A polygenic score for acute vaso-occlusive pain in pediatric sickle cell disease.

Individuals with monogenic disorders can experience variable phenotypes that are influenced by genetic variation. To investigate this in sickle cell disease (SCD), we performed whole-genome sequencing (WGS) of 722 individuals with hemoglobin HbSS or HbSß0-thalassemia from Baylor College of Medicine and from the St. Jude Children's Research Hospital Sickle Cell Clinical Research and Intervention Program (SCCRIP) longitudinal cohort study. We developed pipelines to identify genetic variants that modulate sickle hemoglobin polymerization in red blood cells and combined these with pain-associated variants to build a polygenic score (PGS) for acute vaso-occlusive pain (VOP). Overall, we interrogated the α-thalassemia deletion -α3.7 and 133 candidate single-nucleotide polymorphisms (SNPs) across 66 genes for associations with VOP in 327 SCCRIP participants followed longitudinally over 6 years. Twenty-one SNPs in 9 loci were associated with VOP, including 3 (BCL11A, MYB, and the ß-like globin gene cluster) that regulate erythrocyte fetal hemoglobin (HbF) levels and 6 (COMT, TBC1D1, KCNJ6, FAAH, NR3C1, and IL1A) that were associated previously with various pain syndromes. An unweighted PGS integrating all 21 SNPs was associated with the VOP event rate (estimate, 0.35; standard error, 0.04; P = 5.9 × 10-14) and VOP event occurrence (estimate, 0.42; standard error, 0.06; P = 4.1 × 10-13). These associations were stronger than those of any single locus. Our findings provide insights into the genetic modulation of VOP in children with SCD. More generally, we demonstrate the utility of WGS for investigating genetic contributions to the variable expression of SCD-associated morbidities.

Transition care continuity promotes long-term retention in adult care among young adults with sickle cell disease.

BACKGROUND/OBJECTIVES: Care continuity prevents increased health care utilization and mortality during transition from pediatric to adult care. Our program employs a co-located care delivery model, in which pediatric provider involvement continues during young adulthood. We tested the hypothesis that individuals who participated in the co-located model have greater retention in adult care compared to those who only received pediatric transition services. METHODS: This study consisted of 311 youth with SCD (51.4% male; 63.0% HbSS/HbSß0 -thalassemia) who transferred to adult care from 2007 to 2017. Retention was defined as continuation with an adult provider for ≥12 or ≥24 months post-pediatric care. Logistic regression estimated the association between co-location status and retention at 12 and 24 months. Logistic regression and t-tests were used to evaluate potential predictors of retention in adult care. RESULTS: Individuals who participated in the co-location model were 1.9 times more likely to remain in adult care 12 (95% CI: 1.01, 3.47) and 24 (95% CI: 1.01, 3.70) months post-pediatric care compared to those who did not participate. Individuals with HbSS/HbSß0 -thalassemia were 1.9 times more likely to be retained at 12 months compared to those with HbSC/HbSß+ -thalassemia/HbS/HPFH (95% CI: 1.12, 3.09). For every clinic encounter in the last 2 years of pediatric care, the odds of being retained at least 24 months after initiating adult care increased 1.1 times (95% CI: 1.02, 1.13). CONCLUSIONS: Continuity of providers from pediatric to adult care may increase long-term retention in adult care. Longitudinal monitoring of adult outcomes is critical to identifying the efficacy of transition services.

Cognitive performance as a predictor of healthcare transition in sickle cell disease.

Neurocognitive deficits in sickle cell disease (SCD) may impair adult care engagement. We investigated the relationship between neurocognitive functioning and socio-environmental factors with healthcare transition outcomes. Adolescents aged 15-18 years who had neurocognitive testing and completed a visit with an adult provider were included. Transition outcomes included transfer interval from paediatric to adult care and retention in adult care at 12 and 24 months. Eighty adolescents (59% male, 64% HbSS/HbSß0 -thalassaemia) were included. Mean age at adult care transfer was 18·0 (±0·3) years and transfer interval was 2·0 (±2·3) months. Higher IQ (P = 0·02; PFDR  = 0·05) and higher verbal comprehension (P = 0·008; PFDR  = 0·024) were associated with <2 and <6 month transfer intervals respectively. Better performance on measures of attention was associated with higher adult care retention at 12 and 24 months (P = 0·009; PFDR  = 0·05 and P = 0·04; PFDR  = 0·12 respectively). Transfer intervals <6 months were associated with smaller households (P = 0·02; PFDR  = 0·06) and households with fewer children (P = 0·02; PFDR  = 0·06). Having a working parent was associated with less retention in adult care at 12 and 24 months (P = 0·01; P = 0·02 respectively). Lower IQ, verbal comprehension, attention difficulties and environmental factors may negatively impact transition outcomes. Neurocognitive function should be considered in transition planning for youth with SCD.

