Clinical Characteristics and Treatment Patterns of Children and Adults With IgA Nephropathy or IgA Vasculitis: Findings From the CureGN Study

Introduction: The Cure Glomerulonephropathy Network (CureGN) is a 66-center longitudinal observational study of patients with biopsy-confirmed minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy (IgAN), including IgA vasculitis (IgAV). This study describes the clinical characteristics and treatment patterns in the IgA cohort, including comparisons between IgAN versus IgAV and adult versus pediatric patients. Methods: Patients with a diagnostic kidney biopsy within 5 years of screening were eligible to join CureGN. This is a descriptive analysis of clinical and treatment data collected at the time of enrollment. Results: A total of 667 patients (506 IgAN, 161 IgAV) constitute the IgAN/IgAV cohort (382 adults, 285 children). At biopsy, those with IgAV were younger (13.0 years vs. 29.6 years, P < 0.001), more frequently white (89.7% vs. 78.9%, P = 0.003), had a higher estimated glomerular filtration rate (103.5 vs. 70.6 ml/min per 1.73 m2, P < 0.001), and lower serum albumin (3.4 vs. 3.8 g/dl, P < 0.001) than those with IgAN. Adult and pediatric individuals with IgAV were more likely than those with IgAN to have been treated with immunosuppressive therapy at or prior to enrollment (79.5% vs. 54.0%, P < 0.001). Conclusion: This report highlights clinical differences between IgAV and IgAN and between children and adults with these diagnoses. We identified differences in treatment with immunosuppressive therapies by disease type. This description of baseline characteristics will serve as a foundation for future CureGN studies

Infection-related acute care events among patients with glomerular disease

Background and objectives Infections contribute to patient morbidity and mortality in glomerular disease. We sought to describe the incidence of, and identify risk factors for, infection-related acute care events among Cure Glomerulonephropathy Network (CureGN) study participants. Design, setting, participants, & measurements CureGN is a prospective, multicenter, cohort study of children and adults with biopsy sample–proven minimal change disease, FSGS, membranous nephropathy, or IgA nephropathy/vasculitis. Risk factors for time to first infection-related acute care events (hospitalization or emergency department visit) were identified using multivariable Cox proportional hazards regression. Results Of 1741 participants (43%female, 41%,18 years, 68%White), 163 (9%) experienced infection-related acute care events over a median follow-up of 17months (interquartile range, 9–26months).Unadjusted incidence rates of infection-related acute care events were 13.2 and 6.2 events per 100 person-years among pediatric and adult participants, respectively. Among participants with versus without corticosteroid exposure at enrollment, unadjusted incidence rates were 50.6 and 28.6 per 100 person-years, respectively, during the first year of follow-up (adjusted hazard ratio for time to first infection, 1.31; 95% CI, 0.89 to 1.93), and 4.1 and 1.1 per 100 person-years, respectively, after 1 year of follow-up (hazard ratio, 2.99; 95%CI, 1.54 to 5.79). Hypoalbuminemia combined with nephrotic-range proteinuria (serum albumin #2.5 g/dl and urinary protein-creatinine ratio.3.5 mg/mg), compared with serumalbumin.2.5 g/dl and urinary protein-creatinine ratio#3.5 mg/mg, was associated with higher risk of time to first infection (adjusted hazard ratio, 2.49; 95% CI, 1.51 to 4.12). Conclusions Among CureGN participants, infection-related acute care events were common and associated with younger age, corticosteroid exposure, and hypoalbuminemia with proteinuria

