A simple estimate of glomerular filtration rate in full-term infants during the first year of life

Preservation of renal function in the modern staged repair of classic bladder exstrophy

OBJECTIVE

To compare the estimated glomerular filtration rate (eGFR) in bladder exstrophy patients with published normative GFR estimates.

PATIENTS AND METHODS

eGFR was calculated using the Schwartz formula at three timepoints, with mean eGFR at each timepoint compared to normative values.

RESULTS

At primary closure (n = 53) the mean eGFR (ml/min/1.73 m(2)) in exstrophy patients was similar to norms at 0-7 days (exstrophy vs norm: 42.5 vs 40.6, p > 0.05) and after 2 years of age (108.8 vs 133, p > 0.05). However, the mean eGFR in exstrophy patients was significantly lower than norms between 8 days (44.8 vs 65.8, p < 0.0001) and 2 years of life (68 vs 95.7, p = 0.01). At bladder neck reconstruction (n = 13) no statistically significant difference existed between the exstrophy and normative eGFR values (137.1 vs 133, p > 0.05). Similarly, among 27 patients with at least 1 year follow-up after bladder neck reconstruction, the mean exstrophy eGFR was no worse or higher than normative values (2-12 years: 124.5 vs 133, p > 0.05; males ≥13 years 175.6 vs 140, p = 0.04; females ≥13 years 128.8 vs 126, p > 0.05).

CONCLUSION

The staged reconstruction of exstrophy does not appear to negatively impact renal function in most patients. As eGFR detects only significant changes, surgical reconstruction may still cause more subtle renal damage.

Clinical characteristics of Kawasaki disease with sterile pyuria

Purpose

Kawasaki disease (KD) is a systemic vasculitis and affects many organ systems. It often presents sterile pyuria, microscopic hematuria, and proteinuria due to renal involvement. The aims of this study were to define clinical characteristics of acute KD patients with pyuria and to analyze meaning of pyuria in KD.

Methods

The medical records and laboratory findings including serum and urine test of 133 patients with KD admitted to Yeungnam University Hospital from March 2006 to December 2010 were reviewed retrospectively.

Results

Forty patients had sterile pyuria and their clinical characteristics including age, gender and body weight were not significantly different with those who did not have pyuria. Fever duration after treatment was significantly longer in KD patients with pyuria. Erythrocyte sedimentation rate, C-reactive protein and serum concentration of alanine aminotransferase were significantly higher in patients with pyuria. Hyponatremia and coronary artery lesion were seen more often in patients with pyuria but there was no significant difference. Also serum blood urea nitrogen was significantly higher in KD patients with pyuria. Urine β₂-microglobulin was elevated in both patients groups and showed no difference between two groups.

Conclusion

We found more severe inflammatory reaction in KD patients with pyuria. We also found elevation of some useful parameters like β₂-microglobulin that indicate renal involvement of KD through the urine test. Careful management and follow up will need for KD patients with pyuria and it is necessary in the future to study the specific parameters for renal involvement of KD.

Hemolytic uremic syndrome: late renal injury and changing incidence-a single centre experience in Canada

Aims. To assess trends in the incidence of pediatric diarrhea-associated hemolytic uremic syndrome (D(+) HUS) and document long-term renal sequelae. Methods. We conducted a retrospective cohort study of children with D(+) HUS admitted to a tertiary care pediatric hospital in Montreal, Canada, from 1976 to 2010. In 2010, we recontacted patients admitted before 2000. Results. Of 337 cases, median age at presentation was 3.01 years (range 0.4-14). Yearly incidence peaked in 1988 and 1994-95, returning to near-1977 levels since 2003. Twelve patients (3.6%) died and 19 (5.6%) experienced long-term renal failure. Almost half (47%) The patients required dialysis. Need for dialysis was the best predictor of renal sequelae, accounting for 100% of severe complications. Of children followed ≥1 year (n = 199, mean follow-up 8.20 ± 6.78 years), 19 had severe and 18 mild-to-moderate kidney injury, a total sequelae rate, of 18.6%. Ten years or more after-HUS (n = 85, mean follow-up 15.4 ± 5.32 years), 8 (9.4%) patients demonstrated serious complications and 22 (25.9%) mild-to-moderate, including 14 (16%) microalbuminuria: total sequelae, 35.3%. Conclusions. Patients with D(+) HUS should be monitored at least 5 years, including microalbuminuria testing, especially if dialysis was required. The cause of the declining incidence of D(+)HUS is elusive. However, conceivably, improved public health education may have played an important role in the prevention of food-borne disease.

Comparison of the glomerular filtration rate in children by the new revised Schwartz formula and a new generalized formula

The most widely used formula for estimating glomerular filtration rate (eGFR) in children is the Schwartz formula. It was revised in 2009 using iohexol clearances with measured GFR (mGFR) ranging between 15 and 75 ml/min × 1.73 m(2). Here we assessed the accuracy of the Schwartz formula using the inulin clearance (iGFR) method to evaluate its accuracy for children with less renal impairment comparing 551 iGFRs of 392 children with their Schwartz eGFRs. Serum creatinine was measured using the compensated Jaffe method. In order to find the best relationship between iGFR and eGFR, a linear quadratic regression model was fitted and a more accurate formula was derived. This quadratic formula was: 0.68 × (Height (cm)/serum creatinine (mg/dl))-0.0008 × (height (cm)/serum creatinine (mg/dl))(2)+0.48 × age (years)-(21.53 in males or 25.68 in females). This formula was validated using a split-half cross-validation technique and also externally validated with a new cohort of 127 children. Results show that the Schwartz formula is accurate until a height (Ht)/serum creatinine value of 251, corresponding to an iGFR of 103 ml/min × 1.73 m(2), but significantly unreliable for higher values. For an accuracy of 20 percent, the quadratic formula was significantly better than the Schwartz formula for all patients and for patients with a Ht/serum creatinine of 251 or greater. Thus, the new quadratic formula could replace the revised Schwartz formula, which is accurate for children with moderate renal failure but not for those with less renal impairment or hyperfiltration.

Acute kidney injury is associated with increased in-hospital mortality in mechanically ventilated children with trauma

BACKGROUND

Acute kidney injury (AKI) is associated with significant morbidity and mortality in patients with critical illness; however, its impact on children with trauma is not fully unexplored. We hypothesized that AKI is associated with increased in-hospital mortality.

METHODS

A retrospective review of consecutive mechanically ventilated patients aged 0 years to 20 years from 2004 to 2007 with trauma hospitalized at our institution was performed. Univariate and multivariate analyses were performed to identify whether AKI was a risk factor for hospital mortality.

RESULTS

Eighty-eight patients met inclusion/exclusion criteria. The study cohort included 58 (66%) males with mean (SD) age of 11.6 (5.5) years (median, 13.25; range, 0.083-19.42 years) and mean (SD) Pediatric Expanded Logical Organ Dysfunction score of 24 (11) (median, 22; range 2-51). Mean pediatric intensive care unit length of stay (median, 11; range, 4-43) and duration of mechanical ventilation (median, 9; range, 3-34), was 13.5 (8.2) days and 11.2 (7.2) days, respectively. The mean (SD) Injury Severity Score for the cohort was 28 (14). Pediatric RIFLE identified those at risk (R), those with injury (I), or those with failure (F) in 30 (51%), 10 (17%), and 12 (21%) patients, respectively. There was a 10% (3 of 30 patients) mortality rate in those at risk, 30% (3 of 10 patients) in those with injury, and 33% (4 of 12 patients) in those with failure. AKI (injury and failure groups) was significantly associated with increased in-hospital mortality.

