Pharmacokinetic Variability of Mycophenolic Acid in Pediatric and Adult Patients with Hematopoietic Stem Cell Transplantation

The aim of this study was to evaluate the pharmacokinetic variations of mycophenolic acid (MPA), the active metabolite of mycophenolate mofetil (MMF), in both pediatric and adult patients following hematopoietic stem cell transplantation (HSCT). Twenty pediatric patients with a median age of 3 years (range 0.2-12 years) and 13 adult patients with a median age of 54 years (range 18-63 years) were enrolled. Blood samples were collected on days 0, 7, 14, 21, and 30 after allogeneic HSCT. Total and free (unbound) MPA as well as MPA 7-O-glucuronide (MPAG) were quantified using a validated LC-MS/MS assay. The plasma protein binding of MPA and MPAG did not change significantly in pediatric patients over the 1-month sampling period post-HSCT. However, it increased in adult patients from day 7 to day 30 post-HSCT, from 97.3 ± 0.8% to 98.3 ± 0.6% for MPA (P < .05), and 74.6 ± 9.4% to 82.9 ± 8.1% for MPAG (P < .05). The plasma protein binding of MPA was significantly higher in males compared to females in both pediatric (98.3 ± 1.1% vs 97.4 ± 1.1%) and adult (98.1 ± 0.7% vs 97.4 ± 1.2%) patients (P < .05). The MPAG/MPA ratios on a milligram-per-kilogram dose basis in adult patients were significantly higher than those in pediatric patients (4.3 ± 3.4 vs 2.4 ± 2.6; P < .05). Time-dependent plasma protein binding and age-related differences in MPA metabolism at least in part impact the reported large intra- and interindividual variability in MPA pharmacokinetics. These patient and pharmacologic factors, if incorporated into MMF regimen design and modification, may contribute to the rational dose selection of MMF in HSCT patients

Identifying Genetic Variants in Adolescents With Oppositional Defiant Disorders and/or Conduct Disorders: A Brief Report

PROBLEM To add to diversity in our state biobank, we explored the feasibility of collecting genetic material from adolescents with oppositional defiant disorder (ODD) and/or conduct disorder (CD) and their family members. We also preliminarily explored genetic factors associated with ODD and/or CD by comparing participant data to 1000 Genome Project data on minor allele frequencies. METHODS Adolescents with ODD and/or CD and family members provided saliva samples for genetic testing. We evaluated five single-nucleotide polymorphisms (SNPs), respectively, in the dopamine receptor subtype D2, dopamine receptor subtype D3, dopamine beta-hydroxylase, dopamine transporter gene SLC6A3, and alpha-2-adrenergic receptor genes. Fisher's exact tests were used to examine differences in minor allele frequencies for each SNP. FINDINGS Thirty-one viable samples were genotyped from 15 affected adolescents and 16 unaffected family members; the 60% consent rate reflected high feasibility. Compared with the 1000 Genome Project frequencies, affected adolescents had higher frequencies of the genetic variant in the dopamine receptor subtype D2 (p = .05) and dopamine beta-hydroxylase (p = 0.03), but not of the other three SNPs examined. CONCLUSIONS Collecting genetic materials from an ethnically diverse sample of affected adolescents and their families is feasible. We offer practical suggestions to strengthen the integrity of future research studies

Raising the Level of Nursing Involvement in the National Precision Medicine Initiative: An Example

PURPOSE The Precision Medicine Initiative (PMI) goal of ushering in a new and more effective era of health care that benefits all Americans requires two critical and interdependent components: a cohort assembly of 1 million or more Americans who reflect the diversity of the United States of America and an interdisciplinary workforce that includes nursing. The purpose of this article is to provide an example of nursing involvement in PM, specifically as related to gathering biospecimens (saliva) from vulnerable, understudied adolescents with disruptive behavior disorders and their family members. SOURCE(S) First, we provide a brief description of important concepts related to PM as well as current roles of nurses in PM. Then, we share lessons learned from our feasibility study aimed at increasing the diversity of our statewide cohort assembly that has provided biospecimens for the Indiana Biobank. CONCLUSION Nurses can definitely contribute to biobanks in support of the PMI. This article is a call to action for nurses to take their rightful place in PM

The Immune System in Cancer Pathogenesis: Potential Therapeutic Approaches

Interplay among immune activation and cancer pathogenesis provides the framework for a novel subspecialty known as immunooncology. In the rapidly evolving field of immunooncology, understanding the tumor-specific immune response enhances understanding of cancer resistance. This review highlights the fundamentals of incorporating precision medicine to discover new immune biomarkers and predictive signatures. Using a personalized approach may have a significant, positive impact on the use of oncolytics to better guide safer and more effective therapies

Glutathione-S-transferase P1 may predispose children to a decline in pulmonary function after stem cell transplant

