An expert discussion on the atypical hemolytic uremic syndrome nomenclature-identifying a road map to precision: a report of a National Kidney Foundation Working Group.

The term atypical hemolytic uremic syndrome has been in use since the mid-1970s. It was initially used to describe the familial or sporadic form of hemolytic uremic syndrome as opposed to the epidemic, typical form of the disease. Over time, the atypical hemolytic uremic syndrome term has evolved into being used to refer to anything that is not Shiga toxin-associated hemolytic uremic syndrome. The term describes a heterogeneous group of diseases of disparate causes, a circumstance that makes defining disease-specific natural history and/or targeted treatment approaches challenging. A working group of specialty-specific experts in the thrombotic microangiopathies was convened to review the validity of this broad term in an era of swiftly advancing science and targeted therapeutics. A Delphi approach was used to define and interrogate some of the key issues related to the atypical hemolytic uremic syndrome nomenclature.

The Association of Class I and II Human Leukocyte Antigen Serotypes With End-Stage Kidney Disease Due to Membranoproliferative Glomerulonephritis and Dense Deposit Disease.

RATIONALE & OBJECTIVE: Membranoproliferative glomerulonephritis (MPGN), encompassing several distinct diseases, is a rare but significant cause of kidney failure in the United States. The potential etiologies of MPGN are unclear, but prior studies have suggested dysregulation of the alternative complement pathway and, recently, autoimmunity as potential mechanisms driving MPGN pathogenesis. In this study, we examined HLA associations with end-stage kidney disease (ESKD) due to MPGN and dense deposit disease (DDD) in a large racially and ethnically diverse US-based cohort. STUDY DESIGN: Case-control study. SETTING & PARTICIPANTS: Using US Renal Data System (USRDS) and United Network for Organ Sharing (UNOS) data, we identified 3,424 patients with kidney failure due to MPGN and 263 due to DDD. We matched patients to kidney donor controls on designated race and ethnicity in a 1:15 ratio. EXPOSURE: 58 class I and II HLA serotypes. OUTCOME: Case-control status. ANALYTICAL APPROACH: For each disease cohort, univariable and multivariable logistic regression analyses were used to investigate associations between the disease and 58 HLA serotypes. In subgroup analyses, we investigated HLA associations in White and Black patients. We also studied antiglomerular basement membrane (anti-GBM) nephritis as a positive-control outcome. We applied a Bonferroni correction to account for multiple comparisons. RESULTS: Eighteen serotypes were significantly associated with the odds of having MPGN in univariable analyses, with DR17 having the strongest association (odds ratio [OR], 1.55 [95% CI, 1.44-1.68], P=4.33e-28). No significant associations were found between any HLA serotype and DDD. Designated race-specific analyses showed comparable findings. We recapitulated known HLA associations in anti-GBM nephritis. LIMITATIONS: Reliance on HLA serotypes (rather than genotype), lack of biopsy-confirmed diagnoses. CONCLUSIONS: HLA-DR17 is associated with ESKD due to MPGN in a racially and ethnically diverse cohort. The strength of association was similar in White and Black patients, suggesting a role in the pathogenesis of MPGN. No HLA associations were observed in patients with DDD. PLAIN-LANGUAGE SUMMARY: Prior studies have suggested dysregulation of the alternative complement pathway as a potential etiology of membranoproliferative glomerulonephritis (MPGN), but recent evidence from a British White population has implicated an autoimmune mechanism in MPGN pathogenesis. We investigated HLA associations between MPGN and dense deposit disease (DDD) in a large racially and ethnically diverse cohort of patients. We found that HLA-DR17 is associated with end-stage kidney disease (ESKD) due to MPGN in both White and Black patients. By contrast, no significant HLA associations with ESKD due to DDD were identified. These results suggest a role for autoimmunity in some cases of MPGN and highlight differences in the disease etiology of MPGN compared with DDD.

Better kidney allograft survival despite higher-risk donor and recipient characteristics between 1995-2014.

