The use of plasma creatinine concentration for estimating glomerular filtration rate in infants, children, and adolescents

Pharmacokinetics of Famotidine in Infants

BACKGROUND

Although famotidine pharmacokinetics are similar in adults and children older than 1 year of age, they differ in neonates owing to developmental immaturity in renal function. Little is currently known about the pharmacokinetics of famotidine in infants aged between 1 month and 1 year, a period when renal function is maturing.

OBJECTIVE

To characterise the pharmacokinetics of famotidine in infants.

DESIGN

This was a two-part multicentre study with both single dose (Part I, open-label) and multiple dose (Part II, randomised) arms.

PATIENTS

Thirty-six infants (20 females and 16 males) who required treatment with famotidine and who had an indwelling arterial or venous catheter for reasons unrelated to the study.

METHODS

Infants in Part I were administered a single dose of famotidine 0.5 mg/kg; the dose was intravenous or oral according to the judgement of the attending physician. Infants receiving 0.5 mg/kg intravenously were divided into two groups by age, and pharmacokinetic parameters in infants 0-3 months and >3 to 12 months of age were compared. Infants in Part II were randomised to one of the following treatments: 0.25 mg/kg/dose intravenously or 0.5 mg/kg/dose orally on day 1 and subsequent days, or 0.25 mg/kg/dose intravenously or 0.5 mg/kg/dose orally on day 1 followed by doses of either 0.5 mg/kg/dose intravenously or 1 mg/kg/dose orally on subsequent days. From day 2 onwards, age-adjusted dose administration regimens (once daily in infants <3 months of age and every 12 hours in infants >3 months of age) were used; the total number of famotidine doses ranged from 3 to 11 and the total number of days of dose administration ranged from two to eight.

RESULTS

In infants <3 months of age, plasma and renal clearance of famotidine were decreased compared with infants >3 months of age. Pharmacokinetic parameters for the older infants (i.e. those >3 months) were similar to those previously reported for children and adults. Approximate dose-proportionality, no accumulation on multiple dosing and an estimated bioavailability similar to adult values were also observed.

CONCLUSION

A short course of famotidine therapy in infants appears generally well tolerated, and the characteristics of famotidine pharmacokinetics during the first year of life are explained to a great degree by the development of renal function, the primary route of elimination for this drug.

Diagnosis and outcome of fetal lower urinary tract obstruction in the northern region of England

OBJECTIVE

We reviewed the prenatal and postnatal management of fetal lower urinary tract obstruction (LUTO) in a large geographically defined population.

METHODS

The records of 113 cases of LUTO seen over a 14-year period were examined. The predictive accuracy of prenatal findings for chronic renal failure (CRF) and a comparison of prenatal-suspected and non-suspected cases were made.

RESULTS

The incidence of LUTO was 2.2 in 10 000 births. During the study period, prenatal detection improved from 33 to 62%. Sensitivity of prenatal ultrasound detection of renal dysplasia and fetal urinary sodium, calcium, and beta2-microglobulin for CRF or renal dysplasia on autopsy were 59, 33, 66, and 63% respectively. Compared to undetected cases, those detected prenatally had higher mortality and a higher rate of CRF at 24 months (17% vs 57%, p < 0.01).

CONCLUSION

Our observations confirm the poor prognosis associated with fetal LUTO. The value of serial fetal urine biochemistry, other prenatal predictors of postnatal renal function, and the benefits of vesicoamniotic shunting require larger series and longer follow-up.

Cyclosporin A absorption profiles in pediatric renal transplant recipients predict the risk of acute rejection

The current focus of cyclosporin A (CsA) monitoring in adult transplantation for optimized immunosuppression is on the early portion of the CsA area under the concentration-time curve (AUC), particularly in the first 4 hours postdose, designated as AUC(0-4), and on the blood concentration 2 hours postdose (C2) as a highly predictive marker for AUC(0-4). Because data in pediatric patients are scarce, full-time (12 hours) and absorption profiles of CsA were analyzed in relation to CsA effectiveness in 61 pediatric renal transplant recipients aged 3.2 to 17.4 years on an immunosuppressive triple regimen with CsA, mycophenolate mofetil, and methylprednisolone. CsA dosing was based on body surface area and adjusted to CsA trough levels. Pharmacokinetic (PK) profiles were obtained 1 and 3 weeks (initial period) and 3 and 6 months posttransplant (stable period). Patients with an AUC(0-4) < 4400 microg x h/L at both PK sampling periods in the first 3 weeks posttransplant had an adjusted relative risk of 48.4% to suffer an acute rejection episode (ARE), whereas in patients with at least 1 AUC0-4 above this threshold, the adjusted relative risk for an ARE was only 13.1% (P < 0.02). The single PK parameters C0 or C2 did not discriminate between patients with and without acute rejection. The PK parameters C1.25 (r2 = 0.64) or C2 (r2 = 0.60) showed a stronger relationship to the absorption profile (AUC(0-4)) than C0 (r2 = 0.15). An abbreviated profile consisting of the PK variables C(0.5;2) or C(0;0.5;2) showed the closest correlation to the absorption profile (r2 = 0.89) and the lowest percentage prediction error. These data indicate that absorption profiling in pediatric renal transplant recipients has the potential to optimize immunosuppressive therapy with CsA.

Bone mineral density and bone turnover markers in children with chronic renal failure

Bone mineral density (BMD) at lumbar spine (L2-L4) was measured by dual-energy X-ray absorptiometry (DEXA) in 21 children with predialysis chronic renal failure (CRF) and 44 children with end-stage renal failure (ESRF) on regular hemodialysis. BMD results were expressed as Z-scores. Osteopenia was documented in 13 predialysis patients (61.9%) and 26 patients (59.1%) with ESRF. No significant correlation was observed between Z-scores and the duration of CRF or estimated creatinine clearance. In osteopenic children there was a negative correlation between Z-scores and serum phosphorus (r=-0.61, P=0.004), intact parathyroid hormone (iPTH) (r=-0.47, P=0.03), and bone-specific alkaline phosphatase (r=-0.52, P=0.02) and a positive correlation with total calcium (r=0.41, P=0.07) and 25-hydroxycholecalciferol (r=0.53, P=0.02). Osteopenic children who had iPTH values > or = 200 pg/ml were more osteopenic than those who had lower iPTH levels (P=0.006). In conclusion, osteopenia, assessed by DEXA, is frequent in children with CRF. It occurs early irrespective of the duration or the severity of CRF. In children with ESRF the degree of osteopenia is correlated with laboratory markers of renal osteodystrophy and patients with biochemical findings of secondary hyperparathyroidism are more osteopenic than the others.

Renal arterial resistance index and computerized quantification of fibrosis as a combined predictive tool in chronic allograft nephropathy

The renal arterial resistance index (RI) and the PicroSirius-Red stained cortical fractional interstitial fibrosis volume (VintFib) proved to be two independent methods that are reliable predictive factors of poor renal allograft outcome. No data have been published, which define the correlation between ultrasound assessment and quantitative morphologic changes. Renal biopsies were performed in 56 children according to increases in s-creatinine >10%. VintFib was calculated by computerized image analysis. RI was determined in two segmental arteries, 1 yr after transplantation and at the time-point of biopsy. RIs 1 yr after transplantation correlated significantly with RIs at time of biopsy (r = 0.58, p < 0.001). VintFib was higher in children with a RI = 80 than in children with a RI < 80 (mean VintFib = 9.5 +/- 3.2% vs. 5.2 +/- 5.1%, p = 0.004). In children with VintFib > 10%, the mean RI was 77 +/- 5 compared with 69 +/- 6 in patients with VintFib < 10% (p = 0.0002). The highest positive predictive value to detect the risk of decline of GFR at 2 yr after biopsy was 98% when an RI = 80% was associated with a VintFib > 10%. For VintFib > 10% or RI = 80 alone, it was 87% or 67%, respectively. The combined measurement of RI and VintFib is a reliable predictive tool for the risk of developing long-term graft dysfunction after kidney transplantation.

Managing Henoch-Schonlein purpura in children with fish oil and ACE inhibitor therapy

BACKGROUND

Henoch-Schonlein purpura (HSP) is a vasculitic syndrome with palpable purpura and renal involvement. The treatment for HSP with persistent renal disease remains controversial. The kidney biopsy in HSP shows IgA deposits and fish-oil therapy has proven to be promising in halting the progression of IgA nephropathy.

METHODS

Five children with biopsy-proven HSP with repeated episodes of haematuria and proteinuria were treated with fish oil (1 g orally twice daily). In three of the five patients an angiotensin-converting enzyme inhibitor (ACEI) was added for hypertension.

RESULTS

The mean duration of follow up after starting fish-oil therapy was 49.2 weeks. The protein excretion rate prior to starting fish oil was 1041 mg/day and on the last follow-up visit the rate had decreased to 104 mg/day (P <0.05). The average blood pressure (BP) prior to therapy was 135/82. On the last follow-up visit the average BP off ACEI had decreased to 100/54 (P <0.05). After a year of follow up serum creatinine and glomerular filtration rates have remained stable at 51.2 micromol/L and 128 mL/min/1.73 m2, respectively.

CONCLUSION

This is the first report of abatement of HSP with fish oil and ACEI in children. There is a need for randomized prospective trials to confirm this observation.