Persistent Disease Activity in Patients With Long-Standing Glomerular Disease

Introduction: Glomerular diseases are characterized by variable disease activity over many years. We aimed to analyze the relationship between clinical disease activity and duration of glomerular disease. Methods: Disease activity in adults with chronic minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and IgA nephropathy (IgAN; first diagnostic biopsy >5 years before enrollment; Of Longstanding Disease [OLD] cohort, n = 256) followed at Columbia University Medical Center (CUMC), was compared with disease activity of an internal and external cohort of patients with first diagnostic biopsy <5 years before enrollment drawn from the Cure Glomerulonephropathy Network (CureGN cohort, n = 1182; CUMC-CureGN cohort, n = 362). Disease activity was defined by (i) Kidney Disease: Improving Global Outcomes–recommended threshold criteria for initiation of immunosuppression in primary glomerulonephropathy (GN) and (ii) CureGN's Disease Activity Working Group definitions for activity. Results: No significant differences were detected among the 3 cohorts in terms of age, sex, serum creatinine, and urinary protein-to-creatinine ratio. For each GN subtype, disease activity in the OLD cohort was comparable with disease activity in the entire CureGN and the CUMC-CureGN cohort. When limiting our comparisons to disease activity in incident CUMC-CureGN patients (first diagnostic biopsy within 6 months of enrollment), OLD patients demonstrated similar activity rates as incident patients. Conclusion: Disease activity did not differ among patients with shorter versus longer duration of disease. Such survivor patients, with long-term but persistent disease, are potentially highly informative for understanding the clinical course and pathogenesis of GN and may help identify factors mediating more chronic subtypes of disease

Association of COVID-19 Versus COVID-19 Vaccination With Kidney Function and Disease Activity in Primary Glomerular Disease: A Report of the Cure Glomerulonephropathy Study

Rationale &amp; Objective: Patients with glomerular disease (GN) may be at increased risk of severe COVID-19, yet concerns over vaccines causing disease relapse may lead to vaccine hesitancy. We examined the associations of COVID-19 with longitudinal kidney function and proteinuria and compared these to similar associations with COVID-19 vaccination. Study Design: Observational cohort study from July 1, 2021 to Jan. 1, 2023. Setting &amp; Participants: A prospective observational study network of 71 centers from North America and Europe (CureGN) with children and adults with primary minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy. Exposures: COVID-19 and COVID-19 vaccination. Outcomes: Repeated measure of estimated glomerular filtration rate (eGFR); recurrent time-to-event outcome of GN disease worsening as defined by doubling of UPCR to at least 1.5g/g or increase in dipstick urine protein by two ordinal levels to 3+ (300mg/dL) or above. Analytical Approach: Interrupted time series analysis for eGFR. Prognostic matched sequential stratification recurrent event analysis for GN disease worsening. Results: Among 2,055 participants, 722 (35%) reported COVID-19; of these, 92 (13%) were hospitalized and 3 died (&lt;1%). eGFR slope pre-COVID-19 was -1.40ml/min/1.73m2 (SD 0.29), and -4.26ml/min/1.73m2 (SD 3.02) within 6 months post-COVID-19, which were not significantly different (p=0.34). COVID-19 was associated with increased risk of worsening GN disease activity (HR 1.35, 95% CI 1.01-1.80). Vaccination was not associated with change in eGFR (-1.34ml/min/1.73m2, SD 0.15 vs -2.16ml/min/1.73m2, SD 1.74; p=0.6) or subsequent GN disease worsening (HR 1.02, 95% CI 0.79–1.33) in this cohort. Limitations: Infrequent or short follow-up. Conclusions: Among patients with primary GN, COVID-19 was severe for 1 in 8 cases and was associated with subsequent worsening of GN disease activity, as defined by proteinuria. In contrast, vaccination against COVID-19 was not associated with change in disease activity or kidney function decline. These results support COVID-19 vaccination for patients with GN

Association of COVID-19 Versus COVID-19 Vaccination With Kidney Function and Disease Activity in Primary Glomerular Disease: A Report of the Cure Glomerulonephropathy Study.

