrocellular crescents (Crescent group). The median follow-up time of patients was 47 months, and a total of 54 patients progressed to the composite endpoint. Crescent group had higher serum creatinine, lower serum albumin, higher systemic lupus erythematosus (SLE) disease activity index, and higher activity index of renal tissue. The interaction between cellular/fibrocellular crescents and proteinuria at baseline was associated with the prognostic risk of LN (P = 0.006). In the group with proteinuria < 3.5 g/24 h, the prognosis of crescent group was significantly worse than of non-crescent group (P < 0.001), while in the group with proteinuria ≥ 3.5 g/24 h, there was no significant relationship between crescents and prognosis (p = 0.452). By multivariable Cox hazard analysis, positive anti-dsDNA, chronic index of renal biopsy tissue, cellular/fibrocellular crescents and its interaction with 24 h proteinuria were independent risk factors for poor prognosis of LN.

CONCLUSIONS

LN patients with cellular/fibrocellular crescents had more severe and active disease features, and cellular/fibrocellular crescents is a risk factor for poor prognosis of LN. There was an interaction between cellular/fibrocellular crescents and proteinuria in predicting poor prognosis, and among patients with low levels of proteinuria at the time of renal biopsy, those with crescents had a worse long-term prognosis than those without crescents.

Utility of the 2018 revised ISN/RPS thresholds for glomerular crescents in childhood-onset lupus nephritis: a Pediatric Nephrology Research Consortium study

BACKGROUND

The revised 2018 ISN/RPS Classification System for lupus nephritis (LN) includes calculations for both activity index (A.I.) and chronicity index (C.I.). Unchanged were the thresholds of < 25%, 25-50%, and > 50% crescents to distinguish between mild, moderate, and severe activity/chronicity. We aimed to evaluate these thresholds for percent crescents in childhood-onset LN.

METHODS

Eighty-six subjects < 21 years of age were enrolled from the Pediatric Glomerulonephritis with Crescents Registry, a retrospective multi-center cohort sponsored by the Pediatric Nephrology Research Consortium. Thresholds of 10%, 25%, and 50% for both cellular/fibrocellular and fibrous crescents were interrogated for primary outcomes of kidney failure, eGFR, and eGFR slope.

RESULTS

Median age at time of initial biopsy was 14 years (range 1-21). Median follow-up time was 3 years (range 1-11). Cumulative incidence of kidney failure was 6% at 1 year and 10% at latest follow-up. Median eGFR slope was - 18 mL/1.73 m²/min (IQR - 51 to + 8) at 1 year and - 3 mL/min/1.73 m²/year (IQR - 19 to + 6) at latest follow-up. We found no difference in kidney failure at the proposed < 25% and 25-50% cellular crescents thresholds, and thus added a new provisional threshold of 10% that better predicted outcomes in children. Moreover, use of 10% and 25% thresholds for fibrous crescents showed a fourfold and sevenfold increase in risk of kidney failure.

CONCLUSIONS

In children with crescentic LN, use of 10% and 25% thresholds for cellular crescents better reflects disease activity, while these thresholds for fibrous crescents better discriminates kidney disease outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Urinary galectin-3 binding protein (G3BP) as a biomarker for disease activity and renal pathology characteristics in lupus nephritis

Objective

There is an urgent need to identify novel biomarkers of LN to reflect renal histological changes. This study aims to investigate urinary G3BP levels in LN patients and their association with renal disease activity both clinically and pathologically.

Methods

This is a cross-sectional study. A total of 119 lupus nephritis patients were recruited. Thirty patients with chronic kidney diseases (CKD) and 27 healthy volunteers were also recruited as controls. Urinary G3BP was tested by ELISA. Renal histopathology was reviewed by an experienced renal pathologist. Other clinical variables were collected through chart review.

Results

The levels of uG3BP were significantly increased in active LN patients compared to those in inactive LN (p<0.001), CKD patients (p=0.01), and healthy controls (p<0.001). ROC analysis indicated a good discrimination ability of uG3BP to differentiate active LN from CKD patients (AUC=0.7), inactive LN (AUC=0.76), or healthy controls (AUC=0.87). uG3BP was positively correlated with SLEDAI (ρ=0.352, p<0.001), rSLEDAI (ρ=0.302, p<0.001), and SLICC RAS (ρ=0.465, p<0.001), indicating a role as a biomarker of disease activity. It also correlated with clinical parameters, including 24-h urine protein, ESR, and serum C3 levels. In patients with 24-h urine protein > 3.0 g/24h, uG3BP levels were higher in proliferative LN than in membranous LN (p=0.04). They could discriminate the two pathogenic types of LN (AUC=0.72), and they also positively correlated with AI (ρ=0.389, p=0.008) and scores of hyaline deposits (ρ=0.418, p=0.006). While in patients with 24-h urine protein ≤ 3.0 g/24h, uG3BP levels were not significantly different between proliferative and membranous LN, and there was no apparent relationship between uG3BP levels with AI or with scores of hyaline deposits, but they correlated positively with scores of cellular/fibrocellular crescents (ρ=0.328, p=0.04).

Conclusion

uG3BP is a non-invasive biomarker for clinically and histologically reflecting disease activity. It is associated with active histological changes and can be used as a surrogate biomarker when the renal biopsy is impractical.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02763-4.