The Risk of Cardiovascular Events in Individuals With Primary Glomerular Diseases

Evaluating the risk of cardiovascular events associated with different immunosuppression treatments for glomerular diseases

Patients with glomerular disease are at high risk of cardiovascular disease but the contribution of immunosuppression to this risk is unclear. In this retrospective cohort study of 1912 patients (comprised of 759 with IgA nephropathy, 540 with focal segmental glomerulosclerosis, 387 with membranous nephropathy and 226 with minimal change disease) from British Columbia, Canada, we evaluated the association between exposure to specific immunosuppressive medications and a composite outcome including coronary artery, cerebrovascular and peripheral arterial events. Survival models were adjusted for baseline cardiovascular risk factors, type of glomerular disease, estimated glomerular filtration rate (eGFR) and proteinuria over time. During a median follow-up of 6.8 years, 212 patients (11.1%) experienced the primary outcome. Corticosteroid exposure was not significantly associated with the primary outcome after adjusting for cardiovascular risk factors. In fully adjusted models, cumulative calcineurin inhibitor exposure at modest (150-300 defined daily doses [DDD]) and higher (300 or more DDD) doses were associated with a 2-fold higher risk of cardiovascular events (hazard ratio 2.98, 95% confidence interval 1.27-6.95) and (2.78, 1.32-5.84), respectively. A peak daily dose of antimetabolite (azathioprine, mycophenolate mofetil and mycophenolate sodium) of 0.5 or more DDD was associated with higher risk of cardiovascular events after adjustment for baseline risk factors and type of glomerular disease, but not after adjusting for time-varying eGFR and proteinuria (1.70, 0.91-3.20). Each 10 grams of cumulative cyclophosphamide exposure was associated with a 1.5-fold higher risk of cardiovascular events in a fully adjusted model (1.46, 1.22-1.75) Thus, our findings suggest that immunosuppressive therapies used in the treatment of glomerular disease may have different cardiovascular risk profiles, which should be considered when deciding on immunosuppression for individual patients and as a safety endpoint in future clinical trials.

Association of Obesity With Kidney and Cardiac Outcomes Among Patients With Glomerular Disease: Findings From the Cure Glomerulonephropathy Network

RATIONALE & OBJECTIVE

The influence of obesity on cardiorenal outcomes in individuals with glomerular disease is incompletely known. This study examined the association between obesity and kidney and cardiovascular outcomes in children and adults with glomerular kidney disease.

STUDY DESIGN

Prospective, multicenter, observational study.

SETTING & PARTICIPANTS

Participants in the Cure Glomerulonephropathy Network (CureGN) who were≥5 years of age at enrollment.

EXPOSURE

Adult body mass index (BMI) groups: 20-24 (healthy) versus 25-34 (overweight/class 1 obesity) versus≥35 (class 2-3 obesity); and pediatric BMI percentiles: 5th-84th (healthy) versus 85th-94th (overweight) versus≥95th (obese).

OUTCOME

A composite kidney outcome (40% estimated glomerular filtration rate [eGFR] decline or kidney failure) and a composite cardiovascular outcome (myocardial infarction, stroke, heart failure, or death).

ANALYTICAL APPROACH

Time to composite primary outcomes by BMI strata were estimated using Kaplan-Meier analysis. The adjusted associations between BMI and outcomes were estimated using Cox proportional hazards analysis.

RESULTS

The study included 2,301 participants (1,548 adults and 753 children). The incidence of the primary kidney end point was 90.8 per 1,000 person-years in adults with class 2-3 obesity, compared with 58.0 in normal weight comparators. In the univariable analysis, class 2-3 obesity was associated with the primary kidney outcome only in adults (HR, 1.6 [95% CI, 1.1-2.2], P=0.006) compared with the healthy weight groups. In the multivariable adjusted analysis, class 2-3 obesity did not remain significant among adults when controlling for baseline eGFR and proteinuria. Adults with class 2-3 obesity had an incidence of 19.7 cardiovascular events per 1,000 person-years and greater cardiovascular risk (HR, 3.9 [95% CI, 1.4-10.7], P=0.009) in the fully adjusted model.

LIMITATIONS

BMI is an imperfect indicator of adiposity. Residual confounding may exist from socioeconomic factors.