Polyomavirus nephropathy in pediatric kidney transplant recipients

Given the limited information regarding BK virus-associated nephropathy (BKVN) in pediatric kidney transplant recipients, we assessed the incidence, risk factors, clinical and virologic features of BKVN in pediatric renal transplant recipients at a single transplant center by means of a retrospective cohort study. Histologically confirmed BKVN developed in 6 of 173 (3.5%) kidney transplant recipients at a median of 15 months post-transplant (range: 4-47 months). At a median follow-up of 28 months (range: 5-32), all patients had functioning grafts with mean creatinine and GFR of 1.9 mg/dL and 58 mL/min/1.73 m2, respectively. At the time of diagnosis, all cases had viruria (median 6.1 x 10(6) copies/mL, range: 10(5) to 3.9 x 10(8) copies/mL) and viremia (median 21,000 copies/mL, range: 10,000-40,000 copies/mL). Recipient seronegativity for BKV was significantly associated with the development of BKVN (p = 0.01). BKVN is an important cause of late allograft dysfunction and is strongly associated with recipient seronegativity in pediatric kidney transplant recipients. Further studies to confirm this finding and to define the clinical utility of routine pre-transplant BKV serologic testing are warranted.

A prospective randomized study for the treatment of bone loss with vitamin d during kidney transplantation in children and adolescents

The effect of treatment with alfacalcidol on post-transplantation bone loss in children and adolescents was investigated. Of the 63 young patients who received renal transplant and were subjected to dual-energy x-ray absorptiometry (DEXA), 30 patients had low-bone mineral density (BMD) (z-score < or = -1) and were enrolled into the study. Their mean age at the time of transplantation was 14.5 +/- 4.0 years and the mean duration after transplantation was 48 +/- 34 months. Patients with low BMD were randomized into two equal homogeneous groups: group 1 (control) received placebo and group 2 received daily alfacalcidol 0.25 microg by mouth. Parameters of bone metabolism (intact parathyroid hormone, serum osteocalcin and urinary deoxypyridinoline) and BMD were assessed before and after the study period. After 12 months of treatment BMD at the lumber spine decreased from -2.2 to -2.5 in group 1 while it increased from -2.1 to -0.6 in group 2 (p < 0.001). Serum intact parathyroid hormone level decreased significantly in group 2 (p = 0.042). Apart from transient hypercalcemia in 1 patient in group 2, no other significant adverse effects were noted. This study suggested the value of alfacalcidol in the treatment of bone loss in young renal transplant recipients.

Longitudinal Analysis of T???Helper Cell Phenotypes in Renal-Transplant Recipients Undergoing Growth Hormone Therapy

BACKGROUND

Treatment with recombinant human growth hormone (rhGH) in growth-retarded children after renal transplantation is effective, but there have been concerns regarding the safety of rhGH because of its possible immunomodulatory actions. We therefore evaluated the immune phenotypes of pediatric renal-transplant recipients and controls in response to rhGH with regard to a possible shift toward a T-helper (TH)1-type response.

METHODS

Intracellular cytokines, activation markers, costimulatory, and adhesion molecules were studied in 13 children after renal transplantation (Tx+GH). Children with chronic renal failure (CRF+GH, n=11) before and under rhGH therapy and pediatric renal-transplant recipients without rhGH therapy (Tx, n=33) served as controls. Measurements were performed by four-color flow cytometry before and 4, 12, 18 and 24 weeks after initiation of rhGH therapy.

RESULTS

Under baseline conditions, Tx+GH patients did not differ from Tx patients. During rhGH therapy in children with transplants, interleukin (IL)-2 production increased threefold at 4 weeks, and IL-4 and IL-13 increased by 70% at 12 weeks. All three cytokines returned to baseline after 18 weeks. No patient experienced rejection. In CRF+GH patients, baseline values for all investigated cytokines were higher than in patients with transplants but did not change in response to rhGH therapy.

CONCLUSION

Our data indicates that rhGH therapy in stable, pediatric renal-transplant recipients has a mild and transient immunostimulatory effect in vivo. Immunosuppression and graft function in patients with transplants undergoing rhGH treatment should therefore carefully be monitored.

Investigation of Pediatric Renal Transplant Recipients with Heavy Proteinuria after Sirolimus Rescue

BACKGROUND

Little is known about the incidence and evolution of proteinuria as a complication of sirolimus rescue in children. This study describes pediatric renal transplant (Tx) recipients who were treated with sirolimus and who developed heavy proteinuria. Risk factors for the development of proteinuria and its time course are explored.

METHODS

Data at various time points after sirolimus introduction were abstracted from the records of children treated at the author's center. The repeated measures general linear model and the Student's paired t test were used to analyze changes in laboratory values over time.

RESULTS

Of the 13 children on sirolimus, 12 developed heavy proteinuria after a mean interval of 1 month. The mean urine protein (Up)-to-creatinine (c) ratio increased from 1.1 to a peak value of 3.9 (P=0.003) at 4.6 months after the start of sirolimus. Although not statistically significant, children on no calcineurin inhibitor (CNI) had a greater increase in the Up/c than those on low-dose CNI. At last follow-up, with the use of angiotensin receptor blockers (ARB), the Up/c declined to 2.2. No predictors could be identified for the development of proteinuria.

CONCLUSIONS

Heavy proteinuria is common after the use of sirolimus as rescue therapy in children with renal Tx. Whether this is attributable to a toxic effect of the sirolimus itself or to lower CNI exposure is uncertain. Early detection of proteinuria is important to enable prompt intervention. Most children have a reduction in their Up/c with the use of ARB and can therefore be continued on sirolimus.

Estimating pesticide dose from urinary pesticide concentration data by creatinine correction in the Third National Health and Nutrition Examination Survey (NHANES-III)

The Third National Health and Nutrition Examination Survey (NHANES-III) of the Centers for Disease Control and Prevention (CDC) recorded data on the urinary concentrations of 12 chemicals (analytes), which were either pesticides or their metabolites, that represent exposure to certain pesticides, in urine samples collected from 1988 to 1994 from a cohort of 978 volunteer subjects, aged 20-59 years. We have used each subject's urinary creatinine concentration and their individual daily creatinine excretion rate (g/day) computed from their age, gender, height and weight, to estimate their daily excretion rate in microg analyte/kg/day. We discuss the mechanisms of excretion of the analytes and certain assumptions needed to compute the equivalent daily dietary intake (microg/kg/day) of the most likely parent pesticide compounds for each excreted analyte. We used literature data on the average amount of parent compound ingested per unit amount of the analyte excreted in the urine, and compared these estimated daily intakes to the US EPA's reference dose (RfD) values for each of those parent pesticides. A Johnson S(B) distribution (four-parameter lognormal) was fit to these data to estimate the national distribution of exclusive exposures to these 12 parent compounds. Only three such pesticides had a few predicted values above their RfD (lindane 1.6%; 2,4-dichlorophenol 1.3%; chlorpyrifos 0.02%). Given the possibility of a subject's dietary intake of a pesticide's metabolites incorporated into treated food, our results show that few, if any, individuals in the general US population aged 20-59 years and not employed in pesticide application were likely to have exceeded the USEPA RfD for these parent compounds during the years studied.

Antihypertensive and antiproteinuric efficacy of ramipril in children with chronic renal failure

BACKGROUND

While the antihypertensive and renoprotective potency of angiotensin-converting enzyme (ACE) inhibitors is well-established in adults with hypertension and/or chronic renal failure, little experience exists in pediatric chronic kidney disease.

METHODS

As part of a prospective assessment of the renoprotective efficacy of ACE inhibition and intensified blood pressure (BP) control, 397 children (ages 3 to 18 years) with chronic renal failure [CRF; glomerular filtration rate (GFR) 11 to 80 mL/min/1.73 m2] and elevated or high-normal BP received ramipril (6 mg/m2) following a 6-month run-in period including a two-month washout of any previous ACE inhibitors. Drug efficacy was assessed by two monthly office BP and proteinuria assessments, and by ambulatory BP monitoring at start and after 6 months of treatment.

RESULTS

In the 352 patients completing six months of treatment, 24-hour mean arterial pressure (MAP) had decreased by a mean of 11.5 mm Hg (-2.2 SDS) in initially hypertensive subjects, but only by 4.4 mm Hg (-0.8 SDS) in patients with initially normal BP. A linear correlation was found between MAP at baseline and the change of MAP during treatment (r= 0.51; P < 0.0001). The antihypertensive response was independent of changes in concomitant antihypertensive medication or underlying renal disease. BP was reduced with equal efficacy during day- and nighttime. Urinary protein excretion was reduced by 50% on average, with similar relative efficacy in patients with hypo/dysplastic nephropathies and glomerulopathies. The magnitude of proteinuria reduction depended on baseline proteinuria (r= 0.32, P < 0.0001), and was correlated with the antihypertensive efficacy of the drug (r= 0.22, P < 0.001). The incidence of rapid rises in serum creatinine and progression to end-stage CRF during treatment did not differ from the pretreatment observation period. Mean serum potassium increased by 0.3 mmol/L. Ramipril was discontinued in three patients due to symptomatic hypotension or hyperkalemia. Hemoglobin levels decreased by 0.6 g/dL in the first two treatment months and remained stable thereafter.

CONCLUSION

Ramipril appears to be an effective and safe antihypertensive and antiproteinuric agent in children with CRF-associated hypertension. The BP lowering and antiproteinuric effects are greatest in severely hypertensive and proteinuric children.

