Gad Kainer

BK viral infection in an Australian pediatric renal transplant population

Abstract: BK virus (BKV) is recognized as a significant cause of renal allograft dysfunction in adults, and there is growing awareness of its importance in the pediatric population. Eighteen pediatric renal transplant recipients and 18 age‐matched controls were prospectively studied. Anti‐BKV immunoglobulin G (IgG) and IgM titres were assayed in all subjects at entry to the study. Polymerase chain reaction (PCR) for BKV DNA was performed on urine and serum at entry, and prospectively tested again at 4, 8 and 12 months. Mean age ± s.d. of transplant recipients and controls was 14.6 ± 3.3 and 13.9 ± 0.33 yr respectively [not significant (NS)]. Transplant patients were studied at a mean time of 5.6 ± 4.2 yr post‐transplant. 56% of transplant patients and 39% of controls were seropositive (+ve BKV IgG) (NS). Plasma BKV PCR was positive in one transplant patient (who also had positive urine PCR) and in none of the controls. The prevalence of positive urine PCR in transplant patients was greater than in controls (33% vs. 0%, p = 0.02). Positive urine BKV PCR was more commonly found in patients treated with mycophenolate than azathioprine (p = 0.04). We conclude that the prevalence of BKV seropositivity and viral activation in this Australian pediatric renal transplant population is similar to that reported in adult and pediatric populations in other countries. BK viruria was more common in children with greater immunosuppression, suggesting that this group is at higher risk of BKV induced nephropathy.

Perception of fear, distress and pain by parents of children undergoing a micturating cystourethrogram: a prospective study

Objectives: To investigate whether parents’ expectations of their childs fear, distress or pain during a micturating cystourethrogram (MCU) are realized.

The relationship between serum creatinine, serum cystatin C and glomerular filtration rate in pediatric renal transplant recipients: A pilot study

Abstract: Serum cystatin C more accurately reflects glomerular filtration rate (GFR) in pediatric renal transplant recipients than serum creatinine. Nineteen pediatric renal transplant recipients, 15 male and 4 female, ranging in age from 8.35 yr to 19.06 yr (median 13.52 yr), were enrolled in the study over an 18‐month period. Twenty‐eight measurements of 99mTc‐DTPA GFR were compared with simultaneous measurements of serum cystatin C and Cr. Linear regression analysis, Pearson correlation coefficients and analysis of variance (anova) were used to determine the relationship between creatinine, cystatin C and GFR. The correlation coefficients (R2) for the relationship of 1/Cr to DTPA‐GFR and for 1/cystatin C to DTPA‐GFR were 0.63 and 0.58, respectively. There was no significant difference between serum cystatin C and serum creatinine as markers of GFR. Serum cystatin C, which costs more to measure than serum creatinine, offers no advantage in monitoring the renal function of pediatric renal transplant recipients.

Effects of Growth Hormone Treatment for Short Stature on Calcium Homeostasis, Bone Mineralisation, and Body Composition

We investigated the effect of growth hormone (GH) treatment on mineral and vitamin D homeostasis, bone mineralisation, and body composition in short-statured children without GH deficiency (GHD). 11 children received GH (0.50 +/- 0.08 IU/kg/week) for 24 weeks. 1,25-Dihydroxyvitamin D3 levels (mean +/- SD in pmol/l) rose from a baseline of 73.7 +/- 39.2 to 114.0 +/- 32.7 at 8 weeks (p < 0.05) and 111.9 +/- 39.7 at 24 weeks (p < 0.01). Body composition evaluation using dual-energy X-ray absorptiometry revealed increased lean tissue mass and a reduction in fat tissue. As a percentage of total body mass, fat decreased from 19.0 +/- 11.8% at baseline to 17.3 +/- 11.5% at 8 weeks (p < 0.005) and 16.8 +/- 11.5% at 24 weeks (p < 0.05). L2-L4 bone mineral density was 0.637 +/- 0.155 g/cm2 at baseline and 0.666 +/- 0.160 g/cm2 at 24 weeks (NS). We conclude that recombinant human GH treatment of short children without GHD has significant effects on vitamin D homeostasis and body composition.

Renal effects of growth hormone. II. Electrolyte homeostasis and body composition

Growth hormone (GH), either directly or through insulin-like growth factor-1 (IGF-1), has a wide spectrum of physiological and renal effects. This review concentrates on the effects of GH (derived from either pituitary or recombinant technology) and IGF-1 in three main areas: (1) sodium and water homeostasis; (2) calcium and phosphate balance, bone density and interactions with mineral regulating hormones; (3) fat and lean body mass. Observations of physiological changes in states of GH deficiency and excess in humans and animal models are presented. The lack of long-term toxicological data indicates that GH treatment for short stature in non-GH deficient children, with or without renal disease, should proceed with caution.

