Prevalence and Clinical Correlates of Thirdhand Smoke Exposure in a Pediatric Patient Population

有明确的证据表明，烟草烟雾暴露与临床发病和疾病有关

There is unequivocal evidence that tobacco smoke exposure (TSE) is associated with clinical morbidity and increased healthcare utilization in children. Our team has observed that 91% of smokers’ children have high rates of TSE as assessed with cotinine, a metabolite of nicotine and a measure of recent TSE. In order to provide clinicians with an accurate assessment of their patients’ long-term TSE and associated clinical effects, biomarkers are needed that can demonstrate this clinically relevant information. Our overarching hypothesis is that DNA methylation (DNAm) may serve as a biomarker of long-term postnatal TSE in children. This hypothesis is based on research indicating that DNAm results in gene expression and transcription regulation. Specifically, children with prenatal TSE have lower DNAm levels of the aryl hydrocarbon receptor repression (AHRR) gene cytosine-[phosphate]-guanine (CpG) dinucleotide cg05575921 compared to children with no prenatal TSE; these patterns are similar to those seen in adult smokers. However, there are a paucity of studies examining DNAm and postnatal TSE and they are limited by the: use of blood samples only, lack of inclusion of racially diverse children, and lack of inclusion of children with high TSE levels. To bridge these critical gaps, this diversity supplement will expand our understanding of the use of buccal swabs to analyze DNAm patterns and will elucidate the DNAm patterns present in racially diverse children with high TSE levels. To accomplish this, we will examine DNAm patterns from buccal swabs of Black, Non-Hispanic female children, 0-5 years of age whose mothers are active smokers; child samples will be compared to buccal samples from their mothers, and also matched with a group of children who have no TSE. The overall objective is to measure genome-wide gene expression and DNAm and to identify and compare differentially methylated CpGs in children of smokers and their mothers, and children of nonsmokers, focusing on loci implicated by previous studies (Aim 1) and to examine the association between DNAm levels compared to cotinine levels and maternal-reported TSE patterns in children, maternal-reported tobacco use patterns, and child illness types (Aim 2). This supplement will greatly facilitate the career goals of the candidate, Ms. Olivia Gittens, a Latina and Caribbean undergraduate student. Ms. Gittens’s career goal is to be an independent clinician- scientist studying how potentially modifiable prenatal and postnatal exposures affect young children’s epigenomes and associated clinical outcomes. To support her career development, during this grant period she will obtain training on: 1) laboratory techniques and handling of specimens, 2) research techniques in biochemistry and molecular biology, 3) statistical analyses and interpretation of results, 4) research communication through peer review and academic conferences, and 5) ethics in research and career development. Training in these areas will help prepare Ms. Gittens for an impactful research career.