Increased cystatin C concentration in urine of nephrotic children

The aim of this study was to evaluate changes in urine and plasma concentrations of cystatin C in children with a relapse of the idiopathic nephrotic syndrome(INS). The study group comprised 12 children with INS with proteinuria and 12 children in an 8-week remission,both treated with steroids. Twelve healthy children served as controls. Cystatin C was detectable in the urine of children with proteinuria. The study suggests that massive proteinuria may influence renal cystatin C handling.

Renal effects and erythrocyte oxidative stress in long-term low-level lead-exposed adolescent workers in auto repair workshops

Lead poisoning is an old but persistent public health problem in developing countries. The present study investigated blood lead levels and its effects on markers of renal function and parameters of erythrocyte oxidative stress in adolescent male auto repair workers in Turkey. Blood Pb level and the ALAD index (logarithm of activated delta-aminolaevulinic acid dehydratase/nonactivated delta-aminolaevulinic acid dehydratase) were measured as indicators of exposure to Pb. Markers of tubular damage urine N-acetyl-beta-D-glucosaminidase (NAG), beta2-microglobulin (beta-2 MG), creatinine (Cr), uric acid (UA), and calcium, markers of glomerular filtration blood urea nitrogen (BUN), serum Cr, UA, and parameters of oxidative damage in erythrocyte were studied in 79 Pb-exposed adolescent and 71 healthy control subjects. Blood lead levels and ALAD index were found significantly higher in the study group than that of normal control group. BUN, UA level, and glomerular filtration rates were detected in normal range in the lead-exposed group. Urinary NAG excretion and calciuria were higher in the study group than in controls. Urinary excretion of NAG was positively correlated with the blood lead levels (r=0.427). There was no relationship between blood lead levels and UA or beta-2 MG in urine. Malondialdehyde and glutathione peroxidase levels were significantly elevated in lead-exposed adolescents than controls, but changes in the catalase and superoxide dismutase activities in lead-exposed adolescents did not reach statistical significance. In conclusion, chronic low-dose lead exposure seems as a cause of subtle renal impacts in adolescent workers of auto repair workshops. Lead-induced oxidative stress in erythrocytes probably contributes to these subclinical renal effects.

Increased kidney growth in formula-fed versus breast-fed healthy infants

A high protein intake results in increased kidney growth and glomerular filtration rate in human adults and young rats. It is unknown whether kidney size in young infants is influenced by increased protein intake in formula-fed compared with breast-fed infants. We investigated the effect of formula versus breast feeding on kidney growth in a cohort of 631 healthy children examined at birth, and at 3 and 18 months of age. Kidney size was determined by ultrasonography and related to gender, age, body size, and feeding category (fully breast fed, partially breast fed, or fully formula fed at 3 months). Serum urea nitrogen, serum creatinine, and estimated creatinine clearance were measured at 3 months of age. Kidney growth and serum urea nitrogen were significantly increased in partially or fully formula-fed 3-month-old infants. This effect was more pronounced in boys than in girls. The changes in relative kidney size were temporary, as they did not persist at 18 months of age, when all children received a normal mixed diet. The immediate renal effects of formula feeding should be taken into consideration for recommendations concerning infant feeding. Whether there are any long-term effects of early increased protein intake on later kidney function remains to be seen.

Cationic charge-preferential IgG reabsorption in the renal proximal tubules

BACKGROUND

The brush border of the renal proximal tubules has a polyanionic charge. Since immunoglobulin G (IgG) molecules have a wide range of charge diversity, reabsorption of urinary IgG molecules are supposed to be influenced by the electrostatic interaction.

METHODS

Charge diversity of serum and urinary IgG molecules in patients with various renal diseases (N= 12) and premature neonates (N= 3) were analyzed by isoelectric focusing and Immunoblotting.

RESULTS

In patients with glomerular diseases, urinary IgG was solely composed of neutral and anionic IgG, whereas that of the cationic part (isoelectric point >8) was not observed. By contrast, in patients with proximal tubular diseases (Dent's disease and idiopathic Fanconi syndrome), the proportion of the cationic IgG was similar to that of serum IgG. In addition, the cationic part of IgG in the urine was found in the neonates with a gestational age of 28 and 31 weeks, but not found in those of 35 weeks.

CONCLUSION

The results suggest that renal proximal tubules reabsorb the urinary IgG in a cationic preferential way, and this mechanism requires renal maturation.

Long-term follow-up of pediatric transplant recipients: mycophenolic acid trough levels are not a good indicator for long-term graft function

BACKGROUND

Mycophenolate mofetil (MMF) has the potential of decreasing acute rejection episodes early following renal transplantation. Pharmocokinetic monitoring of mycophenolic acid (MPA) trough levels is performed by many centers. MMF has also proved successful in improving long-term graft function in patients with chronic allograft nephropathy (CAN). However, no data for long-term monitoring of MPA in children have yet been published.

METHODS

MMF therapy with a dose of 600 mg/m2 twice daily was initiated in 42 children (median age 9.4 yr, range 1.4-15.1) after a median period of 3.8 yr (range 1.0-10.6) post-transplantation-- according to significant increases in serum creatinine. CAN was diagnosed by renal biopsy and the amount of fibrosis was quantified with PicroSiriusRed staining. MMF therapy was combined with ciclosporin A and prednisolone. MPA-C0-levels, measured by high-pressure liquid chromatography, were tested every 3 months. In 12 children a full MPA area under the curve concentration (AUC) was measured. The glomerular filtration rate (GFR) was calculated at the start of MMF therapy and 2 yr later.

RESULTS

After initiation of MMF, the calculated GFR did not decrease further in 22 children and mean GFR remained stable for 2 yr in the whole study group. There was a significant correlation between MPA levels 75 min after administration and the full AUC (r = 0.94, p < 0.001) but no correlation between trough levels and AUC (r = -0.07, p > 0.05). The mean MPA trough level was 2.8 +/- 1.3 ng/mL. The intra-individual coefficient of variation was 2.6 +/- 1.4. There was no correlation between mean MPA trough levels and GFR development after 2 yr (r = 0.03, p > 0.05). In children with an MPA level below 1.2 mg/L (n = 5), the mean GFR decline was no different to those with a higher level (p > 0.05).

CONCLUSIONS

Drug monitoring of MPA trough levels had no impact on long-term graft function in kidney recipients. MPA levels taken 75 min after administration showed a high correlation with MPA-AUC whereas C0-levels did not correlate. The value of C75 drug measurements for monitoring renal allograft survival will have to be judged in future studies.

Fluid overload before continuous hemofiltration and survival in critically ill children: a retrospective analysis

OBJECTIVE

Continuous venovenous hemofiltration (CVVH) is used for renal replacement and fluid management in critically ill children. A previous small study suggested that survival was associated with less percent fluid overload (%FO) in the intensive care unit (ICU) before hemofiltration. We reviewed our experience with a large series of pediatric CVVH patients to evaluate factors associated with outcome.

DESIGN

Retrospective chart review.

SETTING

Tertiary children's hospital.

PATIENTS

CVVH pediatric ICU patients from November 1997 to January 2003.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

%FO was defined as total fluid input minus output (up to 7 days before CVVH for both hospital stay and ICU stay) divided by body weight. One hundred thirteen patients received CVVH; 69 survived (61%). Multiple organ dysfunction syndrome (MODS) was present in 103 patients; 59 survived (57%). Median patient age was 9.6 yrs (25th, 75th percentile: 2.5, 14.3). Median %FO was significantly lower in survivors vs. nonsurvivors for all patients (7.8% [2.0, 16.7] vs. 15.1% [4.9, 25.9]; p =.02] and in patients with > or =3-organ MODS (9.2% [5.1,16.7] vs. 15.5% [8.3, 28.6]; p =.01). The Pediatric Risk of Mortality Score III at CVVH initiation also was associated with survival in these groups, but by multivariate analysis, %FO was independently associated with survival in patients with > or =3-organ MODS (p =.01).

CONCLUSIONS

Survival in critically ill children receiving CVVH in this large series was higher than in previous reports. CVVH survival may be associated with less %FO in patients with > or =3-organ MODS. Prospective studies are necessary to determine whether earlier use of CVVH to control fluid overload in critically ill children can improve survival.

Renal venous thrombosis in neonates: prothrombotic risk factors and long-term follow-up

The present study was designed to evaluate prothrombotic risk profiles in 59 consecutively recruited white neonates with renal venous thrombosis (RVT). The rates of prothrombotic risk factors (PRs)—for example, the factor V (FV) 1691G&gt; A mutation, the factor II (FII) 20210G&gt; A variant, antithrombin (AT), protein C (PC), protein S (PS), elevated lipoprotein(a) (Lp(a)), total fasting plasma homocysteine (tHcy) levels, and anticardiolipin antibodies (ACAs)—were compared with those of 118 healthy control children. At onset, 32 (54.2%) of the 59 neonates showed underlying clinical conditions; 40 (67.8%) of them and 23 (85.2%) of the 27 infants with idiopathic RVT showed at least one PR. Univariate analysis revealed significantly elevated odds ratios/95% confidence intervals (ORs/95% CIs) for FV and Lp(a). Additionally, PC/AT deficiency and ACAs were found significantly more often in the patient group (P = .04). Multivariate analysis calculated significant ORs/95% CIs only for FV (OR, 9.4; 95% CI, 3.3-26.6) and elevated Lp(a) (OR, 7.6; 95% CI, 2.4-23.8). Of the 59 neonates investigated, 53 revealed renal atrophy, and 13 children additionally suffered from severe arterial hypertension. In conclusion, the present study demonstrates the significance of genetic PR—especially the FV mutation and elevated Lp(a)—for the etiology of neonatal RVT.

