Capacity for the management of kidney failure in the International Society of Nephrology North America and the Caribbean region: report from the 2023 ISN Global Kidney Health Atlas (ISN-GKHA).

The International Society of Nephrology Global Kidney Health Atlas charts the availability and capacity of kidney care globally. In the North America and the Caribbean region, the Atlas can identify opportunities for kidney care improvement, particularly in Caribbean countries where structures for systematic data collection are lacking. In this third iteration, respondents from 12 of 18 countries from the region reported a 2-fold higher than global median prevalence of dialysis and transplantation, and a 3-fold higher than global median prevalence of dialysis centers. The peritoneal dialysis prevalence was lower than the global median, and transplantation data were missing from 6 of the 10 Caribbean countries. Government-funded payments predominated for dialysis modalities, with greater heterogeneity in transplantation payor mix. Services for chronic kidney disease, such as monitoring of anemia and blood pressure, and diagnostic capability relying on serum creatinine and urinalyses were universally available. Notable exceptions in Caribbean countries included non-calcium-based phosphate binders and kidney biopsy services. Personnel shortages were reported across the region. Kidney failure was identified as a governmental priority more commonly than was chronic kidney disease or acute kidney injury. In this generally affluent region, patients have better access to kidney replacement therapy and chronic kidney disease-related services than in much of the world. Yet clear heterogeneity exists, especially among the Caribbean countries struggling with dialysis and personnel capacity. Important steps to improve kidney care in the region include increased emphasis on preventive care, a focus on home-based modalities and transplantation, and solutions to train and retain specialized allied health professionals.

A Canadian Commentary on the NKF-ASN Task Force Recommendations on Reassessing the Inclusion of Race in Diagnosing Kidney Disease.

In 2021, a committee was commissioned by the Canadian Society of Nephrology to comment on the 2021 National Kidney Foundation-American Society of Nephrology Task Force recommendations on the use of race in glomerular filtration rate estimating equations. The committee met on numerous occasions and agreed on several recommendations. However, the committee did not achieve unanimity, with a minority group disagreeing with the scope of the commentary. As a result, this report presents the viewpoint of the majority members. We endorsed many of the recommendations from the National Kidney Foundation-American Society of Nephrology Task Force, most importantly that race should be removed from the estimated glomerular filtration rate creatinine-based equation. We recommend an immediate implementation of the new Chronic Kidney Disease Epidemiology Collaboration equation (2021), which does not discriminate among any group while maintaining precision. Additionally, we recommend that Canadian laboratories and provincial kidney organizations advocate for increased testing and access to cystatin C because the combination of cystatin C and creatinine in revised equations leads to more precise estimates. Finally, we recommend that future research studies evaluating the implementation of the new equations and changes to screening, diagnosis, and management across provincial health programs be prioritized in Canada.

The Significance of Hematuria in Podocytopathies.

BACKGROUND: Hematuria is frequently present in podocytopathies, but its significance and prognostic value is not well described in these proteinuric kidney diseases. This study describes the prevalence and association between hematuria and kidney-related outcomes in these disorders. METHODS: Hematuria was assessed at the initial urinalysis in participants with the following podocytopathies, membranous nephropathy, minimal change disease, and focal segmental glomerulosclerosis, in the Nephrotic Syndrome Study Network (NEPTUNE) and Cure Glomerulonephropathy (CureGN) cohorts with >24 months of follow-up. Multivariable Cox proportional hazards models were fit for time to composite outcome (end-stage kidney disease or 40% decline in estimated glomerular filtration rate (eGFR) and eGFR <60 ml/min/1.73 m2) and proteinuria remission (UPCR <0.3 mg/mg). RESULTS: Among the 1,516 adults and children in the study, 528 (35%) participants had focal segmental glomerulosclerosis, 499 (33%) had minimal change disease, and 489 (32%) had membranous nephropathy. Median (IQR) time from biopsy until the initial study urinalysis was 260 days (49, 750), and 498 (33%) participants were positive for hematuria. Participants with hematuria compared to those without, were older (37 [16, 55] vs 33 years [12, 55]), more likely to have an underlying diagnosis of membranous nephropathy (44% vs 27%), had shorter time since biopsy (139 [27, 477] vs 325 [89, 878] days) and higher UPCR (3.8 [1.4, 8.0] vs 0.9 [0.1, 3.1]g/g). After adjusting for diagnosis, age, sex, UPCR, eGFR, time since biopsy, and study cohort, hematuria was associated with a higher riskof reaching the composite outcome (HR 1.31 [1.04, 1.65], p-value 0.02) and lower rate of reaching proteinuria remission (HR 0.80 [0.65-0.98], p-value 0.03). CONCLUSIONS: Hematuria is prevalent among participants with the three podocytopathies and is significantly and independently associated with worse kidney-related outcomes, including both progressive loss of kidney function remission of proteinuria.