CONCLUSIONS

Among adult patients in CureGN, class 2-3 obesity is associated with cardiovascular but not kidney outcomes when adjusted for potential confounding factors.

PLAIN-LANGUAGE SUMMARY

Obesity is a risk factor for adverse heart and kidney outcomes in patients with chronic kidney disease, but whether it is associated with these outcomes in patients with glomerulonephropathy is not known. This study used existing data from a large sample of adults and children with glomerular diseases to address this question. The findings suggest that obesity increases the risk of cardiovascular but not kidney disease events in adult patients with glomerular disease.

Cardiovascular, Kidney Failure, and All-Cause Mortality Events in Patients with FSGS in a US Real-World Database

Key Points

In our patients with FSGS, elevated proteinuria and progression to kidney failure (KF) were associated with a higher risk of cardiovascular disease/all-cause mortality events. In addition, elevated pre-KF proteinuria was associated with KF/all-cause mortality events. CKD stage, nephrotic syndrome, and cardiovascular disease event rates, as well as the incremental costs of these events, were high.

Background

FSGS leads to proteinuria and progressive decline in GFR, which correlates with kidney failure (KF) and increased cardiovascular risk. The purpose of this study was to estimate the effects of proteinuria on KF status/all-cause mortality and cardiovascular disease (CVD) events/all-cause mortality, as well as the relationship between progression to KF and occurrence of CVD/mortality events among adult patients (18 years or older) with FSGS.

Methods

This was an observational, retrospective cohort study utilizing Optum deidentified Market Clarity Data and proprietary Natural Language Processing data. The study period was from January 1, 2007, through March 31, 2021, with patients in the overall cohort being identified from July 1, 2007, through March 31, 2021. The index date was the first FSGS ICD-10 diagnosis code or FSGS-related natural language processing term within the identification period.

Results

Elevated proteinuria >1.5 and ≥3.5 g/g increased the risk of KF/all-cause mortality (adjusted hazard ratio [HR] [95% confidence interval (CI)], 2.34 [1.99 to 2.74] and 2.44 [2.09 to 2.84], respectively) and CVD/all-cause mortality (adjusted HR [95% CI], 2.11 [1.38 to 3.22] and 2.27 [1.44 to 3.58], respectively). Progression to KF was also associated with a higher risk of CVD/all-cause mortality (adjusted HR [95% CI], 3.04 [2.66 to 3.48]).

Conclusions

A significant proportion of patients with FSGS experience KF and CVD events. Elevated proteinuria and progression to KF were associated with a higher risk of CVD/all-cause mortality events, and elevated pre-KF proteinuria was associated with progression to KF/all-cause mortality events. Treatments that meaningfully reduce proteinuria and slow the decline in GFR have the potential to reduce the risk of CVD, KF, and early mortality in patients with FSGS.

Long-term outcomes of patients with IgA nephropathy in the German CKD cohort

Background

The importance of albuminuria as opposed to proteinuria in predicting kidney outcomes in primary immunoglobulin A nephropathy (IgAN) is not well established.

Methods

From 2010 to 2012, 421 patients with biopsy-proven IgAN have been enrolled into the German Chronic Kidney Disease (GCKD) cohort, a prospective observational cohort study (N = 5217). Adjudicated endpoints include a composite kidney endpoint (CKE) consisting of eGFR decline >40%, eGFR <15 ml/min/1.73 m2 and initiation of kidney replacement therapy; the individual components of the CKE; and combined major adverse cardiac events (MACE), including non-fatal myocardial infarction, non-fatal stroke and all-cause mortality. The associations between the incidence of CKE and baseline factors, including demographics, laboratory values and comorbidities were analysed using the Cox proportional hazards regression model.

