Discrepancy between Medical Evidence Form 2728 and renal biopsy for glomerular diseases

Developing a genetic testing panel for evaluation of morbidities in kidney transplant recipients

Cardiovascular disease, infection, malignancy, and thromboembolism are major causes of morbidity and mortality in kidney transplant recipients (KTR). Prospectively identifying monogenic conditions associated with post-transplant complications may enable personalized management. Therefore, we developed a transplant morbidity panel (355 genes) associated with major post-transplant complications including cardiometabolic disorders, immunodeficiency, malignancy, and thrombophilia. This gene panel was then evaluated using exome sequencing data from 1590 KTR. Additionally, genes associated with monogenic kidney and genitourinary disorders along with American College of Medical Genetics (ACMG) secondary findings v3.2 were annotated. Altogether, diagnostic variants in 37 genes associated with Mendelian kidney and genitourinary disorders were detected in 9.9% (158/1590) of KTR; 25.9% (41/158) had not been clinically diagnosed. Moreover, the transplant morbidity gene panel detected diagnostic variants for 56 monogenic disorders in 9.1% KTRs (144/1590). Cardiovascular disease, malignancy, immunodeficiency, and thrombophilia variants were detected in 5.1% (81), 2.1% (34), 1.8% (29) and 0.2% (3) among 1590 KTRs, respectively. Concordant phenotypes were present in half of these cases. Reviewing implications for transplant care, these genetic findings would have allowed physicians to set specific risk factor targets in 6.3% (9/144), arrange intensive surveillance in 97.2% (140/144), utilize preventive measures in 13.2% (19/144), guide disease-specific therapy in 63.9% (92/144), initiate specialty referral in 90.3% (130/144) and alter immunosuppression in 56.9% (82/144). Thus, beyond diagnostic testing for kidney disorders, sequence annotation identified monogenic disorders associated with common post-transplant complications in 9.1% of KTR, with important clinical implications. Incorporating genetic diagnostics for transplant morbidities would enable personalized management in pre- and post-transplant care.

Characteristics and Outcomes of Patients With Pregnancy-Related End-Stage Kidney Disease

Importance

The incidence of pregnancy-related acute kidney injury is increasing and is associated with significant maternal morbidity including progression to end-stage kidney disease (ESKD). Little is known about characteristics and long-term outcomes of patients who develop pregnancy-related ESKD.

Objectives

To examine the characteristics and clinical outcomes of patients with pregnancy-related ESKD and to investigate associations between pre-ESKD nephrology care and outcomes.

Design, Setting, and Participants

This was a cohort study of 183 640 reproductive-aged women with incident ESKD between January 1, 2000, and November 20, 2020, from the US Renal Data System and maternal data from births captured in the US Centers for Disease Control and Prevention publicly available natality data. Data were analyzed from December 2022 to June 2023.

Exposure

Pregnancy-related primary cause of ESKD, per International Classification of Diseases, Ninth Revision (ICD-9) and ICD-10 codes reported at ESKD onset by the primary nephrologist on Centers for Medicare and Medicaid Services form 2728.

Main Outcomes Measures

Multivariable Cox proportional hazards and competing risk models were constructed to examine time to (1) mortality, (2) access to kidney transplant (joining the waiting list or receiving a live donor transplant), and (3) receipt of transplant after joining the waitlist.

Results

A total of 341 patients with a pregnancy-related primary cause of ESKD were identified (mean [SD] age 30.2 [7.3]). Compared with the general US birthing population, Black patients were overrepresented among those with pregnancy-related ESKD (109 patients [31.9%] vs 585 268 patients [16.2%]). In adjusted analyses, patients with pregnancy-related ESKD had similar or lower hazards of mortality compared with those with glomerulonephritis or cystic kidney disease (adjusted hazard ratio [aHR], 0.96; 95% CI, 0.76-1.19), diabetes or hypertension (aHR, 0.49; 95% CI, 0.39-0.61), or other or unknown primary causes of ESKD (aHR, 0.60; 95% CI, 0.48-0.75). Despite this, patients with pregnancy-related ESKD had significantly lower access to kidney transplant compared with those with other causes of ESKD, including (1) glomerulonephritis or cystic kidney disease (adjusted subhazard ratio [aSHR], 0.51; 95% CI, 0.43-0.66), (2) diabetes or hypertension (aSHR, 0.81; 95% CI, 0.67-0.98), and (3) other or unkown cause (aSHR, 0.82; 95% CI, 0.67-0.99). Those with pregnancy-related ESKD were less likely to have nephrology care or have a graft or arteriovenous fistula placed before ESKD onset (nephrology care: adjusted relative risk [aRR], 0.47; 95% CI, 0.40-0.56; graft or arteriovenous fistula placed: aRR, 0.31; 95% CI, 0.17-0.57).

Conclusion and Relevance

In this study, those with pregnancy-related ESKD had reduced access to transplant and nephrology care, which could exacerbate existing disparities in a disproportionately Black population. Increased access to care could improve quality of life and health outcomes among these young adults with high potential for long-term survival.

Association between cause of kidney failure and fracture incidence in a national US dialysis population cohort study

Background

Whether fracture rates, overall and by fracture site, vary by cause of kidney failure in patients receiving dialysis is unknown.

Methods

Using the US Renal Data System, we compared fracture rates across seven causes of kidney failure in patients who started dialysis between 1997 and 2014. We computed unadjusted and multivariable adjusted proportional sub-distribution hazard models, with fracture events (overall, and by site) as the outcome and immunoglobulin A nephropathy as the reference group. Kidney transplantation and death were competing events.

Results

Among 491 496 individuals, with a median follow-up of 2.0 (25%, 75% range 0.9–3.9) years, 62 954 (12.8%) experienced at least one fracture. Patients with diabetic nephropathy, vasculitis or autosomal polycystic kidney disease (ADPKD) had the highest (50, 46 and 40 per 1000 person-years, respectively), and patient with lupus nephritis had the lowest (20 per 1000 person-years) fracture rates. After multivariable adjustment, diabetic nephropathy [hazard ratio (HR) 1.43, 95% confidence interval 1.33–1.53], ADPKD (HR 1.37, 1.26–1.48), vasculitis (HR 1.22, 1.09–1.34), membranous nephropathy (HR 1.16, 1.02–1.30) and focal segmental glomerulosclerosis (FSGS) (HR 1.13, 1.02–1.24) were associated with a significantly higher, and lupus nephritis with a significantly lower (HR 0.85, 0.71–0.98) fracture hazard. The hazards for upper extremity and lower leg fractures were significantly higher in diabetic nephropathy, ADPKD, FSGS and membranous nephropathy, while the hazard for vertebral fracture was significantly higher in vasculitis. Our findings were limited by the lack of data on medication use and whether fractures were traumatic or non-traumatic, among other factors.

Conclusions

Fracture risk, overall and by fracture site, varies by cause of end-stage kidney disease. Future work to determine underlying pathogenic mechanisms contributing to differential risks might inform more tailored treatment strategies. Our study was limited by lack of data regarding numerous potential confounders or mediators including medications and measures or bone biomarkers.

Transplantation Mediates Much of the Racial Disparity in Survival from Childhood-Onset Kidney Failure

BACKGROUND

The role of kidney transplantation in differential survival in Black and White patients with childhood-onset kidney failure is unexplored.