Cardiovascular Risk Factor Burden and Association With CKD in Ghana and Nigeria.

Introduction: Cardiovascular disease is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD); however, the burden of cardiovascular risk factors in patients with CKD in Africa is not well characterized. We determined the prevalence of selected cardiovascular risk factors, and association with CKD in the Human Heredity for Health in Africa Kidney Disease Research Network study. Methods: We recruited patients with and without CKD in Ghana and Nigeria. CKD was defined as estimated glomerular filtration rate of <60 ml/min per 1.73 m2 and/or albuminuria as albumin-to-creatinine ratio <3.0 mg/mmol (<30 mg/g) for ≥3 months. We assessed self-reported (physician-diagnosis and/or use of medication) hypertension, diabetes, and elevated cholesterol; and self-reported smoking as cardiovascular risk factors. Association between the risk factors and CKD was determined by multivariate logistic regression. Results: We enrolled 8396 participants (cases with CKD, 3956), with 56% females. The mean age (45.5 ± 15.1 years) did not differ between patients and control group. The prevalence of hypertension (59%), diabetes (20%), and elevated cholesterol (9.9%), was higher in CKD patients than in the control participants (P < 0.001). Prevalence of risk factors was higher in Ghana than in Nigeria. Hypertension (adjusted odds ratio [aOR] = 1.69 [1.43-2.01, P < 0.001]), elevated cholesterol (aOR = 2.0 [1.39-2.86, P < 0.001]), age >50 years, and body mass index (BMI) <18.5 kg/m2 were independently associated with CKD. The association of diabetes and smoking with CKD was modified by other risk factors. Conclusion: Cardiovascular risk factors are prevalent in middle-aged adult patients with CKD in Ghana and Nigeria, with higher proportions in Ghana than in Nigeria. Hypertension, elevated cholesterol, and underweight were independently associated with CKD.

Rapid Progression of Focal Segmental Glomerulosclerosis in Patients with High-Risk APOL1 Genotypes.

BACKGROUND: FSGS is a heterogeneous diagnosis with a guarded prognosis. Polymorphisms in the apolipoprotein L1 ( APOL1 ) gene are associated with developing FSGS and faster progression to kidney failure in affected patients. Better understanding the natural history of patients with FSGS and APOL1 risk alleles is essential to improve patient care and support the design and interpretation of interventional studies. The objective of this study was to evaluate the quantitative association between APOL1 and kidney disease progression and the interaction with other clinical and laboratory factors. METHODS: CureGN cohort study participants with biopsy diagnosis of FSGS, regardless of self-identified race, were included. The exposure of interest was two APOL1 risk alleles (high risk) versus zero to one risk alleles (low risk). The primary outcome was eGFR slope categorized as rapid progressor (eGFR slope ≤-5 ml/min per year), intermediate progressor (slope between 0 and -5), or nonprogressor (slope ≥0). Multivariable ordinal logistic and linear regressions were used for adjusted analyses. Missing data were addressed using multiple imputation. RESULTS: Of 650 participants, 476 (73%) had genetic testing, among whom 87 (18%) were high risk. High-risk participants were more likely to have lower median eGFR (62 [interquartile range, 36-81] versus low-risk participants 76 ml/min per 1.73 m 2 [interquartile range, 44-106]; P <0.01). In adjusted analysis, the odds of more rapid progression of eGFR was 2.75 times higher (95% confidence interval, 1.67 to 4.53; P <0.001) in the high-risk versus low-risk groups. CONCLUSIONS: In patients with FSGS, high-risk APOL1 genotype is the predominant factor associated with more rapid loss of kidney function.