BACKGROUND AND HYPOTHESIS: Advances in organ procurement, surgical techniques, immunosuppression regimens and prophylactic antibiotic therapies have dramatically improved short term kidney transplant graft failure. It is unclear how these interventions have affected longer term graft failure. It is hypothesised that graft failure has improved over the last 20 years. METHODS: Data on all first kidney transplants from 1995-2014 were extracted from the Australia and New Zealand Dialysis and Transplant Registry with follow-up as of 31 December, 2021. Primary exposure was transplant era, classified into 5-year intervals. Primary outcome was all-cause 5-year graft failure. Secondary outcomes included all-cause 10-year graft failure and cause-specific graft failure. Kaplan Meier curves and multivariable Cox Proportional Hazards Regression models were used to assess trends in all-cause graft failure. Fine-Gray subdistribution hazard models verified that changes in death rates were not biasing the Cox Proportional Hazards Regression models. Cumulative incidence functions were used to assess temporal trends in cause-specific graft failure. RESULTS: Across 10 871 kidney transplants, there was a shift towards transplanting more recipients aged over 45 years old, with more comorbidities, longer dialysis vintage, body mass index greater than 30 kg/m2 and greater human leukocyte antigen mismatches. Donor age has increased but no clear shift in donor source was observed. Compared to 1995-1999 (reference), the adjusted hazard ratio for 5-year graft failure was 0.78 (95% CI 0.67-0.91), 0.70 (95% CI 0.59-0.83) and 0.60 (95% CI 0.50-0.73) for 2000-2004, 2005-2009, and 2010-2014, respectively. Ten-year graft failure similarly reduced from 0.83 (95% CI 0.74-0.93) for 2000-04 to 0.78 (95% CI 0.68-0.89) for 2010-14, compared to 1995-99. CONCLUSION: Medium and long term all-cause graft failure has improved steadily since 1995-99. Significant reductions in graft failure due to rejection and vascular causes were observed at 5 years, and due to rejection, vascular causes, death and glomerular disease at 10 years.

Effect of Immunosuppression on the Immune Response to SARS-CoV-2 Infection and Vaccination.

Immunosuppressive treatment in patients with rheumatic diseases can maintain disease remission but also increase risk of infection. Their response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is frequently blunted. In this study we evaluated the effect of immunosuppression exposure on humoral and T cell immune responses to SARS-CoV-2 infection and vaccination in two distinct cohorts of patients; one during acute SARS-CoV-2 infection and 3 months later during convalescence, and another prior to SARS-CoV-2 vaccination, with follow up sampling 6 weeks after vaccination. Results were compared between rituximab-exposed (in previous 6 months), immunosuppression-exposed (in previous 3 months), and non-immunosuppressed groups. The immune cell phenotype was defined by flow cytometry and ELISA. Antigen specific T cell responses were estimated using a whole blood stimulation interferon-γ release assay. A focused post-vaccine assessment of rituximab-treated patients using high dimensional spectral cytometry was conducted. Acute SARS-CoV-2 infection was characterised by T cell lymphopenia, and a reduction in NK cells and naïve CD4 and CD8 cells, without any significant differences between immunosuppressed and non-immunosuppressed patient groups. Conversely, activated CD4 and CD8 cell counts increased in non-immunosuppressed patients with acute SARS-CoV-2 infection but this response was blunted in the presence of immunosuppression. In rituximab-treated patients, antigen-specific T cell responses were preserved in SARS-CoV-2 vaccination, but patients were unable to mount an appropriate humoral response.

Precision nephrology identified tumor necrosis factor activation variability in minimal change disease and focal segmental glomerulosclerosis.

The diagnosis of nephrotic syndrome relies on clinical presentation and descriptive patterns of injury on kidney biopsies, but not specific to underlying pathobiology. Consequently, there are variable rates of progression and response to therapy within diagnoses. Here, an unbiased transcriptomic-driven approach was used to identify molecular pathways which are shared by subgroups of patients with either minimal change disease (MCD) or focal segmental glomerulosclerosis (FSGS). Kidney tissue transcriptomic profile-based clustering identified three patient subgroups with shared molecular signatures across independent, North American, European, and African cohorts. One subgroup had significantly greater disease progression (Hazard Ratio 5.2) which persisted after adjusting for diagnosis and clinical measures (Hazard Ratio 3.8). Inclusion in this subgroup was retained even when clustering was limited to those with less than 25% interstitial fibrosis. The molecular profile of this subgroup was largely consistent with tumor necrosis factor (TNF) pathway activation. Two TNF pathway urine markers were identified, tissue inhibitor of metalloproteinases-1 (TIMP-1) and monocyte chemoattractant protein-1 (MCP-1), that could be used to predict an individual's TNF pathway activation score. Kidney organoids and single-nucleus RNA-sequencing of participant kidney biopsies, validated TNF-dependent increases in pathway activation score, transcript and protein levels of TIMP-1 and MCP-1, in resident kidney cells. Thus, molecular profiling identified a subgroup of patients with either MCD or FSGS who shared kidney TNF pathway activation and poor outcomes. A clinical trial testing targeted therapies in patients selected using urinary markers of TNF pathway activation is ongoing.