Smell and taste function in children with chronic kidney disease

Loss of appetite and poor growth are common in children with chronic kidney disease (CKD), and changes in smell and/or taste function may be responsible, but the hypothesis has not been proven. This aims of this prospective age- and gender-controlled study were to determine whether: (1) changes in smell and taste function occur in children with CKD; (2) smell or taste dysfunction are associated with estimated glomerular filtration rate (eGFR); (3) there is an association between smell or taste loss and body mass index (BMI). The study cohort consisted of 72 children of whom 20 were CKD stage 3–5 patients, 12 were CKD stage 2 patients, 20 were clinical controls (CC) and 20 were healthy children (HC). The CKD patients and clinical controls were recruited from Sydney Children’s Hospital and The Children’s Hospital, Westmead, and healthy controls were recruited from a local school. Scores for each group from taste and smell chemosensory function tests were compared, and their relationship with renal function and BMI investigated. The CKD stage 3–5 group had a significantly lower taste identification score (85.6%, P < 0.001) than the CC (94.8%) and HC (94.8%) groups, with almost one third of the children in the CKD stage 3–5 group exhibiting taste loss. Decreased taste function was associated with decreased eGFR (r = 0.43, P < 0.01), but no association between BMI and taste function was found (r = 0.001, P > 0.9). Odour identification scores were not different; however, there was a positive relationship with BMI (r = 0.427, P = 0.006). We conclude that a loss of taste can occur in children with CKD and that when it occurs, it worsens as eGFR declines and is found early in kidney disease.

Low incidence of new renal scars after ureteral reimplantation for vesicoureteral reflux in children: a prospective study.

PURPOSE The major aim of treating vesicoureteral reflux in children is the prevention of renal scars. Dimercapto-succinic acid (DMSA) is the modality of choice for detecting renal scars. We documented the incidence of new renal scarring and measured changes in differential renal function after ureteral reimplantation using DMSA studies. MATERIALS AND METHODS We evaluated 45 boys and 98 girls with a median age of 2 years who had vesicoureteral reflux and underwent ureteral reimplantation. DMSA scans were done preoperatively and at a median of 3.4 years postoperatively. Maximal reflux grade was III in 84 children (59%), IV in 27 (19%) and V in 6 (4%). RESULTS Preoperatively DMSA studies showed scarred or contracted kidneys in 106 of the 143 patients (74%). After reimplantation mean change in differential function was 2.5%. New scars developed in 3 children (2%). We noted greater than 6% decrease in relative differential function without new scarring in 7 cases (5%). CONCLUSIONS The incidence of new renal scars in our study using DMSA was lower than that in previous series using excretory urography and imaging. Surgical correction of vesicoureteral reflux may offer better protection of kidneys in childhood than previously believed.

Atorvastatin treatment for hyperlipidemia in pediatric renal transplant recipients

Abstract: The objective of this prospective study was to determine the prevalence of hyperlipidemia in our pediatric renal transplant patients and to treat those with persistently elevated cholesterol and/or low‐density lipoprotein (LDL) levels. All patients with a functioning renal allograft for greater than 6 months were studied (n = 18). Patients with cholesterol and/or LDL levels greater than the 95th percentile (n = 9) were commenced on an HMG‐CoA reductase inhibitor, Atorvastatin and monitoring was performed for efficacy and adverse effects. Total serum cholesterol was elevated in 11 of 18 (61%) and triglyceride (TG) was elevated in 12 of 18 (67%) patients. Atorvastatin treatment was effective with a mean percentage reduction of total cholesterol of 41 ± 10% (p < 0.01 vs. before treatment), LDL 57 ± 7% (p < 0.01 vs. before treatment) and TG 44 ±25% (p = 0.05 vs. before treatment). No adverse effects on allograft function or cyclosporin levels were experienced. Hyperlipidemia is a common problem and Atorvastatin is a safe and effective treatment in pediatric renal transplant recipients.

Recurrent bacteremia with enteric pathogens in recessive polycystic kidney disease

Abstract Eight children with autosomal recessive polycystic kidney disease (ARPKD) and recurrent bacteremia with enteric pathogens are described. Typical clinical features of bacterial cholangitis were absent, although in five patients histological and/or microbiological data indicated that the bacteremic episodes originated in the biliary tree. Bacteremia with enteric pathogens or recurrent culture-negative febrile illness in a child with ARPKD should raise suspicion of cholangitis, even in the absence of typical clinical findings.

Renal effects of growth hormone. I. Renal function and kidney growth

Growth hormone (GH) affects renal function and kidney growth. Pituitary-derived or recombinant human GH (rhGH), acting via insulin-like growth factor-1 (IGF-1), increases glomerular filtration rate (GFR) and renal plasma flow (RPF) in GH-deficient as well as in normal adults. Furthermore, GFR and RPF are low in hypopituitarism and elevated in acromegaly. These effects of GH on GFR and RPF have not been demonstrated in moderate renal insufficiency. IGF-1 is implicated in compensatory renal hypertrophy. Markedly elevated levels of serum GH accelerate glomerular sclerosis in rodents, although the significance of these findings for GH treatment in humans is uncertain. rhGH therapy offers great promise to children with short stature from various aetiologies. Preliminary report on the use of rhGH in children with renal disease and after renal transplantation have not shown any consistent change in kidney function, although follow-up times are short. The long-term impact of rhGH therapy on kidney function in short children needs further evaluation.