A randomized, placebo-controlled trial of amlodipine in children with hypertension

OBJECTIVES

Evaluation of the efficacy and safety of amlodipine in hypertensive children.

STUDY DESIGN

A randomized, double blinded, placebo-controlled, parallel-group, dose-ranging study was conducted at 49 centers in North and South America. The primary end point was the effect of amlodipine on systolic blood pressure (BP); secondary end points included the effect of amlodipine on diastolic BP, the effect of amlodipine as a function of dose and body size, and evaluation of safety.

RESULTS

We enrolled 268 hypertensive children (mean age, 12.1 +/- 3.3 years); 84 (31.3%) had primary hypertension, and 177 (66%) were boys. Amlodipine produced significantly greater reductions in systolic BP than placebo; these were -6.9 mm Hg for 2.5 mg daily (P=.045 vs placebo) and -8.7 mm Hg for 5 mg daily (P=.005 vs placebo). The underlying cause of hypertension had no effect on the response to amlodipine. There was a significant dose-response effect of amlodipine on both systolic and diastolic BP beginning at doses > or =0.06 mg/kg per day. Systolic BP < or =95(th) percentile was achieved in 34.6% of subjects with systolic hypertension. Amlodipine was well tolerated, with just 6 children withdrawn from treatment because of drug-related adverse events.

CONCLUSIONS

Amlodipine effectively lowers systolic BP in a dose-dependent manner in hypertensive children who require drug treatment.

Successful withdrawal of steroids in pediatric renal transplant recipients receiving cyclosporine A and mycophenolate mofetil treatment: results after four years

BACKGROUND

Despite their numerous systemic side effects, glucocorticoids (steroids) still form a cornerstone in immunosuppressive regimens in pediatric renal transplant recipients. The addition of mycophenolate mofetil (MMF) to a cyclosporine A (CsA)-based immunosuppressive regimen after renal transplantation may allow steroid withdrawal and amelioration or avoidance of steroid-specific side effects.

METHODS

In a retrospective case-control study, covering a mean follow-up period of 46 +/- 2.3 months and 40 patients aged 11.4 +/- 4.9 years, we analyzed the safety and efficacy of steroid withdrawal in pediatric renal transplant recipients receiving CsA micoroemulsion, MMF, and low-dose prednisone treatment.

RESULTS

: Steroid withdrawal in all 20 pediatric renal transplant recipients receiving CsA and MMF was successful and not associated with an acute rejection episode; graft function remained stable. At baseline, the degree of growth retardation was comparable between the groups (mean height standard deviation scores [SDSs] -1.60 +/- 0.30 [withdrawal group] and -1.32 +/- 0.39 [case-control group]). After steroid withdrawal, prepubertal patients exhibited a significant catch-up growth with a mean height gain of 1.47 +/- 0.32 SDS, whereas height SDS did not improve in patients receiving steroids. Growth was also improved in pubertal patients who stopped taking steroids. Standardized body mass index in patients who stopped taking steroids decreased significantly by 49% from 0.87 +/- 0.31 SDS to 0.45 +/- 0.30 SDS. After steroid withdrawal, mean arterial blood pressure SDS decreased significantly by 45%. Moreover, the need for antihypertensive medication declined significantly in patients who stopped taking steroids. The white blood cell counts and hemoglobin levels were comparable between the groups.

CONCLUSIONS

: This study suggests that steroids can be safely and successfully withdrawn in selected pediatric renal transplant recipients receiving immunosuppressive maintenance therapy consisting of CsA and MMF.

Long-term renal function in pediatric liver and heart recipients

Long-term survivors of pediatric liver and heart transplantation are at risk for progressive renal dysfunction as a result of chronic exposure to calcineuron inhibitors. This class of drugs causes alterations in renal perfusion that can result in irreversible renal injury including afferent arteriopathy, glomerulosclerosis, tubular atrophy and interstitial fibrosis. Approximately 3-6% of pediatric liver and heart recipients will develop end stage renal failure. A much larger percentage has chronic renal insufficiency and hypertension. Children with significant renal compromise in the pretransplant period and those with significantly elevated serum creatinine levels during the first post-transplant year may be at the highest risk to develop irreversible renal injury in long-term follow-up. Serum creatinine is a poor screening tool as it rises late in the course when the injury may no longer be reversible. Strategies to minimize long-term exposure to calcineuron inhibitors may reduce the prevalence of renal insufficiency in this vulnerable population.

Effect of renal transplantation in childhood on longitudinal growth and adult height

BACKGROUND

Severe growth failure is frequently observed in children suffering from end-stage renal disease (ESRD).

METHODS

We analyzed the effect of renal transplantation (RTx) on longitudinal growth and final height in 37 children (19 girls) with ESRD with a mean follow-up of 8.5 years. The mean age at RTx was 11.3 years.

RESULTS

In children transplanted before start of puberty, mean height velocity increased significantly from 4.9 to 8.0 cm/year (P < 0.01), resulting in an increase in standardized height of 0.6 SD within two years post RTx. Although peak height velocity during puberty was significantly increased compared with healthy children, total pubertal height gain was reduced by 20% because of its shortened duration. Mean standardized height significantly increased from the time of RTx until final height by 1.3 SD and 0.7 SD in children transplanted before and after start of puberty, respectively. Mean adult height (boys 170 cm; girls 151 cm) was normal (> -2 SD) in 68% of patients. Change in standardized height from RTx until adult height was associated with initial degree of stunting and glomerular filtration rate (GFR; cumulative r2 0.49). Total pubertal height gain was associated with the age at start of puberty, GFR, and age at RTx (cumulative r2 0.57).

CONCLUSION

RTx in children with ESRD induces moderate catch-up growth during the prepubertal growth period. However, final height is reduced in about one third of patients due to the reduced pubertal height gain and preexisting height deficit at the time of RTx.

Treatment of osteopenia and osteoporosis in renal transplant children and adolescents

Successful renal transplantation corrects many of the metabolic abnormalities associated with the development of renal osteodystrophy, but despite a well-functioning graft osteopenia, growth failure, spontaneous fractures, and avascular necrosis remain prevalent in adult and pediatric kidney recipients. A paucity of information exists regarding the effects of different therapies to prevent and treat bone loss in the renal transplant recipients. We constructed a design to study the effect of different modalities of treatment on bone mass in our renal transplant children. Among 93 patients who underwent renal transplantation at the age of 17 yr or less and were subjected to dual-energy X-ray absorptiometry (DEXA), we blindly randomized 60 patients who had osteopenia or osteoporosis (T-score = -1 by DEXA) in a prospective study. Their mean age at time of transplantation was 13.4 +/- 4.3 yr. The mean duration after transplantation was 48 +/- 34 months. The patients were classified randomly into four groups. Each group consisted of 15 patients: group 1 was the control group, group 2 received oral alfacalcidol 0.25 microg daily, group 3 received oral alendronate 5 mg daily, and group 4 received 200 IU/day nasal spray calcitonin. Parameters of bone turnover, calcium metabolism, and DEXA were measured before and after 12 months of treatment duration. The characteristics of all groups were comparable at the beginning of the study. At the lumber spine, bone mass density decreased from -2.4 to -2.8 in group 1, increased from -2.3 to -0.5 in group 2, from -2.3 to -1.9 in group 3, and from -2.3 to -1.0 in group 4. The four groups had similar patient profiles, serum creatinine, intact parathyroid hormone, osteocalcin, and deoxypyridinoline. This study confirmed the value of alfacalcidol and antiresorptive agents in the treatment of osteopenia and osteoporosis in young renal transplant recipients.These therapies were safe, tolerable, simple to administer and potentially applicable to other renal transplant patients.

Microarray analysis of focal segmental glomerulosclerosis

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a leading cause of chronic renal failure in children. Recent studies have begun to define the molecular pathogenesis of this heterogeneous condition. Here we use oligonucleotide microarrays to obtain a global gene expression profile of kidney biopsy specimens from patients with FSGS in order to better understand the pathogenesis of this disease.

METHODS

We extracted RNA from renal biopsy samples of 10 patients with the diagnosis of FSGS and from 5 control kidney samples, and produced labeled cRNA for hybridization to Affymetrix human U133A microarrays.

RESULTS

We identified a gene expression fingerprint for FSGS that contained 429 of 22,283 possible genes, each with a p < 0.01, using RMA normalization, Welch t test, and at least a 1.8-fold change in 5 of the 10 patients examined. We also found gene expression differences in samples from subsets of patients who had either nephrotic syndrome or renal insufficiency. This screen identified many genes and genetic pathways that have already been implicated in the pathogenesis of FSGS. In addition, we found changes in gene expression in genetic pathways that have not been studied in FSGS.

CONCLUSIONS

Oligonucleotide DNA microarray analysis of renal biopsy specimens identified a gene expression fingerprint in samples from a heterogeneous population of patients with FSGS. The genes and genetic pathways identified in this study can be compared to results of similar studies of other diseases to examine specificity and used to study the pathogenesis of FSGS.

