The scope of treatment of pediatric IgA vasculitis nephritis and its outcome: a Pediatric Nephrology Research Consortium study.

BACKGROUND: IgA vasculitis (IgAV) is the most common type of vasculitis in children. There is a lack of consensus for management of significant IgAV nephritis (IgAVN). This study was designed to identify the most used treatment options and describe their efficacy. METHODS: This is a multicenter retrospective study of children age 1-21 years with IgAVN who were managed for at least 6 months by a nephrologist. Subjects with at least microscopic hematuria and proteinuria and/or decreased kidney function were enrolled. Kidney outcome was assessed by eGFR and urine protein/creatinine (UPC) ratios at 2-4 weeks, 3, 6, and 12 months post-diagnosis. RESULTS: A total of 128 subjects with median age of 7 years (range 2-18) were included. Of these, 69 subjects had kidney biopsy with crescents detected in 53%. AKI (P = 0.039), nephrosis (P = 0.038), and crescents on biopsy (P = 0.013) were more likely in older patients. Patients with UPC > 1 mg/mg were more likely to get a kidney biopsy (P < 0.001) and to be treated with steroids ± immunosuppressive (IS) agents (P = 0.001). Sixty-six percent of patients were treated with steroids and/or IS agents for variable durations. Anti-metabolite agents were the most common IS agents used with variability in dosing and duration. At 12 months, most subjects had a normal eGFR (79%) (median 123, range 68-207 mL/min/1.73 m2) and no proteinuria (median UPC 0.15, range 0.01-4.02 mg/mg). CONCLUSIONS: IS agents are frequently used in managing IgAVN associated with heavy proteinuria, nephrosis, and/or AKI. Prospective studies are needed to determine indications and needed duration of IS therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

The role of continuous renal replacement therapy in the management of acute kidney injury associated with sinusoidal obstruction syndrome following hematopoietic cell transplantation.

Maintaining fluid balance, pre- and post-MA-HCT is essential and usually requires frequent administration of diuretics. Hepatic sinusoidal obstructive syndrome is potentially life-threatening, especially when associated with AKI and MOF. This study describes six patients who developed AKI-associated SOS and diuretic-resistant FO who subsequently underwent CRRT using standardized management guidelines for fluid balance post-HCT. Retrospective chart review was done for HCT patients between September 2011 and October 2013 at a tertiary care children's hospital. Thirty-four patients underwent MA-HCT in the study period. Six patients had SOS complicated by diuretic-resistant FO and underwent CRRT. Defibrotide was used in three patients. Median time on CRRT was 10.5 days. Sixty-six percent (N = 4 of 6) of patients had full resolution of SOS symptoms with a mortality rate of 34% (N = 2 of 6). Among patients who had full recovery of SOS symptoms, one patient developed AKI, end-stage renal diseases and underwent kidney transplantation 34-months post-HCT. Thus, of six included patients, two died and one developed ESRD with only 50% (N = 3 of 6) good outcome. Use of a standardized, evidence-based fluid balance protocol and early initiation of CRRT for HCT-related AKI/SOS was associated with good outcomes.

Nephrology Update: Glomerular Disease in Children.

Although kidney disease is much less common in children than in adults, clinicians must remain alert for the renal conditions that occur in this population because prompt diagnosis and management are essential. Acute postinfectious glomerulonephritis occurs as an uncommon sequela of streptococcal and other infections. Management is focused on providing supportive measures, including management of fluid-electrolyte imbalance and hypertension, until the patient recovers. Immunoglobulin (Ig) A nephropathy is a primary glomerulonephritis related to abnormal IgA glycosylation. The most common renal issue in children involves recurrent episodes of painless macroscopic hematuria during times of acute infection. Renal involvement occurs in the majority of children with Henoch-Schönlein purpura (HSP), with most experiencing asymptomatic hematuria and low level proteinuria. More severe forms of HSP nephritis, including rapidly progressive glomerulonephritis, may progress to end-stage kidney disease. Nephrotic syndrome commonly is related to steroid-responsive minimal change disease, and follows a course of relapses and remissions over time. However, a minority of children have steroid-resistant disease with potential for poor renal outcome.