Racial and Ethnic Disparities in Acute Care Utilization Among Patients With Glomerular Disease.

RATIONALE & OBJECTIVE: The effects of race, ethnicity, socioeconomic status (SES), and disease severity on acute care utilization in patients with glomerular disease are unknown. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 1,456 adults and 768 children with biopsy-proven glomerular disease enrolled in the Cure Glomerulonephropathy (CureGN) cohort. EXPOSURE: Race and ethnicity as a participant-reported social factor. OUTCOME: Acute care utilization defined as hospitalizations or emergency department visits. ANALYTICAL APPROACH: Multivariable recurrent event proportional rate models were used to estimate associations between race and ethnicity and acute care utilization. RESULTS: Black or Hispanic participants had lower SES and more severe glomerular disease than White or Asian participants. Acute care utilization rates were 45.6, 29.5, 25.8, and 19.2 per 100 person-years in Black, Hispanic, White, and Asian adults, respectively, and 55.8, 42.5, 40.8, and 13.0, respectively, for children. Compared with the White race (reference group), Black race was significantly associated with acute care utilization in adults (rate ratio [RR], 1.76 [95% CI, 1.37-2.27]), although this finding was attenuated after multivariable adjustment (RR, 1.31 [95% CI, 1.03-1.68]). Black race was not significantly associated with acute care utilization in children; Asian race was significantly associated with lower acute care utilization in children (RR, 0.32 [95% CI 0.14-0.70]); no significant associations between Hispanic ethnicity and acute care utilization were identified. LIMITATIONS: We used proxies for SES and lacked direct information on income, household unemployment, or disability. CONCLUSIONS: Significant differences in acute care utilization rates were observed across racial and ethnic groups in persons with prevalent glomerular disease, although many of these difference were explained by differences in SES and disease severity. Measures to combat socioeconomic disadvantage in Black patients and to more effectively prevent and treat glomerular disease are needed to reduce disparities in acute care utilization, improve patient wellbeing, and reduce health care costs.

Therapeutics in rheumatology and the kidney.

The field of rheumatology has advanced significantly in recent years to provide rheumatologists with an extensive array of medications to combat rheumatic joint conditions. In contrast to an older era, when NSAIDs and other nephrotoxic agents were the mainstay of treatment, modern DMARDs vary considerably in their nephrotoxic potential and their use is not always precluded in populations with pre-existing chronic kidney disease (CKD). This review will explore in detail the safety and efficacy profiles of medications used to treat rheumatologic disease, specifically in the setting of CKD. Specifically, we discuss both traditional agents used, i.e. NSAIDs, CSs and conventional synthetic DMARDs, as well as novel biologic DMARDs and targeted synthetic DMARDs. Anti-gout prescribing in CKD is also reviewed. We aim to provide practical guidance to rheumatologists, nephrologists and general physicians when prescribing these medications in the setting of CKD.

IgA nephropathy in adults-treatment standard.