Intentional and unintentional nonadherence to hydroxyurea among people with sickle cell disease: a qualitative study.

Hydroxyurea is an efficacious treatment for sickle cell disease (SCD), but adoption is low among individuals with SCD. The objective of this study was to examine barriers to patients' adherence to hydroxyurea use regimens by using the intentional and unintentional medication nonadherence framework. We interviewed individuals with SCD age 15 to 49.9 years who were participants in the Sickle Cell Disease Implementation Consortium (SCDIC) Needs Assessment. The intentional and unintentional medication nonadherence framework explains barriers to using hydroxyurea and adds granularity to the understanding of medication adherence barriers unique to the SCD population. In total, 90 semi-structured interviews were completed across 5 of the 8 SCDIC sites. Among interviewed participants, 57.8% (n = 52) were currently taking hydroxyurea, 28.9% (n = 26) were former hydroxyurea users at the time of the interview, and 13.3% (n = 12) had never used hydroxyurea but were familiar with the medication. Using a constructivist grounded theory approach, we discovered important themes that contributed to nonadherence to hydroxyurea, which were categorized under unintentional (eg, Forgetfulness, External Influencers) and intentional (Negative Perceptions of Hydroxyurea, Aversion to Taking Any Medications) nonadherence types. Participants more frequently endorsed adherence barriers that fell into the unintentional nonadherence type (70%) vs intentional nonadherence type (30%). Results from this study will help SCD health care providers understand patient choices and decisions as being either unintentional or intentional, guide tailored clinical discussions regarding hydroxyurea therapy, and develop specific, more nuanced interventions to address nonadherence factors.

Web-Based Technology to Improve Disease Knowledge Among Adolescents With Sickle Cell Disease: Pilot Study.

BACKGROUND: Advancements in treatment have contributed to increased survivorship among children with sickle cell disease (SCD). Increased transition readiness, encompassing disease knowledge and self-management skills before transfer to adult care, is necessary to ensure optimal health outcomes. The Sickle Cell Transition E-Learning Program (STEP) is a public, Web-based, 6-module tool designed to increase transition readiness for youth with SCD. OBJECTIVE: The objective of our study was to investigate the participation rate of youth with SCD in STEP and its association with transition readiness. METHODS: This was a single-center, Institution Review Board-approved, retrospective cohort review. A total of 183 youths with SCD, aged between 12 and 15 years, were offered STEP as an adjunct to in-clinic disease education sessions. Participation rate (number of patients who used at least one STEP module divided by those approached) was calculated. The association among the number of STEP modules completed, disease knowledge, and self-management was explored. RESULTS: Overall, 53 of the 183 approached adolescents completed at least one STEP module, yielding a participation rate in STEP of 29.0%. Of the 53 participants, 37 and 39 adolescents had disease knowledge and self-management confidence rating available, respectively. A positive correlation (r=0.47) was found between the number of STEP modules completed and disease knowledge scores (P=.003). No association was found between the number of modules completed and self-management confidence ratings. Disease knowledge scores were significantly higher among participants who completed ≥3 STEP modules compared with those who completed <3 STEP modules (U=149.00; P=.007). CONCLUSIONS: Improvement in disease knowledge in adolescence is critical to ensure the youth's ability to self-care during the period of transition to adult care. Despite low participation, the cumulative exposure to the STEP program suggested greater promotion of disease knowledge among adolescents with SCD before transfer to adult care.

Neighborhood effect and obesity in adult survivors of pediatric cancer: A report from the St. Jude lifetime cohort study.