Relationship of urinary endothelin-1 with estimated glomerular filtration rate in autosomal dominant polycystic kidney disease: a pilot cross-sectional analysis.

BACKGROUND: The pathogenesis of progressive renal insufficiency in autosomal dominant polycystic kidney disease (ADPKD) is unclear. Evidence from experimental models of ADPKD suggests that elevated endothelin-1 (ET-1) drives cyst growth, renal fibrosis and loss of renal function, but whether ET-1 is elevated in humans with ADPKD is uncertain. METHODS: In a cross-sectional study of ADPKD we measured urinary ET-1, a surrogate for ET-1 in kidney cortex, in spot collections corrected for creatinine. The volume of each kidney was measured using MRI-based stereology. The relationship of urine ET-1 with MDRD eGFR and kidney volume was modeled by multiple linear regression with adjustment for clinical covariates. RESULTS: Patients with ADPKD were ages 18 to 53 with eGFRs (median, interquartile range) of 63.2 (43.5-80.2) ml/min/1.73 m(2) and albumin/creatinine ratios (ACR) of 115.0 (7.5-58.5) µg/mg. Urine ET-1 was inversely associated with eGFR (r = -0.480, P < 0.05) and positively (r = 0.407, P = 0.066) with ACR independent of age and female sex (P < 0.01). ET-1 appeared to be positively associated with total kidney volume (r = 0.426, P = 0.100), with a test for trend across urine ET-1 quartiles yielding z = 1.83, P = 0.068. ET-1 strongly correlated with NAGase (r = 0. 687, P = 0.001), a marker of tubular damage and a surrogate marker of renal disease progression in ADPKD. Of note, ET-1 levels in urine were not correlated with hypertension. CONCLUSIONS: In a translational study of patients with ADPKD, urinary ET-1 was inversely associated with eGFR and positively correlated with total kidney volume. Taken together with results from experimental models, these findings suggest that the role of ET-1 in ADPKD warrants further investigation.

Outcome differences between young children and adolescents undergoing kidney transplantation.

BACKGROUND/PURPOSE: Although graft loss remains the biggest challenge for all pediatric kidney transplant (KT) recipients, unique challenges exist within different age groups. We aim to evaluate the different characteristics and graft survival outcomes of young children and adolescents undergoing KT. METHODS: Children who underwent isolated KT between 2000 and 2013 at our institution were included in this retrospective analysis. Patient characteristics and outcomes were compared using student's t-test, chi-square test, Kaplan-Meier curve and Cox proportional hazards model. RESULTS: Of 73 children who underwent KT, 31 were <12 (young children), and 42 were ≥ 12 years old (adolescents). Overall patient survival was 100%. The younger group had superior 5-year (100% vs. 75.5%) and 10-year (94.4% vs. 43.8%) graft survival (p=0.008). Factors predictive of poor graft survival on multivariate analysis were older age at transplantation (HR 1.2, CI 1-1.4, p=0.047), female gender (HR 9.0, CI 1.9-43, p=0.006), and acute rejection episodes (HR 13, CI 2-90, p=0.008). The most common causes of graft loss were acute and chronic rejection episodes and immunosuppression nonadherence. CONCLUSION: Adolescents undergoing KT have inferior graft survival compared to younger children. In adjusted modeling, children with older age, female gender, and acute rejection episodes have inferior graft survival.

A multicenter study of the pharmacokinetics of lisinopril in pediatric patients with hypertension.

The pharmacokinetic (PK) parameters of lisinopril were obtained in 46 children aged 6 months to 15 years. A lisinopril suspension (0.15 mg/kg per day) was administered to patients <6 years of age; the remaining children received lisinopril tablets, the daily dose being adjusted according to body weight, i.e., 2.5 mg if <25 kg, 5 mg if 25-45 kg, and 10 mg if >45 kg. Blood was drawn predose and on eight occasions postdose in children aged 4-15 years, and on five occasions in those aged <4 years. PK data are reported for the 46 children in terms of age groups: Group I (n=9), aged 6-23 months; Group II (n=8), aged 2-5 years; Group III (n=12), aged 6-11 years; Group IV (n=17), aged 12-15 years. The dose of lisinopril ranged from 3.07 mg/m(2) per day in Group I to 4.78 mg/m(2) per day in Group IV. C(max) of lisinopril, which occurred 5-6 h postdose, varied from 22 ng/ml in Groups I and II to 44 ng/ml in Groups III and IV; AUC(0-24 h) ranged from 301-311 ng.h/ml in Groups I and II to 550-570 ng.h/ml in Groups III and IV. No serious adverse events related to lisinopril were reported.