METHODS

We analyzed 30-year cohort data of children beginning RRT before 18 years of age between January 1980 and December 2017 (n=28,337) in the US Renal Data System. Cox regression identified transplant factors associated with survival by race. The survival mediational g-formula estimated the excess mortality among Black patients that could be eliminated if an intervention equalized their time with a transplant to that of White patients.

RESULTS

Black children comprised 24% of the cohort and their crude 30-year survival was 39% compared with 57% for White children (log rank P<0.001). Black children had 45% higher risk of death (adjusted hazard ratio [aHR], 1.45; 95% confidence interval [95% CI], 1.36 to 1.54), 31% lower incidence of first transplant (aHR, 0.69; 95% CI, 0.67 to 0.72), and 39% lower incidence of second transplant (aHR, 0.61; 95% CI, 0.57 to 0.65). Children and young adults are likely to require multiple transplants, yet even after their first transplant, Black patients had 11% fewer total transplants (adjusted incidence rate ratio [aIRR], 0.89; 95% CI, 0.86 to 0.92). In Black patients, grafts failed earlier after first and second transplants. Overall, Black patients spent 24% less of their RRT time with a transplant than did White patients (aIRR, 0.76; 95% CI, 0.74 to 0.78). Transplantation compared with dialysis strongly protected against death (aHR, 0.28; 95% CI, 0.16 to 0.48) by time-varying analysis. Mediation analyses estimated that equalizing transplant duration could prevent 35% (P<0.001) of excess deaths in Black patients.

CONCLUSIONS

Equalizing time with a functioning transplant for Black patients may equalize survival of childhood-onset ESKD with White patients.

Validation of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis as the Cause of End-Stage Renal Disease in the US Renal Data System

Objective

The objective of this study was to validate the diagnosis of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) as the primary cause of end‐stage renal disease (ESRD) in the US Renal Data System (USRDS).

Methods

We identified patients with ESRD in the Mass General Brigham (MGB) health care system who were enrolled in the USRDS. The health records of those with AAV listed as the primary cause of ESRD in the USRDS were reviewed to confirm the diagnosis and estimate positive predictive value (PPV). Sensitivity was estimated by evaluating the primary cause of ESRD listed in the USRDS for patients with ESRD due to AAV in the MGB AAV cohort.

Results

We identified 89 MGB patients with ESRD due to AAV in the USRDS. Of these, 85 cases were confirmed to be true cases of AAV (PPV = 94%). Among the patients classified as having AAV, 84 (99%) had an ANCA test, which was predominantly myeloperoxidase/P‐ANCA (47 [55%]); 36 (42%) had a renal biopsy, and all biopsies were supportive of the diagnosis. The majority (81 [90%]) was identified as AAV by International Classification of Diseases Ninth Revision or International Classification of Diseases 10th Revision codes for granulomatosis with polyangiitis (446.4 or M313.1). Of the 77 MGB AAV cohort patients with ESRD who were linked to the USRDS, 41 (53%) had AAV listed as the cause of ESRD; in the remainder, ESRD was attributed to nonspecific nephritis.

Conclusion

The diagnosis of AAV as the cause of ESRD in the USRDS has a high PPV; sensitivity was moderate. These findings support the continued use of the USRDS to study ESRD due to AAV.

Sequential genetic testing of living-related donors for inherited renal disease to promote informed choice and enhance safety of living donation

Living kidney donors (LKDs) with a family history of renal disease are at risk of kidney disease as compared to LKDs without such history suggesting that some LKDs may be pre-symptomatic for monogenic kidney disease. LKDs with related transplant candidates whose kidney disease was considered genetic in origin were selected for genetic testing. In each case, the transplant candidate was first tested to verify the genetic diagnosis. A genetic diagnosis was confirmed in 12 of 24 transplant candidates (ADPKD-PKD1: 6, ALPORT-COL4A3: 2, ALPORT-COL4A5: 1: nephronophthisis-SDCCAG8: 1; CAKUT-HNF1B and ADTKD-MUC1: 1 each) and 2 had variants of unknown significance (VUS) in phenotype-relevant genes. Focused genetic testing was then done in 20 of 34 LKDs. 12 LKDs screened negative for the familial variant and were permitted to donate; seven screened positive and were counseled against donation. One, the heterozygous carrier of a recessive disorder was also cleared. Six of seven LKDs with a family history of ADPKD were under 30 years and in 5, by excluding ADPKD, allowed donation to safely proceed. The inclusion of genetic testing clarified the diagnosis in recipient candidates, improving safety or informed decision-making in LKDs.

End-stage renal disease and metalworking fluid exposure

OBJECTIVE

Despite increasing prevalence of end-stage renal disease (ESRD), little attention has been directed to how occupational exposures may contribute to risk. Our objective was to investigate the relationship between metalworking fluids (MWF) and ESRD in a cohort of 36 703 male autoworkers.

METHODS

We accounted for competing risk of death, using the subdistribution hazard approach to estimate subhazard ratios (sHRs) and 95% CIs in models with cubic splines for cumulative exposure to MWF (straight, soluble or synthetic).

RESULTS

Based on 501 ESRD cases and 13 434 deaths, we did not observe an association between MWF and ESRD overall. We observed modest associations between MWF and ESRD classification of glomerulonephritis and diabetic nephropathy. For glomerulonephritis, the 60th percentile of straight MWF was associated with an 18% increased subhazard (sHR=1.18, 95% CI: 0.99 to 1.41). For diabetic nephropathy, the subhazard increased 28% at the 60th percentile of soluble MWF (sHR=1.28, 95% CI: 1.00 to 1.64). Differences by race suggest that black males may have higher disease rates following MWF exposure.

CONCLUSIONS

Exposure to straight and soluble MWF may be related to ESRD classification, though this relationship should be further examined.

Morbidity and Mortality of Spinal Epidural Abscess in End-Stage Renal Disease Patients: A Case-Control Study

BACKGROUND

Spinal epidural abscess (SEA) is an uncommon and highly morbid infection of the epidural space. End-stage renal disease (ESRD) patients are known to be at increased risk of developing SEA; however, there are no studies that have described the risk factors and outcomes of SEA in ESRD patients utilizing the United States Renal Data System (USRDS).

METHODS

To determine risk factors, morbidity, and mortality associated with SEA in ESRD patients, a retrospective case-control study was conducted using the USRDS. ESRD patients diagnosed with SEA between 2005 and 2010 were identified, and logistic regression was performed to examine correlates of SEA, as well as risk factors associated with mortality in SEA-ESRD patients.

RESULTS

The prevalence of SEA amongst ESRD patients was 0.39% (n = 1,697). Patients with SEA were more likely to be male [adjusted Odds Ratio (OR) = 1.22], black (OR = 1.19), diabetic (OR = 1.26), with catheter access (OR = 1.29), and less likely to be ≥65 years old (OR = 0.64). Osteomyelitis, bacteremia/septicemia, MRSA, and endocarditis were all significantly associated with increased risk of SEA (OR = 1.54-5.14). Age ≥65 years (HR = 1.45), urinary tract infections (HR = 1.26), decubitus ulcers (HR=1.37), and post-SEA paraplegia (HR = 1.25) were significantly associated with mortality among those with SEA.