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

RATIONALE & OBJECTIVE: Adolescent- and adult-onset minimal change disease (MCD) may have a clinical course distinct from childhood-onset disease. We characterized the course of children and adults with MCD in the Cure Glomerulonephropathy Network (CureGN) and assessed predictors of rituximab response. STUDY DESIGN: Prospective, multicenter, observational study. STUDY PARTICIPANTS: CureGN participants with proven MCD on biopsy. EXPOSURE: Age at disease onset, initiation of renin-angiotensin-aldosterone system (RAAS) blockade, and immunosuppression including rituximab during the study period. OUTCOME: Relapse and remission, change in estimated glomerular filtration rate (eGFR), and kidney failure. ANALYTICAL APPROACH: Remission and relapse probabilities were estimated using Kaplan-Meier curves and gap time recurrent event models. Linear regression models were used for the outcome of change in eGFR. Cox proportional hazards models were used to estimate the association between rituximab administration and remission. RESULTS: The study included 304 childhood- (≤12 years old), 49 adolescent- (13-17 years old), and 201 adult- (≥18 years) onset participants with 2.7-3.2 years of follow-up after enrollment. Children had a longer time to biopsy (238 vs 23 and 36 days in adolescent- and adult-onset participants, respectively; P<0.001) and were more likely to have received therapy before biopsy. Children were more likely to be treated with immunosuppression but not RAAS blockade. The rate of relapse was higher in childhood- versus adult-onset participants (HR, 1.69 [95% CI, 1.29-2.21]). The probability of remission was also higher in childhood-onset disease (HR, 1.33 [95%CI, 1.02-1.72]). In all groups eGFR loss was minimal. Children were more likely to remit after rituximab than those with adolescent- or adult-onset disease (adjusted HR, 2.1; P=0.003). Across all groups, glucocorticoid sensitivity was associated with a greater likelihood of achieving complete remission after rituximab (adjusted HR, 2.62; P=0.002). LIMITATIONS: CureGN was limited to biopsy-proven disease. Comparisons of childhood to nonchildhood cases of MCD may be subject to selection bias, given that childhood cases who undergo a biopsy may be limited to patients who are least responsive to initial therapy. CONCLUSIONS: Among patients with MCD who underwent kidney biopsy, there were differences in the course (relapse and remission) of childhood-onset compared with adolescent- and adult-onset disease, as well as rituximab response. PLAIN-LANGUAGE SUMMARY: Minimal change disease is a biopsy diagnosis for nephrotic syndrome. It is diagnosed in childhood, adolescence, or adulthood. Patients and clinicians often have questions about what to expect in the disease course and how to plan therapies. We analyzed a group of patients followed longitudinally as part of the Cure Glomerulonephropathy Network (CureGN) and describe the differences in disease (relapse and remission) based on the age of onset. We also analyzed rituximab response. We found that those with childhood-onset disease had a higher rate of relapse but also have a higher probability of reaching remission when compared with adolescent- or adult-onset disease. Children and all steroid-responsive patients are more likely to achieve remission after rituximab.

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.

Outcomes of skin cancers in pediatric solid organ transplant patients: A systematic review.

BACKGROUND: The most frequently reported malignancies after solid organ transplant are cutaneous, but data on the risk in pediatric populations varies across studies. OBJECTIVES: To perform a systematic review including reported features and outcomes of skin cancers in pediatric solid organ transplant recipients. METHODS: EMBASE and MEDLINE were systematically searched (Prospero CRD42020201659). RESULTS: The review summarizes data from 20 studies on 337 patients, with a median age ranging from 15.0 to 19.5 years as reported in 4 studies, who developed skin malignancies after pediatric solid organ transplantation. Median ages at transplant and skin cancer diagnosis ranged from 1.5 to 17.0 years and 15.3 to 33.5 years, respectively. Squamous cell carcinoma (SCC) was most commonly reported (218 cases), followed by basal cell carcinoma (BCC) (91 cases), melanoma (18 cases), and unspecified keratinocyte carcinomas (2 cases). The median latency period between transplantation and cancer diagnosis ranged from 2.2 to 21.0 years. Overall, 4 studies reported 17 cases of metastasis in total, and recurrence was reported in one case. Six deaths were reported in one study related to SCC and melanoma metastases. The incidence rate of skin cancer after pediatric transplantation per 100 person-years of follow-up was 2.1 based on 5 studies. CONCLUSION: The most frequent post-transplant malignancy in pediatric organ transplant recipients was SCC.