Immunoglobulin A nephropathy (IgAN) is the most common primary form of glomerular disease worldwide and carries a high lifetime risk of kidney failure. The underlying pathogenesis of IgAN has been characterized to a sub-molecular level; immune complexes containing specific O-glycoforms of IgA1 are central. Kidney biopsy remains the gold-standard diagnostic test for IgAN and histological features (i.e. MEST-C score) have also been shown to independently predict outcome. Proteinuria and blood pressure are the main modifiable risk factors for disease progression. No IgAN-specific biomarker has yet been validated for diagnosis, prognosis or tracking response to therapy. There has been a recent resurgence of investigation into IgAN treatments. Optimized supportive care with lifestyle interventions and non-immunomodulatory drugs remains the backbone of IgAN management. The menu of available reno-protective medications is rapidly expanding beyond blockade of the renin-angiotensin-aldosterone system to include sodium-glucose cotransporter 2 and endothelin type A receptor antagonism. Systemic immunosuppression can further improve kidney outcomes, although recent randomized controlled trials have raised concerns regarding infectious and metabolic toxicity from systemic corticosteroids. Studies evaluating more refined approaches to immunomodulation in IgAN are ongoing: drugs targeting the mucosal immune compartment, B-cell promoting cytokines and the complement cascade are particularly promising. We review the current standards of treatment and discuss novel developments in pathophysiology, diagnosis, outcome prediction and management of IgAN.

Tobacco exposure in adults and children with proteinuric glomerulopathies: a NEPTUNE cohort study.

BACKGROUND: Tobacco exposure has been recognized as a risk factor for cardiovascular disease (CVD) and progression of kidney disease. Patients with proteinuric glomerulopathies are at increased risk for cardiovascular morbidity and mortality. Multiple studies have linked tobacco exposure to CVD and chronic kidney disease, but the relationships between smoking and proteinuric glomerulopathies in adults and children have not been previously explored. METHODS: Data from the Nephrotic Syndrome Study Network (NEPTUNE), a multi-center prospective observational study of participants with proteinuric glomerulopathies, was analyzed. 371 adults and 192 children enrolled in NEPTUNE were included in the analysis. Self-reported tobacco exposure was classified as non-smoker, active smoker, former smoker, or exclusive passive smoker. Baseline serum cotinine levels were measured in a sub-cohort of 178 participants. RESULTS: The prevalence of active smokers, former smokers and exclusive passive smoking among adults at baseline was 14.6%, 29.1% and 4.9%, respectively. Passive smoke exposure was 16.7% among children. Active smoking (reference non-smoking) was significantly associated with greater total cholesterol among adults (ß 17.91 95% CI 0.06, 35.76, p = 0.049) while passive smoking (reference non-smoking) was significantly associated with greater proteinuria over time among children (ß 1.23 95% CI 0.13, 2.33, p = 0.03). Higher cotinine levels were associated with higher baseline eGFR (r = 0.17, p = 0.03). CONCLUSION: Tobacco exposure is associated with greater risk for CVD and worse kidney disease outcomes in adults and children with proteinuric glomerulopathies. Preventive strategies to reduce tobacco exposure may help protect against future cardiovascular and kidney morbidity and mortality in patients with proteinuric glomerulopathies.

National and international kidney failure registries: characteristics, commonalities, and contrasts.

Registries are essential for health infrastructure planning, benchmarking, continuous quality improvement, hypothesis generation, and real-world trials. To date, data from these registries have predominantly been analyzed in isolated "silos," hampering efforts to analyze "big data" at the international level, an approach that provides wide-ranging benefits, including enhanced statistical power, an ability to conduct international comparisons, and greater capacity to study rare diseases. This review serves as a valuable resource to clinicians, researchers, and policymakers, by comprehensively describing kidney failure registries active in 2021, before proposing approaches for inter-registry research under current conditions, as well as solutions to enhance global capacity for data collaboration. We identified 79 kidney-failure registries spanning 77 countries worldwide. International Society of Nephrology exemplar initiatives, including the Global Kidney Health Atlas and Sharing Expertise to support the set-up of Renal Registries (SharE-RR), continue to raise awareness regarding international healthcare disparities and support the development of universal kidney-disease registries. Current barriers to inter-registry collaboration include underrepresentation of lower-income countries, poor syntactic and semantic interoperability, absence of clear consensus guidelines for healthcare data sharing, and limited researcher incentives. This review represents a call to action for international stakeholders to enact systemic change that will harmonize the current fragmented approaches to kidney-failure registry data collection and research.

Chronic kidney disease and adverse pregnancy outcomes: a systematic review and meta-analysis.