Results

The mean age of IgAN patients at baseline was 51.6 years (± 13.6) and 67% were male. The patient-reported duration of disease at baseline was 5.9 ± 8.1 years. Baseline median urine albumin:creatinine ratio (UACR) was 0.4 g/g [interquartile range (IQR) 0.1-0.8] and mean eGFR was 52.5 ± 22.4 ml/min/1.73 m2. Over a follow-up of 6.5 years, 64 (15.2%) patients experienced a >40% eGFR decline, 3 (0.7%) reached eGFR <15 ml/min/1.73 m2, 53 (12.6%) initiated kidney replacement therapy and 28% of the patients experienced the CKE. Albuminuria, with reference to <0.1 g/g, was most associated with CKE. Hazard ratios (HRs) at UACRs of 0.1-0.6 g/g, 0.6-1.4 g/g, 1.4-2.2 g/g and >2.2 g/g were 2.03 [95% confidence interval (CI) 1.02-4.05], 3.8 (95% CI 1.92-7.5), 5.64 (95% CI 2.58-12.33) and 5.02 (95% CI 2.29-11-03), respectively. Regarding MACE, the presence of diabetes [HR 2.53 (95% CI 1.11-5.78)] was the most strongly associated factor, whereas UACR and eGFR did not show significant associations.

Conclusion

In the GCKD IgAN subcohort, more than every fourth patient experienced a CKE event within 6.5 years. Our findings support the use of albuminuria as a surrogate to assess the risk of poor kidney outcomes.

Association of Preterm Birth with Adverse Glomerular Disease Outcomes in Children and Adults

Key Points

Preterm birth was a risk factor for adverse outcomes in this heterogeneous cohort of children and adults with glomerular disease. In analyses adjusted for diagnosis and apolipoprotein L1 risk status, there was less remission and faster progression of kidney disease in those born preterm. A novel finding from this study is that adults born preterm were more likely to have an apolipoprotein L1 high-risk genotype.

Background

While some studies of children with nephrotic syndrome have demonstrated worse outcomes in those born preterm compared with term, little data exist on associations of preterm birth with outcomes in adult-onset glomerular disease. Cardiovascular outcomes in those born preterm with glomerular disease are unknown.

Methods

We performed a cross-sectional and longitudinal analysis of participants in the Cure Glomerulonephropathy cohort. Preterm (<37 weeks' gestation) was compared with term (≥37 weeks' gestation). A survival analysis and adjusted Cox proportional hazards model were used to examine a composite outcome of 40% decline in eGFR or progression to kidney failure. An adjusted logistic regression model was used to examine remission of proteinuria.

Results

There were 2205 term and 235 preterm participants. Apolipoprotein L1 (APOL1 ) risk alleles were more common in those born preterm. More pediatric than adult participants in Cure Glomerulonephropathy were born preterm: 12.8% versus 7.69% (P < 0.001). Adults born preterm compared with term had a higher prevalence of FSGS (35% versus 25%, P = 0.01) and APOL1 high-risk genotype (9.4% versus 4.2%, P = 0.01). Participants born preterm had a shorter time interval to a 40% eGFR decline/kidney failure after biopsy (P = 0.001). In adjusted analysis, preterm participants were 28% more likely to develop 40% eGFR decline/kidney failure (hazard ratio: 1.28 [1.07 to 1.54], P = 0.008) and 38% less likely to attain complete remission of proteinuria (odds ratio: 0.62 [0.45 to 0.87], P = 0.006). There was no significant difference in cardiovascular events.

Conclusions

Preterm birth was a risk factor for adverse outcomes in this heterogeneous cohort of children and adults with glomerular disease. Adults born preterm were more likely to have an APOL1 high-risk genotype and FSGS. In analyses adjusted for FSGS and APOL1 risk status, there was less remission and faster progression of kidney disease in those born preterm.

Routine cardiac biomarkers for the prediction of incident major adverse cardiac events in patients with glomerulonephritis: a real-world analysis using a global federated database

RATIONALE & OBJECTIVE

Glomerulonephritis (GN) is a leading cause of chronic kidney disease (CKD). Major adverse cardiovascular events (MACE) are prolific in CKD. The risk of MACE in GN cohorts is multifactorial. We investigated the prognostic significance of routine cardiac biomarkers, Troponin I and N-terminal pro-BNP (NT-proBNP) in predicting MACE within 5 years of GN diagnosis.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Data were obtained from TriNetX, a global federated health research network of electronic health records (EHR).

EXPOSURE OR PREDICTOR

Biomarker thresholds: Troponin I: 18 ng/L, NT-proBNP: 400 pg/mL.

OUTCOMES

Primary outcome: Incidence of major adverse cardiovascular events (MACE).

SECONDARY OUTCOME

was the risk for each individual component of the composite outcome.