Racial-ethnic differences in health-related quality of life among adults and children with glomerular disease.

INTRODUCTION: Disparities in health-related quality of life (HRQOL) have been inadequately studied in patients with glomerular disease. The aim of this study was to identify relationships between race/ethnicity, socioeconomic status, disease severity, and HRQOL in an ethnically and racially diverse cohort of patients with glomerular disease. METHODS: Cure Glomerulonephropathy (CureGN) is a multinational cohort study of patients with biopsy-proven glomerular disease. Associations between race/ethnicity and HRQOL were determined by the following: 1. Missed school or work due to kidney disease; 2. Responses to Patient Reported Outcomes Measurement Information System (PROMIS) questionnaires. We adjusted for demographics, socioeconomic status, and disease characteristics using multivariable logistic and linear regression. RESULTS: Black and Hispanic participants had worse socioeconomic status and more severe glomerular disease than White or Asian participants. Black adults missed work or school most frequently due to kidney disease (30% versus 16-23% in the other three groups, p=0.04), and had the worst self-reported global physical health (median score 44.1 versus 48.0-48.2, p<0.001) and fatigue (53.8 versus 48.5-51.1, p=0.002), compared to other racial/ethnic groups. However, these findings were not statistically significant with adjustment for socioeconomic status and disease severity, both of which were strongly associated with HRQOL in adults. Among children, disease severity but not race/ethnicity or socioeconomic status were associated with HRQOL. CONCLUSIONS: Among patients with glomerular disease enrolled in CureGN, the worse HRQOL reported by Black adults was attributable to lower socioeconomic status and more severe glomerular disease. No racial/ethnic differences in HRQOL were observed in children.

Long-Term Kidney Outcomes Following Dialysis-Treated Childhood Acute Kidney Injury: A Population-Based Cohort Study.

BACKGROUND: AKI is common during pediatric hospitalizations and associated with adverse short-term outcomes. However, long-term outcomes among survivors of pediatric AKI who received dialysis remain uncertain. METHODS: To determine the long-term risk of kidney failure (defined as receipt of chronic dialysis or kidney transplant) or death over a 22-year period for pediatric survivors of dialysis-treated AKI, we used province-wide health administrative databases to perform a retrospective cohort study of all neonates and children (aged 0-18 years) hospitalized in Ontario, Canada, from April 1, 1996, to March 31, 2017, who survived a dialysis-treated AKI episode. Each AKI survivor was matched to four hospitalized pediatric comparators without dialysis-treated AKI, on the basis of age, sex, and admission year. We reported the incidence of each outcome and performed Cox proportional hazards regression analyses, adjusting for relevant covariates. RESULTS: We identified 1688 pediatric dialysis-treated AKI survivors (median age 5 years) and 6752 matched comparators. Among AKI survivors, 53.7% underwent mechanical ventilation and 33.6% had cardiac surgery. During a median 9.6-year follow-up, AKI survivors were at significantly increased risk of a composite outcome of kidney failure or death versus comparators. Death occurred in 113 (6.7%) AKI survivors, 44 (2.6%) developed kidney failure, 174 (12.1%) developed hypertension, 213 (13.1%) developed CKD, and 237 (14.0%) had subsequent AKI. AKI survivors had significantly higher risks of developing CKD and hypertension versus comparators. Risks were greatest in the first year after discharge and gradually decreased over time. CONCLUSIONS: Survivors of pediatric dialysis-treated AKI are at higher long-term risks of kidney failure, death, CKD, and hypertension, compared with a matched hospitalized cohort.

Trends in the epidemiology of childhood nephrotic syndrome in Africa: A systematic review.