Comparison of two formulae for estimation of glomerular filtration rate in children

Glomerular filtration rate (GFR) was measured in 216 studies in 151 children using the cimetidine protocol. This was compared with the GFR calculated using Léger's pharmacokinetic equation and with that calculated using k*L/[Cr](s )(constant x length in centimeters divided by serum creatinine concentration). The GFR calculated using the equation GFR=k*L/[Cr](s) yielded a closer approximation to the measured GFR than that using Léger's pharmacokinetic equation. Currently there is focus on screening children for decreased GFR to identify those with asymptomatic chronic kidney disease at a time when intervention may delay progression to chronic renal failure. This study showed close approximation of the calculated GFR with the measured GFR using the equation GFR=k*L/[Cr](s), when the values for k were determined in the laboratory in which creatinine was measured.

Renal allograft function in matched pediatric and adult recipient pairs of the same donor

BACKGROUND

To study the effect of donor age on kidney function, the authors investigated matched pairs from the same kidney donor given to a pediatric or an adult recipient.

METHODS

Fifteen matched pairs of an adult and a pediatric patient, selected from the Eurotransplant registry, receiving the renal graft from the same cadaveric donor were selected for analysis of graft function over 7 years. Nine matched pairs were from adult donors (mean age, 40 years; range, 23-60 years) and six from pediatric donors (mean age, 11 years; range, 4-15 years). All recipients had comparable immunosuppression with cyclosporine A, prednisolone, and azathioprine and comparable numbers of acute rejection, cytomegalovirus reactivation, and antihypertensive therapy. Mean age of pediatric and adult recipients at transplantation was 5 years (range, 1-9 years) and 38 years (range, 25-60 years), respectively.

RESULTS

The calculated glomerular filtration rate (GFR) corrected to body surface area was not different in adult and pediatric recipients. Initial absolute GFR was significantly lower in pediatric recipients (27 mL/ min; range, 17-38 mL/min) than in adult recipients (54 mL/min; range, 25-74 mL/min) (P <0.05) and remained lower in the following years. Initially, pediatric donor kidneys transplanted into pediatric recipients showed a lower absolute GFR than those transplanted into adults, however, approaching the GFR in adult recipients later. Adult donor kidneys transplanted into pediatric recipients showed a persistently lower absolute GFR in children compared with those transplanted into adult recipients.

CONCLUSIONS

The authors conclude that adult donor kidneys in pediatric recipients decrease GFR in the early stages and lack an increase in GFR with growth of the child.

Pretreatment cystatin C in children with malignancy: can it predict chemotherapy-induced glomerular filtration rate reduction during the induction phase?

BACKGROUND

Monitoring of kidney function is essential during chemotherapy. Serum creatinine is of limited value in early detection of renal insufficiency. The cystatin C level has been proved to be a good marker for detection of mild reduction in glomerular filtration rate.

PURPOSE

To evaluate the validity of the pretreatment serum cystatin C level in predicting significant reduction of the glomerular filtration rate during the induction phase of chemotherapy.

PATIENTS AND METHODS

Serum levels of cystatin C and creatinine and corrected creatinine clearance were assessed in 34 children with different types of malignancy just before the start of chemotherapy and again in 33 of them 1 month later. Patients were compared with 14 healthy controls of matched age and sex.

RESULTS

Before chemotherapy, all patients when compared with controls had normal levels of cystatin C (P = 0.1) and creatinine (P = 0.62) and normal corrected creatinine clearance (P = 0.76). One month after chemotherapy, patients showed a significant increase in their cystatin C levels (P < 0.001) and a significant decrease in their corrected creatinine clearance (P < 0.001). However, creatinine levels did not change significantly (P = 0.65). Corrected creatinine clearance negatively correlated significantly with both cystatin C and creatinine levels (r = -0.622, P < 0.001; r = -0.346, P = 0.045, respectively) before chemotherapy and also 1 month after chemotherapy (r = -0.577, P < 0.001; r = -0.45, P = 0.009, respectively). When pretreatment levels of cystatin C and creatinine were used to predict patients who developed a reduction in corrected creatinine clearance of more than 20% after therapy, only the cystatin C level was statistically significant (P = 0.03). A cutoff point of 0.57 mg/L with sensitivity of 77.8%, specificity of 63%, and overall accuracy of 74% was suggested.

CONCLUSIONS

Children with malignant diseases develop significant reduction in their glomerular filtration rate during the induction phase of chemotherapy, although their serum creatinine level may not change significantly. Cystatin C, as a more sensitive marker than creatinine for the assessment of glomerular filtration rate, can be used to predict patients who would have a higher risk of renal impairment during the induction phase of chemotherapy and who thus would require more frequent renal function assessment to consider adjustment of the chemotherapy dose if indicated.

Population pharmacokinetics of arbekacin, vancomycin, and panipenem in neonates

Immature renal function in neonates requires antibiotic dosage adjustment. Population pharmacokinetic studies were performed to determine the optimal dosage regimens for three types of antibiotics: an aminoglycoside, arbekacin; a glycopeptide, vancomycin; and a carbapenem, panipenem. Eighty-three neonates received arbekacin (n = 41), vancomycin (n = 19), or panipenem (n = 23). The postconceptional ages (PCAs) were 24.1 to 48.4 weeks, and the body weights (BWs) ranged from 458 to 5,200 g. A one-compartment open model with first-order elimination was applied and evaluated with a nonlinear mixed-effect model for population pharmacokinetic analysis. In the fitting process, the fixed effects significantly related to clearance (CL) were PCA, postnatal age, gestational age, BW, and serum creatinine level; and the fixed effect significantly related to the volume of distribution (V) was BW. The final formulas for the population pharmacokinetic parameters are as follows: CL(arbekacin) = 0.0238 x BW/serum creatinine level for PCAs of <33 weeks and CL(arbekacin) = 0.0367 x BW/serum creatinine level for PCAs of > or = 33 weeks, V(arbekacin) = 0.54 liters/kg, CL(vancomycin) = 0.0250 x BW/serum creatinine level for PCAs of <34 weeks and CL(vancomycin) = 0.0323 x BW/serum creatinine level for PCAs of > or = 34 weeks, V(vancomycin) = 0.66 liters/kg, CL(panipenem) = 0.0832 for PCAs of <33 weeks and CL(panipenem) = 0.179 x BW for PCAs of > or = 33 weeks, and V(panipenem) = 0.53 liters/kg. When the CL of each drug was evaluated by the nonlinear mixed-effect model, we found that the mean CL for subjects with PCAs of <33 to 34 weeks was significantly smaller than those with PCAs of > or = 33 to 34 weeks, and CL showed an exponential increase with PCA. Many antibiotics are excreted by glomerular filtration, and maturation of glomerular filtration is the most important factor for estimation of antibiotic clearance. Clinicians should consider PCA, serum creatinine level, BW, and chemical features when determining the initial antibiotic dosing regimen for neonates.

Ambulatory blood pressure correlates with renal volume and number of renal cysts in children with autosomal dominant polycystic kidney disease

OBJECTIVE

In adult patients with autosomal dominant polycystic kidney disease (ADPKD) renal volume was found to be significantly greater in hypertensive compared to normotensive patients. The purpose of this study was to find out if blood pressure (BP) is related to renal size also in children with ADPKD, for example, in an early stage of the disease.

METHOD AND RESULTS

Sixty-two children with ADPKD and normal renal function (mean age 12.3+/-4.3 years) were examined by renal ultrasound and ambulatory BP monitoring (ABPM). Twenty-two children were hypertensive and 40 normotensive. Mean renal volume was significantly greater in hypertensive than in normotensive children (2.7+/-2.3 SDS versus 1.2+/-2.5 SDS, P<0.01) despite similar anthropometric data and renal function. Similarly the mean number of cysts was significantly higher in hypertensive patients than in normotensive (35+/-15 cysts versus 23+/-14 cysts, P<0.01). Renal volume correlated with daytime as well as with night-time systolic and diastolic BP (r=0.41-0.47, P<0.01). Correlations with renal length and the number of renal cysts were somewhat less (r=0.29-0.43, P<0.05 and 0.01, respectively).

CONCLUSIONS

This study revealed a significant relationship between renal volume, renal length and number of renal cysts and BP. It is suggested that children with ADPKD should regularly be checked for BP changes by ABPM, especially those who show increased renal size or a high number of renal cysts on ultrasound. All these children are at high risk for development of hypertension.

Unilateral multicystic dysplastic kidney: experience in children

OBJECTIVES

To report a retrospective study of unilateral multicystic dysplastic kidneys (MCDK) in children, assessing the contralateral kidneys and urinary tract, the functional consequences, and the urological and nephrological management and outcome, as unilateral MCDK is the most common cause of renal cystic disease in children, and malformations of the contralateral urinary tract and kidney (pelvi-ureteric obstruction, megaureter, reflux, renal dysplasia) have been reported.

PATIENTS AND METHODS

The study included 97 patients (60 boys, 37 girls) with MCDK seen between 1985 and 1998; 82 were diagnosed in utero by ultrasonography (US). After birth, the diagnosis was verified by US, renal scanning (in 93) or intravenous urography (in four), and 89 (92%) had voiding cysto-urethrography (VCUG). Of the 97 children, 87 (90% had a mean (range) follow-up of 44.3 (15-115) months.