ANALYTICAL APPROACH

1:1 propensity score matching using logistic regression. Cox proportional hazard models were used to assess the association of cardiac biomarkers with the primary and secondary outcomes, reported as Hazard Ratio (HR) and 95% confidence intervals (CI). Survival analysis was performed which estimates the probability of an outcome over a 5-year follow-up from the index event.

RESULTS

Following PSM, 34,974 and 18,218 patients were analysed in the Troponin I and NTproBNP cohorts, respectively. In the Troponin I all cause GN cohort, 3,222 (9%) developed composite MACE outcome HR 1.79; (95% CI, 1.70, 1.88, p < 0.0001). In the NTproBNP GN cohort, 1,686 (9%) developed composite MACE outcome HR 1.99; (95% CI, 1.86, 2.14, p < 0.0001).

LIMITATIONS

The data are derived from EHR for administrative purposes; therefore, there is the potential for data errors or missing data.

CONCLUSIONS

In GN, routinely available cardiac biomarkers can predict incident MACE. The results suggest the clinical need for cardiovascular and mortality risk profiling in glomerular disease using a combination of clinical and laboratory variables.

Does Metabolic Syndrome and Its Components Have Prognostic Significance for Renal and Cardiovascular Outcomes in IgA Nephropathy?

BACKGROUND

Patients with IgA nephropathy (IgAN), a chronic kidney disease (CKD), are significantly more likely to have cardiovascular (CV) mortality and morbidity than the general population. The occurrence of metabolic syndrome (MetS) and metabolic risk factors are independent risk factors for CV disease and renal progression. The purpose of this study was to determine how metabolic characteristics in a homogeneous population of CKD patients relate to prognosis.

METHODS

A total of 145 patients with CKD stages 1-4 diagnosed with IgA nephropathy (92 men and 53 women, aged 54.7 ± 13 years) were examined and monitored for a median of 190 months. All-cause mortality and any CV event, such as stroke, myocardial infarction, revascularization (CV), end-stage renal disease, and renal replacement therapy (renal), have been included in the composite endpoints (CV and renal).

RESULTS

Patients with MetS had significantly more primary endpoint events (23/65 patients vs. 15/60 patients, p < 0.001) compared to the non-MetS group. The MetS group had a statistically significant increase in both primary renal and CV endpoints (18/65 vs. 10/60, p = 0.001), and in CV endpoint events (7/65 vs. 6/60, p = 0.029) among the secondary endpoints (CV and renal separately). Based on Cox regression analysis, the main endpoint independent predictors of survival were dyslipidemia, eGFR, hemoglobin, urine albuminuria, and diabetes mellitus. Independent predictors of secondary renal endpoints were dyslipidemia, hemoglobin, urine albumin, and eGFR. Predictors of secondary cardiovascular endpoints were gender, BMI, and diabetes. When Kaplan-Meier curves were analyzed at the combined endpoints (CV and renal) or each endpoint independently, significant differences were seen between MetS and non-MetS. With more MetS components, the primary endpoint rate increased significantly (MetS comp. 0 vs. MetS comp. 2+, primary endpoints, p = 0.012).

CONCLUSIONS

Our results show that the metabolic profile has a prognostic role not only for renal endpoints but also for CV endpoints in IgAN. BMI, hyperuricemia, hypertension, and diabetes have a predictive value for the prognosis of IgA nephropathy.

Kidney Failure Events, Cardiovascular Disease Events, and All-Cause Mortality in Patients with IgA Nephropathy in a Real-World Database

Key Points

In our US real-world cohort study of patients with IgA nephropathy, elevated proteinuria and progression to kidney failure (KF) were associated with a higher risk of cardiovascular disease/mortality events. Elevated pre-KF proteinuria was also associated with progression to KF/mortality events. Incremental costs associated with CKD stage, nephrotic syndrome, and cardiovascular disease events and of these events were high.

Background

IgA nephropathy (IgAN)–associated glomerular injury leads to proteinuria, hematuria, and progressive loss of GFR, with progression to kidney failure (KF). This retrospective study evaluated the prognostic effects of proteinuria and progression to KF on cardiovascular disease (CVD)/mortality events and KF/mortality events in the United States.