Background: Childhood nephrotic syndrome, if left untreated, leads to progressive kidney disease or death. We quantified the prevalence of steroid-sensitive nephrotic syndrome, steroid-resistant nephrotic syndrome, and histological types as the epidemiology of nephrotic syndrome in Africa remains unknown, yet impacts outcomes. Methods: We searched MEDLINE, Embase, African Journals Online, and WHO Global Health Library for articles in any language reporting on childhood nephrotic syndrome in Africa from January 1, 1946 to July 1, 2020. Primary outcomes included steroid response, biopsy defined minimal change disease, and focal segmental glomerulosclerosis (FSGS) by both pooled and individual proportions across regions and overall. Findings: There were 81 papers from 17 countries included. Majority of 8131 children were steroid-sensitive (64% [95% CI: 63-66%]) and the remaining were steroid-resistant (34% [95% CI: 33-35%]). Of children biopsied, pathological findings were 38% [95% CI: 36-40%] minimal change, 24% [95% CI: 22-25%] FSGS, and 38% [95% CI: 36-40%] secondary causes of nephrotic syndrome. Interpretation: Few African countries reported on the prevalence of childhood nephrotic syndrome. Steroid-sensitive disease is more common than steroid-resistant disease although prevalence of steroid-resistant nephrotic syndrome is higher than reported globally. Pathology findings suggest minimal change and secondary causes are common. Scarcity of data in Africa prevents appropriate healthcare resource allocation to diagnose and treat this treatable childhood kidney disease to prevent poor health outcomes. Funding: Funding was provided by the Canadian Institute for Health Research (CIHR) and the National Institute of Health (NIH) for the H3 Africa Kidney Disease Research Network. This research was undertaken, in part, from the Canada Research Chairs program.

Incidence and Risk Factors of Obesity in Childhood Solid-Organ Transplant Recipients.

BACKGROUND: Obesity is a significant public health concern; however, the incidence post solid-organ transplantation is not well reported. METHODS: This study determined the incidence and risk factors of obesity among pediatric solid-organ transplant recipients (heart, lung, liver, kidney, multiorgan) at The Hospital for Sick Children (2002-2011), excluding prevalent obesity. Follow-up occurred from transplantation until development of obesity, last follow-up, or end of study. Incidence of obesity was determined overall, by baseline body mass index, and organ group. Risk factors were assessed using Cox proportional-hazards regression. RESULTS: Among 410 (55% male) children, median transplant age was 8.9 (interquartile range [IQR]: 1.0-14.5) years. Median follow-up time was 3.6 (IQR: 1.5-6.4) years. Incidence of obesity was 65.2 (95% confidence interval [CI]: 52.7-80.4) per 1000 person-years. Overweight recipients had a higher incidence, 190.4 (95% CI: 114.8-315.8) per 1000 person-years, than nonoverweight recipients, 56.1 (95% CI: 44.3-71.1). Cumulative incidence of obesity 5-years posttransplant was 24.1%. Kidney relative to heart recipients had the highest risk (3.13 adjusted hazard ratio [aHR]; 95% CI: 1.53-6.40) for obesity. Lung and liver recipients had similar rates to heart recipients. Those with higher baseline body mass index (z-score; 1.72 aHR; 95% CI: 1.39-2.14), overweight status (2.63 HR; 95% CI: 1.71-4.04), and younger transplant age (y; 1.18 aHR; 95% CI: 1.12-1.25) were at highest risk of obesity. Higher cumulative steroid dosage (per 10 mg/kg) was associated with increased risk of obesity after adjustment. CONCLUSIONS: Among all transplanted children at The Hospital for Sick Children, 25% developed obesity within 5-years posttransplant. Kidney recipients, younger children, those overweight at transplant, and those with higher cumulative steroid use (per 10 mg/kg) were at greatest risk. Early screening and intervention for obesity are important preventative strategies.

Prevalence of Cardiovascular Disease Risk Factors in Childhood Glomerular Diseases.

Background Cardiovascular disease is a major cause of morbidity and mortality in children with chronic kidney disease. We sought to determine the prevalence of cardiovascular risk factors in children with glomerular disease and to describe current practice patterns regarding risk factor identification and management. Methods and Results Seven-hundred sixty-one children aged 0 to 17 years with any of 4 biopsy-confirmed primary glomerular diseases (minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and IgA nephropathy/vasculitis) were enrolled at a median of 16 months from glomerular disease diagnosis in the multicenter prospective Cure Glomerulonephropathy Network study. Prevalence of traditional (hypertension, hypercholesterolemia, and obesity) and novel (proteinuria, prematurity, and passive smoke exposure) cardiovascular risk factors were determined at enrollment and compared across glomerular disease subtypes. Frequency of screening for dyslipidemia and prescribing of lipid-lowering or antihypertensive medications were compared across glomerular disease subtype, steroid exposure, and remission status groups. Compared with the general population, all traditional risk factors were more frequent: among those screened, 21% had hypertension, 51% were overweight or obese, and 71% had dyslipidemia. Children who were not in remission at enrollment were more likely to have hypertension and hypercholesterolemia. Fourteen percent of hypertensive children were not receiving antihypertensives. Only 49% underwent screening for dyslipidemia and only 9% of those with confirmed dyslipidemia received lipid-lowering medications. Conclusions Children with primary glomerular diseases exhibit a high frequency of modifiable cardiovascular risk factors, particularly untreated dyslipidemia. Lipid panels should be routinely measured to better define the burden of dyslipidemia in this population. Current approaches to screening for and treating cardiovascular risk factors are not uniform, highlighting a need for evidence-based, disease-specific guidelines.

