Encouraging outcomes of using a small-donor single graft in pediatric kidney transplantation.

BACKGROUND: The use of small pediatric kidneys as single grafts for transplantation is controversial, due to the potential risk for graft thrombosis and insufficient nephron mass. METHODS: Aiming to test the benefits of transplanting these kidneys, 375 children who underwent kidney transplantation in a single center were evaluated: 49 (13.1%) received a single graft from a small pediatric donor (≤ 15 kg, SPD group), 244 (65.1%) from a bigger pediatric donor (> 15 kg, BPD group), and 82 (21.9%) from adult living donors (group ALD). RESULTS: Groups had similar baseline main characteristics. After 5 years of follow-up, children from the SPD group were comparable to children from BPD and ALD in patient survival (94%, 96%, and 98%, respectively, p = 0.423); graft survival (89%, 88%, and 93%, respectively, p = 0.426); the frequency of acute rejection (p = 0.998); the incidence of post-transplant lymphoproliferative disease (p = 0.671); the odds ratio for severely increased proteinuria (p = 0.357); the rates of vascular thrombosis (p = 0.846); and the necessity for post-transplant surgical intervention prior to discharge (p = 0.905). The longitudinal evolution of eGFR was not uniform among groups. The three groups presented a decrease in eGFR, but the slope of the curve was steeper in ALD children. At 5 years, the eGFR of the ALD group was 10 ml/min/1.73m2 inferior to the others. At that time, the eGFR from the SPD group was statistically similar to the BPD group (p = 0.952). CONCLUSION: In a specialized transplant center, the use of a single small pediatric donor kidney for transplantation is as successful as bigger pediatric or adult living donors, after 5 years of follow-up. A higher resolution version of the Graphical abstract is available as Supplementary information.

APOL1 in an ethnically diverse pediatric population with nephrotic syndrome: implications in focal segmental glomerulosclerosis and other diagnoses.

BACKGROUND: APOL1 high-risk genotypes (HRG) are associated with increased risk of kidney disease in individuals of African ancestry. We analyzed the effects of APOL1 risk variants on an ethnically diverse Brazilian pediatric nephrotic syndrome (NS) cohort. METHODS: Multicenter study including 318 NS patients, categorized as progressors to advanced CKD [estimated glomerular filtration rate (eGFR)] < 30 mL/min/1.73 m2] and slow/non-progressors (eGFR > 30 mL/min/1.73 m2 through the study). We employed Cox regression with progression time as the outcome and APOL1 genotype as the independent variable. We tested this association in the entire cohort and three subgroups; (1) focal segmental glomerulosclerosis (FSGS), (2) steroid-resistant NS (SRNS), and (3) those who underwent kidney biopsy. RESULTS: Nineteen patients (6%) had an HRG. Of these, 47% were self-reported White. Patients with HRG manifested NS at older ages and presented higher frequencies of FSGS and SRNS. HRG patients progressed to advanced CKD more often than low-risk-genotype (LRG) children in the whole NS cohort (p = 0.001) and the three subgroups. In SRNS and biopsied patients, a single risk variant was associated with trends of higher CKD progression risk. CONCLUSIONS: Novel discoveries include a substantial prevalence of HRG among patients self-reported White, worse kidney outcomes in HRG versus LRG children in the FSGS subgroup, and a trend of higher CKD progression risk associated with a single risk variant in the SRNS cohort. These findings suggest APOL1-associated NS extends beyond patients self-reported non-White, the HRG effect is independent of FSGS, and a single risk variant may have a detrimental impact in children with NS.

Inequality in pediatric kidney transplantation in Brazil.

BACKGROUND: The aim of this study was to describe the access and factors associated with kidney transplantation for children in different regions of Brazil. METHODS: We analyzed a cohort of 1211 children enrolled on the transplant list from January 2011 to December of 2013. We fitted regression models to investigate factors associated with: (a) undergoing kidney transplantation from a deceased donor, and (b) being removed from the waiting list. RESULTS: The incidence of transplantation was uneven across regions, with the lowest rate at 0.4 per million age-related population (pmarp) in the Midwest and the highest incidence rate of 8.3 cases pmarp in the South. Children from the North and the Midwest regions had a 3-4 times lower probability of undergoing a deceased donor transplant (p < 0.05). Apart from the geographic region, age of recipients and GDP influenced the outcome. The likelihood of undergoing transplantation was very low in the youngest children in the North and Midwest. The number of transplant centers was not associated with either outcome. CONCLUSIONS: Factors of inequality in transplantation in Brazil are of macroeconomic origin, but there is room to reduce inequalities. Training existing transplant center professionals in the care of children could diminish the discrepancies.