CONCLUSIONS

As described in previous literature, risk factors for SEA included infections, diabetes, and indwelling catheters. Additionally, clinicians should be aware of the risk factors for mortality in SEA-ESRD patients. As the largest study of SEA to date, our report identifies important risk factors for SEA in ESRD patients, and novel data regarding their mortality-associated risk factors.

Four steps to standardize reporting of peritoneal dialysis technique failure: A proposed approach

BACKGROUND

Technique failure is an important outcome measure in research and quality improvement in peritoneal dialysis (PD) programs, but there is a lack of consistency in how it is reported.

METHODS

We used data collected about incident dialysis patients from 10 Canadian dialysis programs between 1 January 2004 and 31 December 2018. We identified four main steps that are required when calculating the risk of technique failure. We changed one variable at a time, and then all steps, simultaneously, to determine the impact on the observed risk of technique failure at 24 months.

RESULTS

A total of 1448 patients received PD. Selecting different cohorts of PD patients changed the observed risk of technique failure at 24 months by 2%. More than one-third of patients who switched to hemodialysis returned to PD-90% returned within 180 days. The use of different time windows of observation for a return to PD resulted in risks of technique failure that differed by 16%. The way in which exit events were handled during the time window impacted the risk of technique failure by 4% and choice of statistical method changed results by 4%. Overall, the observed risk of technique failure at 24 months differed by 20%, simply by applying different approaches to the same data set.

CONCLUSIONS

The approach to reporting technique failure has an important impact on the observed results. We present a robust and transparent methodology to track technique failure over time and to compare performance between programs.

Assessing the Impacts of Misclassified Case-Mix Factors on Health Care Provider Profiling: Performance of Dialysis Facilities

Quantitative metrics are used to develop profiles of health care institutions, including hospitals, nursing homes, and dialysis clinics. These profiles serve as measures of quality of care, which are used to compare institutions and determine reimbursement, as a part of a national effort led by the Center for Medicare and Medicaid Services in the United States. However, there is some concern about how misclassification in case-mix factors, which are typically accounted for in profiling, impacts results. We evaluated the potential effect of misclassification on profiling results, using 20 744 patients from 2740 dialysis facilities in the US Renal Data System. In this case study, we compared 30-day readmission as the profiling outcome measure, using comorbidity data from either the Center for Medicare and Medicaid Services Medical Evidence Report (error-prone) or Medicare claims (more accurate). Although the regression coefficient of the error-prone covariate demonstrated notable bias in simulation, the outcome measure—standardized readmission ratio—and profiling results were quite robust; for example, correlation coefficient of 0.99 in standardized readmission ratio estimates. Thus, we conclude that misclassification on case-mix did not meaningfully impact overall profiling results. We also identified both extreme degree of case-mix factor misclassification and magnitude of between-provider variability as 2 factors that can potentially exert enough influence on profile status to move a clinic from one performance category to another (eg, normal to worse performer).

Primary causes of kidney disease and mortality in dialysis-dependent children

BACKGROUND

Congenital anomalies of the kidney and urinary tract (CAKUT) is associated with a slower progression to end-stage renal disease (ESRD) in pre-dialysis patients. However, little is known about the associated mortality risks after transitioning to dialysis.

METHODS

This retrospective cohort study included 0-21 year-old incident dialysis patients from the United States Renal Data System starting dialysis between 1995 and 2016. We examined the association of CAKUT vs. non-CAKUT with all-cause mortality, using Cox regression adjusted for case mix variables. We also examined the mortality risk associated with 14 non-CAKUT vs. CAKUT ESRD etiologies and under stratification by estimated glomerular filtration rate (eGFR).

RESULTS

Among 25,761 patients, the median (interquartile range) age was 17 (11-19) years, and 4780 (19%) had CAKUT. CAKUT was associated with lower mortality, with an adjusted hazard ratio (aHR) of 0.72 (95%CI, 0.64-0.81) (reference: non-CAKUT). In age-stratified analyses, CAKUT vs. non-CAKUT aHRs (95%CI) were 0.66 (0.54-0.80), 0.56 (0.39-0.80), 0.66 (0.50-0.86), and 0.97 (0.80-1.18) among patients < 6, 6-< 13, 13-< 18, and ≥ 18 years at dialysis initiation, respectively. Among non-CAKUT ESRD etiologies, the risk of mortality associated with primary glomerulonephritis (aHR, 0.93; 95%CI 0.80-1.09) and focal segmental glomerulosclerosis (aHR, 0.89; 95%CI, 0.75-1.04) were comparable or slightly lower compared to CAKUT, whereas most other primary causes were associated with higher mortality risk. While the CAKUT group had lower mortality risk compared to the non-CAKUT group patients with eGFR ≥5 mL/min/1.73m², CAKUT was associated with higher mortality in patients with eGFR < 5 mL/min/1.73 m².

CONCLUSIONS

CAKUT is associated with lower mortality among children < 18 years old, but showed comparable mortality with non-CAKUT among patients ≥ 18 years old. ESRD etiology should be considered in risk assessment for children initiating dialysis.

Initial experience from a renal genetics clinic demonstrates a distinct role in patient management

Purpose

A Renal Genetics Clinic (RGC) was established to optimize diagnostic testing, facilitate genetic counseling, and direct clinical management.

Methods

Retrospective review of patients seen over a two-year period in the RGC.

Results

One hundred eleven patients (mean age: 39.9 years) were referred to the RGC: 65 for genetic evaluation, 19 for management of a known genetic disease, and 18 healthy living kidney donors (LKDs) and their 9 related transplant candidates for screening. Forty-three patients underwent genetic testing with a diagnosis in 60% of patients including 9 with Alport syndrome, 7 with autosomal dominant polycystic kidney disease (ADPKD), 2 with genetic focal segmental glomerulosclerosis (FSGS), 2 with PAX2-mediated CAKUT, and 1 each with autosomal recessive polycystic kidney disease (ARPKD), Dent, Frasier, Gordon, Gitelman, and Zellweger syndromes. Four of 18 LKDs were referred only for APOL1 screening. For the remaining 14 LKDs, their transplant candidates were first tested to establish a genetic diagnosis. Five LKDs tested negative for the familial genetic variant, four were positive for their familial variant. In five transplant candidates, a genetic variant could not be identified.

Conclusion

An RGC that includes genetic counseling enhances care of renal patients by improving diagnosis, directing management, affording presymptomatic family focused genetic counseling, and assisting patients and LKDs to make informed decisions.

Recurrence of FSGS after Kidney Transplantation in Adults

BACKGROUND AND OBJECTIVES

FSGS recurrence after kidney transplantation is a major risk factor for graft loss. However, the natural history, clinical predictors, and response to treatment remain unclear because of small sample sizes and poor generalizability of single-center studies, and disease misclassification in registry-based studies. We therefore aimed to determine the incidence, predictors, and treatment response of recurrent FSGS in a large cohort of kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Post-Transplant Glomerular Disease (TANGO) project is an observational, multicenter, international cohort study that aims to investigate glomerular disease recurrence post-transplantation. Transplant recipients were screened for the diagnosis of idiopathic FSGS between 2005 and 2015 and details were recorded about the transplant, clinical outcomes, treatments, and other risk factors.