Elevated Risk of Cancer After Solid Organ Transplant in Childhood: A Population-based Cohort Study.

BACKGROUND: Cancer risk is elevated among adult transplant recipients, but there is limited data regarding long-term cancer risk and mortality in pediatric recipients. METHODS: We conducted a population-based retrospective cohort study in Ontario, Canada. We included pediatric recipients of solid organ transplants at the Hospital for Sick Children, Toronto, from 1991 to 2014, and compared rates of new cancers and cancer-specific mortality to nontransplanted Ontario children born in the same year. We constructed standard and time-dependent Cox proportional hazards models accounting for competing risk of death. RESULTS: A total of 951 recipients (kidney, n = 400; liver, n = 283; heart, n = 218; lung, n = 36; multiorgan/small bowel, n = 14) were compared with 5.3 million general population children. Mean (SD) age was 8.2 (6.4) years; 50% were male. Over a mean (SD) follow-up of 10.8 (7.1) years, cumulative incidence of cancer was 20% in recipients and 1.2% in the general population (incidence rate ratio, 32.9; 95% confidence interval [CI], 26.6-40.8). Risk was highest in the first year posttransplant (adjusted hazard ratio [aHR],176; 95% CI, 117-264), but remained elevated beyond 10 years (aHR, 10.8; 95% CI, 6.3-18.6). Lymphoproliferative disorders were predominant (77%); however, solid cancers (renal, sarcomas, genital, thyroid) were seen. Recipients of lung or multiorgan transplants were at highest risk. Cancer-specific mortality was also higher among recipients (HR, 93.1; 95% CI, 59.6-145.2). CONCLUSIONS: Childhood transplant recipients have a 30 times greater cancer incidence versus the general population. Further investigation is needed to guide screening strategies in this at-risk population.

Examination of Potential Modifiers of the Association of APOL1 Alleles with CKD Progression.

BACKGROUND AND OBJECTIVES: Common apolipoprotein L1 (APOL1) variants are associated with increased risk of progressive CKD; however, not all individuals with high-risk APOL1 variants experience CKD progression. Identification of factors contributing to heterogeneity has important scientific and clinical implications. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using multivariable Cox models, we analyzed data from 693 participants in the African American Study of Kidney Disease and Hypertension to identify factors that modify the association between APOL1 genotypes and CKD progression (doubling of serum creatinine or incident ESRD). RESULTS: Participant mean age was 54 years old, median GFR was 49 ml/min per 1.73 m(2), and 23% had the APOL1 high-risk genotype (two copies of the high-risk allele). Over a mean follow-up of 7.8 years, 288 (42%) participants experienced CKD progression. As previously reported, the high-risk genotype was associated with higher risk of CKD progression compared with the low-risk genotype (hazard ratio [HR], 1.88; 95% confidence interval [95% CI], 1.46 to 2.41). Although we found some suggestion that obesity (HR, 1.48; 95% CI, 1.05 to 2.08 and HR, 2.44; 95% CI, 1.66 to 3.57 for body mass index ≥ 30 versus <30 kg/m(2); P interaction =0.04) and increased urinary excretion of urea nitrogen (HR, 1.43; 95% CI, 0.98 to 2.09 versus HR, 2.33; 95% CI, 1.65 to 3.30 for urine urea nitrogen ≥ 8 versus <8 g/d; P interaction =0.04) were associated with lower APOL1-associated risk for CKD progression, these findings were not robust in sensitivity analyses with alternative cut points. No other sociodemographic (e.g., education and income), clinical (e.g., systolic BP and smoking), or laboratory (e.g., net endogenous acid production, urinary sodium and potassium excretions, 25-hydroxy vitamin D, intact parathyroid hormone, or fibroblast growth factor 23) variables modified the association between APOL1 and CKD progression (P interaction >0.05 for each). CONCLUSIONS: Sociodemographic factors and common risk factors for CKD progression do not seem to alter APOL1-related CKD progression. Additional investigation is needed to identify nontraditional factors that may affect the association between APOL1 and progressive CKD.