CONCLUSION

Development of AKI (injury or failure) is a significant risk factor associated with in-hospital mortality. Our study highlights the need to consider both urine output as well as creatinine-based components of the pRIFLE criteria to define AKI.

LEVEL OF EVIDENCE

Prognostic and epidemiological study, level II.

Is the new Schwartz equation derived from serum creatinine and body length suitable for evaluation of renal function in Japanese children?

The present study was performed to determine whether the new Schwartz "bedside" equation can be used to estimate the glomerular filtration rate (GFR) in Japanese children as there are differences in renal function and muscle mass between Japanese and American individuals. It is also important to determine whether one common equation can be used in children from 1 to 16 years old, including the period of adolescence. Blood samples were collected from a total of 1,074 healthy children (466 males and 608 females) between 1 and 16 years old. The estimated GFR (eGFR) derived by the new Schwartz bedside formula [eGFR (in milliliters per minute per 1.73 m(2)) = 0.413 × body length (in centimeters)/serum Cr value (in milligrams per deciliter)] was calculated in all subjects, and the relationship between age and eGFR was analyzed. The eGFR decreased gradually with age, and the decrease was more marked in males than females, mainly in adolescence. Weak negative but significant correlations were observed in 466 males and 608 females. The median of the eGFR value showed a gradual significant decrease with age.

CONCLUSION

A common coefficient cannot be used in children between 1 and 16 years old, including the period of adolescence, with the Schwartz type formula, and the new Schwartz bedside formula cannot be used when we estimated GFR in Japanese children. It is necessary to establish an eGFR equation specifically for Japanese children.

Urine interleukin-18 and cystatin-C as biomarkers of acute kidney injury in critically ill neonates

BACKGROUND

Urinary interleukin-18 and cystatin-C are suggested to be biomarkers for predicting acute kidney injury (AKI). The aims of this study are to examine whether the urinary concentrations of interleukin-18 and cystatin-C vary with gestational age and other factors in non-AKI control neonates, and to determine whether urinary interleukin-18 and cystatin-C can predict AKI development in non-septic critically ill neonates, independently of potential confounders.

METHODS

We enrolled 62 non-septic critically ill neonates. Urine was collected every 48-72 h during the first 10 days of life.

RESULTS

Urinary concentration of cystatin-C, but not interleukin-18, decreased with increasing gestational age and body weight, but not with increasing postnatal age in non-AKI control neonates. Both urinary interleukin-18 and cystatin-C were associated with AKI, even after controlling for gestational and postnatal age, birth weight, gender, Apgar score and the score for neonatal acute physiology in non-septic critically ill neonates. Urinary interleukin-18 and cystatin-C had odds ratios of 2.27 and 2.07, and achieved the area under-the-receiver-operating-characteristic curve of 0.72 and 0.92, respectively, for predicting AKI.

CONCLUSIONS

The urinary concentration of cystatin-C, but not interleukin-18, may decrease with increasing renal maturity. Both urinary interleukin-18 and cystatin-C are independently predictive of AKI in non-septic critically ill neonates.

Interpretation of body mass index in children with CKD

BACKGROUND AND OBJECTIVES

Clinical practice guidelines recommend that body mass index (BMI) in children with CKD be expressed relative to height-age (BMI-height-age-z) rather than chronologic age (BMI-age-z) to account for delayed growth and sexual maturation. This approach has not been validated. This study sought to (1) compare children who have CKD with healthy children regarding the relationships between BMI-age-z and each of relative lean mass (LM) and adiposity and (2) determine whether BMI-height-age-z reflects relative LM and adiposity in CKD in the same way that BMI-age-z does in healthy children.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a cross-sectional study, dual-energy x-ray absorptiometry was used to assess whole-body fat mass (FM) and LM in 143 participants with CKD and 958 healthy participants (age, 5-21 years); FM and LM were expressed as sex-specific Z-scores relative to height (LM-height-z, FM-height-z), with healthy participants as the reference. BMI-age-z and BMI-height-age-z were determined using the 2000 Centers for Disease Control and Prevention reference data.

RESULTS

Compared with healthy children of the same sex, age, race, and BMI-age-z, LM-height-z was significantly higher in males with all CKD stages (by 0.41-0.43 SDs) and in females with mild to moderate CKD (by 0.38 SD); FM-height-z was significantly higher in both males (by 0.26 SD) and females (by 0.52 SD) with severe CKD. Underestimation of relative LM and adiposity was improved by expressing BMI relative to height-age.

CONCLUSIONS

In children with CKD, BMI-height-age-z reflects relative LM and adiposity in the same way that BMI-age-z does in healthy children.

Adenine phosphoribosyltransferase deficiency in children

Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive disorder characterized by 2,8-dihydroxyadenine (2,8-DHA) crystalluria that can cause nephrolithiasis and chronic kidney disease. The aim of our study was to assess the clinical presentation, diagnosis, and outcome of APRT deficiency in a large pediatric cohort. All pediatric cases of APRT deficiency confirmed at the same French reference laboratories between 1978 and 2010 were retrospectively reviewed. Twenty-one patients from 18 families were identified. The median age at diagnosis was 3 years. Diagnosis was made after one or more episodes of nephrolithiasis (17 patients), after urinary tract infection (1 patient), and by family screening (3 patients). The diagnosis was based on stone analysis and microscopic examination of urine and/or enzymatic determination of APRT on red blood cells. All children had null APRT enzyme activity in erythrocytes. APRT gene sequencing was performed on 18 patients, revealing six homozygous and 12 compound heterozygous mutations. At diagnosis, half of the patients had decreased kidney function, and two children presented with acute renal failure. Allopurinol treatment was given to all patients at a median dose of 9 mg/kg/day. After a median follow-up of 5 years, all patients showed stabilization or improvement of kidney function, normal growth and development, and six patients had recurrence of nephrolithiasis. Based on these results, we conclude that an excellent outcome can be achieved in children with APRT deficiency who receive the proper treatment.