OBJECTIVE: Limited evidence exists on the role that the cause of chronic kidney disease plays in determining pregnancy outcomes. The aim of this systematic review and meta-analysis was to examine the association between chronic kidney disease and adverse pregnancy outcomes by the cause and severity of chronic kidney disease where reported. The protocol was registered under the International Prospective Register of Systematic Reviews (CRD42020211925). DATA SOURCES: PubMed, Embase, and Web of Science were searched until May 24, 2021, supplemented with reference list checking. STUDY ELIGIBILITY CRITERIA: Studies that compared the pregnancy outcomes in women with or without chronic kidney disease were included. Two reviewers independently screened titles, abstracts, and full-text articles according to a priori defined inclusion criteria. METHODS: Data extraction and quality appraisal were performed independently by 3 reviewers. The grading of recommendations, assessment, development, and evaluation approach was used to assess the overall certainty of the evidence. Random-effects meta-analyses were used to calculate the pooled estimates using the generic inverse variance method. The primary outcomes included preeclampsia, cesarean delivery, preterm birth (<37 weeks' gestation), and small for gestational age babies. RESULTS: Of 4076 citations, 31 studies were included. Prepregnancy chronic kidney disease was significantly associated with a higher odds of preeclampsia (pooled crude odds ratio, 8.13; [95% confidence interval, 4.41-15], and adjusted odds ratio, 2.58; [1.33-5.01]), cesarean delivery (adjusted odds ratio, 1.65; [1.21-2.25]), preterm birth (adjusted odds ratio, 1.73; [1.31-2.27]), and small for gestational age babies (adjusted odds ratio, 1.93; [1.06-3.52]). The association with stillbirth was not statistically significant (adjusted odds ratio, 1.67; [0.96-2.92]). Subgroup analyses indicated that different causes of chronic kidney disease might confer different risks and that the severity of chronic kidney disease is associated with a risk of adverse pregnancy outcomes, as pregnancies with later stages of chronic kidney disease had higher odds of preeclampsia, preterm birth, and small for gestational age babies than those at earlier stages. The grading of recommendations, assessment, development, and evaluation certainty of the evidence overall was "very low". CONCLUSION: This meta-analysis quantified the associations between prepregnancy chronic kidney disease and adverse pregnancy outcomes, both overall and according to the cause and severity of the disease. These findings might support the clinicians aiming to counsel women having chronic kidney disease by allowing them to tailor their advice according to cause and severity of the chronic kidney disease. We identified the gaps in the literature, and further studies examining the effect of specific kidney diseases and other clinical characteristics (eg, proteinuria, hypertension) on adverse pregnancy outcomes are warranted.

Cause of kidney disease and cardiovascular events in a national cohort of US patients with end-stage renal disease on dialysis: a retrospective analysis.

AIMS: End-stage renal disease (ESRD) is a strong cardiovascular risk factor. We aimed to determine the extent to which cause of kidney disease independently contributes to this risk. METHODS AND RESULTS: Using a national US ESRD registry, we selected patients with eight different causes of ESRD who initiated dialysis 1997-2014. We used proportional sub-distribution hazard models, with non-cardiovascular death or kidney transplantation as competing risks, to estimate hazard ratios (HRs) for a first composite cardiovascular event (myocardial infarction, ischaemic stroke, or cardiovascular or cerebrovascular death), by cause of ESRD. The population was restricted to those using Medicare insurance at Day 91 after dialysis initiation (when most patients become Medicare eligible). Outcomes were ascertained from Medicare claims or Death Notifications. Among the 658 168 patients identified, composite event rates ranged from 3.5/100 person-years in IgA nephropathy to 14.6/100 person-years in diabetic nephropathy (DN). After adjusting for demographics, socioeconomic factors, comorbidities, dialysis modality, and laboratory values, cardiovascular event HRs differed significantly by cause of ESRD. Comparing to IgA nephropathy, the adjusted HR was highest for DN [aHR = 2.97, 95% confidence interval (CI) 2.77-3.20], next highest for lupus nephritis (aHR = 1.86, 95% CI 1.71-2.03), and thereafter ranged from 1.29 (95% CI 1.19-1.39) in autosomal dominant polycystic kidney disease to 1.67 (95% CI 1.52-1.83) in membranous nephropathy. CONCLUSION: High cardiovascular event rates in dialysis patients vary considerably by cause of ESRD. Determining underlying reasons for these differences might provide new insights in to cardiovascular disease mechanisms as well as inform future drug development and clinical trial design.