RESULTS

Among 11,742 kidney transplant recipients screened for FSGS, 176 had a diagnosis of idiopathic FSGS and were included. FSGS recurred in 57 patients (32%; 95% confidence interval [95% CI], 25% to 39%) and 39% of them lost their graft over a median of 5 (interquartile range, 3.0-8.1) years. Multivariable Cox regression revealed a higher risk for recurrence with older age at native kidney disease onset (hazard ratio [HR], 1.37 per decade; 95% CI, 1.09 to 1.56). Other predictors were white race (HR, 2.14; 95% CI, 1.08 to 4.22), body mass index at transplant (HR, 0.89 per kg/m²; 95% CI, 0.83 to 0.95), and native kidney nephrectomies (HR, 2.76; 95% CI, 1.16 to 6.57). Plasmapheresis and rituximab were the most frequent treatments (81%). Partial or complete remission occurred in 57% of patients and was associated with better graft survival.

CONCLUSIONS

Idiopathic FSGS recurs post-transplant in one third of cases and is associated with a five-fold higher risk of graft loss. Response to treatment is associated with significantly better outcomes but is achieved in only half of the cases.

Pathological spectrum of glomerular disease in patients with renal insufficiency: a single-center study in Northeastern China

Background: To investigate the pathological spectrum of glomerular disease in patients with renal insufficiency (RI) from 2008 to 2017. Methods and results: We calculated the estimated glomerular filtration rate (eGFR) with the Chronic Kidney Disease Epidemiology Collaboration creatinine (CKD-EPI) equation and defined RI as an eGFR <60 ml/min/1.73 m². A total of 969 RI patients were included in our study. IgA nephropathy (IgAN) was the most common subtype of primary glomerulonephritis (37.2%). The frequencies of IgAN and non-IgA mesangioproliferative glomerulonephritis decreased from 27.3% and 9.5% during 2008-2012 to 20.7% and 2.6% during 2013-2017, respectively. However, the frequency of membranous nephropathy increased from 6.8% to 16.2%. Lupus nephritis was the most common subtype of secondary glomerulonephritis (32.1%). The frequencies of both ANCA-associated systemic vasculitis and diabetic nephropathy increased from 3.8% to 7.6% and from 4.3% to 7.6%, respectively. The number of elderly patients (≥60 years) in our study increased sharply, from 15.6% in 2008 to 35.0% in 2017. Membranous nephropathy, minimal change disease, membranoproliferative glomerulonephritis, lupus nephritis and renal amyloidosis are more frequently observed in the elderly patients than in nonelderly patients (<60 years) (p < .05). Excluding those with acute kidney injury, IgAN was the leading cause of RI (24.9%), followed by membranous nephropathy (13.3%) and lupus nephritis (12.0%). Conclusions: IgAN and lupus nephritis were the most prevalent primary glomerulonephritis and secondary glomerulonephritis in patients with RI, respectively. The frequencies of membranous nephropathy, ANCA-associated systemic vasculitis and diabetic nephropathy increased significantly. The number of elderly patients with RI increased sharply.

The association of acute rejection vs recurrent glomerular disease with graft outcomes after kidney transplantation

BACKGROUND

It has been shown that glomerulonephritis (GN) recurrence affects graft survival more than acute rejection. Thus, we assessed allograft survival after biopsy-confirmed diagnosis of acute rejection or recurrent GN in current era of immunosuppression.

METHODS

Allograft survival following a biopsy diagnosis of acute rejection or recurrent GN was determined in adult kidney transplant recipients from 1994 to 2013. A total of 306 patients (35%) with IgA, 298 (35%) with FSGS, 177 (21%) with lupus nephritis, and 81 (9%) with membranous nephropathy were followed for a median of 6.3 years.

RESULTS

Among the 862 transplant recipients with primary GN, allograft loss was similar following a biopsy diagnosis of acute rejection or recurrent glomerular disease (11.5 vs 14.2/100 person-years, P = .15). Differences in allograft survival emerged after 2.5 years following recurrent disease, with significantly higher graft failure in patients with FSGS, MN, or LN compared with IgA after recurrence of disease (16.7 vs 7.5/100 person-years, P = .05). The advantage in allograft survival for IgA patients did not achieve significance after acute rejection (P = .10 for IgA vs FSGS, MN, and LN).

CONCLUSIONS

Allograft survival was similar after disease recurrence or acute rejection after kidney transplant in patients with ESRD due to GN.

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.

Non-recovery from dialysis-requiring acute kidney injury and short-term mortality and cardiovascular risk: a cohort study

Background

The high mortality and cardiovascular disease (CVD) burden in patients with end-stage renal disease (ESRD) is well-documented. Recent literature suggests that acute kidney injury is also associated with CVD. It is unknown whether patients with incident ESRD due to dialysis-requiring acute kidney injury (AKI-D) are at higher short-term risk for death and CVD events, compared with incident ESRD patients without preceding AKI-D. Few studies have examined the impact of recovery from AKI-D on subsequent CVD risk.

Methods

In this retrospective cohort study, we evaluated adult members of Kaiser Permanente Northern California who initiated dialysis from January 2009 to September 2015. Preceding AKI-D and subsequent outcomes of death and CVD events (acute coronary syndrome, heart failure, ischemic stroke or transient ischemic attack) were identified from electronic health records. We performed multivariable Cox regression models adjusting for demographics, comorbidities, medication use, and laboratory results.

Results

Compared to incident ESRD patients who experienced AKI-D (n = 1865), patients with ESRD not due to AKI-D (n = 3772) had significantly lower adjusted rates of death (adjusted hazard ratio [aHR] 0.56, 95% CI: 0.47–0.67) and heart failure hospitalization (aHR 0.45, 0.30–0.70). Compared to AKI-D patients who did not recover and progressed to ESRD, AKI-D patients who recovered (n = 1347) had a 30% lower adjusted relative rate of death (aHR 0.70, 0.55–0.88).

Conclusions

Patients who transition to ESRD via AKI-D are a high-risk subgroup that may benefit from aggressive monitoring and medical management, particularly for heart failure. Recovery from AKI-D is independently associated with lower short-term mortality.

Mortality and Allograft Loss Trends Among US Pediatric Kidney Transplant Recipients With and Without Focal Segmental Glomerulosclerosis

BACKGROUND

Pediatric patients with focal segmental glomerulosclerosis (FSGS) have high rates of disease recurrence and allograft failure after kidney transplantation, but there are few data for long-term survival posttransplantation.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

12,303 pediatric patients (aged <18 years), including 1,408 (11%) patients with FSGS, who received a first kidney transplant in 1990 through 2009 and were followed up through June 2015 were identified from the US Renal Data System database.

PREDICTORS

Primary cause of end-stage renal disease, FSGS or other.

OUTCOMES

All-cause patient mortality and allograft loss.

RESULTS

All-cause mortality significantly improved for patients with FSGS who underwent transplantation in the 2000s versus the 1990s (6.72 vs 12.24 deaths/1,000 patient-years; HR, 0.55; 95% CI, 0.39-0.78; P<0.001). Reductions in allograft loss were less dramatic (75.91 vs 89.05 events/1,000 patient-years; HR, 0.85; 95% CI, 0.74-0.98; P=0.02). After adjusting for baseline characteristics at the time of transplantation, patients with FSGS had similar rates of death compared with patients without FSGS (HRs of 0.81 [P=0.6] and 1.06 [P=0.2] among those who underwent transplantation in the 2000s and 1990s, respectively) despite higher rates of allograft loss (HRs of 1.17 [P=0.03] and 1.27 [P<0.001], respectively). Among patients who underwent transplantation in the 2000s, further adjustment for allograft failure as a time-varying covariate demonstrated a lower rate of death among patients with FSGS compared with those without FSGS (HR, 0.70; P=0.02).