Acquired and genetic complement abnormalities play a critical role in dense deposit disease and other C3 glomerulopathies

Dense deposit disease and glomerulonephritis with isolated C3 deposits are glomerulopathies characterized by deposits of C3 within or along the glomerular basement membrane. Previous studies found a link between dysregulation of the complement alternative pathway and the pathogenesis of these diseases. We analyzed the role of acquired and genetic complement abnormalities in a cohort of 134 patients, of whom 29 have dense deposit disease, 56 have glomerulonephritis with isolated C3 deposits, and 49 have primary membranoproliferative glomerulonephritis type I, with adult and pediatric onset. A total of 53 patients presented with a low C3 level, and 65 were positive for C3 nephritic factor that was significantly more frequently detected in patients with dense deposit disease than in other histological types. Mutations in CFH and CFI genes were identified in 24 patients associated with a C3 nephritic factor in half the cases. We found evidence for complement alternative pathway dysregulation in 26 patients with membranoproliferative glomerulonephritis type I. The complement factor H Y402H variant was significantly increased in dense deposit disease. We identified one at-risk membrane cofactor protein (MCP) haplotype for glomerulonephritis with isolated C3 deposits and membranoproliferative glomerulonephritis type I. Thus, our results suggest a critical role of fluid-phase alternative pathway dysregulation in the pathogenesis of C3 glomerulopathies as well as in immune complex-mediated glomerular diseases. The localization of the C3 deposits may be under the influence of MCP expression.

Acute kidney injury is associated with higher morbidity and resource utilization in pediatric patients undergoing heart surgery

BACKGROUND

The RIFLE (risk, injury, failure, loss, and end-stage renal disease) classification system was developed to standardize the definition of acute kidney injury (AKI) in adults. We hypothesized that AKI was associated with increased mortality and morbidity.

METHODS

Acute kidney injury was defined as a decrease in the amount of estimated creatinine clearance based on pediatric-modified RIFLE (pRIFLE) criteria. Using propensity score analysis, 325 patients who had AKI were matched to 325 patients who did not have AKI from a database of 1,510 consecutive pediatric patients who underwent cardiac surgery between January 2004 and December 2008 at a single center. The association between AKI and outcome was analyzed after propensity score matching of perioperative variables.

RESULTS

Four hundred eighty-one patients (31.9%) had AKI according to the RIFLE categories. Of those 1,510, 173 (11.5%) reached pRIFLE criteria for risk; 26 (1.7%) reached the criteria for injury; and 282 (18.7%) reached the criteria for failure. Fifty-five patients (3.6%) died. The 2 matched groups were well balanced in terms of measured perioperative variables. Mortality rate was 5.2% in the AKI and 2.5% in the matched control group (p=0.09). Occurrence of low cardiac output syndrome (p=0.002), need for dialysis (p<0.001), and infection (p=0.03) were significantly higher, and duration of mechanical ventilation (p<0.001) and length of intensive care unit stay (p<0.001) were significantly longer compared with the matched control group.

CONCLUSIONS

Acute kidney injury was independently associated with an increased occurrence of postoperative complications but not with mortality after pediatric cardiac surgery.

Acute kidney injury after cardiac surgery in infants and children: evaluation of the role of angiotensin-converting enzyme inhibitors

Children with congenital heart disease who undergo cardiac surgery are vulnerable to acute kidney injury (AKI). This study sought to evaluate the role of angiotensin-converting enzyme (ACE) inhibitors and other nephrotoxic medications in the risk for the development of AKI in neonates and children undergoing cardiac surgery. A retrospective review of all patients younger than 2 years admitted to the cardiac intensive care unit after cardiac surgery from March 2007 to September 2008 was conducted. Patients were included in the review if they received furosemide alone or in combination with an ACE inhibitor. Creatinine clearance was calculated, and the patient's maximal degree of AKI was classified by pRIFLE. A P value less than 0.05 was considered significant. Of the 319 patients who met the inclusion criteria, 149 (47%) received furosemide therapy alone and 170 (53%) received a combination of furosemide and an ACE inhibitor. Patients in the furosemide-only group (age, 5 months) were older than the patients who received both furosemide and an ACE inhibitor (age, 3.8 months; P = 0.024). Despite statistically higher Aristotle scores in the ACE-inhibitor group, the intraoperative variables did not differ between the two groups. Postoperatively, the ACE-inhibitor group had a decreased creatinine clearance (55.3 ml/min/1.73 m(2)) compared with the furosemide group (64.4 ml/min/1.73 m(2); P = 0.015) and an increased incidence of a pRIFLE maximal score of "F" (odds ratio [OR], 1.75; P = 0.033). However, after adjustment for additional risk factors, no difference in the occurrence of AKI resulted (OR, 0.939; P = 0.85) when patients received an ACE inhibitor. More than half of the study population received ACE inhibitors, but this treatment was not associated with an increase in AKI.

Antimicrobial therapy of urinary tract infections in children

The main objectives in childhood urinary tract infections are rapid recovery from complaints, prevention of urosepsis and infection-related complications as well as the prevention of renal parenchymal damage. Calculated antibiotic therapy should take the local resistance rates of uropathogens into consideration. The current situation of bacterial resistances differs from region to region. In Escherichia coli, resistance rates against cephalosporins, aminoglycosides, nitrofurantoin und chinolones have been relatively low. In contrast, resistance rates against ampicillin have increased over the last 20 years. A similar trend has been observed for TMP/SMX. The choice of appropriate antibiotics, the duration of therapy and the form of application depend on age, severity of clinical symptoms and the presence of complicating factors. In early infancy, a combination of aminoglycoside/ampicillin or ceftazidime/ampicillin is commonly recommended as first-line treatment in pyelonephritis. Pyelonephritis in young infants should always be treated in a paediatric clinic. In later infancy and childhood, an oral third-generation cephalosporin can be used.

Urinary neutrophil gelatinase-associated lipocalin at birth predicts early renal function in very low birth weight infants

Preterm infants are exposed to conditions that can impair renal function. We evaluated the ability of serum and urinary neutrophil gelatinase-associated lipocalin (sNGAL and uNGAL) to predict renal function in the first weeks of life. From September 2008 to July 2009, infants weighing ≤1500 g at birth with no major congenital anomalies or sepsis were eligible. We measured sNGAL and uNGAL levels at birth. To evaluate renal function, we determined changes in serum creatinine (sCreat) and estimated GFR (eGFR) from birth to d 21. Forty neonates (mean GA, 27 ± 2 wk) completed the study. Renal function improved in 32 of 40 (80%) infants (normal renal function, NRF group) (sCreat, from 0.97 ± 0.2 to 0.53 ± 0.13 mg/dL; eGFR, from 15.3 ± 4.1 to 28.6 ± 7.9 mL/min), whereas renal function worsened in 8 of 40 (20%) infants (impaired renal function, IRF group) (sCreat, from 0.71 ± 0.27 to 0.98 ± 0.43 mg/dL; eGFR from 23 ± 14.7 to 16.4 ± 9.1 mL/min). The uNGAL/urinary creatinine (uCreat) ratio at birth was higher in the IRF group (31.05 ng/mg) than the NRF group (6.0 ng/mg), and uNGAL was significantly higher in IRF group, detecting IRF with a cutoff of 100 ng/mL. uNGAL levels at birth may have a predictive role in very LBW (VLBW) infants.

Dosing regimens of oral ciprofloxacin for children with severe malnutrition: a population pharmacokinetic study with Monte Carlo simulation

Background

Severe malnutrition is frequently complicated by sepsis, leading to high case fatality. Oral ciprofloxacin is a potential alternative to the standard parenteral ampicillin/gentamicin combination, but its pharmacokinetics in malnourished children is unknown.