Survivors of childhood cancer are at risk for obesity, a condition potentially modifiable if dietary intake and physical activity are optimized. These health behaviors are likely influenced by neighborhood of residence, a determinant of access to healthy, affordable food and safe and easy exercise opportunities. We examined associations between neighborhood level factors and obesity among survivors in the St. Jude Lifetime cohort and community comparison group members. Persons with residential addresses available for geocoding were eligible for analysis (n = 2,265, mean age 32.5 [SD 9.1] years, 46% female, 85% white). Survivors completed questionnaires regarding individual behaviors; percent body fat was assessed via dual X-ray absorptiometry (obesity: ≥25% males; ≥35% females); neighborhood effect was characterized using census tract of residence (e.g., neighborhood socioeconomic status [SES], rurality). Structural equation modeling was used to determine associations between neighborhood effect, physical activity, diet, smoking, treatment exposures and obesity. Obese survivors (n = 1,420, 62.7%) were more likely to live in neighborhoods with lower SES (RR: 1.23, 95% CI: 1.10-1.38) and rural areas (RR: 1.22, 95% CI: 1.07-1.39) compared to survivors with normal percent body fat. Resource-poor neighborhoods (standardized effect: 0.06, p < 0.001) and cranial radiation (0.16, p < 0.001) had direct effects on percent body fat. Associations between neighborhood of residence and percent body fat were increased (0.01, p = 0.04) among individuals with a poor diet. Neighborhoods where survivors reside as an adult is associated with obesity. Interventions targeting survivors should incorporate strategies that address environmental influences on obesity.

Height-corrected low bone density associates with severe outcomes in sickle cell disease: SCCRIP cohort study results.

Low bone mineral density (BMD) disproportionately affects people with sickle cell disease (SCD). Growth faltering is common in SCD, but most BMD studies in pediatric SCD cohorts fail to adjust for short stature. We examined low BMD prevalence in 6- to 18-year-olds enrolled in the Sickle Cell Clinical Research and Intervention Program (SCCRIP), an ongoing multicenter life span SCD cohort study initiated in 2014. We calculated areal BMD for chronological age and height-adjusted areal BMD (Ht-aBMD) z scores for the SCCRIP cohort, using reference data from healthy African American children and adolescents enrolled in the Bone Mineral Density in Childhood Study. We defined low BMD as Ht-aBMD z scores less than or equal to -2 and evaluated its associations with demographic and clinical characteristics by using logistic regression analyses. Of the 306 children and adolescents in our study cohort (mean age, 12.5 years; 50% female; 64% HbSS/Sß0-thalassemia genotype; 99% African American), 31% had low areal BMD for chronological age z scores and 18% had low Ht-aBMD z scores. In multivariate analyses, low Ht-aBMD z scores associated with adolescence (odds ratio [OR], 7.7; 95% confidence interval [CI], 1.94-30.20), hip osteonecrosis (OR, 4.0; 95% CI, 1.02-15.63), chronic pain (OR, 10.4; 95% CI, 1.51-71.24), and hemoglobin (OR, 0.74; 95% CI, 0.57-0.96). Despite adjusting for height, nearly 20% of this pediatric SCD cohort still had very low BMD. As the SCCRIP cohort matures, we plan to prospectively evaluate the longitudinal relationship between Ht-aBMD z scores and markers of SCD severity and morbidity.

Sickle Cell Clinical Research and Intervention Program (SCCRIP): A lifespan cohort study for sickle cell disease progression from the pediatric stage into adulthood.