Methods

We conducted a noninterventional, retrospective cohort study in adult patients with IgAN using Optum's deidentified Market Clarity Data (January 1, 2007, to March 31, 2021). Adult (age ≥18 years) patients with at least two signs, disease, symptoms natural language processing term entries for IgAN, within 180 and ≥30 days apart within the identification period were included. Outcomes were assessed by time-dependent proteinuria (≥1 versus <1 g/d) and KF status (pre versus post). Descriptive statistics were used for categorical and continuous variables. Multivariable Cox proportional hazard models with time-dependent predictors were used to estimate differences across groups.

Results

Patients with pre-KF status and proteinuria ≥1 g/d were more likely to have a CVD/mortality event during follow-up (adjusted hazard ratio [HR; 95% confidence interval (CI)]: 1.80 [1.12 to 2.89]; P < 0.001) or a KF/mortality event (adjusted HR [95% CI]: 2.10 [1.73 to 2.56]; P < 0.001). Patients with post-KF status were more likely to have a CVD/mortality event during follow-up (adjusted HR [95% CI]: 3.28 [2.82 to 3.81]; P < 0.001).

Conclusions

Elevated proteinuria and progression to KF were associated with a higher risk of CVD/mortality events. Elevated pre-KF proteinuria was also associated with progression to KF/mortality events. On the basis of our real-world retrospective database analysis, we hypothesize that novel IgAN therapies that reduce proteinuria and slow the rate of progression to KF have the potential to reduce CVD risk, improve kidney outcomes, and prolong/increase overall survival.

Underlying Mechanisms and Treatment of Hypertension in Glomerular Diseases

PURPOSE OF REVIEW

This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases.

RECENT FINDINGS

In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.

Cardiovascular Risk in Patients With Glomerular Disease: A Narrative Review of the Epidemiology, Mechanisms, Management, and Patient Priorities

Purpose of review

Cardiovascular (CV) disease is a major cause of morbidity and mortality for patients with glomerular disease. Despite the fact that mechanisms underpinning CV disease risk in this population are likely distinct from other forms of kidney disease, treatment and preventive strategies tend to be extrapolated from studies of patients with undifferentiated chronic kidney disease (CKD). There is an unmet need to delineate the pathophysiology of CV disease in patients with glomerular disease, establish unique risk factors, and identify novel therapeutic targets for disease prevention. The aims of this narrative review are to summarize the existing knowledge regarding the epidemiology, molecular mechanisms, and management of CV disease in patients with common glomerular disease, highlight the patient perspective, and propose specific areas for future study.

Sources of information

The literature for this narrative review was accessed using common research search engines, including PubMed, PubMed Central, Medline, and Google Scholar. Information for the patient perspective section was collected through iterative discussions with a patient partner.

Methods

We reviewed the epidemiology, molecular mechanisms of disease, management approaches, and the patient perspective in relation to CV disease in patients with glomerulopathies. Throughout, we have highlighted the current knowledge and have discussed future research approaches, both clinical and translational, while integrating the patient perspective.

Key findings

Patients with glomerular disease have significant CV disease risk driven by multifactorial, molecular mechanisms originating from their glomerular disease but complicated by existing comorbidities, kidney disease, and medication side effects. The current approach to risk stratification and treatment relies heavily on existing data from CKD patients, but this may not always be appropriate given the unique pathophysiology and mechanisms associated with CV disease risk in patients with glomerular disease. We highlight the need for ongoing glomerular disease-focused studies aimed to better delineate CV disease risk, while integrating the patient perspective.

Limitations

This is a narrative review and does not represent a comprehensive and systematic review of the literature.

Years of life lost and long-term outcomes due to glomerular disease in a Southeast Asian Cohort

Death and end-stage kidney disease (ESKD) are major outcomes of glomerular disease. (GD) The years of potential life lost (YLL) may provide additional insight into the disease burden beyond death rates. There is limited data on premature mortality in GD. In this retrospective observational cohort study, we evaluated the mortality, ESKD rates, and YLL in Thais with biopsy-proven GD. The mortality and combined outcome rates were determined by log-rank test and ESKD by using a competing risk model. YLL and premature life lost before age 60 were calculated for different GD based on the life expectancy of the Thai population. Patients with GD (n = 949) were followed for 5237 patient years. The death rate and ESKD rates (95%CI) were 4.2 (3.7-4.9) and 3.3 (2.9-3.9) per 100 patient-years, respectively. Paraprotein-related kidney disease had the highest death rate, and diabetic nephropathy had the highest ESKD rate. Despite not having the highest death rate, lupus nephritis (LN) had the highest YLL (41% of all GD) and premature loss of life before age 60. In conclusion, YLL provided a different disease burden assessment compared to mortality rates and identified LN as the major cause of premature death due to GD in a Southeast Asian cohort.