RESULTS

The MCDK was removed in 17 children; the follow-up of 75 children (five lost to follow-up) showed total involution of the MCDK in 25%, shrinkage in 60% and a stable size in 15%. None had any sign of malignancy. The contralateral kidney showed anomalies in 19 of 97 children (20%); 12 had a dilated renal pelvis (two with megaureter), six had a high echogenicity of the contralateral kidney (one had reflux, and two also pelvic dilatation). In only four of the 89 children was reflux found by VCUG; 16 of the 19 anomalies were detected by US. Five children needed surgery on the contralateral urinary tract (three a pyeloplasty, and one each a pyeloplasty plus ureteroneocystostomy, and an antireflux procedure). Of the contralateral kidneys 43% showed compensatory hypertrophy. There was mild renal insufficiency in three children; renal function seemed to be slightly impaired in many. Five infants had hypertension (four with spontaneous resolution) caused by renal scarring after pyelonephritis or inborn dysplasia of the contralateral kidney. There were symptomatic urinary tract infections in seven children.

CONCLUSION

US can be used safely to diagnose unilateral MCDKs and malformations of the contralateral urinary tract and kidney. In cases where US of the dysplastic kidney remains uncertain renal scintigraphy is necessary to detect the lack of renal function. The low rate of reflux makes routine VCUG unnecessary if the contralateral upper urinary tract and kidney appear to be normal on US. Nephrectomy of the dysplastic kidney in typical cases is also unnecessary. A long-term nephro-urological follow-up of children with MCDK is recommended.

Cardiac disease in children with primary glomerular disorders-role of focal segmental glomerulosclerosis

Anecdotal reports suggest a higher frequency of serious cardiac complications, particularly cardiomyopathy and congestive heart failure (CHF), in children with focal segmental glomerulosclerosis (FSGS). We report the occurrence of cardiac disease in children with FSGS compared with other glomerular causes of primary nephrotic syndrome (NS). A chart review was performed on all patients evaluated at the Schneider Children's Hospital between 1985 and 2003 with a diagnosis of membranoproliferative glomerulonephritis (MPGN), membranous nephropathy (MN), focal global glomerulosclerosis (FGGS), and FSGS. Clinical and demographic data were compiled, specifically whether or not the patient had clinically evident cardiac disease. The blood pressure (BP) and hematocrit in patients with FSGS and chronic renal failure (CRF) (glomerular filtration rate <30 ml/min per 1.73 m(2)) in the 3 months prior to the development of cardiac complications were compared with the values in FSGS patients with CRF but no cardiac complications, and in patients with the other causes of primary NS in whom CRF developed. There were 48 patients with FSGS, 22 with MPGN, 19 with MN, and 4 with FGGS. Cardiac disease occurred in 6 children (mean age 11 years), all with FSGS. Four of these patients were black and 5 were female. CHF occurred in all patients, cardiomyopathy in 4, and left ventricular hypertrophy in 5 patients. There was no significant difference in the BP and the hematocrit levels between the 6 patients with both FSGS and cardiac disease, 3 patients with FSGS and CRF but no cardiac disease, and the 5 patients with the other glomerulopathies in whom CRF occurred ( P>0.1). Our findings suggest that there is a clinical association between FSGS and cardiac disease in pediatric patients. We speculate that the immune mechanism responsible for the development of FSGS may also affect the heart.

Late effects surveillance system for sarcoma patients

BACKGROUND

In 1998, a prospective multicenter pilot study of the 'Late Effects Surveillance System' (LESS) was started to investigate late effects of patients with Ewing, osteo- or soft-tissue sarcoma.

PROCEDURE

Two hundred thirty patients were included in this pilot study. The patients were treated between 1/1/1998 and 6/30/1999 according to the sarcoma protocols COSS-96, CWS-96, and EICESS-92, the median cumulative doses of the focussed drugs were for cisplatin: 360 mg/m(2), for doxorubicin: 270 mg/m(2), and for ifosfamide: 24 g/m(2). The patients were investigated using an organ related standardized screening methodology. We report on toxicities in the first year after cessation of therapy-the beginning of the patient follow-up-and the feasibility of LESS.

RESULTS

Cardiotoxicity: 16/129 (12%) patients treated with doxorubicin exhibited a reduced systolic heart function (fractional shortening (FS) <29%). Altogether three patients required cardiac drug therapy. Ototoxicity: In 5/73 (7%) patients treated with cisplatin a hearing deficit <4 kHz (>20 dB) was found. One patient needed a hearing aid. Nephrotoxicity: 2 of 214 (1%) patients treated with ifosfamide suffered from a tubulopathy, which required supplementation therapy. 10/50 (20%) showed a reduced fractional phosphate reabsorption. Incidence of hypomagnesemia was significantly increased in patients additionally treated with cisplatin.

CONCLUSIONS

Some relevant impairments are noted in the first year after antineoplastic therapy. We expect to detect more major late sequelae in our prospective study during the increasing posttherapeutic interval. Our pilot study shows the feasibility of the methodology.

Cyclosporin A monitoring by 2-h levels: preliminary target levels in stable pediatric kidney transplant recipients

Clinical trials in adults have shown that management of transplanted patients with cyclosporin A (CsA) 2-h levels (C2) lead to superior outcome compared with monitoring of 12-h trough levels (C0). In both adults and children, C2 levels enabled a better estimation of the area under the curve concentration than C0 levels. Therefore, it can be suspected that C2 monitoring might also lead to a better outcome in children. Until now C2 target levels for children have not been defined. We measured C2 levels in 101 stable pediatric kidney recipients with a minimum time of 1 yr after transplantation. C2 levels were compared with changes in glomerular filtration rate (GFR) 6 months later. Median C2 levels in children after renal transplantation were 714 ng/mL (95% confidence interval 654-774). Patients with C2 levels below 750 ng/mL had a significantly higher percentage of decline in GFR than patients with C2 levels above 750 ng/mL (p < 0.05). In children with C2 levels below 500 ng/mL three acute rejections occurred in comparison with no rejection in the remaining patients (p < 0.05). We conclude that the lower C2 target level should be above 750 ng/mL in stable pediatric transplant recipients. An upper target level above 1000 ng/mL should be avoided. The question, whether C2 monitoring in pediatric kidney recipients is superior to C0 monitoring, is yet to be answered.

A prospective trial of steroid withdrawal after renal transplantation in children: results obtained 1990 and 2002

Ten-year graft survival rate was 89% after immunosuppressive therapy with cyclosporine, methylprednisolone, and mizoribine in pediatric renal transplant recipients enrolled in our multicenter study. Adrenocorticosteroids, which cause growth retardation, were reduced by administration on alternate days in 67% and withdrawn in 23% of recipients. Acute rejection episodes occurred in 30% of patients after withdrawal of steroids. Graft function returned to prerejection levels after treatment with high-dose methylprednisolone. Catch-up growth occurred after alternate day administration and steroid withdrawal. Twenty-eight of 94 patients reached the final height of 156 cm in boys and 145 cm in girls, because of the gradually reduced growth rate. Management of growth retardation before transplantation, especially in patients with congenital renal diseases, and early reduction of the steroid dose after transplantation will increase the final height of children with chronic renal failure.

The use of art therapy to detect depression and post-traumatic stress disorder in pediatric and young adult renal transplant recipients

Pediatric and young adult renal transplant recipients may experience feelings of depression and emotional trauma. A study was conducted to (1) determine the prevalence of depression and emotional trauma and (2) assess the utility of the Formal Elements of Art Therapy Scale (FEATS). Sixty-four renal transplant recipients, 6-21 yr of age, were evaluated using self-report measures (CDI and Davidson) and art-based assessments. Subject art was analyzed by art therapists using seven of the 14 elements of the (FEATS), to assess depression. Unlike CDI and Davidson self-report testing, all patients were able to complete the art-based directives. When self-report measures and art-based assessments were combined, 36% of the study population had testing results consistent with depression and/or post-traumatic stress. The FEATS assessments identified a subset of patients who were not identified using the self-report measures. There was a correlation between CDI and Davidson scores (p < 0.0001), Davidson scores correlated with hospital days (p = 0.05), and FEATS correlated with height Z score (p = 0.04) and donor type (p = 0.01). Patients who required psychological interventions including antidepressant therapy, psychological counseling and psychiatric hospitalization during the year after the study were identified as depressed. Sensitivity for FEATS and CDI were 22 and 50% respectively. The results suggest that while art therapy may be of utility in the identification of pediatric and young adult transplant recipients who are suffering from depression, FEATS analysis appears to lack sufficient sensitivity to warrant its use in this population. Study of other quantitative art-based assessment techniques may be warranted.