Methods

Ciprofloxacin (10 mg/kg, 12 hourly) was administered either 2 h before or up to 2 h after feeds to Kenyan children hospitalized with severe malnutrition. Four plasma ciprofloxacin concentrations were measured over 24 h. Population analysis with NONMEM investigated factors affecting the oral clearance (CL) and the oral volume of distribution (V). Monte Carlo simulations investigated dosage regimens to achieve a target AUC_0–24/MIC ratio of ≥125.

Results

Data comprised 202 ciprofloxacin concentration measurements from 52 children aged 8–102 months. Absorption was generally rapid but variable; C_max ranged from 0.6 to 4.5 mg/L. Data were fitted by a one-compartment model with first-order absorption and lag. The parameters were CL (L/h) = 42.7 (L/h/70 kg) × [weight (kg)/70]^0.75 × [1 + 0.0368 (Na⁺ – 136)] × [1 – 0.283 (high risk)] and V (L) = 372 × (L/70 kg) × [1 + 0.0291 (Na⁺ – 136)]. Estimates of AUC_0–24 ranged from 8 to 61 mg·h/L. The breakpoint for Gram-negative organisms was <0.06 mg/L with doses of 20 mg/kg/day and <0.125 mg/L with doses of 30 or 45 mg/kg/day. The cumulative fraction of response with 30 mg/kg/day was ≥80% for Escherichia coli, Klebsiella pneumoniae and Salmonella species, but <60% for Pseudomonas aeruginosa.

Conclusions

An oral ciprofloxacin dose of 10 mg/kg three times daily (30 mg/kg/day) may be a suitable alternative antibiotic for the management of sepsis in severely malnourished children. Absorption was unaffected by the simultaneous administration of feeds.

Preliminary reference intervals for cystatin C and beta-trace protein in preterm and term neonates

OBJECTIVE

To determine the reference intervals for serum cystatin C (CysC) and beta-trace protein (BTP) as markers of renal function in preterm and term neonates.

DESIGN AND METHODS

Blood samples of 128 neonates (34% female) admitted to the NICU were analyzed to determine the levels of serum creatinine (enzymatically), CysC and BTP (nephelometric, Siemens Health Care).

RESULTS

The reference intervals, categorized by age, were reported for the 128 neonates. Median (lower/upper limit) BTP were 1.85 (0.57/3.16) and 1.27 (0.51/2.07) mg/L on days 1 and 3. In keeping with maturation of renal function after birth, CysC and BTP fell from days one to day three after birth, whereas creatinine did not.

CONCLUSION

Our data provides reference intervals for the levels of creatinine, CysC, and BTP in neonates on days 1 and 3 after birth and demonstrates that CysC and BTP reflect neonatal renal function, whereas creatinine reflects maternal renal function.

Focusing on the clinical impact of standardization of creatinine measurements: a report by the EFCC Working Group on Creatinine Standardization

The recent campaign for standardization of creatinine measurements has been promoted to allow the widespread use of formulas for estimating the glomerular filtration rate (GFR). However, studies on trueness verification and measurement interferences still show disappointing interassay variation of serum creatinine results. Creatinine recalibration has major clinical consequences. In particular, in pediatrics where reference ranges for serum and plasma creatinine are low, calculation of the GFR is problematic when based on alkaline picrate methods because of method non-specificity and the lack of appropriate GFR estimating formulas. Therefore, enzymatic creatinine assays are preferred. In the near future, cystatin C might offer an interesting alternative for GFR estimation. For the calculation of drug doses, the Modification of Diet in Renal Disease study formula generally offers reliable data. However, attention has to be paid to the elderly. Also, the calculation of the Model for End-Stage Liver Disease score, which is used to prioritize patients for liver transplantation, may significantly be influenced by recalibration of creatinine assays. Creatinine restandardization may also affect the current guidelines for referral of chronic kidney disease patients to nephrologists.

Aberrant glycosylation of IgA1 is inherited in both pediatric IgA nephropathy and Henoch-Schönlein purpura nephritis

Serum galactose-deficient immunoglobulin A1 (Gd-IgA1) is an inherited risk factor for adult IgA nephropathy (IgAN). In this paper, we determined the heritability of serum Gd-IgA1 levels in children with IgAN and Henoch-Schönlein purpura nephritis (HSPN), two disorders with clinical phenotypes sharing common pathogenic mechanisms. Serum Gd-IgA1 concentrations were quantified using a Helix aspersa-lectin-based enzyme-linked immunosorbent assay. As a group, 34 children with either disorder (20 with HSPN and 14 with IgAN) had significantly higher Gd-IgA1 levels compared with 51 age- and ethnicity-matched pediatric controls. Serum levels of Gd-IgA1 were also elevated in a large fraction of 54 first-degree relatives of pediatric IgAN and HSPN patients compared with 141 unrelated healthy adult controls. A unilineal transmission of the trait was found in 17, bilineal transmission in 1, and sporadic occurrence in 5 of 23 families when both parents and the patient were analyzed. There was a significant age-, gender-, and household-adjusted heritability of serum galactose-deficient IgA1 estimated at 76% in pediatric IgAN and at 64% in HSPN patients. Thus, serum galactose-deficient IgA1 levels are highly inherited in pediatric patients with IgAN and HSPN, providing support for another shared pathogenic link between these disorders.

Association of chronic kidney disease with muscle deficits in children

The effect of chronic kidney disease (CKD) on muscle mass in children, independent of poor growth and delayed maturation, is not well understood. We sought to characterize whole body and regional lean mass (LM) and fat mass (FM) in children and adolescents with CKD and to identify correlates of LM deficits in CKD. We estimated LM and FM from dual energy x-ray absorptiometry scans in 143 children with CKD and 958 controls at two pediatric centers. We expressed whole body, trunk, and leg values of LM and FM as Z-scores relative to height, sitting height, and leg length, respectively, using the controls as the reference. We used multivariable regression models to compare Z-scores in CKD and controls, adjusted for age and maturation, and to identify correlates of LM Z-scores in CKD. Greater CKD severity associated with greater leg LM deficits. Compared with controls, leg LM Z-scores were similar in CKD stages 2 to 3 (difference: 0.02 [95% CI: -0.20, 0.24]; P = 0.8), but were lower in CKD stages 4 to 5 (-0.41 [-0.66, -0.15]; P = 0.002) and dialysis (-1.03 [-1.33, -0.74]; P < 0.0001). Among CKD participants, growth hormone therapy associated with greater leg LM Z-score (0.58 [0.03, 1.13]; P = 0.04), adjusted for CKD severity. Serum albumin, bicarbonate, and markers of inflammation did not associate with LM Z-scores. CKD associated with greater trunk LM and FM, variable whole body LM, and normal leg FM, compared with controls. In conclusion, advanced CKD associates with significant deficits in leg lean mass, indicating skeletal muscle wasting. These data call for prospective studies of interventions to improve muscle mass among children with CKD.

Efficacy and safety of thymoglobulin induction as an alternative approach for steroid-free maintenance immunosuppression in pediatric renal transplantation

BACKGROUND

Given the recent withdrawal of daclizumab (DAC), the safety and efficacy of thymoglobulin (TMG) was tested as an alternative induction agent for steroid-free (SF) immunosuppression in pediatric kidney transplant recipients.