Kidney function and cardiovascular diseases: a large-scale observational and Mendelian randomization study

Background

Prior observational studies have found an association between kidney function and cardiovascular diseases (CVDs). However, these studies did not investigate causality. Therefore, the aim of this study is to examine the causal relationship between kidney function and CVDs.

Methods

We utilized data from the eICU Collaborative Research Database (eICU-CRD) from the years 2014-2015 to evaluate the observational association between renal failure (RF) and CVDs. To investigate the causal effects of kidney function (estimated glomerular filtration rate [eGFR] and chronic kidney disease [CKD]) and CVDs (including atrial fibrillation [AF], coronary artery disease [CAD], heart failure [HF], any stroke [AS], and any ischemic stroke [AIS]), we conducted a two-sample bidirectional Mendelian randomization (MR) analysis.

Results

In the observational analysis, a total of 157,883 patients were included. After adjusting for potential confounding factors, there was no significant association between baseline RF and an increased risk of developing CVDs during hospitalization [adjusted odds ratio (OR): 1.056, 95% confidence interval (CI): 0.993 to 1.123, P = 0.083]. Conversely, baseline CVDs was significantly associated with an increased risk of developing RF during hospitalization (adjusted OR: 1.189, 95% CI: 1.139 to 1.240, P < 0.001). In the MR analysis, genetically predicted AF was associated with an increased risk of CKD (OR: 1.050, 95% CI: 1.016 to 1.085, P = 0.004). HF was correlated with lower eGFR (β: -0.056, 95% CI: -0.090 to -0.022, P = 0.001). A genetic susceptibility for AS and AIS was linked to lower eGFR (β: -0.057, 95% CI: -0.079 to -0.036, P < 0.001; β: -0.029, 95% CI: -0.050 to -0.009, P = 0.005; respectively) and a higher risk of CKD (OR: 1.332, 95% CI: 1.162 to 1.528, P < 0.001; OR: 1.197, 95% CI: 1.023 to 1.400, P = 0.025; respectively). Regarding the reverse direction analysis, there was insufficient evidence to prove the causal effects of kidney function on CVDs. Outcomes remained consistent in sensitivity analyses.

Conclusion

Our study provides evidence for causal effects of CVDs on kidney function. However, the evidence to support the causal effects of kidney function on CVDs is currently insufficient. Further mechanistic studies are required to determine the causality.

The Development of a Comprehensive Clinicopathologic Registry for Glomerular Diseases Using Natural Language Processing

Background

Glomerulonephritis (GN) represents a common cause of chronic kidney disease, and treatment to slow or prevent progression of GN is associated with significant morbidity. Large patient registries have improved the understanding of risk stratification, treatment selection, and definitions of treatment response in GN, but can be resource-intensive, with incomplete patient capture.

Objective

To describe the creation of a comprehensive clinicopathologic registry for all patients undergoing kidney biopsy in Manitoba, using natural language processing software for data extraction from pathology reports, as well as to describe cohort characteristics and outcomes.

Design

Retrospective population-based cohort study.

Setting

Tertiary care center in the province of Manitoba.

Patients

All patients undergoing a kidney biopsy in the province of Manitoba from 2002 to 2019.

Measurements

Descriptive statistics are presented for the most common glomerular diseases, along with outcomes of kidney failure and mortality for the individual diseases.

Methods

Data from native kidney biopsy reports from January 2002 to December 2019 were extracted into a structured database using a natural language processing algorithm employing regular expressions. The pathology database was then linked with population-level clinical, laboratory, and medication data, creating a comprehensive clinicopathologic registry. Kaplan-Meier curves and Cox models were constructed to assess the relationship between type of GN and outcomes of kidney failure and mortality.