LIMITATIONS

Lack of information about certain risk factors for mortality, including duration of chronic kidney disease; missing data; and potential primary disease misclassification.

CONCLUSIONS

Survival of pediatric kidney transplant recipients with FSGS improved between the 1990s and 2000s and was similar to that of recipients without FSGS. Interestingly, adjustment for allograft failure showed greater survival for pediatric patients with FSGS who underwent transplantation in the 2000s as compared with others, suggesting that effective interventions to decrease allograft loss due to disease recurrence may improve patient survival.

End-Stage Kidney Disease From Scleroderma in the United States, 1996 to 2012

Introduction

Although the management of scleroderma continues to evolve, it is unknown whether the burden of end-stage kidney disease (ESKD) treated with maintenance renal replacement therapy from SD has changed.

Methods

We examined United States Renal Data System data (n = 1,677,303) for the years 1996 to 2012 to quantify the incidence and outcomes of ESKD from scleroderma treated with renal replacement therapy (n = 2398). Outcomes assessed through demography-matched scleroderma-positive/scleroderma-negative comparisons included recovery of kidney function, mortality, listing for transplant, renal transplantations, and graft failure.

Results

Overall ESKD rates from scleroderma were 0.5 per million per year. Adjusted incidence ratios fell over time, to 0.42 in 2012 (vs. 1996, 95% confidence interval [CI] = 0.32−0.54, P < 0.001). Adjusted incidence ratios for ESKD from scleroderma fell over time in both sexes, all age, race, and ethnicity categories except age < 20 years and Asian race, and in all regions of the United States. After initiating renal replacement therapy, patients with scleroderma had a greater likelihood of recovery of kidney function (hazards ratio [HR] = 2.67, 95% CI = 1.90−3.76, P < 0.001) and death (HR = 1.44, 95% CI = 1.34−1.54, P < 0.001) and a lower likelihood of transplantation (HR = 0.51, 95% CI = 0.44−0.59, P < 0.001) than demography-matched patients without scleroderma.

Conclusion

The incidence of ESKD from scleroderma appears to have declined in the United States since 1996. ESKD from scleroderma is associated with an enhanced likelihood of recovery of kidney function and death, a reduced likelihood of transplantation, and similar outcomes after transplantation.

Validation of Systemic Lupus Erythematosus Diagnosis as the Primary Cause of Renal Failure in the US Renal Data System

OBJECTIVE

Using American College of Rheumatology (ACR) and Systemic Lupus International Collaborating Clinics (SLICC) criteria for systemic lupus erythematosus (SLE) classification as gold standards, we determined sensitivity, specificity, positive and negative predictive values (PPV and NPV) of having SLE denoted as the primary cause of end-stage renal disease (ESRD) in the US Renal Data System (USRDS).

METHODS

ESRD patients were identified by International Classification of Diseases, Ninth Revision codes in electronic medical records of 1 large tertiary care center, Montefiore Hospital, from 2006 to 2012. Clinical data were extracted and reviewed to establish SLE diagnosis. Data were linked by social security number, name, and date of birth to the USRDS, where primary causes of ESRD were ascertained.

RESULTS

Of 7,396 ESRD patients at Montefiore, 97 met ACR/SLICC SLE criteria, and 86 had SLE by record only. Among the 97 SLE patients, the attributed causes of ESRD in the USRDS were 77 SLE and 12 with other causes (unspecified glomerulonephritis, hypertension, scleroderma), and 8 missing. Sensitivity, specificity, PPV, and NPV for SLE in the USRDS were 79%, 99.9%, 93%, and 99.7%, respectively. Of the 60 patients with biopsy-proven lupus nephritis, 44 (73%) had SLE as primary ESRD cause in the USRDS. Attribution of the primary ESRD causes among SLE patients with ACR/SLICC criteria differed by race, ethnicity, and transplant status.

CONCLUSION

The diagnosis of SLE as the primary cause of ESRD in the USRDS has good sensitivity, and excellent specificity, PPV, and NPV. Nationwide access to medical records and biopsy reports may significantly improve sensitivity of SLE diagnosis.

ESRD Databases, Public Policy, and Quality of Care: Translational Medicine and Nephrology

Efforts to improve care of patients with ESRD and the policies that guide those activities depend on evidence-based best practices derived from clinical trials and carefully conducted observational studies. Our review describes this process in the context of the translational research model (bench to bedside to populations), with a particular emphasis on bedside care. We illustrate some of its accomplishments and describe the limitations of the data and evidence supporting policy and practice.

Diabetic nephropathy as the cause of end-stage kidney disease reported on the medical evidence form CMS2728 at a single center

Background: End-stage renal disease (ESRD) incidence due to Type 2 diabetic nephropathy (DN) is 35-50%, according to the United States Renal Data System. Methods: A single-center, retrospective cohort study to determine incidence and diagnostic accuracy for Type 2 DN as the primary cause of ESRD (Code 250.40) on the Center for Medicare & Medicaid (CMS) Medical Evidence Report form (CMS2728) submitted at renal replacement therapy initiation. All patients  ≥18 years of age with a CMS2728 submitted between 1 March 2006 and 31 March 2015 at a single academic military medical center (ESRD Network 5) were included. Medical records of those with a Code 250.40 diagnosis were reviewed to determine whether they met the Kidney Disease Outcomes Quality Initiative (KDOQI) 2007 criteria for DN. Results: ESRD incidence secondary to Type 2 DN was 18.7% (56/299 individual CMS2728 submissions over 9.09 years). In all, 12/56 (21.4%) did not meet KDOQI criteria for Type 2 DN. Although all had diabetes, those not meeting criteria had shorter disease duration (P  =  0.007), were more likely to have active urine sediment (P  =  0.006), and were less likely to have macroalbuminuria (P  =  0.037) or retinopathy (P  =  0.002) prior to ESRD. On exact logistic regression, retinopathy was significantly associated with KDOQI-predicted DN [odds ratio  =  19.16 (confidence interval 2.76-223.7), P  =  0.0009]. Conclusions: In this single-center cohort, 21.4% identified as having Type 2 DN as the primary cause of ESRD were incorrectly assigned per KDOQI 2007 clinical criteria. If replicated in larger populations, this could have substantial implications regarding the epidemiology of ESRD in the USA.

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.

Comparison of vascular access outcomes in patients with end-stage renal disease attributed to systemic lupus erythematosus vs. other causes: a retrospective cohort study

BACKGROUND

U.S. hemodialysis patients with systemic lupus erythematosus (SLE) and end-stage renal disease (ESRD) are less likely than other ESRD patients to have a permanent vascular access (fistula or graft) in place at the dialysis start. We examined whether vascular access outcomes after dialysis start differed for SLE vs. other ESRD patients.

METHODS

Among U.S. patients initiating hemodialysis in 2010 with only a catheter (n = 40,911; 384 with SLE) and using a permanent access on first dialysis (n = 13,073; 48 with SLE), we examined the association of SLE status with time to first placement of a permanent access (among catheter-only patients) and to loss of access patency (among patients using a permanent access on first dialysis), both censored 1 year after dialysis start, using multivariable Cox proportional hazards models.