METHODS

Thirteen pediatric renal transplant recipients meeting defined high-risk criteria at transplantation were offered TMG induction and SF immunosuppression with maintenance mycophenolate mofetil and tacrolimus between October 2008 and January 2010. Patients were closely monitored at baseline, 3, 6, 9, and 12 months posttransplant for protocol biopsy and clinical outcomes. Outcomes were compared with 13 consecutively transplanted low-risk patients receiving an established DAC-based SF protocol (Sarwal et al., WA, American Transplant Congress 2003).

RESULTS

There was a significant trend for overall decrease in the absolute lymphocyte counts in TMG group (F=5.86, mixed model group effect P=0.02), predominately at 3 months compared with DAC group (0.7±0.6 vs. 2.1±1.0, P=0.0004); however, lymphocyte count was recovered and was back to reference range by 6 months in TMG. There was trend toward more subclinical cytomegalovirus (15% vs. 0%) and BK viremia (17% vs. 0%) in the TMG group, with no differences in the incidence of subclinical Epstein Barr virus viremia (23% vs. 31%) or clinical viral disease. Mean graft function was excellent, and with a minimum follow-up of 6 months, there were no episodes of acute rejection.

CONCLUSION

TMG seems to be a safe alternative induction strategy in patients for SF immunosuppression in pediatric renal transplantation. Extended follow-up and greater enrollment are necessary to fully explore the impact of TMG dosing on viral replication posttransplantation.

First-dose pharmacokinetics of lithium carbonate in children and adolescents

This study examines the pharmacokinetics of oral doses of lithium carbonate immediate-release capsules after administration of 600 or 900 mg in children and adolescents with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, bipolar I disorder. Lithium plasma concentrations were followed over 48 to 72 hours in 39 subjects (20 male and 19 female subjects; ages, 7-17 years) with mixed or manic episodes enrolled at 7 clinical sites participating in the Collaborative Lithium Trials. Population pharmacokinetic modeling was performed using NONMEM, and influences of patient covariates on pharmacokinetics parameters were examined. The pharmacokinetics of lithium was best described using a 2-compartment model with a lag time and first-order absorption. There was considerable variability in lithium exposures. Lithium clearance related best to fat-free mass. Inclusion of fat-free mass as a covariate reduced the between-subject variability from 52% to 42%. Lithium clearances did not vary systematically with age group, dose, sex, or creatinine clearances. Allometrically scaled clearance and volume of distribution from the population analysis were within the range reported in adults. Single-dose profiles of lithium in young patients with BP-1 show marked variability. Therefore, ongoing serum monitoring is needed during continued therapy. The developed population pharmacokinetic model may be used to predict other dosage regimens, support scaling from adult to pediatric pharmacokinetics, and support the design of future clinical trials.

Galactose-deficient IgA1 in African Americans with IgA nephropathy: serum levels and heritability

BACKGROUND AND OBJECTIVES

Serum levels of galactose-deficient IgA1 (Gd-IgA1) are elevated and heritable in Caucasian and Asian patients with IgA nephropathy (IgAN), but have not been characterized in African Americans (AA). Our objective was to determine whether serum Gd-IgA1 levels are increased in AA patients with IgAN and whether this is a heritable trait in this group.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Blood and urine samples were obtained from 18 adult and 11 pediatric AA patients with biopsy-proven IgAN and from 34 of their first-degree relatives. Healthy controls included 150 Caucasian adults, 65 AA adults, 45 Caucasian children, and 49 AA children. Serum total IgA and Gd-IgA1 levels were measured in patients and controls. Significant differences between patient and control groups for serum total IgA, Gd-IgA1, and ratio of Gd-IgA1/total IgA were determined by the Mann-Whitney U test. Heritability was calculated using SOLAR.

RESULTS

After stratifying by age, 7 of 11 pediatric and 9 of 18 adult AA patients with IgAN had serum Gd-IgA1 levels above the 95th percentile for age-appropriate AA controls. For first-degree relatives, the serum Gd-IgA1 level was >95th percentile for 1 of 8 when the patient's level was <95th percentile and 12 of 26 when the patient's level was >95th percentile (P = 0.116, Fisher exact test). Heritability was 0.74 (P = 0.007).

CONCLUSIONS

Serum levels of Gd-IgA1 are often elevated in AA patients with IgAN and their first-degree relatives. Thus, aberrant IgA1 glycosylation is a heritable risk factor for IgAN in African Americans.

Pre-emptive liver transplantation for primary hyperoxaluria (PH-I) arrests long-term renal function deterioration

BACKGROUND

Primary hyperoxaluria-I (PH-I) is a serious metabolic disease resulting in end-stage renal disease. Pre-emptive liver transplantation (PLT) for PH-I is an option for children with early diagnosis. There is still little information on its effect on long-term renal function in this situation.

METHODS

Long-term assessment of renal function was conducted using Schwartz's formula (estimated glomerular filtration rate-eGFR) in four children (Group A) undergoing PLT between 2002 and 2008, and a comparison was done with eight gender- and sex-matched controls (Group B) having liver transplantation for other indications.

RESULTS

All patients received a liver graft from a deceased donor. Median follow-up for the two groups was 64 and 94 months, respectively. One child in Group A underwent re-transplantation due to hepatic artery thrombosis, while acute rejection was seen in one. A significant difference was seen in eGFR at transplant (81 vs 148 mL/min/1.73 m(2)) with greater functional impairment seen in the study population. In Group A, renal function reduced by 21 and 11% compared with 37 and 35% in Group B at 12 and 24 months, respectively. At 2 years post-transplantation, there was no significant difference in eGFR between the two groups (72 vs 100 mL/min/1.73 m(2), respectively; P = 0.06).

CONCLUSIONS

Renal function remains relatively stable following pre-emptive LTx for PH-I. With early diagnosis of PH-I, isolated liver transplantation may prevent progression to end-stage renal disease and the need for renal transplantation.

On the relationship between glomerular filtration rate and serum creatinine in children

The Schwartz formula (eGFR = kL/Scr, with k = 0.55) to determine the estimated glomerular filtration rate (eGFR) in children with chronic kidney disease (CKD), based on length (L) and serum creatinine (Scr) has recently been updated for enzymatic serum creatinine concentrations, resulting in k = 0.413. Based on a meta-analysis, we evaluated the validity of this updated equation and other published equations for healthy children. This is the first time that publicly available data for healthy children of uncorrected and body surface area (BSA)-corrected median GFR have been combined with median serum creatinine values and median lengths and weights from different sources in the literature to evaluate several statistical models to estimate GFR in children. For enzymatic serum creatinine, we show that the simple model for uncorrected GFR (uGFR = k'L(3)/Scr, with k' = 1.32 x 10(-5)) and the BSA-corrected GFR (cGFR = kL/Scr, analogous to the Schwartz formula), with an important age-dependent adaptation for k (k = 0.0414 x 1n (Age) + 0.3018), correlate extremely well with chromium-51-ethylenediamine tetra-acetic acid ((51)Cr-EDTA) data for children between 1 month and 14 years of age. With this age-dependent modification for k, presented here, the simple bedside calculation tool derived by Schwartz can be used for screening all children for CKD. When height information is not available, the Lund-Malmö equation is an excellent alternative.