Results

Of 2421 available biopsies, 2103 individuals were linked to administrative data, of which 1292 had a common glomerular disease. The incidence of yearly biopsies increased almost 3-fold over the study period. Among common glomerular diseases, immunoglobulin A (IgA) nephropathy was the most common (28.6%), whereas infection-related GN had the highest proportions of kidney failure (70.3%) and all-cause mortality (42.3%). Predictors of kidney failure included urine albumin-to-creatinine ratio at the time of biopsy (adjusted hazard ratio [HR] = 1.43, 95% confidence interval [CI] = 1.24-1.65), whereas predictors of mortality included age at the time of biopsy (adjusted HR = 1.05, 95% CI = 1.04-1.06) and infection-related GN (adjusted HR = 1.85, 95% CI = 1.14-2.99, compared with the reference category of IgA nephropathy).

Limitations

Retrospective, single-center study with a relatively small number of biopsies.

Conclusions

Creation of a comprehensive glomerular diseases registry is feasible and can be facilitated through the use of novel data extraction methods. This registry will facilitate further epidemiological research in GN.

Associations Between Kidney Histopathologic Lesions and Incident Cardiovascular Disease in Adults With Chronic Kidney Disease

Importance

Histologic lesions in the kidney may reflect or contribute to systemic processes that may lead to adverse cardiovascular events.

Objective

To assess the association between kidney histopathologic lesion severity and the risk of incident major adverse cardiovascular events (MACE).

Design, Setting, and Participants

This prospective observational cohort study included participants without a history of myocardial infarction, stroke, or heart failure from the Boston Kidney Biopsy Cohort recruited from 2 academic medical centers in Boston, Massachusetts. Data were collected from September 2006 and November 2018, and data were analyzed from March to November 2021.

Exposures

Semiquantitative severity scores for kidney histopathologic lesions adjudicated by 2 kidney pathologists, a modified kidney pathology chronicity score, and primary clinicopathologic diagnostic categories.

Main Outcomes and Measures

The main outcome was the composite of death or incident MACE, which included myocardial infarction, stroke, and heart failure hospitalization. All cardiovascular events were independently adjudicated by 2 investigators. Cox proportional hazards models estimated associations of histopathologic lesions and scores with cardiovascular events adjusted for demographic characteristics, clinical risk factors, estimated glomerular filtration rate (eGFR), and proteinuria.

Results

Of 597 included participants, 308 (51.6%) were women, and the mean (SD) age was 51 (17) years. The mean (SD) eGFR was 59 (37) mL/min per 1.73 m2, and the median (IQR) urine protein to creatinine ratio was 1.54 (0.39-3.95). The most common primary clinicopathologic diagnoses were lupus nephritis, IgA nephropathy, and diabetic nephropathy. Over a median (IQR) of 5.5 (3.3-8.7) years of follow-up, the composite of death or incident MACE occurred in 126 participants (37 per 1000 person-years). Compared with the reference group of individuals with proliferative glomerulonephritis, the risk of death or incident MACE was highest in individuals with nonproliferative glomerulopathy (hazard ratio [HR], 2.61; 95% CI, 1.30-5.22; P = .002), diabetic nephropathy (HR, 3.56; 95% CI, 1.62-7.83; P = .002), and kidney vascular diseases (HR, 2.86; 95% CI, 1.51-5.41; P = .001) in fully adjusted models. The presence of mesangial expansion (HR, 2.98; 95% CI, 1.08-8.30; P = .04) and arteriolar sclerosis (HR, 1.68; 95% CI, 1.03-2.72; P = .04) were associated with an increased risk of death or MACE. Compared with minimal chronicity, greater chronicity was significantly associated with an increased risk of death or MACE (severe: HR, 2.50; 95% CI, 1.06-5.87; P = .04; moderate: HR, 1.66; 95% CI, 0.74-3.75; P = .22; mild: HR, 2.22; 95% CI, 1.01-4.89; P = .047) in fully adjusted models.

Conclusions and Relevance

In this study, specific kidney histopathological findings were associated with increased risks of CVD events. These results provide potential insight into mechanisms of the heart-kidney relationship beyond those provided by eGFR and proteinuria.