Proteinuria as a predictor of disease progression in children with hypodysplastic nephropathy. Data from the Ital Kid Project

Little is known about the role of proteinuria in the progression of childhood renal diseases. We analyzed the decline in creatinine clearance ( C(Cr)) and kidney survival in 225 children (185 males) with chronic renal failure (CRF) due to isolated hypodysplasia or hypodysplasia associated with urological abnormalities. The data were based on the information available in the Italian Pediatric Registry of CRF (ItalKid Project), which includes patients from all of Italy aged <20 years with C(Cr )levels of <75 ml/min per 1.73 m(2). Patients aged <2 years and those with C(Cr )levels of <20 ml/min per 1.73 m(2) or a follow-up of <1 year were excluded from the analysis, as were those receiving angiotensin-converting enzyme inhibitors. At baseline, the patients had a mean age of 7.8+/-4.2 years, a mean C(Cr )of 50+/-16.3 ml/min per 1.73 m(2), a median urinary protein/urinary creatinine (uPr/uCr) ratio of 0.38 (range 0.02-7.21), and a mean duration of follow-up of 3.5+/-1.1 years. The patients were divided into three groups on the basis of their baseline proteinuria levels: group A normal (uPr/uCr <0.2) n=83; group B low (uPr/uCr 0.2-0.9) n=71; and group C mild (uPr/uCr >0.9) n=71. Patients in groups A and B showed a significantly slower decline in C(Cr )than those in group C (slope +0.16+/-3.64 and -0.54+/-3.67 vs. -3.61+/-5.47, P<0.0001) and a higher rate of kidney survival after 5 years (96.7% and 94.1% vs. 44.9%, P<0.01). By multivariate analysis, the baseline uPr/uCr ratio ( P<0.01) and age ( P<0.0001) correlated with a faster decline in C(Cr )irrespective of baseline C(Cr). There was no correlation with mean arterial blood pressure. We conclude that proteinuria is an independent predictor of progression to end-stage renal failure also in children whose renal impairment is due to congenital hypodysplasia.

Surveillance biopsies are superior to functional studies for the diagnosis of acute and chronic renal allograft pathology in children

In this report of our 3-yr protocol biopsy program, we describe the evolution of acute rejection (AR) and chronic renal allograft nephropathy (CAN) in a cohort of 21 children treated with antibody induction, tacrolimus, mycophenolate mofetil, and prednisone. The aims of this study were to compare the pathogenicity of clinical acute rejection (CAR) and subclinical acute rejection (SAR), and to determine whether functional studies accurately represent acute and chronic renal allograft pathology in pediatric recipients with disproportionately large grafts. Using concurrent biopsies, we evaluated: (i) the utility of changes in the baseline sCr (DeltasCr) to predict both the onset of AR and the response to immunosuppressive therapy; and (ii) the relationship of the calculated creatinine clearance and the presence of pathologic proteinuria to the severity of CAN. We performed 112 biopsies: 11 donor, 73 protocol, 16 acute graft dysfunction and 12 1-month follow-up AR therapy. CAR and SAR were similar in incidence, timing and histologic severity. Progression of CAN was associated with the first episode of CAR (p < 0.02) and the cumulative number of episodes of CAR (p < 0.01), SAR (p < 0.05), CAR plus SAR (p < 0.002) and borderline SAR (B-SAR) (p < 0.006). One-month post-treatment DeltasCrs could not distinguish 1-month follow-up biopsies with histologically confirmed worsened or unchanged AR from those with improved histology (35.2 +/- 74.8% vs. 23.8 +/- 24.9%, p = NS). These findings led to the addition of anti-lymphocyte antibody therapy in five of 10 (50%) cases. Despite 100% 3-yr actuarial graft survival and excellent function (GFR = 111 +/- 36 mL/min/1.73 m(2)), 18 of 21 (86%) patients had grade I CAN or greater chronic histology at a mean +/- sd follow-up period of 18.2 +/- 13.1 months. Thirteen of 21 (62%) patients progressed to grade I CAN at 5.2 +/- 3.6 months and five (38%) of these patients progressed to grade II CAN at 17.8 +/- 11.3 months. Schwartz GFR did not differ between patients with or without CAN (108 +/- 38 mL/min/1.73 m(2) vs. 127 +/- 8 mL/min/1.73 m(2), p = NS). In biopsies with CAN and no associated AR, neither the Banff chronic tubulointerstitial (Banff ci) score nor the Banff chronic grade correlated with the GFR. Proteinuria was not associated with CAN. Clinical AR and SAR are similar histologic lesions with a capacity for CAN progression. In pediatric renal transplant recipients, longitudinal protocol biopsies are superior to functional studies for the diagnosis and post-therapeutic monitoring of AR and for the surveillance of CAN.

Henoch-Schönlein purpura nephritis: course of disease and efficacy of cyclophosphamide

Nephritis in Henoch-Schönlein purpura (HSP) is the primary cause of morbidity and mortality. Although many therapeutic regimens have been reported to be effective, no therapy has been shown in a controlled trial to be beneficial. Fifty-six patients with histopathologically severe HSP nephritis were randomized to receive supportive therapy with or without cyclophosphamide, 90 mg/m(2)/day for 42 days. Patients were classified according to status at final follow-up: Fully Recovered 48.2%, Persistent Abnormalities 39.3%, or ESRD/Death 12.5%. There were no differences in onset data or outcome between the two trial groups or in outcome between trial and 23 non-trial patients followed concurrently. Therefore, data from trial and non-trial patients were combined for further analysis. There was no correlation between outcome and age, blood pressure, serum total protein, or serum albumin. Although rates of proteinuria did not correlate with outcome, all those with progression to ESRD had nephrotic levels of proteinuria at onset. Only five of 28 patients with nephrotic levels of proteinuria and severe onset histopathology recovered fully. No patient with crescents in 50% or more of glomeruli went on to full recovery. Recurrence of non-renal symptoms did not correlate with outcome. Nephrotic syndrome, decreased GFR, and more severe histopathology at onset, as well as persistence of urinary abnormalities for several years, are ominous signs.

Pulse cyclophosphamide therapy for steroid-resistant focal segmental glomerulosclerosis in children

BACKGROUND

In children, steroid-resistant nephritic syndrome due to focal segmental glomerulosclerosis (FSGS) is frequently a progressive condition resulting in end-stage renal disease (ESRD). We report the response of 15 patients with steroid resistant FSGS to treatment with intravenous pulse cyclophosphamide (IVCP) and oral prednisone after 4 years of follow up. Five patients had initial steroid resistance and ten patients had late steroid resistance.

PATIENTS AND METHODS

All patients were treated with IVCP at a dose of 500 mg/m2/month for 6 months. Adjunctive prednisolone was given at a dose of 60 mg/m2/day for 4 weeks followed by 40 mg/m2/ on alternate days for 4 weeks and then tapered over next 4 weeks.

RESULTS

All patients with initial resistance to steroids showed no response to IVCP and continued to be steroid resistant. Three developed CRF during the observation period. The other ten patients with late steroid resistance responded to IVCP, but all were steroid dependent at the end of the observation period. Five could not be weaned from steroids during the IVCP treatment period. The other five patients achieved relatively prolonged remission (7 months to 24 months), but eventually become steroid dependent.

CONCLUSION

Sixty-seven percent of steroid-resistant FSGS becomes steroid dependent. Patients with initial steroid resistance did not respond to IVCP. We found no correlation between IgM deposition and the response to therapy. The side effects of IVCP were negligible. Beneficial therapy for initial steroid-resistant FSGS remains to be determined.

Lupus nephritis in childhood: a review of 53 patients followed at a single center

We retrospectively evaluated the clinical and histopathological features, treatment modalities, and outcome of 53 children and adolescents with biopsy-proven lupus nephritis (LN), followed between September 1983 and September 2001. The mean age (+/-SD) at the time of diagnosis of systemic lupus erythematosus (SLE) was 12.9+/-2.6 years and the mean follow-up from the time of biopsy was 4.8+/-3.4 years. At the time of biopsy, all 53 patients had proteinuria, 21 (40%) had nephrotic syndrome, and 14 (26%) had impaired renal function. Class IV nephritis, observed in 34 (64%) patients, was the most frequent histopathology on initial renal biopsy. The patients with class IV LN had a significant tendency to develop hypertension ( P=0.04) and nephrotic syndrome ( P=0.027), and a lower mean glomerular filtration rate ( P=0.000). Based on the renal histopathology and clinical presentation, patients were treated with corticosteroids alone or combined with azathioprine or with intravenous cyclophosphamide. Plasmapheresis or cyclosporine was used in 4 and 1 patient, respectively. Follow-up biopsies, performed in 13 patients, showed no change in 6 patients, were progressive in 4, and regressive in 3. On final clinical evaluation, renal disease was in complete or partial remission in 42 of 53 patients (80%), 4 had clinically active disease but with normal renal function, and 7 (13%), all with WHO class IV LN, were classified as having an adverse outcome, i.e., either preterminal (2) or terminal (4) renal failure or death (1). Five-year kidney and patient survival rates from the time of biopsy to the endpoints of terminal renal failure or death were 88.6% and 98.1%, respectively, in the whole group, and 82.4% and 97.1%, respectively, in the WHO class IV group. Nephrotic syndrome and class IV nephritis at initial biopsy were the only parameters significantly associated with adverse outcome in our study group. There was no association with gender, age, hypertension, impaired renal function, anemia, increased morphological index scores, and treatment modalities. We conclude that clinical and histopathological features of LN and treatment regimens in our study do not differ markedly from those in most pediatric series. However, the 5-year kidney and patient survival rates are among the best reported in recent pediatric series. The prognosis of LN is primarily dependent on the histopathological lesions.

[Estimation of creatinine clearance by the height/plasma creatinine formula in critically-ill children]

INTRODUCTION

Critically-ill children frequently show impaired renal function, necessitating adjustment of drug dosages. Our objectives were to study estimated creatinine clearance through the correlation between the height/plasma creatinine formula (CrClest) and measured creatinine clearance (CrClms) and to examine whether CrClest over- or underestimates CrClms by analyzing the influence of diagnosis, severity, and the practical consequences.