RESULTS

Among catheter-only patients, 46.1 % vs. 54.5 % of those with SLE-ESRD vs. other ESRD had a permanent access placed within 1 year after dialysis start. However, with adjustment, there was no association of 1-year placement with SLE status [HR = 1.00 (95 % CI, 0.86-1.17)]. SLE-ESRD vs. other ESRD patients starting dialysis with a permanent access were less likely to experience a 1-year loss of patency (43.8 % vs. 55.0 %), but this association was not statistically significant after adjustment [HR = 0.88 (0.57-1.37)].

CONCLUSION

These results suggest that SLE-ESRD patients starting dialysis with a catheter are not more likely to have a permanent access placed in the first year of dialysis, despite an observed lack of association of SLE status with subsequent loss of vascular access patency among those starting dialysis with a permanent access.

A comparison between physicians and computer algorithms for form CMS-2728 data reporting

INTRODUCTION

CMS-2728 form (Medical Evidence Report) assesses 23 comorbidities chosen to reflect poor outcomes and increased mortality risk. Previous studies questioned the validity of physician reporting on forms CMS-2728. We hypothesize that reporting of comorbidities by computer algorithms identifies more comorbidities than physician completion, and, therefore, is more reflective of underlying disease burden.

METHODS

We collected data from CMS-2728 forms for all 296 patients who had incident ESRD diagnosis and received chronic dialysis from 2005 through 2014 at Indiana University outpatient dialysis centers. We analyzed patients' data from electronic medical records systems that collated information from multiple health care sources. Previously utilized algorithms or natural language processing was used to extract data on 10 comorbidities for a period of up to 10 years prior to ESRD incidence. These algorithms incorporate billing codes, prescriptions, and other relevant elements. We compared the presence or unchecked status of these comorbidities on the forms to the presence or absence according to the algorithms.

FINDINGS

Computer algorithms had higher reporting of comorbidities compared to forms completion by physicians. This remained true when decreasing data span to one year and using only a single health center source. The algorithms determination was well accepted by a physician panel. Importantly, algorithms use significantly increased the expected deaths and lowered the standardized mortality ratios.

DISCUSSION

Using computer algorithms showed superior identification of comorbidities for form CMS-2728 and altered standardized mortality ratios. Adapting similar algorithms in available EMR systems may offer more thorough evaluation of comorbidities and improve quality reporting.

Attribution of cause of end-stage renal disease among patients with systemic lupus erythematosus: the Georgia Lupus Registry

Objective

Whether using provider-attributed end-stage renal disease (ESRD) cause of systemic lupus erythematosus (SLE) in national surveillance data captures the entire population of patients with SLE and ESRD remains uncertain. Our goal was to examine attributed cause of ESRD in US surveillance data among patients with SLE who have developed ESRD.

Methods

Data from a national registry of treated ESRD (United States Renal Data System (USRDS)) were linked to the population-based Georgia Lupus Registry (GLR). The provider-attributed cause of ESRD was extracted from the USRDS for each validated patient with SLE in the GLR (diagnosed through 2004) who initiated treatment for ESRD through 2012. The percentage of these patients with SLE whose ESRD was subsequently attributed to SLE in the USRDS was calculated, overall and by patient characteristics.

Results

Among 251 patients with SLE who progressed to ESRD, 78.9% had SLE as their attributed cause of ESRD. Of the remaining 53 patients, 43.4%, 18.9% and 15.6% had ESRD attributed to hypertension, diabetes mellitus type II and non-SLE-related glomerulonephritis, respectively. Attribution of ESRD to SLE was higher among patients aged ≤30 (87.9–93.9%) vs >30 (52.6%; p<0.001) but did not differ by sex or race. Having Medicaid (86.2%) or no insurance (93.5%) was associated with greater attribution of ESRD to SLE than having private insurance (72.5%; p=0.02), as was having two or more providers state a diagnosis of SLE (89.0% vs 73.5% with a rheumatologist diagnosis alone; p=0.008).

Conclusions

These estimates indicate that USRDS-based studies may underreport ESRD among US patients with SLE. However, observed patterns of differential attribution of ESRD cause, particularly by age, suggest that providers may be correctly attributing ESRD to causes other than SLE among some patients with SLE.

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.

Racial and Ethnic Differences in Mortality and Cardiovascular Events Among Patients With End-Stage Renal Disease Due to Lupus Nephritis

OBJECTIVE

To identify racial and ethnic differences in mortality and cardiovascular (CV) risk among patients with end-stage renal disease (ESRD) due to lupus nephritis (LN).

METHODS

Within the US ESRD registry (1995-2008), we identified individuals ages >17 years with incident ESRD due to systemic lupus erythematosus. We ascertained demographics, clinical factors, and deaths from registry patient files and CV events (myocardial infarction, heart failure, and hemorrhagic and ischemic strokes) from inpatient Medicare claims. We calculated incidence rates (95% confidence intervals [95% CIs]) per 1,000 person-years for study events, stratified by race and ethnicity. We compared probabilities of the events among racial and ethnic groups using cumulative incidence function curves and multivariable-adjusted subdistribution proportional hazard ratios (HRsd), taking into account the competing events of kidney transplantation and death (for nonfatal CV events).

RESULTS

Of 12,533 patients with LN-associated ESRD, the mean ± SD age was 40.7 ± 14.9 years, 82% were women, and 49% were African American. The overall mortality rate was 98.1/1,000 person-years (95% CI 95.3-100.9). In multivariable models, Asian and Hispanic LN-associated ESRD patients had lower mortality than whites (HRsd 0.70 [95% CI 0.58-0.84] and 0.79 [95% CI 0.71-0.88], respectively), whereas African Americans had higher mortality (HRsd 1.27 [95% CI 1.18-1.36]). African American patients >40 years old had higher mortality than their white counterparts (HRsd 1.67 [95% CI 1.44-1.93]). African Americans were more likely to be admitted for heart failure or hemorrhagic stroke.

CONCLUSION

Among patients with LN-associated ESRD, Asians and Hispanics experienced lower mortality and CV event risks than whites, and African Americans had higher mortality and CV event risks than whites.

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.

Trends in the outcomes of end-stage renal disease secondary to human immunodeficiency virus-associated nephropathy

BACKGROUND

Little is known about the trends in the incidence and outcomes of patients with end-stage renal disease (ESRD) attributed to human immunodeficiency virus-associated nephropathy (HIVAN). We sought to define relative incidence among ESRD patients, changes in mortality among patients with ESRD attributed to HIVAN, as well as changes in the excess mortality experienced by patients with ESRD attributed to HIVAN compared with otherwise similar ESRD patients with non-HIVAN causes.

METHODS

We used the US Renal Data System to identify all individuals with reported HIVAN who initiated treatment for ESRD between 1989 and 2011. We plotted their counts and proportions among all incident ESRD patients and tabulated their characteristics across years. We then compared mortality within the HIVAN group across years using Cox regression. In addition, we studied the trends in relative mortality of HIVAN patients versus those with ESRD not reported as HIVAN.