A New Grading System for the Management of Antenatal Hydronephrosis.

BACKGROUND AND OBJECTIVES: Standard clinical assessments do not predict surgical intervention in patients with a moderate degree of upper tract hydronephrosis. This study investigated whether combined measures of renal calyceal dilation and anteroposterior diameter (APD) of the renal pelvis at the first postnatal ultrasound better predict surgical intervention beyond standard assessments of the APD or Society of Fetal Urology (SFU) grading system. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective cohort of 348 children with antenatal hydronephrosis followed from 2003 to 2013 were studied. Using Cox regression, the risk for surgery by APD, SFU, and combined grading on the basis of the first postnatal ultrasound was calculated. The predictive capability of each grading system for surgery was determined by calculating the positive likelihood ratio (LR+). RESULTS: The combination of APD≥6-9 mm and diffuse caliectasis had a hazard ratio (HR) of 19.5 (95% confidence interval [95% CI], 3.94 to 96.9) versus 0.59 (95% CI, 0.05 to 6.53) for APD≥6-9 mm alone and a similar risk of 8.9 for SFU grade 3 (95% CI, 3.84 to 20.9). The combination of APD≥9-15 mm and diffuse caliectasis had an HR of 18.7 (95% CI, 4.36 to 80.4) versus 1.75 (95% CI, 0.29 to 10.5) for APD≥9-15 mm alone. The LR+ for surgery for diffuse caliectasis and APD≥6-9 mm was higher than for APD≥6-9 mm alone (HR=2.62; 95% CI, 0.87 to 7.94 versus HR=0.04; 95% CI, 0.01 to 0.32) and was higher for APD≥9-15 mm and diffuse caliectasis than APD≥9-15 mm alone (HR=2.0; 95% CI, 1.15 to 3.45 versus HR=0.14; 95% CI, 0.04 to 0.43). Both combined groups of moderate hydronephrosis (APD≥6-9 mm or ≥9-15 mm with diffuse caliectasis) had only slightly higher LR+ than SFU grade 3 (HR=1.89; 95% CI, 1.17 to 3.05). CONCLUSIONS: These results suggest a grading system combining APD and diffuse caliectasis distinguishes those children with moderate degrees of upper tract hydronephrosis that are at higher risk of surgery.

Human Heredity and Health (H3) in Africa Kidney Disease Research Network: A Focus on Methods in Sub-Saharan Africa.

CKD affects an estimated 14% of adults in sub-Saharan Africa, but very little research has been done on the cause, progression, and prevention of CKD there. As part of the Human Heredity and Health in Africa (H3Africa) Consortium, the H3Africa Kidney Disease Research Network was established to study prevalent forms of kidney disease in sub-Saharan Africa and increase the capacity for genetics and genomics research. The study is performing comprehensive phenotypic characterization and analyzing environmental and genetic factors from nine clinical centers in four African countries (Ghana, Nigeria, Ethiopia, and Kenya) over a 5-year period. Approximately 4000 participants with specified kidney disease diagnoses and 4000 control participants will be enrolled in the four African countries. In addition, approximately 50 families with hereditary glomerular disease will be enrolled. The study includes both pediatric and adult participants age <1 to 74 years across a broad spectrum of kidney diseases secondary to hypertension-attributed nephropathy, diabetes, HIV infection, sickle cell disease, biopsy-proven glomerular disease, and CKD of unknown origin. Clinical and demographic data with biospecimens are collected to assess clinical, biochemical, and genetic markers of kidney disease. As of March 2015, a total of 3499 patients and controls have been recruited and 1897 had complete entry data for analysis. Slightly more than half (50.2%) of the cohort is female. Initial quality control of clinical data collection and of biosample and DNA analysis is satisfactory, demonstrating that a clinical research infrastructure can be successfully established in Africa. This study will provide clinical, biochemical, and genotypic data that will greatly increase the understanding of CKD in sub-Saharan Africa.

APOL1 Genotype and Glomerular and Tubular Kidney Injury in Women With HIV.