A double-blind, dose-response study of losartan in hypertensive children.

BACKGROUND: The aim of this study was to determine the dose-response relationship for losartan, 2.5 to 100 mg, and to assess the safety and tolerability of losartan in hypertensive children 6 to 16 years of age. METHODS: This was a multicenter, randomized, double-blind, dose-response study. In Period 1, a total of 175 patients were stratified by weight (<50 kg and >/=50 kg) and randomized to one of three dose groups by stratum (low, 2.5/5.0 mg; middle, 25/50 mg; or high, 50/100 mg) for 3 weeks. The ratio of the three dose levels for both weight strata was 1:10:20. In Period 2, patients in each dose group were randomized to continue the same treatment or placebo washout for 2 additional weeks. RESULTS: In Period 1, sitting trough diastolic blood pressure (DBP) decreased in a dose-dependent manner (P < .0001). At week 3, changes in DBP from baseline in the low-, middle-, and high-dose groups were -6.0 mm Hg, -11.7 mm Hg, and -12.2 mm Hg, respectively. In Period 2, DBP increased significantly in patients who switched from middle- and high-dose losartan to placebo (mean increase 6.0 mm Hg, P = .003) relative to DBP in patients who remained on active treatment; however, these levels remained stable in those patients who switched from low-dose losartan to placebo (mean increase 1.1 mm Hg, P = .628). CONCLUSIONS: In hypertensive children 6 to 16 years of age, losartan given once daily reduced blood pressure in a dose-dependent fashion. A once-daily starting dose of losartan, 0.75 mg/kg (maximum 50 mg) effectively lowered DBP within 3 weeks. Losartan up to a dosage of 1.44 mg/kg (maximum 100 mg) once daily is generally well tolerated.

A double-blind, placebo-controlled, dose-response study of the effectiveness and safety of lisinopril for children with hypertension.

BACKGROUND: Despite widespread use in hypertensive children, the safety and effectiveness of lisinopril had not been previously tested in a controlled study. METHODS: This study explored the dose-response relationship and safety of lisinopril in 115 hypertensive children, aged 6 to 16 years. Patients were randomized in a double-blind fashion for 2 weeks to one of three doses by body weight at baseline: <50 kg: low (0.625 mg), middle (2.5 mg), high (20 mg), and > or =50 kg: low (1.25 mg), middle (5 mg), high (40 mg). The dose-response for lisinopril was evaluated by analyzing the change in slope in sitting diastolic and systolic blood pressure (BP) by dose after 2 weeks of therapy compared to baseline. Patients then entered a double-blind withdrawal, where patients were either switched to placebo or continued their current lisinopril treatment for up to 2 weeks. Patients completed period II when their BP returned to baseline. Antihypertensive effectiveness, between placebo and lisinopril was determined for all doses. Adverse events were carefully monitored. RESULTS: There was a dose-response relationship between the lowest and each of the higher doses of lisinopril. Blood pressure in the placebo group increased after withdrawal of lisinopril. The dose-response relationship was consistent across all subgroups (ie, age, Tanner stage, ethnicity, gender). CONCLUSIONS: Lisinopril, once daily, is an effective and well-tolerated antihypertensive in children aged 6 to 16 years. An initial dose of 0.07 mg/kg, administered once daily, effectively lowered BP within 2 weeks. Blood pressure was reduced in a dose-dependent fashion.

Effect of the peritoneal dialysis prescription on pentosidine in children.