Predictive value of albuminuria in American Indian youth with or without type 2 diabetes

OBJECTIVE

To examine the prognostic significance of elevated albuminuria in youth with type 2 diabetes.

PATIENTS AND METHODS

Cross-sectional and prospective studies were conducted on Pima Indian youth aged 5 to 19 years at baseline who were examined between July 1, 1982, and December 31, 2007. Prevalence and sequential changes in the level of microalbuminuria (30 < or = albumin-to-creatinine ratio [ACR] < 300 mg/g) and macroalbuminuria (ACR > or = 300 mg/g) and incidence of macroalbuminuria were computed according to the presence or absence of type 2 diabetes.

RESULTS

The prevalence of microalbuminuria and macroalbuminuria was 6.5% and 0.6% in the 3856 nondiabetic youth and 18.5% and 2.9% in the 103 youth with diabetes, respectively. One hundred forty-one of 187 (75.4%) nondiabetic youth, but only 1 of 14 (7.1%) diabetic youth with an elevated ACR (> or =30 mg/g) regressed to an undetectable or normal ACR (<30 mg/g) on subsequent examination. In a subset of 2666 youth with a median follow-up of 8.1 years, 36 nondiabetic and 30 diabetic youth with baseline ACRs of <300 mg/g developed macroalbuminuria. For a given ACR, the incidence of macroalbuminuria was 15.9-fold (95% confidence interval: 11.1-22.6) higher in the diabetic than in the nondiabetic youth.

CONCLUSIONS

Elevated albuminuria is infrequent and largely transient in nondiabetic youth, but it is relatively frequent and largely persistent in those with diabetes. Microalbuminuria in youth with type 2 diabetes strongly predicts progression to macroalbuminuria, which supports annual screening for albuminuria.

[Hemolytic uremic syndrome: long term renal injury]

INTRODUCTION

Hemolytic uremic syndrome (HUS) is the most frequent cause of non-pre-renal acute renal failure in pediatrics and it is usually secondary to acute infectious diarrhea, generally due to Shiga-toxin producing E. coli. It is characterized by acute renal failure, hemolytic anemia and thrombocytopenia. It can lead to renal sequels in the long term and to end-stage renal disease.

METHODS

The aim of this retrospective study is to describe and analyze renal sequels and their prognostic factors in pediatric patients suffering from HUS in a Spanish tertiary hospital during the last 28 years.

RESULTS

43 children with this condition were admitted, with 38 of them having presented with diarrhea previously. Among those with a follow-up longer than 3 months, 21.6% (8/37) had a reduction in glomerular filtration rate (GFR) in the last visit. Including proteinuria and hypertension, we found up to 35.1% (13/37) prevalence of chronic kidney disease, with 8.1% (3/37) of the patients with end-stage renal disease. We found the following to be prognostic factors for renal injury in the long term in a univariate logistic regression: hypertension, a longer stay in the hospital, more prolonged anuria, more severe leukocytosis and lower GFR at discharge. Multivariate logistic regression showed an association with time in anuria.

CONCLUSIONS

Approximately one third of our cases of hemolytic uremic syndrome developed some degree of chronic kidney disease in the long term. A deeper and longer initial renal disfunction is associated with a higher probability of subsequent renal problems.

Blood lead level and kidney function in US adolescents: The Third National Health and Nutrition Examination Survey

BACKGROUND

Chronic, high-level lead exposure is a known risk factor for kidney disease. The effect of current low-level environmental lead exposure is less well known, particularly among children, a population generally free from kidney disease risk factors such as hypertension and diabetes mellitus. Therefore, in this study, we investigated the association between lead exposure and kidney function in a representative sample of US adolescents.

METHODS

Participants included 769 adolescents aged 12 to 20 years for whom whole blood lead and serum cystatin C were measured in the Third National Health and Nutrition Examination Survey, conducted from 1988-1994. The association between blood lead level and level of kidney function (glomerular filtration rate [GFR]), determined by cystatin C-based and creatinine-based estimating equations, was examined.

RESULTS

Median whole blood lead level was 1.5 microg/dL (to convert to micromoles per liter, multiply by 0.0483), and median cystatin C-estimated GFR was 112.9 mL/min/1.73 m(2). Participants with lead levels in the highest quartile (> or =3.0 microg/dL) had 6.6 mL/min/1.73 m(2)-lower estimated GFR (95% confidence interval, -0.7 to -12.6 mL/min/1.73 m(2)) compared with those in the first quartile (<1 microg/dL). A doubling of blood lead level was associated with a 2.9 mL/min/1.73 m(2)-lower estimated GFR (95% confidence interval, -0.7 to -5.0 mL/min/1.73 m(2)). Lead levels were also associated with lower creatinine-based estimated GFR levels, but the association was weaker than with cystatin C-based GFR and not statistically significant.

CONCLUSIONS

Higher blood lead levels in a range below the current Centers for Disease Control and Prevention-designated level of concern (10 microg/dL) were associated with lower estimated GFRs in a representative sample of US adolescents. This finding contributes to the increasing epidemiologic evidence indicating an adverse effect of low-level environmental lead exposure.

Compartmental localization and clinical relevance of MICA antibodies after renal transplantation

BACKGROUND

Antibodies (Ab) responses to major and minor human leukocyte antigen loci may impact graft survival after organ transplantation.

METHODS

A ProtoArray platform was used to study 37 serum samples from 15 renal transplant patients with (n=10) and without (n=5) acute rejection (AR) and seven normal controls, and the clinical relevance of major histocompatibility complex class I chain-related gene-A (MICA)-Ab measurements were investigated. Biopsy immunohistochemistry was conducted for localization of the MICA antigen.

RESULTS

De novo MICA-Ab were detected in 11 of the 15 transplant patients in this study, irrespective of interval acute graft rejection. Mean MICA-Ab signal intensity was higher in transplant patients with C4d+AR (121.4) versus C4d-AR (4.3), correlated with donor-specific Ab to human leukocyte antigens (r=0.66, P=0.0078), was not elevated in cellular rejections, and correlated with decline in graft function over the subsequent year (r=0.73, P=0.0022). Integrative genomics accurately predicted localization of the MICA antigen to the glomerulus in the normal kidney (Li et al. Proc Natl Acad Sci USA 2009; 106: 4148), because this was confirmed subsequently by immunohistochemistry.

CONCLUSIONS

Integrative genomics analysis of ProtoArray data is a powerful tool to ascertain de novo antibody responses after renal transplantation and to accurately predict the anatomical location of the target renal antigens. This proof-of-concept study on MICA measurements by ProtoArray demonstrates that antibody responses modulated to MICA after transplantation in patients, irrespective of graft rejection, may be high at the time of humoral rejection and may not be elevated in cellular rejection. Understanding that MICA is preferentially localized to the glomerulus may explain both immunoregulatory and pathogenic roles for MICA after transplantation.