BACKGROUND: Previous natural history studies have advanced the understanding of sickle cell disease (SCD), but generally have not included sufficient lifespan data or investigation of the role of genetics in clinical outcomes, and have often occurred before the widespread use of disease-modifying therapies, such as hydroxyurea and chronic erythrocyte transfusions. To further advance knowledge of SCD, St. Jude Children's Research Hospital established the Sickle Cell Clinical Research and Intervention Program (SCCRIP), to conduct research in a clinically evaluated cohort of individuals with SCD across their lifetime. PROCEDURES: Initiated in 2014, the SCCRIP study prospectively recruits patients diagnosed with SCD and includes retrospective and longitudinal collection of clinical, neurocognitive, geospatial, psychosocial, and health outcomes data. Biological samples are banked for future genomics and proteomics studies. The organizational structure of SCCRIP is based upon organ/system-specific working groups and is opened to the research community for partnerships. RESULTS: As of August 2017, 1,044 (92.3% of eligible) patients with SCD have enrolled in the study (860 children and 184 adults), with 11,915 person-years of observation. Population demographics included mean age at last visit of 11.3 years (range 0.7-30.1), 49.8% females, 57.7% treated with hydroxyurea, 8.5% treated with monthly transfusions, and 62.9% hemoglobin (Hb) SS or HbSB0 -thalassemia, 25.7% HbSC, 8.4% HbsB+ -Thalassemia, 1.7% HbS/HPFH, and 1.2% other. CONCLUSIONS: The SCCRIP cohort will provide a rich resource for the conduct of high impact multidisciplinary research in SCD.

Fertility as a priority among at-risk adolescent males newly diagnosed with cancer and their parents.

PURPOSE: Infertility is a frequent consequence of cancer therapy and is often associated with psychological distress. Although adult survivors prioritize fertility and parenthood, this issue remains unexplored among adolescent males. This study examined future fertility as a priority (relative to other life goals) at time of diagnosis for at-risk adolescents and their parents. METHODS: Newly diagnosed adolescent males (n = 96; age = 13.0-21.9 years) at increased risk for infertility secondary to cancer treatment prioritized eight life goals: to have school/work success, children, friends, wealth, health, a nice home, faith, and a romantic relationship. Patients' parents (fathers, n = 30; mothers, n = 61) rank-ordered the same priorities for their children. RESULTS: "Having children" was ranked as a "top 3" life goal among 43.8 % of adolescents, 36.7 % of fathers, and 21.3 % of mothers. Fertility ranked third among adolescents, fourth among fathers, and fifth among mothers. Future health was ranked the top priority across groups, distinct from all other goals (ps < 0.001), and fertility ranked higher than home ownership and wealth for all groups (ps < 0.001). For adolescents, low/moderate fertility risk perception was associated with higher fertility rankings than no/high risk perceptions (p = 0.01). CONCLUSIONS: Good health is the most important life goal among adolescents newly diagnosed with cancer and their parents. In this relatively small sample, adolescents prioritized fertility as a top goal, parents also rated fertility as being more important than home ownership and financial wealth. Health care providers should communicate fertility risk and preservation options at diagnosis and facilitate timely discussion among families, who may differ in prioritization of future fertility.

Risk factors for non-initiation of the human papillomavirus vaccine among adolescent survivors of childhood cancer.

Effective vaccination is now available to prevent human papillomavirus (HPV), the most common sexually transmitted infection and cause of cervical cancer. This study aimed to estimate the prevalence of HPV vaccination among childhood cancer survivors and identify factors associated with HPV vaccine initiation and completion. Mothers of daughters of ages 9 to 17 years with/without a history of childhood cancer (n = 235, Mage = 13.2 years, SD = 2.69; n = 70, Mage = 13.3 years, SD = 2.47, respectively) completed surveys querying HPV vaccination initiation and completion along with sociodemographic, medical, HPV knowledge and communication, and health belief factors, which may relate to vaccination outcomes. Multivariate logistic regression was used to identify factors that associate with HPV vaccination initiation and completion. Among cancer survivors, 32.6% initiated and 17.9% completed the three-dose vaccine series, whereas 34.3% and 20.0% of controls initiated and completed, respectively. Univariate analyses indicated no differences between cancer/no cancer groups on considered risk factors. Among all participants, multivariate logistic regression analyses found vaccine initiation associated with older age of daughter and physician recommendation, whereas increased perceived barriers associated with a decreased likelihood of initiation (all P < 0.05). Among those having initiated, risk factors for noncompletion included being non-White, increased perceived severity of HPV, and increased perceived barriers to vaccination (all P < 0.05). A minority of adolescents surviving childhood cancer has completed vaccination despite their increased risk for HPV-related complication. These results inform the prioritization of strategies to be included in vaccine promotion efforts.