RATIONALE & OBJECTIVE: Patients with glomerular disease (GN) may be at increased risk of severe COVID-19, yet concerns over vaccines causing disease relapse may lead to vaccine hesitancy. We examined the associations of COVID-19 with longitudinal kidney function and proteinuria and compared these with similar associations with COVID-19 vaccination. STUDY DESIGN: Observational cohort study from July 1, 2021, to January 1, 2023. SETTING & PARTICIPANTS: A prospective observational study network of 71 centers from North America and Europe (CureGN) with children and adults with primary minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy. EXPOSURE: COVID-19 and COVID-19 vaccination. OUTCOME: Repeated measure of estimated glomerular filtration rate (eGFR); recurrent time-to-event outcome of GN disease worsening as defined by doubling of the urinary protein-creatinine ratio (UPCR) to at least 1.5g/g or increase in dipstick urine protein by 2 ordinal levels to 3+(300mg/dL) or above. ANALYTICAL APPROACH: Interrupted time series analysis for eGFR. Prognostic matched sequential stratification recurrent event analysis for GN disease worsening. RESULTS: Among 2,055 participants, 722 (35%) reported COVID-19 infection; of these, 92 (13%) were hospitalized, and 3 died ( LIMITATIONS: Infrequent or short follow-up. CONCLUSIONS: Among patients with primary GN, COVID-19 infection was severe for 1 in 8 cases and was associated with subsequent worsening of GN disease activity, as defined by proteinuria. By contrast, vaccination against COVID-19 was not associated with change in disease activity or kidney function decline. These results support COVID-19 vaccination for patients with GN. PLAIN-LANGUAGE SUMMARY: In this cohort study of 2,055 patients with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy, COVID-19 resulted in hospitalization or death for 1 in 8 cases and was associated with a 35% increase in risk for worsening proteinuria. By contrast, vaccination did not appear to adversely affect kidney function or proteinuria. Our data support vaccination for COVID-19 in patients with glomerular disease

Association of COVID-19 Versus COVID-19 Vaccination With Kidney Function and Disease Activity in Primary Glomerular Disease: A Report of the Cure Glomerulonephropathy Study.

RATIONALE & OBJECTIVE: Patients with glomerular disease (GN) may be at increased risk of severe COVID-19, yet concerns over vaccines causing disease relapse may lead to vaccine hesitancy. We examined the associations of COVID-19 with longitudinal kidney function and proteinuria and compared these with similar associations with COVID-19 vaccination. STUDY DESIGN: Observational cohort study from July 1, 2021, to January 1, 2023. SETTING & PARTICIPANTS: A prospective observational study network of 71 centers from North America and Europe (CureGN) with children and adults with primary minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy. EXPOSURE: COVID-19 and COVID-19 vaccination. OUTCOME: Repeated measure of estimated glomerular filtration rate (eGFR); recurrent time-to-event outcome of GN disease worsening as defined by doubling of the urinary protein-creatinine ratio (UPCR) to at least 1.5g/g or increase in dipstick urine protein by 2 ordinal levels to 3+(300mg/dL) or above. ANALYTICAL APPROACH: Interrupted time series analysis for eGFR. Prognostic matched sequential stratification recurrent event analysis for GN disease worsening. RESULTS: Among 2,055 participants, 722 (35%) reported COVID-19 infection; of these, 92 (13%) were hospitalized, and 3 died ( LIMITATIONS: Infrequent or short follow-up. CONCLUSIONS: Among patients with primary GN, COVID-19 infection was severe for 1 in 8 cases and was associated with subsequent worsening of GN disease activity, as defined by proteinuria. By contrast, vaccination against COVID-19 was not associated with change in disease activity or kidney function decline. These results support COVID-19 vaccination for patients with GN. PLAIN-LANGUAGE SUMMARY: In this cohort study of 2,055 patients with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, or IgA nephropathy, COVID-19 resulted in hospitalization or death for 1 in 8 cases and was associated with a 35% increase in risk for worsening proteinuria. By contrast, vaccination did not appear to adversely affect kidney function or proteinuria. Our data support vaccination for COVID-19 in patients with glomerular disease

Age of Onset and Disease Course in Biopsy-Proven Minimal Change Disease: An Analysis From the Cure Glomerulonephropathy Network.