Serum adiponectin levels and ambulatory blood pressure monitoring in pediatric renal transplant recipients

BACKGROUND.: Reduced levels of serum adiponectin, an adipokine, are associated with cardiovascular and obesity-related diseases; however, relations between adiponectin and hypertension are unclear. METHODS.: This cross-sectional study examined adiponectin and ambulatory blood pressure monitoring (ABPM) in 33 pediatric renal transplant recipients (TXP), aged 8 to 19 years, median of 1.9 years after transplant. Serum total adiponectin (microg/mL) and high molecular weight-to-total adiponectin ratio (HMWr), 24-hr ABPM, and dual x-ray absorptiometry measures of fat mass were obtained. RESULTS.: The 12 TXP with hypertension (defined as BP index >1.0 and BP load >25%) had lower total adiponectin levels (7.4+/-3.2 vs. 10.9+/-5.2 microg/mL, P=0.045) compared with nonhypertensive TXP. Hypertensive TXP trended toward lower HMWr compared with nonhypertensive TXP (0.40+/-0.09 vs. 0.47+/-0.11, P=0.064). Levels did not differ according to sex, obesity or dipper status. In univariate analyses, total adiponectin and HMWr were negatively and significantly correlated with indexed BP in the daytime, nighttime, and 24-hr periods (R=-0.35 to -0.57). After adjustment for estimated glomerular filtration rate, fat mass, anti-hypertensive medication and fasting glucose, (1) lower total adiponectin was significantly and independently associated with greater elevations in all ABPM indexes except for nighttime systolic indexed BP, and (2) HMWr was inversely associated with all ABPM indexes. Lower adiponectin levels (P=0.049) and HMWr (P=0.042) were associated with greater odds of hypertension. CONCLUSION.: These data indicate that lower total adiponectin and HMWr were significantly and independently associated with greater ambulatory blood pressure.

The pharmacokinetics of valganciclovir prophylaxis in pediatric solid organ transplant patients at risk for Epstein-Barr virus disease

Antiviral prophylaxis with valganciclovir is used frequently in pediatric solid organ transplant patients to prevent Epstein-Barr virus (EBV)-induced infections and tissue-invasive disease including post-transplant lymphoproliferative disorder (PTLD). This approach is untested in clinical trials and valganciclovir dosing strategies in children are highly variable. Our objective was to characterize the pharmacokinetics of ganciclovir in the plasma of pediatric kidney and liver transplant patients taking valganciclovir for EBV prophylaxis. Virologic response was also evaluated. Ganciclovir was measured by liquid chromatography/ultraviolet detection. EBV DNA was quantified by TaqMan(®) polymerase chain reaction. NONMEM(®) VI was used for data analysis. Ganciclovir plasma profiles were consistent with a one-compartment model. Final model estimates of apparent oral clearance (L/h), apparent volume of distribution (L), and absorption rate constant were 7.33, 35.1, and 0.85, respectively. There was evidence of lower bioavailability in children younger than three years. All eight subjects achieved ganciclovir plasma concentrations above reported in vitro concentrations needed to inhibit EBV replication by 50%. However, four subjects had detectable EBV DNA with a median (range) of 18,300 (4,400 to 54,900) copies/mL of whole blood. These findings support the need for further studies of the clinical pharmacology and efficacy of valganciclovir for EBV prophylaxis.

Incidence and risk factors for cardiovascular events and death in pediatric renal transplant patients: a single center long-term outcome study

There are considerable mortality data associated with renal transplantation in children; however, morbidity data, especially related to CV disease, are scarce. The objectives of this study were to determine incidence of non-fatal and fatal CV events and all-cause mortality in PRTx and evaluate risk factors for these conditions. Using a population-based retrospective cohort design, 274 PRTx with or without a functioning graft was followed until death or date of last contact (median follow-up 11.9 yr). Primary outcomes (time to first fatal or non-fatal CV event and all-cause mortality after first transplant) were ascertained from chart review and linkage with administrative databases of a universal health care system. During 3073 patient-years, there were 46 deaths; 13 were because of CV disease. Twenty patients had CV events that did not result in death. Post-transplant diabetes mellitus (10.5%) was associated with increased risk of death (HR: 2.79, 95% CI: 1.04-7.44) and CV events (HR: 3.90, 95% CI: 1.31-11.59). Low estimated glomerular filtration rate at one yr post-transplant was also associated with increased risk of death. The rates of developing CV disease and dying prematurely are extraordinarily high in PRTx, underscoring the need for early and aggressive intervention to reduce the burden of suffering in this patient population.

Management of arterial hypertension occurring early after living donor liver transplantation in children: report of three cases and review of the literature

Three pediatric patients with hypertension occurring early after liver transplantation are reviewed. The patients were all female, and underwent living donor liver transplantation at the age of 9 years, 1 month, and 7 months. The etiology of liver disease was cirrhosis due to biliary atresia in two patients and fulminant hepatitis in one patient. Antihypertensive therapy with calcium channel blocker alone was not effective. Blood pressure was eventually controlled after the administration of a beta-adrenergic blocker in addition to the calcium channel blocker to all patients. No end-organ damage was observed, except that two patients developed temporary left ventricular hypertrophy.

Measurement and estimation of GFR in children and adolescents

GFR is the best indicator of renal function in children and adolescents and is critical for diagnosing acute and chronic kidney impairment, intervening early to prevent end-stage renal failure, prescribing nephrotoxic drugs and drugs cleared by a failing kidney, and monitoring for side effects of medications. Renal inulin clearance was the gold standard for GFR but is compromised by lack of availability, difficult assays, and problems of collecting timed urine samples, especially in children with vesicoureteral reflux or bladder dysfunction. Creatinine clearance-based estimates of GFR are often used in pediatrics. The addition of cimetidine to eliminate creatinine secretion permits accurate measurement of GFR in those who can completely empty their bladders to provide timed urine collections. Radioisotopes are used in plasma disappearance GFR determinations; however, these are not ideal for use in children, especially for repeated studies. The plasma disappearance of iohexol serves as a promising alternative GFR marker, because it is safe and not radioactive, easily measured, not metabolized or transported by the kidney, and excreted primarily by glomerular filtration. GFR estimating equations, based on serum concentrations of creatinine or cystatin C, are popular clinically and in research studies. Efforts are ongoing to improve these estimating equations for children and make the results readily available to clinicians obtaining standard chemistry profiles, as is being done for adults. However, at this time, there is no dependable substitute for an accurately determined GFR, and iohexol plasma disappearance offers the best combination of safety, accuracy, and reproducible precision.

Fulminant hepatic failure in children: superior and durable outcomes with liver transplantation over 25 years at a single center

OBJECTIVE(S)

Death occurs in half of all children with fulminant hepatic failure (FHF). Although liver transplantation (LT) is potentially life-saving, there are only a few published series with limited experience. The aim was to examine predictors of survival after LT for FHF.