Glomerular disease frequencies by race, sex and region: results from the International Kidney Biopsy Survey.

Background: Large-scale studies comparing glomerular disease frequencies across continents are lacking. Methods: We surveyed 29 nephropathology laboratories in four continents using a standardized data collection form. We obtained recent consecutive kidney biopsy diagnosis frequencies at each center and summary demographics for each diagnosis. This report focuses on glomerular disease frequencies by region and race/ethnicity. Results: Among 42 603 glomerular disease diagnoses reported (median age 47 years, 52% male, 57% white), from a total of 60 340 diagnoses, glomerular disease subtype frequencies differed considerably by continent. Diabetic glomerulosclerosis (GS; 19.1%) and focal segmental glomerulosclerosis (FSGS; 19.1%) predominated in North America; lupus nephritis (38.1%) and FSGS (15.8%) predominated in Latin America; IgA nephropathy (IgAN; 22.1%) and FSGS (14.9%) predominated in Europe; and IgAN (39.5%) and lupus nephritis (16.8%) predominated in Asia. After stratifying by race, diabetic GS (17.4% versus 4.3%, P < 0.001) and FSGS (17.3% versus 11.8%, P < 0.001) were more, and lupus nephritis less (15.8% versus 45.6%, P < 0.001), frequent among Latinos in North versus Latin America; FSGS was more (13.1% versus 7.1%, P < 0.001), and IgAN less (27.4% versus 40.5%, P < 0.001), frequent among Asians in North America versus Asia; and FSGS (18.9% versus 13.5%, P < 0.001) and diabetic GS (18.7% versus 6.5%, P < 0.001) were more, and IgAN less (14.4% versus 25.4%, P < 0.001), frequent among whites in North America versus Europe. Conclusions: We determined that glomerular disease frequencies differed by continent, even among patients of similar race/ethnicity. Regional environmental and lifestyle factors, and local biopsy policies, might influence glomerular disease epidemiology independently of race/ethnicity.

A large, international study on post-transplant glomerular diseases: the TANGO project.

BACKGROUND: Long-term outcomes in kidney transplantation (KT) have not significantly improved during the past twenty years. Despite being a leading cause of graft failure, glomerular disease (GD) recurrence remains poorly understood, due to heterogeneity in disease pathogenesis and clinical presentation, reliance on histopathology to confirm disease recurrence, and the low incidence of individual GD subtypes. Large, international cohorts of patients with GD are urgently needed to better understand the disease pathophysiology, predictors of recurrence, and response to therapy. METHODS: The Post-TrANsplant GlOmerular Disease (TANGO) study is an observational, multicenter cohort study initiated in January 2017 that aims to: 1) characterize the natural history of GD after KT, 2) create a biorepository of saliva, blood, urine, stools and kidney tissue samples, and 3) establish a network of patients and centers to support novel therapeutic trials. The study includes 15 centers in America and Europe. Enrollment is open to patients with biopsy-proven GD prior to transplantation, including IgA nephropathy, membranous nephropathy, focal and segmental glomerulosclerosis, atypical hemolytic uremic syndrome, dense-deposit disease, C3 glomerulopathy, complement- and IgG-positive membranoproliferative glomerulonephritis or membranoproliferative glomerulonephritis type I-III (old classification). During phase 1, patient data will be collected in an online database. The biorepository (phase 2) will involve collection of samples from patients for identification of predictors of recurrence, biomarkers of disease activity or response to therapy, and novel pathogenic mechanisms. Finally, through phase 3, we will use our multicenter network of patients and centers to launch interventional studies. DISCUSSION: Most prior studies of post-transplant GD recurrence are single-center and retrospective, or rely upon registry data that frequently misclassify the cause of kidney disease. Systematically determining GD recurrence rates and predictors of clinical outcomes is essential to improving post-transplant outcomes. Furthermore, accurate molecular phenotyping and biomarker development will allow better understanding of individual GD pathogenesis, and potentially identify novel drug targets for GD in both native and transplanted kidneys. The TANGO study has the potential to tackle GD recurrence through a multicenter design and a comprehensive biorepository.