RATIONALE: Pulmonary complications after hematopoietic stem cell transplant (SCT) are associated with increased mortality. Genetic markers for those at risk for pulmonary impairment post-SCT have not been widely investigated. METHODS: Forty-nine patients were retrospectively selected from a single institution's biorepository with linked clinical data. All subjects performed pre-SCT PFTs. Genotyping was conducted using the Infinium Exome-24 BeadChip. Four single nucleotide polymorphisms (SNPs) were selected (rs1800871, rs1695, rs1800629, rs12477314) and evaluated for association with PFT parameters as change over time from baseline. Associations between SNPs and PFT parameters were assessed and adjusted for the following confounding variables: age, gender, and race. RESULTS: Using the recessive genetic model, patients with one or two minor alleles for the glutathione S-transferase P1 (GSTP1) SNP rs1695 had a lower decline in FEV1 and FEF25-75 at 1-year post-SCT compared to patients who were homozygous for the ancestral allele (adjusted P-values <0.01 and 0.02, respectively). No other SNPs were significantly associated with other PFT parameters. CONCLUSIONS: Our findings suggest that GSTP1 genotype may be associated with lung function during the first year post-SCT. Identifying and investigating genes that predispose patients to pulmonary complications after SCT may allow for more personalized patient management based on pre-emptive genetic testing. The glutathione S-transferase gene merits further investigation

Low serum albumin levels prior to pediatric allogeneic HCT are associated with increased need for critical care interventions and increased 6-month mortality

Poor nutritional status in HCT patients is a negative prognostic factor. There are no pediatric studies evaluating albumin levels prior to HCT and need for critical care interventions. We hypothesized that pediatric patients with low albumin levels, routinely measured 30 days (±10 days) prior to allogeneic HCT, have a higher risk of critical care interventions in the post-transplant period. We performed a 5-year retrospective study of pediatric patients who underwent allogeneic HCT for any indication. Patients were categorized based on albumin level. Hypoalbuminemia was defined as <3.1 g/dL. A total of 73 patients were included, with a median age of 7.4 years (IQR 3.3, 13.2). Patients with hypoalbuminemia had higher needs for critical care interventions including non-invasive ventilation (44% vs 8%, P=.01), mechanical ventilation (67% vs 17%, P<.01), and vasoactive therapy (56% vs 16%, P=.01). Patients with hypoalbuminemia also had a higher 6-month mortality (56% vs 17%, P=.02). Our data demonstrate that children undergoing allogeneic HCT with hypoalbuminemia in the pretransplant period are more likely to require critical care interventions and have higher 6-month mortality. These findings identify an at-risk population in which nutritional improvements may be instituted prior to HCT in hopes of improving outcomes

Differential effects of hydrocortisone, prednisone, and dexamethasone on hormonal and pharmacokinetic profiles: a pilot study in children with congenital adrenal hyperplasia

BACKGROUND: Little is known about the comparative effects of different glucocorticoids on the adrenal and growth hormone (GH) axes in children with congenital adrenal hyperplasia (CAH). We sought to compare the effects of hydrocortisone (HC), prednisone (PDN), and dexamethasone (DEX) in children with classic CAH and to investigate a potential role of pharmacogenetics. METHODS: Subjects were randomly assigned to three sequential 6-week courses of HC, PDN, and DEX, each followed by evaluation of adrenal hormones, IGF-1, GH, and body mass index (BMI). Single nucleotide polymorphism (SNP) analysis of genes in the glucocorticoid pathway was also performed. RESULTS: Nine prepubertal subjects aged 8.1 ± 2.3 years completed the study. Mean ACTH, androstenedione, and 17-hydroxyprogesterone (17-OHP) values were lower following the DEX arm of the study than after subjects received HC (p ≤ 0.016) or PDN (p ≤ 0.002). 17-OHP was also lower after HC than PDN (p < 0.001). There was no difference in IGF-1, GH, or change in BMI. SNP analysis revealed significant associations between hormone concentrations, pharmacokinetic parameters, and variants in several glucocorticoid pathway genes (ABCB1, NR3C1, IP013, GLCCI1). CONCLUSIONS: DEX resulted in marked adrenal suppression suggesting that its potency relative to hydrocortisone and prednisone was underestimated. SNPs conferred significant differences in responses between subjects. Although preliminary, these pilot data suggest that incorporating pharmacogenetics has the potential to eventually lead to targeted therapy in children with CAH

Collection of human genomic DNA from neonates: a comparison between umbilical cord blood and buccal swabs

OBJECTIVE: To compare DNA yield from neonatal umbilical cord blood and buccal swab specimens. STUDY DESIGN: Umbilical cord blood was obtained at birth in a cohort of women enrolled in a preterm labor study. If cord blood was not obtained, neonatal buccal samples were obtained using the Oragene saliva kits. DNA was extracted from all samples using the QIAamp extraction kits. DNA concentration and yield were compared between umbilical cord blood and buccal swabs. RESULTS: DNA concentrations from umbilical cord blood (n = 35) was greater than that obtained from buccal swabs (n = 20) (total sample: 209.0 ± 110.7 ng/μL vs 6.9 ± 6.7 ng/μL respectively, P < .001; partial sample: n = 30 cord blood vs n = 11 buccal, 70.0 ± 51.4 ng/μL vs 11.3 ± 6.7 ng/μL, respectively, P < .001) and produced more total DNA (total sample: 116.5 ± 70.8 μg vs 4.2 ± 4.0 μg, P < .001; partial:14.0 ± 10.3 μg vs 1.1 ± 0.7 μg, respectively, P < .001). CONCLUSION: Buccal swabs yield less neonatal DNA than umbilical cord blood specimens