Pediatric Chronic Dialysis in Brazil: Epidemiology and Regional Inequalities.

INTRODUCTION: There are few reports in the literature estimating the epidemiologic characteristics of pediatric chronic dialysis. These patients have impaired physical growth, high number of comorbidities and great need for continuous attention of specialized services with high demand for complex and costly procedures. OBJECTIVE: The aim of this study was to estimate the incidence and prevalence rates and describe the characteristics of children and adolescents undergoing chronic dialysis treatment in a Brazilian demographic health survey. MATERIALS AND METHODS: A cross-sectional study was performed in a representative sample of dialysis centers (nc = 239) that was established from the 2011 Brazilian Nephrology Society Census (Nc = 708). We collected data encompassing the five Brazilian macro-regions. We analyzed the data from all patients under 19 years of age. The sample population consisted of 643 children and adolescents who were on chronic dialysis program anytime in 2012. Data collection was carried out in the dialysis services by means of patients' records reviews and personal interviews with the centers' leaders. RESULTS: We estimated that there were a total of 1,283 pediatric patients on chronic dialysis treatment in Brazil, resulting in a prevalence of 20.0 cases per million age-related population (pmarp) (95% CI: 14.8-25.3) and an incidence of 6.6 cases pmarp in 2012 (95% CI: 4.8-8.4). The South region had the highest prevalence and incidence rates of patients under dialysis therapy, 27.7 (95% CI: 7.3-48.1) and 11.0 (95% CI: 2.8-19.3) cases pmarp, respectively; the lowest prevalence and incidence rates were found in the North-Midwest region, 13.8 (95% CI: 6.2-21.4), and in the Northeast region, 3.8 (95% CI: 1.4-6.3) cases pmarp, respectively. CONCLUSION: Brazil has an overall low prevalence of children on chronic dialysis treatment, figuring near the rates from others countries with same socioeconomic profile. There are substantial differences among regions related to pediatric chronic dialysis treatment. Joint strategies aiming to reduce inequities and improving access to treatment and adequacy of services across the Brazilian regions are necessary to provide an appropriate care setting for this population group.

Renal complications of sickle cell disease: managing for optimal outcomes.

A broad spectrum of renal changes is observed in patients with sickle cell anemia, and ideal therapeutic measures for the management of these alterations are still being studied. Affected patients have deficient urinary concentration and potassium excretion. Perhaps owing to a compensatory mechanism, the proximal tubules are in a condition of "hyperfunction", with increased sodium and phosphorus reabsorption and greater creatinine and uric acid secretion. Mild tubular acidosis may be present. No treatment has been reported for these tubular changes, except for care in the maintenance of hydration. The use of anti-inflammatory drugs is being studied in order to inhibit the prostaglandins involved in the process. Increased renal blood flow, glomerular filtration rate, and filtration fraction are frequent findings. Hematuria commonly occurs as a consequence of red blood cell sickling in the renal medulla, papillary necrosis, or even renal medullary carcinoma. Measures such as increased fluid ingestion, urine alkalinization and, if necessary, administration of epsilon-aminocaproic acid and certain invasive procedures have been proposed to treat hematuria. Nephropathy in patients with sickle cell anemia can be manifested by proteinuria and, more rarely, nephrotic syndrome. Drugs such as prednisone and cyclophosphamide are ineffective for the treatment of patients with nephrotic syndrome. Angiotensin converting enzyme inhibitors decrease proteinuria, but their long-term effect in preventing the progression of glomerular disease has not been established. Chronic renal failure, although infrequent, may be one of the manifestations of this disease. Hemodialysis and transplantation are satisfactory therapeutic options for patients with end-stage renal disease.