BACKGROUND: APOL1 genotype is associated with advanced kidney disease in African Americans, but the pathogenic mechanisms are unclear. Here, associations of APOL1 genotype with urine biomarkers of glomerular and tubular injury and kidney function decline were evaluated. STUDY DESIGN: Observational study. SETTING & PARTICIPANTS: 431 human immunodeficiency virus (HIV)-infected African American women enrolled in Women's Interagency HIV Study (WIHS). PREDICTOR: APOL1 genotype. OUTCOMES: Albumin-creatinine ratio (ACR), 4 tubular injury biomarkers (interleukin 18 [IL-18], kidney injury molecule 1 [KIM-1], neutrophil gelatinase-associated lipocalin [NGAL], and α1-microglobulin [A1M]), and kidney function estimated using the CKD-EPI cystatin C equation. MEASUREMENTS: Participants were genotyped for APOL1 single-nucleotide polymorphisms rs73885319 (G1 allele) and rs71785313 (G2 allele). Urine biomarkers were measured using stored samples from 1999-2000. Cystatin C was measured using serum collected at baseline and 4- and 8-year follow-ups. RESULTS: At baseline, ACRs were higher among 47 women with 2 APOL1 risk alleles versus 384 women with 0/1 risk allele (median, 24 vs 11mg/g; P<0.001). Compared with women with 0/1 risk allele, women with 2 risk alleles had 104% higher ACRs (95% CI, 29-223mg/g) and 2-fold greater risk of ACR>30 (95% CI, 1.17-3.44) mg/g after multivariable adjustment. APOL1 genotype showed little association with urine IL-18:Cr ratio, KIM-1:Cr ratio, and NGAL:Cr ratio (estimates of -5% [95% CI, -24% to 18%], -20% [95% CI, -36% to -1%], and 10% [95% CI, -26% to 64%], respectively) or detectable urine A1M (prevalence ratio, 1.13; 95% CI, 0.65-1.97) in adjusted analyses. Compared with women with 0/1 allele, women with 2 risk alleles had faster eGFR decline, by 1.2 (95% CI, 0.2 to 2.2) mL/min/1.73m(2) per year, and 1.7- and 3.4-fold greater rates of incident chronic kidney disease (95% CI, 1.1 to 2.5) and 10% annual eGFR decline (95% CI, 1.7 to 6.7), respectively, with minimal attenuation after adjustment for glomerular and tubular injury biomarker levels. LIMITATIONS: Results may not be generalizable to men. CONCLUSIONS: Among HIV-infected African American women, APOL1-associated kidney injury appears to localize to the glomerulus, rather than the tubules.

The association between APOL1 risk alleles and longitudinal kidney function differs by HIV viral suppression status.

BACKGROUND: Existing data suggest that human immunodeficiency virus (HIV)-infected African Americans carrying 2 copies of the APOL1 risk alleles have greater risk of kidney disease than noncarriers. We sought to determine whether HIV RNA suppression mitigates APOL1-related kidney function decline among African Americans enrolled in the Multicenter AIDS Cohort Study. METHODS: We genotyped HIV-infected men for the G1 and G2 risk alleles and ancestry informative markers. Mixed-effects models were used to estimate the annual rate of estimated glomerular filtration rate (eGFR) decline, comparing men carrying 2 (high-risk) vs 0-1 risk allele (low-risk). Effect modification by HIV suppression status (defined as HIV type 1 RNA level <400 copies/mL for >90% of follow-up time) was evaluated using interaction terms and stratified analyses. RESULTS: Of the 333 African American men included in this study, 54 (16%) carried the APOL1 high-risk genotype. Among HIV-infected men with unsuppressed viral loads, those with the high-risk genotype had a 2.42 mL/minute/1.73 m(2) (95% confidence interval [CI], -3.52 to -1.32) faster annual eGFR decline than men with the low-risk genotype. This association was independent of age, comorbid conditions, baseline eGFR, ancestry, and HIV-related factors. In contrast, the rate of decline was similar by APOL1 genotype among men with sustained viral suppression (-0.16 mL/minute/1.73 m(2)/year; 95% CI, -.59 to .27; P for interaction <.001). CONCLUSIONS: Unsuppressed HIV-infected African Americans with the APOL1 high-risk genotype experience an accelerated rate of kidney function decline; HIV suppression with antiretroviral therapy may reduce these deleterious renal effects.