Kidney Transplantation Outcomes across GN Subtypes in the United States.

Differences in kidney transplantation outcomes across GN subtypes have rarely been studied. From the US Renal Data System, we identified all adult (≥18 years) first kidney transplant recipients (1996-2011) with ESRD attributed to one of six GN subtypes or two comparator kidney diseases. We computed hazard ratios (HRs) for death, all-cause allograft failure, and allograft failure excluding death as a cause (competing risks framework) using Cox proportional hazards regression. Among the 32,131 patients with GN studied, patients with IgA nephropathy (IgAN) had the lowest mortality rates and patients with IgAN or vasculitis had the lowest allograft failure rates. After adjusting for patient- and transplant-related factors, compared with IgAN (referent), FSGS, membranous nephropathy, membranoproliferative GN, lupus nephritis, and vasculitis associated with HRs (95% confidence intervals) for death of 1.57 (1.43 to 1.72), 1.52 (1.34 to 1.72), 1.76 (1.55 to 2.01), 1.82 (1.63 to 2.02), and 1.56 (1.34 to 1.81), respectively, and with HRs for allograft failure excluding death as a cause of 1.20 (1.12 to 1.28), 1.27 (1.14 to 1.41), 1.50 (1.36 to 1.66), 1.11 (1.02 to 1.20), and 0.94 (0.81 to 1.09), respectively. Considering external comparator groups, and comparing with IgAN, autosomal dominant polycystic kidney disease (ADPKD) and diabetic nephropathy associated with higher HRs for mortality [1.22 (1.12 to 1.34) and 2.57 (2.35 to 2.82), respectively], but ADPKD associated with a lower HR for allograft failure excluding death as a cause [0.85 (0.79 to 0.91)]. Reasons for differential outcomes by GN subtype and cause of ESRD should be examined in future research.

Pregnancy Outcomes in Patients with Glomerular Disease Attending a Single Academic Center in North Carolina.

BACKGROUND: Contemporary data regarding pregnancy outcomes in US patients with primary glomerular diseases are lacking. We aimed to report fetal and maternal outcomes among women with biopsy-proven primary glomerular disease who received obstetric care at a single large academic US center. METHODS: All women with a biopsy-confirmed primary glomerular disease diagnosis and without end-stage kidney disease who received obstetric care at the University of North Carolina (UNC) Hospitals (1996-2015) were identified using the Glomerular Disease Collaborative Network registry and the UNC Hospitals Perinatal Database. The primary study outcome was perinatal death (stillbirth at >20 weeks or neonatal death). Secondary outcomes included premature birth (<37 weeks), birth weight, preeclampsia, and kidney function changes (postpartum vs. baseline). Demographics, clinical characteristics, and outcomes were compared across glomerular disease subtypes. RESULTS: Among 48 pregnancies in 43 women (IgA nephropathy n = 17, focal segmental glomerulosclerosis [FSGS] n = 16, membranous nephropathy n = 6, minimal change disease n = 4), 13% of pregnancies resulted in perinatal death and 48% of babies were born prematurely. From a maternal perspective, 33% of pregnancies were complicated by preeclampsia, 39% by a doubling of urinary protein, and 27% by a ≥50% increase in serum creatinine. Outcome differences across glomerular disease subtypes were not statistically significant, although decline in kidney function appeared most frequent in FSGS. CONCLUSION: Adverse pregnancy outcomes are frequently observed in women with glomerular disease. The independent influence of glomerular disease subtype on outcomes requires further study. More widespread reporting and analysis of pregnancy outcomes in women with glomerular disease are urgently needed.

Differences in Initial Hemodialysis Vascular Access Use Among Glomerulonephritis Subtypes in the United States.