RESULTS

Overall, 14 719 individuals with HIVAN-ESRD were recorded, with significant reductions in recent years (893 in 2006; 525 in 2011). Compared with patients initiating dialysis between 1989 and 1992, mortality declined by 40% (HR = 0.60; 95% CI, 0.55-0.65) and 64% (HR = 0.36; 95% CI, 0.32-0.40) for patients initiating dialysis in 1999/2000 and 2009-11, respectively. The adjusted excess mortality of HIVAN-ESRD patients versus incident ESRD patients from other causes was >5-fold in 1989-92 (HR = 5.21; 95% CI, 4.84-5.60); this excess mortality has subsequently declined but remained at almost 3-fold in recent years (e.g. HR = 2.58; 95% CI, 2.37-2.80, 2009-11 incidence cohort).

CONCLUSIONS

Concurrent with the increasing availability of highly active antiretroviral therapy (HAART), both the incidence of ESRD due to HIVAN and the mortality of such patients have decreased substantially. However, HIVAN patients reaching ESRD continue to experience substantial excess mortality compared with other ESRD patients even in the current era of modern HAART.

Trends in Timing of Dialysis Initiation within Versus Outside the Department of Veterans Affairs

BACKGROUND AND OBJECTIVES

The secular trend toward dialysis initiation at progressively higher levels of eGFR is not well understood. This study compared temporal trends in eGFR at dialysis initiation within versus outside the Department of Veterans Affairs (VA)-the largest non-fee-for-service health system in the United States.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study used linked data from the US Renal Data System, VA, and Medicare to compare temporal trends in eGFR at dialysis initiation between 2000 and 2009 (n=971,543). Veterans who initiated dialysis within the VA were compared with three groups who initiated dialysis outside the VA: (1) veterans whose dialysis was paid for by the VA, (2) veterans whose dialysis was not paid for by the VA, and (3) nonveterans. Logistic regression was used to estimate average predicted probabilities of dialysis initiation at an eGFR≥10 ml/min per 1.73 m(2).

RESULTS

The adjusted probability of starting dialysis at an eGFR≥10 ml/min per 1.73 m(2) increased over time for all groups but was lower for veterans who started dialysis within the VA (0.31; 95% confidence interval [95% CI], 0.30 to 0.32) than for those starting outside the VA, including veterans whose dialysis was (0.36; 95% CI, 0.35 to 0.38) and was not (0.40; 95% CI, 0.40 to 0.40) paid for by the VA and nonveterans (0.39; 95% CI, 0.39 to 0.39). Differences in eGFR at initiation within versus outside the VA were most pronounced among older patients (P for interaction <0.001) and those with a higher risk of 1-year mortality (P for interaction <0.001).

CONCLUSIONS

Temporal trends in eGFR at dialysis initiation within the VA mirrored those in the wider United States dialysis population, but eGFR at initiation was consistently lowest among those who initiated within the VA. Differences in eGFR at initiation within versus outside the VA were especially pronounced in older patients and those with higher 1-year mortality risk.

Patient characteristics and outcomes by GN subtype in ESRD

BACKGROUND AND OBJECTIVES

Outcomes-based research rarely focuses on patients with ESRD caused by GN. The hypotheses were that the GN subtype would clinically discriminate patient groups and independently associate with survival after ESRD therapy initiation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were extracted from the US Renal Data System for adult patients with incident (1996-2011) ESRD attributed to six GN subtypes: FSGS, IgA nephropathy (IgAN), membranous nephropathy, membranoproliferative glomeruonephritis, lupus nephritis (LN), and vasculitis. ESRD attributed to diabetes and autosomal dominant polycystic kidney disease served as non-GN comparators. Unadjusted and adjusted mortality hazard ratios (aHRs) with 95% confidence intervals (95% CIs) were estimated using Cox regression (reference, IgAN). Models sequentially adjusted for sociodemographic (model 2), comorbidity/laboratory (model 3), and ESRD treatment modality (model 4) variables.

RESULTS

Among 84,301 patients with ESRD attributed to GN, the median age ranged from 39 (LN) to 66 (vasculitis) years, male sex ranged from 18% (LN) to 68% (IgAN), and black race ranged from 7% (IgAN) to 49% (LN). Patients with IgAN had the fewest comorbidities and lowest use of hemodialysis (70.1%). After a median follow-up of 2.5 (interquartile range, 1.0-4.9) years, crude mortality was lowest in IgAN (3.7 deaths/100 person years). Compared to IgAN, adjusted mortality was highest in LN (model 4 aHR=1.75; 95% CI, 1.68 to 1.83) and in diabetes (aHR=1.73; 95% CI, 1.67 to 1.79), and was also higher in all other GN subtypes (membranous nephropathy: aHR=1.23; 95% CI, 1.17 to 1.29; FSGS: aHR=1.37; 95% CI, 1.32 to 1.42; membranoproliferative GN: aHR=1.38; 95% CI, 1.31 to 1.45; vasculitis: aHR=1.51; 95% CI, 1.45 to 1.58) and in autosomal dominant polycystic kidney disease (aHR=1.22; 95% CI, 1.18 to 1.27).

CONCLUSIONS

This study exposes substantial heterogeneity across GN subtypes at ESRD therapy initiation and identifies independent associations between GN subtype and post-ESRD mortality. These survival discrepancies warrant further study, and the utility of current research practice to group GN subtypes together when evaluating ESRD outcomes should be questioned.

Association of time to kidney transplantation with graft failure among U.S. patients with end-stage renal disease due to lupus nephritis

OBJECTIVE

Providers recommend waiting to transplant patients with end-stage renal disease (ESRD) secondary to lupus nephritis (LN), to allow for quiescence of systemic lupus erythematosus (SLE)-related immune activity. However, these recommendations are not standardized, and we sought to examine whether duration of time to transplant was associated with risk of graft failure in US LN-ESRD patients.

METHODS

Using national ESRD surveillance data (United States Renal Data System), we identified 4,743 US patients with LN-ESRD who received a first transplant on or after January 1, 2000 (followup through September 30, 2011). The association of wait time (time from ESRD start to transplant) with graft failure was assessed with Cox proportional hazards models, with splines of the exposure to allow for nonlinearity of the association and with adjustment for potential confounding by demographic, clinical, and transplant factors.

RESULTS

White LN-ESRD patients who were transplanted later (versus at <3 months receiving dialysis) were at increased risk of graft failure (3-12 months: adjusted hazard ratio [HR] 1.23, 95% confidence interval [95% CI] 0.93-1.63; 12-24 months: adjusted HR 1.37, 95% CI 0.92-2.06; 24-36 months: adjusted HR 1.34, 95% CI 0.92-1.97; and >36 months: adjusted HR 1.98, 95% CI 1.31-2.99). However, no such association was seen among African American recipients (3-12 months: adjusted HR 1.07, 95% CI 0.79-1.45; 12-24 months: adjusted HR 1.01, 95% CI 0.64-1.60; 24-36 months: adjusted HR 0.78, 95% CI 0.51-1.18; and >36 months: adjusted HR 0.74, 95% CI 0.48-1.13).

CONCLUSION

While future studies are needed to examine the potential confounding effect of clinically recognized SLE activity on the observed associations, these results suggest that longer wait times to transplant may be associated with equivalent or worse, not better, graft outcomes among LN-ESRD patients.

Survival Disparity of African American Versus Non-African American Patients With ESRD Due to SLE

BACKGROUND

A recent study showed an increased risk of death in African Americans compared with whites with end-stage renal disease (ESRD) due to lupus nephritis (LN). We assessed the impact of age stratification, socioeconomic factors, and kidney transplantation on the disparity in patient survival among African American versus non-African American patients with LN-caused ESRD, compared with other causes.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Using the US Renal Data System database, we identified 12,352 patients with LN-caused ESRD among 1,132,202 patients who initiated maintenance dialysis therapy from January 1, 1995, through December 31, 2006, and were followed up until December 31, 2010.