PATIENTS AND METHODS

Seventy-seven patients admitted to the pediatric intensive care unit were included. CrClms was calculated using serum creatinine and creatinine in urine collected over 24 hours. CrClest was estimated using serum creatinine, height, and a constant. The difference between CrClms and CrClest was expressed as a percentage: (CrClms CrClest) x 100/CrClms. Differences of greater than 15 % were considered poor estimates. ResultsThe mean percentage difference was 29.2 (standard error: 39.9). There were no differences among diagnoses in the distribution of significant bias, although the frequency of metabolic diagnoses was high. Incorrect evaluation of CrClest would result in a therapeutic error in 11.69 % of the cases, with overdosage in 10.39 %. The Pediatric Risk of Mortality (PRISM) score was higher (p < 0.05) in patients at risk for overdosage.

CONCLUSIONS

CrClest estimation using the height/plasma creatinine formula was not an accurate method in critically ill children. In 10.39 % of patients with more severe illness, the dosage of renally excreted drugs would be too high. The highest risk was found in patients with metabolic and neurological diagnoses.

Psychological distress and adherence to the medical regimen among adolescent renal transplant recipients

This longitudinal pilot study of adolescent renal transplant recipients (a) describes the prevalence of psychological distress, (b) describes the prevalence of nonadherence, and (c) explores the association between the recipient's psychological distress and his/her subsequent medical adherence. Twenty-two adolescents, aged 13-18 years, completed two interviews that were separated by approximately 12 months. Psychological distress was assessed in three domains: symptoms of depression, anxiety, and anger. Adherence was assessed in three domains: medication taking, blood work, and clinic attendance. At the initial interview, 36.4% had symptoms of depression, 36.4% endorsed anxiety, and 18.2% endorsed excessive state anger. Non-adherence rates were 13.6% for medication, 22.7% for blood work, and 50% for missed clinic. At the second interview, nonadherence with medication remained the same and the other domains decreased. Our small pilot sample, however, limited our ability to detect statistically significant changes over time. Predictive analyses demonstrated that adolescents with excessive anger were at greater risk for subsequently missing medications than adolescents without excessive anger. These findings suggest that while symptoms of depression and anxiety are observed among some adolescents with renal transplants, only anger is associated with elevated risk for nonadherence with medication.

Predicting GFR in children and adults: a comparison of the Cockcroft-Gault, Schwartz, and modification of diet in renal disease formulas

BACKGROUND

A rapid prediction of glomerular filtration rate (GFR) is often needed in clinics. Formulas based on plasma creatinine level are being increasingly used, Schwartz for children, supposed to give GFR; Cockcroft-Gault for adults, supposed to indicate the creatinine clearance; and a recent formula introduced by the Modification of Diet in Renal Disease (MDRD) group. Our objective was to test whether one single formula could suffice and which one gives the best estimation of GFR.

METHODS

In 198 children (with two kidneys, single kidney, or renal transplant) and 116 adults (single kidney and transplanted), we measured inulin clearance and creatinine clearance and calculated Cockcroft-Gault, MDRD and, in children only, Schwartz. Data were compared with analysis of variance (ANOVA), regression statistics, and concordance studies.

RESULTS

In patients over 12 years of age, Cockcroft-Gault was almost similar to GFR corrected for body surface and creatinine clearance exceeded GFR by more than 20%; Schwartz was above creatinine clearance excepted for transplanted children. In younger children, no prediction approached GFR. Predictions were well correlated with GFR, but concordance studies showed Schwartz with dispersed results and GFR overestimated (20 mL/min/1.73 m2); Cockcroft-Gault was close to GFR and results were dispersed; MDRD in children gave a large overestimation and badly dispersed results; in transplanted adults its prediction was good.

CONCLUSION

Cockcroft-Gault prediction could be used for children over 12 years of age and adults; it should not be considered as creatinine clearance but as GFR corrected for body surface, it is merely a prediction, 95% of the results are between +/-40 mL/min/1.73 m(2) in children and +/-30 mL/min/1.72 m(2) in adults. In younger children no formula is satisfying.

Simple estimation of the glomerular filtration rate in sick Thai children

The objective of this study was to establish an appropriate formula for the estimation of creatinine clearance (CCr) in sick Thai children, and to evaluate the accuracy of using the Schwartz formula. Children aged between 0 and 19 years with various diseases and varying levels of renal function (but remained stable) were studied. Height in centimetres (L) and weight in kilograms (W), time of urine collection and urine volume were measured to provide urine flow (mL/min (V)) measurements. Body surface area (m2; SA) was also assessed. Quantitative urinary and plasma creatinine concentration (UCr and PCr, respectively) were determined. Creatinine clearance was calculated by using the following formula: UCr x V x 1.73/(PCr x SA). The linear association between CCr and L/PCr derived from these data was compared with the Schwartz formula by using bootstrap statistics. One-hundred and sixty children were studied. A least squares straight-line regression through the origin of CCr against L/PCr provided a good fit to the data. Our dataset revealed no evidence of an age or sex affect on the relationship. Creatinine clearance was estimated by using the following formula: 0.465 x (L/PCr), in which the calculated 95% confidence interval of the coefficient was 0.44-0.49. A comparison of this coefficient with that for the Schwartz formula for children aged > or =1 year (0.55), using 1000 bootstrapped resamples, showed an incompatibility between the two coefficients (P < 0.00005). In conclusion, we suggest estimating CCr in sick Thai children of either sex by using a modification of the Schwartz formula in which the coefficient equals 0.465.

End-stage renal disease after high-dose carboplatinum in preparation of autologous stem cell transplantation

Stem cell transplantation is one therapy employed in the management of children with high-risk solid tumors. However, this therapy is not without risk, having been associated with multiple end-organ toxicities. Both acute renal failure and chronic renal insufficiency have been reported in marrow transplant recipients, primarily in the context of the use of calcineurin inhibitors and radiation therapy. This report reviews our experience in managing an adolescent with metastatic Ewing's sarcoma who developed rapid progression to end-stage renal disease following a pretransplant conditioning regimen with high-dose carboplatinum. She had not received radiation or prior cisplatinum therapy. The possible reasons for the patient's highly unusual course and recommendations on ways to prevent this complication are discussed.

The neonatal variant of Bartter syndrome and deafness: preservation of renal function

BACKGROUND

A subtype of antenatal Bartter syndrome and sensorineural deafness (BSND) was originally described among families from southern Israel, and its gene (Barttin, OMIM #606412) has recently been identified. A report has suggested that these children develop chronic renal insufficiency during childhood attributable to chronic tubulointerstitial fibrosis and atrophy.

METHODS

Data from 13 infants with BSND, who were born during a 20-year period in our institution, were retrospectively analyzed.

RESULTS

All pregnancies were complicated by polyhydramnion and premature birth. All patients have sensorineural deafness, as well as hypokalemic metabolic alkalosis. Persistent hypercalciuria or nephrocalcinosis were absent in most children. All children have been treated with indomethacin (2 mg/kg/d) and potassium supplementation. The current average serum creatinine and calculated creatinine clearance from the older group (n = 8; mean age: 8.8 +/- 1.4 years) is 60.8 +/- 16.5 micro mol/L and 95 +/- 20 mL/min/1.73m(2), respectively. Kidney biopsies from two 7-year-old patients revealed mild focal tubulointerstitial fibrosis and minimal mesangial proliferation but no glomerulosclerosis.

CONCLUSIONS

Early renal function deterioration is not a uniform finding among children with BSND mutations.

Pharmacodynamics and dosing of aminoglycosides

Aminoglycosides are concentration-dependent killing agents whose pharmacodynamic predictors of efficacy are the area-under-the-curve to minimum inhibitory concentration ratio and the peak to minimum inhibitory concentration ratio. Prospective studies have shown that these agents can be given once-daily or less frequently in most clinical settings, with equal efficacy and possible reduced toxicity. Dosages for different clinical settings have been studied and methods are available to monitor once-daily dosing.

Novel therapy of focal glomerulosclerosis with mycophenolate and angiotensin blockade

Steroid-resistant nephrotic syndrome of childhood poses a dilemma in attempting to balance toxicity of medications against long-term prognosis. This report presents our preliminary experience with the novel use of combined mycophenolate mofetil (MMF) and angiotensin blockade (AB) in the treatment of nine children and young adults with focal glomerulosclerosis (FSGS). All patients were steroid resistant and had failed conventional treatment regimens. Prior to the initiation of the MMF-AB protocol, the patients were pre-treated with weekly intravenous methylprednisolone (MP) (15 mg/kg per week) for 4-8 weeks. Angiotensin-converting-enzyme inhibitors and/or angiotensin receptor blockers were begun when intravascular volume was restored. MMF was given at a dose of 250-500 mg/m(2) per day. Proteinuria, as measured by urine protein/creatinine ratios (Up/c), decreased by 43% following MP ( P<0.05). After 6 months of MMF-AB protocol, the Up/c was 72% below baseline ( P<0.01). This level was maintained for a minimum of 24 months of observation. Similarly, hyperlipidemia, as measured by total cholesterol and triglycerides, improved significantly with treatment (536+/-163 to 265+/-70 mg/dl, 447+/-168 to 230+/-92 mg/dl, respectively, P<0.01). Our data support the use of MMF and AB for treatment of steroid-resistant FSGS when other conventional treatments have failed and/or induced toxicity.