RATIONALE & OBJECTIVE: Adolescent- and adult-onset minimal change disease (MCD) may have a clinical course distinct from childhood-onset disease. We characterized the course of children and adults with MCD in the Cure Glomerulonephropathy Network (CureGN) and assessed predictors of rituximab response. STUDY DESIGN: Prospective, multicenter, observational study. STUDY PARTICIPANTS: CureGN participants with proven MCD on biopsy. EXPOSURE: Age at disease onset, initiation of renin-angiotensin-aldosterone system (RAAS) blockade, and immunosuppression including rituximab during the study period. OUTCOME: Relapse and remission, change in estimated glomerular filtration rate (eGFR), and kidney failure. ANALYTICAL APPROACH: Remission and relapse probabilities were estimated using Kaplan-Meier curves and gap time recurrent event models. Linear regression models were used for the outcome of change in eGFR. Cox proportional hazards models were used to estimate the association between rituximab administration and remission. RESULTS: The study included 304 childhood- (≤12 years old), 49 adolescent- (13-17 years old), and 201 adult- (≥18 years) onset participants with 2.7-3.2 years of follow-up after enrollment. Children had a longer time to biopsy (238 vs 23 and 36 days in adolescent- and adult-onset participants, respectively; P LIMITATIONS: CureGN was limited to biopsy-proven disease. Comparisons of childhood to nonchildhood cases of MCD may be subject to selection bias, given that childhood cases who undergo a biopsy may be limited to patients who are least responsive to initial therapy. CONCLUSIONS: Among patients with MCD who underwent kidney biopsy, there were differences in the course (relapse and remission) of childhood-onset compared with adolescent- and adult-onset disease, as well as rituximab response. PLAIN-LANGUAGE SUMMARY: Minimal change disease is a biopsy diagnosis for nephrotic syndrome. It is diagnosed in childhood, adolescence, or adulthood. Patients and clinicians often have questions about what to expect in the disease course and how to plan therapies. We analyzed a group of patients followed longitudinally as part of the Cure Glomerulonephropathy Network (CureGN) and describe the differences in disease (relapse and remission) based on the age of onset. We also analyzed rituximab response. We found that those with childhood-onset disease had a higher rate of relapse but also have a higher probability of reaching remission when compared with adolescent- or adult-onset disease. Children and all steroid-responsive patients are more likely to achieve remission after rituximab

Longitudinal Changes in Health-Related Quality of Life in Primary Glomerular Disease: Results From the CureGN Study.

Introduction: Prior cross-sectional studies suggest that health-related quality of life (HRQOL) worsens with more severe glomerular disease. This longitudinal analysis was conducted to assess changes in HRQOL with changing disease status. Methods: Cure Glomerulonephropathy (CureGN) is a cohort of patients with minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, IgA vasculitis, or IgA nephropathy. HRQOL was assessed at enrollment and follow-up visits 1 to 3 times annually for up to 5 years with the Patient-Reported Outcomes Measurement Information System (PROMIS). Global health, anxiety, and fatigue domains were measured in all; mobility was measured in children; and sleep-related impairment was measured in adults. Linear mixed effects models were used to evaluate HRQOL responsiveness to changes in disease status. Results: A total of 469 children and 1146 adults with PROMIS scores were included in the analysis. HRQOL improved over time in nearly all domains, though group-level changes were modest. Edema was most consistently associated with worse HRQOL across domains among children and adults. A greater number of symptoms also predicted worse HRQOL in all domains. Sex, age, obesity, and serum albumin were associated with some HRQOL domains. The estimated glomerular filtration rate (eGFR) was only associated with fatigue and adult physical health; proteinuria was not associated with any HRQOL domain in adjusted models. Conclusion: HRQOL measures were responsive to changes in disease activity, as indicated by edema. HRQOL over time was not predicted by laboratory-based markers of disease. Patient-reported edema and number of symptoms were the strongest predictors of HRQOL, highlighting the importance of the patient experience in glomerular disease. HRQOL outcomes inform understanding of the patient experience for children and adults with glomerular diseases