PREDICTORS

Baseline demographics and comorbid conditions, Hispanic ethnicity, socioeconomic factors (employment status, Medicare/Medicaid insurance, and area-level median household income based on zip code as obtained from the 2000 US census), and kidney transplantation as a time-dependent variable.

OUTCOME

All-cause mortality.

MEASUREMENTS

Multivariable Cox and competing-risk regressions.

RESULTS

Mean duration of follow-up in the LN-caused ESRD and other-cause ESRD cohorts were 6.24±4.20 (SD) and 4.06±3.61 years, respectively. 6,106 patients with LN-caused ESRD (49.43%) and 853,762 patients with other-cause ESRD (76.24%) died during the study period (P<0.001). Patients with LN-caused ESRD were significantly younger (mean age, 39.92 years) and more likely women (81.65%) and African American (48.13%) than those with other-cause ESRD. In the fully adjusted multivariable Cox regression model, African American (vs non-African American) patients with LN-caused ESRD had significantly increased risk of death at age 18 to 30 years (adjusted HR, 1.43; 95% CI, 1.24-1.65) and at age 31 to 40 years (adjusted HR, 1.17; 95% CI, 1.02-1.34). Among patients with other-cause ESRD, African Americans were at significantly increased risk at age 18 to 30 years (adjusted HR, 1.17; 95% CI, 1.11-1.22).

LIMITATIONS

We used zip code-based median household income as a surrogate for patient income. Residual socioeconomic confounders may exist.

CONCLUSIONS

African Americans are at significantly increased risk of death compared with non-African Americans with LN-caused ESRD at age 18 to 40 years, a racial disparity risk that is 10 years longer than that in the general ESRD population. Accounting for area-level median household income and transplantation significantly attenuated the disparity in mortality of African American versus non-African American patients with LN-caused ESRD.

Comparison of quality-of-care measures in U.S. patients with end-stage renal disease secondary to lupus nephritis vs. other causes

BACKGROUND

Patients with end-stage renal disease (ESRD) due to lupus nephritis (LN-ESRD) may be followed by multiple providers (nephrologists and rheumatologists) and have greater opportunities to receive recommended ESRD-related care. We aimed to examine whether LN-ESRD patients have better quality of ESRD care compared to other ESRD patients.

METHODS

Among incident patients (7/05-9/11) with ESRD due to LN (n = 6,594) vs. other causes (n = 617,758), identified using a national surveillance cohort (United States Renal Data System), we determined the association between attributed cause of ESRD and quality-of-care measures (pre-ESRD nephrology care, placement on the deceased donor kidney transplant waitlist, and placement of permanent vascular access). Multivariable logistic and Cox proportional hazards models were used to estimate adjusted odds ratios (ORs) and hazard ratios (HRs).

RESULTS

LN-ESRD patients were more likely than other ESRD patients to receive pre-ESRD care (71% vs. 66%; OR = 1.68, 95% CI 1.57-1.78) and be placed on the transplant waitlist in the first year (206 vs. 86 per 1000 patient-years; HR = 1.42, 95% CI 1.34-1.52). However, only 24% had a permanent vascular access (fistula or graft) in place at dialysis start (vs. 36%; OR = 0.63, 95% CI 0.59-0.67).

CONCLUSIONS

LN-ESRD patients are more likely to receive pre-ESRD care and have better access to transplant, but are less likely to have a permanent vascular access for dialysis, than other ESRD patients. Further studies are warranted to examine barriers to permanent vascular access placement, as well as morbidity and mortality associated with temporary access, in patients with LN-ESRD.

Underreporting of nursing home utilization on the CMS-2728 in older incident dialysis patients and implications for assessing mortality risk

BACKGROUND

The usage of nursing home (NH) services is a marker of frailty among older adults. Although the Centers for Medicare & Medicaid Services (CMS) revised the Medical Evidence Report Form CMS-2728 in 2005 to include data collection on NH institutionalization, the validity of this item has not been reported.

METHODS

There were 27,913 patients ≥ 75 years of age with incident end-stage renal disease (ESRD) in 2006, which constituted our analysis cohort. We determined the accuracy of the CMS-2728 using a matched cohort that included the CMS Minimum Data Set (MDS) 2.0, often employed as a "gold standard" metric for identifying patients receiving NH care. We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the CMS-2728 NH item. Next, we compared characteristics and mortality risk by CMS-2728 and MDS NH status agreement.

RESULTS

The sensitivity, specificity, PPV and NPV of the CMS-2728 for NH status were 33%, 97%, 80% and 79%, respectively. Compared to those without the MDS or CMS-2728 NH indicator (No MDS/No 2728), multivariable adjusted hazard ratios (95% confidence interval) for mortality associated with NH status were 1.55 (1.46 - 1.64) for MDS/2728, 1.48 (1.42 - 1.54) for MDS/No 2728, and 1.38 (1.25 - 1.52) for No MDS/2728. NH utilization was more strongly associated with mortality than other CMS-2728 items in the model.

CONCLUSIONS

The CMS-2728 underestimated NH utilization among older adults with incident ESRD. The potential for misclassification may have important ramifications for assessing prognosis, developing advanced care plans and providing coordinated care.

Sociodemographic and geographic predictors of quality of care in United States patients with end-stage renal disease due to lupus nephritis

OBJECTIVE

To describe end-stage renal disease (ESRD) quality of care (receipt of pre-ESRD nephrology care, access to kidney transplantation, and placement of permanent vascular access for dialysis) in US patients with ESRD due to lupus nephritis (LN-ESRD) and to examine whether quality measures differ by patient sociodemographic characteristics or US region.

METHODS

National surveillance data on patients in the US in whom treatment for LN-ESRD was initiated between July 2005 and September 2011 (n = 6,594) were analyzed. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were determined for each quality measure, according to sociodemographic factors and US region.

RESULTS

Overall, 71% of the patients received nephrology care prior to ESRD. Black and Hispanic patients were less likely than white patients to receive pre-ESRD care (OR 0.73 [95% CI 0.63-0.85] and OR 0.73 [95% CI 0.60-0.88], respectively) and to be placed on the kidney transplant waitlist within the first year after the start of ESRD (HR 0.78 [95% CI 0.68-0.91] and HR 0.82 [95% CI 0.68-0.98], respectively). Those with Medicaid (HR 0.51 [95% CI 0.44-0.58]) or no insurance (HR 0.36 [95% CI 0.29-0.44]) were less likely than those with private insurance to be placed on the waitlist. Only 24% had a permanent vascular access, and placement was even less likely among the uninsured (OR 0.62 [95% CI 0.49-0.79]). ESRD quality-of-care measures varied 2-3-fold across regions of the US, with patients in the Northeast and Northwest generally having higher probabilities of adequate care.

CONCLUSION

LN-ESRD patients have suboptimal ESRD care, particularly with regard to placement of dialysis vascular access. Minority race/ethnicity and lack of private insurance are associated with inadequate ESRD care. Further studies are warranted to examine multilevel barriers to, and develop targeted interventions to improve delivery of, care among patients with LN-ESRD.