BACKGROUND: The type of vascular access used for hemodialysis affects patient morbidity and mortality. Whether vascular access types differ by glomerulonephritis (GN) subtype in the US hemodialysis population has not been investigated. STUDY DESIGN: Cross-sectional observational study. SETTING & PARTICIPANTS: We identified all adult (aged ≥ 18 years) patients within the US Renal Data System who initiated hemodialysis therapy from July 2005 through December 2011 with a diagnosis of end-stage renal disease attributed to any of 4 primary (focal segmental glomerulosclerosis, immunoglobulin A nephropathy [reference group], membranous nephropathy, and membranoproliferative GN) or 2 secondary (lupus nephritis and vasculitis) GN subtypes. PREDICTOR: GN subtype. OUTCOMES: ORs with 95% CIs for arteriovenous fistula versus central venous catheter (CVC) use and for arteriovenous graft versus CVC use were computed using multinomial logistic regression, with adjustment for demographic, socioeconomic, comorbidity, and duration of nephrology care covariates. RESULTS: Among 29,015 patients, CVC use at initiation of hemodialysis therapy was substantially higher in patients with lupus nephritis (89.2%) or vasculitis (91.2%) compared with patients with primary GN subtypes (72.7%-79.8%). After adjustment and compared with patients with immunoglobulin A nephropathy, patients with lupus nephritis or vasculitis were as likely to have used an arteriovenous graft (ORs of 0.94 [95% CI, 0.70-1.27] and 0.80 [95% CI, 0.56-1.13], respectively) but significantly less likely to have used an arteriovenous fistula (ORs of 0.66 [95% CI, 0.57-0.76] and 0.54 [95% CI, 0.45-0.63], respectively), whereas patients with any comparator primary GN subtype were at least as likely to have used either of these 2 access types. LIMITATIONS: Potential misclassification of exposure; residual confounding by unmeasured covariates; inability to determine causes of observed associations; lacking longitudinal data for vascular access use. CONCLUSIONS: Significant differences in vascular access distributions at initiation of hemodialysis therapy are apparent among GN subtypes. The unacceptably high use of CVCs in patients with lupus nephritis and vasculitis is particularly concerning. Further studies are needed to identify any potentially modifiable factors underlying these findings.

Differences in initial treatment modality for end-stage renal disease among glomerulonephritis subtypes in the USA.

BACKGROUND: Kidney transplantation is the preferred treatment for end-stage renal disease (ESRD), while peritoneal dialysis affords certain benefits over hemodialysis. Distributions and determinants of first ESRD treatment modality have not been compared across glomerulonephritis (GN) subtypes. METHODS: We identified all adult (18-75 years) patients with ESRD attributed to any of six GN subtypes [focal segmental glomerulosclerosis (FSGS), IgA nephropathy (IgAN), membranous nephropathy (MN), membranoproliferative GN (MPGN), lupus nephritis (LN) and vasculitis] who were first registered in the US Renal Data System (USRDS) between 1996 and 2011. We used multinomial logistic regression--adjusting for temporal, geographic, demographic, socioeconomic and comorbid factors--to determine odds ratios (ORs) with 95% confidence intervals (CIs) for transplantation versus hemodialysis, and for peritoneal dialysis versus hemodialysis, comparing other GN subtypes to IgAN. RESULTS: Among the 75 278 patients studied, patients with comparator GN subtypes were significantly less likely than those with IgAN to receive either transplantation or peritoneal dialysis. After adjusting for potentially confounding covariates, patients with comparator primary GN subtypes (FSGS, MN, MPGN) were at least as likely to receive transplantation [FSGS OR 0.98 (95% CI 0.93-1.15), MN OR 1.19 (95% CI 1.01-1.39), MPGN OR 1.08 (95% CI 0.93-1.26)] or peritoneal dialysis [FSGS OR 1.05 (95% CI 0.98-1.12), MN OR 1.30 (95% CI 1.18-1.43), MPGN OR 0.95 (95% CI 0.85-1.06)] as patients with IgAN. Conversely, patients with the secondary GN subtypes LN and vasculitis remained significantly less likely to receive either modality [transplantation OR 0.49 (95% CI 0.43-0.56) for LN and 0.27 (95% CI 0.22-0.34) for vasculitis, peritoneal dialysis OR 0.76 (95% CI 0.70-0.82) for LN and 0.54 (95% CI 0.48-0.60) for vasculitis]. CONCLUSIONS: Significant differences in ESRD treatment practice patterns are apparent among GN subtypes. To ensure equitable care for all patients, regardless of GN subtype, reasons for observed disparities should be elucidated and-if appropriate-eliminated.