METHODS

Between 1984 and 2008, all LT for FHF performed in recipients less than or equal to 18 years of age were analyzed from a prospectively maintained database using 35 demographic, laboratory, and operative variables. Unique calculated variables included creatinine clearance (cCrCl) and Pediatric End-Stage Liver Disease score (PELD). Study end-points were patient and death censored graft survival. Median follow-up was 98 months. Statistical analysis involved the log-rank test and Cox proportional hazards model.

RESULTS

A total of 122 children underwent 159 LTx. Cryptogenic was the primary etiology (70%) and the median age was 53 months. The significant (P < 0.05) univariate predictors of worse graft survival were: recipient age <24 months, cCrCl <60 mL/min/1.73m, PELD >25 points, and warm ischemia time >60 minutes. The significant (P < 0.05) univariate predictors of worse patient survival were: recipient African-American and Asian race, recipient age <24 months, cCrCl <60 mL/min/1.73m, and time from onset jaundice to encephalopathy <7 days. On multivariate analysis, survival was significantly impacted by 4 variables: cCrCl <60 mL/min/1.73m (GRAFT and PATIENT), PELD >25 points (GRAFT), recipient age <24 months (GRAFT), and time from onset jaundice to encephalopathy <7 days (PATIENT). While overall 5- and 10-year survival was 73% and 72% (GRAFT) and 77% and 73% (PATIENT), these were significantly worse when a combination of multivariate risk-factors were present.

CONCLUSIONS

This data from a large, single-center experience demonstrates that LT is the treatment of choice for FHF and results in durable survival. Analysis revealed 4 novel outcome predictors. Young children with rapid onset acute liver failure are a high-risk subpopulation. Unique to this study, cCrCl and PELD accurately predicted the end-points. This analysis identifies patient subpopulations requiring early aggressive intervention with LT.

Dystroglycan in the diagnosis of FSGS

BACKGROUND AND OBJECTIVES

alpha- and beta-dystroglycan (DG), which link the actin cytoskeleton of the podocyte to the glomerular basement membrane, are maintained in FSGS but decreased in minimal change disease (MCD). Fibrosis has been linked to increased fibroblast-specific protein-1 (FSP1) and epithelial-mesenchymal transition. We studied DG, FSP1, and podocyte differentiation in FSGS variants and cases of suspected FSGS.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied renal biopsies with FSGS, not otherwise specified (NOS), tip lesion, or collapsing variants (COLL), versus secondary FSGS or cases without segmental sclerotic lesions where a diagnosis of MCD versus FSGS could not be established (undefined [UNDEF]) and compared the expression of DG, FSP1, and podocyte Wilms' tumor antigen (WT1).

RESULTS

WT1 is markedly decreased in NOS versus normal and correlates with the extent of sclerosis. alpha- and beta-DG are maintained in most primary and secondary FSGS cases. In contrast, alpha-DG is significantly decreased in UNDEF, supporting a diagnosis of MCD. Furthermore, follow-up shows remission or decreased proteinuria in four of six of these UNDEF cases in response to therapy. Interstitial FSP1 is numerically highest in COLL but is only rarely found in tubules or podocytes in any other forms of FSGS.

CONCLUSIONS

We conclude that increased FSP1 may be a marker of the aggressive course of collapsing FSGS. Furthermore, DG staining is a useful adjunct to assist in distinction of FSGS versus MCD in biopsies without defining lesions.

Cardiorespiratory fitness in pediatric renal transplant recipients

BACKGROUND

The impact of body size, fat-free mass (FFM), and fat mass (FM) on cardiorespiratory fitness in pediatric renal transplant recipients (TX) has not been established. Study objectives were to assess maximal oxygen consumption (VO2max) in TX and controls, adjusted for body composition, and to identify risk factors for reduced fitness in TX.

METHODS

Cycle ergometry and dual-energy X-ray absorptiometry were obtained in 50 TX and 70 controls, ages 8 to 21 years. Control recruitment was targeted to include obese subjects with body mass index Z-scores comparable with TX. Allometric regression models were used.

RESULTS

TX had significantly lower height Z-scores (P<0.001) and comparable body mass index Z-scores. VO2max per body weight (mL/kg/min) and per FFM (mL/kgFFM/min) did not differ between groups. However, VO2max was 13% lower (95% CI 18, 8; P<0.001) in TX, compared with controls, adjusted for FM, FFM, sex, and race. Greater FFM, lower FM, non-black race, and male sex were independently associated with greater VO2max. Within TX, hemoglobin levels were positively associated with VO2max (P=0.04) and sirolimus use was associated with lower VO2max (P<0.01).

CONCLUSIONS

TX had significant VO2max deficits that were not captured by conventional measures (mL/kg/min). Greater FM was an independent risk factor for low VO2max. Lower fitness in TX may be related to sirolimus effects on skeletal muscle.

Reference serum creatinine levels determined by an enzymatic method in Japanese children: relationship to body length

BACKGROUND

It is necessary to set the standard serum creatinine (Cr) values for the medical care of pediatric chronic kidney disease patients. The estimated glomerular filtration rate (eGFR, ml/min/1.73 m(2)) = kappa x body length (cm)/serum Cr value (mg/dl) determined by the Jaffe method devised by Schwartz has been used clinically. However, enzymatic methods have recently been used to measure Cr instead of the Jaffe method, making it necessary to reevaluate the coefficient kappa of the above equation. Following transformation of the above formula, the normal serum Cr level should be proportional to body length: normal serum Cr value (mg/dl) = k x body length (m).

METHODS

Serum Cr values were measured by an enzymatic method in children who did not present with kidney disease or infectious disease, and the relationship between the body length and serum Cr level was determined by linear regression analysis.

RESULTS

We found a regression equation capable of estimating the reference value of serum Cr from body length. In children aged 1-12 years, body length (m) x 0.30 yielded a value similar to the reference serum Cr level.

CONCLUSION

There have been no previous reports of the determination of reference serum Cr levels by enzymatic methods in Japanese children. Our formula will be applicable for screening of renal function in Japanese children.

Steroid-free immunosuppression since 1999: 129 pediatric renal transplants with sustained graft and patient benefits

Despite early promising patient and graft outcomes with steroid-free (SF) immunosuppression in pediatric kidney transplant recipients, data on long-term safety and efficacy results are lacking. We present our single-center experience with 129 consecutive pediatric kidney transplant recipients on SF immunosuppression, with a mean follow-up of 5 years. Outcomes are compared against a matched cohort of 57 concurrent recipients treated with steroid-based (SB) immunosuppression. In the SF group, 87% of kidney recipients with functioning grafts remain corticosteroid-free. Actual intent-to-treat SF (ITT-SF) and still-on-protocol SF patient survivals are 96% and 96%, respectively, actual graft survivals for both groups are 93% and 96%, respectively and actual death-censored graft survivals for both groups are 97% and 99%, respectively. Unprecedented catch-up growth is observed in SF recipients below 12 years of age. Continued low rates of acute rejection, posttransplant diabetes mellitus (PTDM), hypertension and hyperlipidemia are seen in SF patients, with sustained benefits for graft function. In conclusion, extended enrollment and longer experience with SF immunosuppression for renal transplantation in low-risk children confirms protocol safety, continued benefits for growth and graft function, low acute rejection rates and reduced cardiovascular morbidity.