Treatment of membranous nephropathy: Perspectives on current and future therapies

Primary membranous nephropathy remains one of the most frequent causes of nephrotic syndrome in adults. It is an autoimmune disorder in which auto-antibodies target antigens at the podocytes cell membrane-basement membrane interface. Our understanding of membranous nephropathy has expanded dramatically as of late. After the initial discovery of the phospholipase A2 receptor auto-antibody in 2009, eight more antigens have been discovered. These discoveries have led to refinement in our understanding of the pathogenesis, diagnosis, and natural history of primary membranous nephropathy. Now, many experts advocate for redefining primary membranous nephropathy based on antigen, potentially shedding the primary and secondary nomenclature. Recently, therapies for primary membranous have also expanded. Immunosuppressive therapies like cyclophosphamide and rituximab, which primarily target B-cells, remain the cornerstone of therapy. However, there is still significant room for improvement, as many as 30-40% do not respond to this therapy according to recent trials. Additionally, drugs targeting complement, and other novel therapies are also under investigation. In this review we will discuss the available therapies for primary membranous nephropathy in light of recent clinic trials like GEMRITUX, MENTOR, RI-CYCLO, and STARMEN, as well as management strategies. While the last 10 years have seen a boom in our mechanistic understanding of this ever-diversifying disease, we are likely to see a similar boom in the therapeutic options in the years to come.

CureGN-Diabetes Study: Rationale, Design, and Methods of a Prospective Observational Study of Glomerular Disease Patients with Diabetes

Glomerular diseases (GDs) represent the third leading cause of end-stage kidney disease (ESKD) in the US Diabetes was excluded from the CureGN Study, an NIH/NIDDK-sponsored observational cohort study of four leading primary GDs: IgA nephropathy (IgAN), membranous nephropathy (MN), focal segmental glomerulosclerosis (FSGS), and minimal change disease (MCD). CureGN-Diabetes, an ancillary study to CureGN, seeks to understand how diabetes influences the diagnosis, treatment, and outcomes of GD. It is a multicenter, prospective cohort study, targeting an enrollment of 300 adults with prevalent type 1 or type 2 diabetes and MCD, FSGS, MN, or IgAN, with first kidney biopsy obtained within 5 years of enrollment in 80% (20% allowed if biopsy after 2010). CureGN and Transformative Research in DiabEtic NephropaThy (TRIDENT) provide comparator cohorts. Retrospective and prospective clinical data and patient-reported outcomes are obtained. Blood and urine specimens are collected at study visits annually. Kidney biopsy reports and digital images are obtained, and standardized pathologic evaluations performed. Light microscopy images are uploaded to the NIH pathology repository. Outcomes include relapse and remission rates, changes in proteinuria and estimated glomerular filtration rate, infections, cardiovascular events, malignancy, ESKD, and death. Multiple analytical approaches will be used leveraging the baseline and longitudinal data to compare disease presentation and progression across subgroups of interest. With 300 patients and an average of 3 years of follow-up, the study has 80% power to detect a HR of 1.4-1.8 for time to complete remission of proteinuria, a rate ratio for hospitalizations of 1.18-1.56 and difference in eGFR slope of 6.0-8.6 mL/min/year between two groups of 300 participants each. CureGN-Diabetes will enhance our understanding of diabetes as a modifying factor of the pathology and outcomes of GDs and support studies to identify disease mechanisms and improve patient outcomes in this understudied patient population.

Immunosenescence: an unexplored role in glomerulonephritis

Immunosenescence is a natural ageing phenomenon with alterations in innate and especially adaptive immunity and contributes to reduced antimicrobial defence and chronic low‐grade inflammation. This is mostly reflected by an increase in organ‐directed and/or circulating reactive and cytolytic terminally differentiated T cells that have lost their expression of the costimulatory receptor CD28. Apart from being induced by a genetic predisposition, ageing or viral infections (particularly cytomegalovirus infection), immunosenescence is accelerated in many inflammatory diseases and uraemia. This translates into an enhancement of vascular inflammation and cardiovascular disease varying from endothelial dysfunction to plaque rupture. Emerging data point to a mechanistic role of CD28^null T cells in glomerulonephritis, where they initiate and propagate local inflammation in concordance with dendritic cells and macrophages. They are suitably equipped to escape immunological dampening by the absence of homing to lymph nodes, anti‐apoptotic properties and resistance to suppression by regulatory T cells. Early accumulation of senescent CD28^null T cells precedes glomerular or vascular injury, and targeting these cells could open avenues for early treatment interventions that aim at abrogating a detrimental vicious cycle.