Supplementary Material for: CureGN Pathology Classification and Core Scoring Criteria, Reproducibility, and Clinicopathologic Correlations

Introduction: CureGN is an observational cohort study of patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), or IgA nephropathy (IgAN). We developed a conventional, consensus-based scoring system to document pathologic features for application across multiple pathologists and herein describe the protocol, reproducibility and correlation with clinical parameters at biopsy. Methods: Definitions were established for glomerular, tubular, interstitial and vascular lesions evaluated semi-quantitatively using digitized light microscopy slides and electron micrographs, and reported immunofluorescence. Cases with curated pathology materials as of April 2019 were scored by a randomly assigned pathologist, with at least 10% of cases scored by a second pathologist. Scoring reproducibility was assessed using Gwet’s AC1 statistic and correlations with clinical variables were performed. Results: Of 800 scored biopsies (143 MCD, 185 FSGS, 206 MN, 266 IgA), 94 were scored twice (11.8%). Of 60 pathology features, 46 (76.7%) demonstrated excellent (AC1>0.8), and 12 (20.0%) had good (AC1 0.6-0.8) reproducibility. Mesangial hypercellularity scored as absent, focal or diffuse had moderate reproducibility (AC1=0.58), but good reproducibility (ACI=0.71) when scored as absent or focal vs diffuse. The percent glomeruli scored as no lesions had fair reproducibility (AC1=0.34). Strongest correlations between pathologic features and clinical characteristics at biopsy included interstitial inflammation, interstitial fibrosis and tubular atrophy with eGFR, foot process effacement with UPCR, and active crescents with hematuria. Conclusions: Most scored pathology features showed excellent reproducibility, demonstrating consistency for these features across multiple pathologists. Correlations between certain pathologic features and expected clinical characteristics show the value of this approach for future studies on clinicopathologic correlations and biomarker discovery

Supplementary Material for: CureGN Pathology Classification and Core Scoring Criteria, Reproducibility, and Clinicopathologic Correlations

Introduction: CureGN is an observational cohort study of patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), or IgA nephropathy (IgAN). We developed a conventional, consensus-based scoring system to document pathologic features for application across multiple pathologists and herein describe the protocol, reproducibility and correlation with clinical parameters at biopsy. Methods: Definitions were established for glomerular, tubular, interstitial and vascular lesions evaluated semi-quantitatively using digitized light microscopy slides and electron micrographs, and reported immunofluorescence. Cases with curated pathology materials as of April 2019 were scored by a randomly assigned pathologist, with at least 10% of cases scored by a second pathologist. Scoring reproducibility was assessed using Gwet’s AC1 statistic and correlations with clinical variables were performed. Results: Of 800 scored biopsies (143 MCD, 185 FSGS, 206 MN, 266 IgA), 94 were scored twice (11.8%). Of 60 pathology features, 46 (76.7%) demonstrated excellent (AC1>0.8), and 12 (20.0%) had good (AC1 0.6-0.8) reproducibility. Mesangial hypercellularity scored as absent, focal or diffuse had moderate reproducibility (AC1=0.58), but good reproducibility (ACI=0.71) when scored as absent or focal vs diffuse. The percent glomeruli scored as no lesions had fair reproducibility (AC1=0.34). Strongest correlations between pathologic features and clinical characteristics at biopsy included interstitial inflammation, interstitial fibrosis and tubular atrophy with eGFR, foot process effacement with UPCR, and active crescents with hematuria. Conclusions: Most scored pathology features showed excellent reproducibility, demonstrating consistency for these features across multiple pathologists. Correlations between certain pathologic features and expected clinical characteristics show the value of this approach for future studies on clinicopathologic correlations and biomarker discovery