Enhanced formation of advanced glycation end products (AGEs) by peritoneal dialysate containing high dextrose concentrations has been implicated as a source of peritoneal membrane toxicity and loss of viability in patients treated with peritoneal dialysis (PD). The goal of this project was to elucidate the relationship between the structurally defined AGE pentosidine accumulation on peritoneal and plasma proteins and peritoneal membrane function, and to identify clinical factors leading to alterations in these parameters. The study comprised 27 pediatric patients (14 continuous ambulatory PD, 13 chronic cycling PD) on PD for a mean duration of 37.0+/-22.8 months (range 1-120 months) and with a mean age of 13.3+/-4.4 years (range 2.4-20 years). The pentosidine contents of plasma and peritoneal proteins were significantly lower in patients with residual renal function than in patients who were anuric (plasma pentosidine 11.2+/-8.8 vs. 24.1+/-16.6, P=0.02, respectively, peritoneal pentosidine 14.9+/-11.9 vs. 31.1+/-3.7, P=0.01, respectively). There was no effect of treatment modality on plasma pentosidine (18.1+/-11.2, 18.8+/-19.3, CAPD vs. CCPD, P>0.05) or peritoneal pentosidine content (24.1+/-14.1, 24.9+/-19.6, CAPD vs. CCPD, P>0.05). There was no evidence that increased levels of pentosidine on peritoneal proteins reflect or affect peritoneal membrane function in these patients. Furthermore, there was no effect of peritonitis on the pentosidine content of peritoneal proteins or peritoneal function as measured by peritoneal equilibration test. In conclusion, PD represents a well-tolerated therapy in children with no evidence that current practice causes changes in peritoneal membrane function, or in the peritoneal clearance of plasma or peritoneal proteins rich in pentosidine.

Complications of peritoneal dialysis in children with Eagle-Barrett syndrome.

Eagle Barrett syndrome (EBS) is characterized by the triad of abdominal muscle deficiency, urinary tract abnormalities, and cryptorchidism. Approximately 25% of patients with EBS progress to end-stage renal disease. It is speculated that the abdominal muscular defects in EBS pose technical problems in achieving successful peritoneal dialysis (PD). In this retrospective analysis, we reviewed the medical records of EBS and non-EBS PD patients cared for at Rainbow Babies and Children's Hospital from 1985 to 2002; 5 EBS and 9 non-EBS patients were analyzed. PD duration, total complication rates, and catheter usage rates in the two groups were not significantly different. The two most frequent complications were peritonitis and catheter mechanical malfunction during 103 patient-months in EBS patients and 296 patient-months in non-EBS patients. Peritonitis occurred 1 episode every 20.6 patient-months and 14.8 patient-months in EBS and non-EBS patients, respectively. The time from PD initiation to onset of any complication, including first peritonitis, was not significantly different in the two groups. Although the age at PD initiation was significantly different between the groups, there was no correlation between age at onset of PD and complication rates or time to first complication. Despite their abdominal muscle defects, EBS patients do not have more-frequent PD complications.

Famotidine disposition in children and adolescents with chronic renal insufficiency.

The pharmacokinetics of intravenous famotidine (0.5 mg/kg, maximum 20 mg) were evaluated in 18 pediatric patients (ages 1-18 years) with stable, chronic renal insufficiency. Subjects were stratified by calculated creatinine clearance (Clcr) into mild (Clcr > or = 50 to < 90 mL/min/1.73 m2), moderate (Clcr > or = 25 to < 50 mL/min/1.73 m2), and severe (Clcr < or = 10 mL/min/1.73 m2) renal insufficiency groups. Significant differences between the mild, moderate, and severe groups were found for elimination rate (Kel), apparent elimination half-life (t1/2), area under the curve (AUC), and total plasma clearance (Clp) (p < 0.01). Famotidine renal clearance (Clr) was found to be significantly different between the mild and severe groups (p < 0.05). A linear relationship was observed between Clcr and Clp (p < 0.0001; R2 = 0.70). No significant differences in nonrenal clearance (Clnr) were found between groups; however, Clnr as a percentage of Clp was significantly different in the severe group (92.9% +/- 7.3% Clnr) compared to the combined mild and moderate groups (21.9% +/- 45.6% Clnr) (p < 0.05). It was concluded that the pharmacokinetics of famotidine are significantly altered in children with chronic renal insufficiency; accordingly, dosing should be based on glomerular filtration rate (i.e., Clcr).