A Comparative Study of B Cell Blast Isolation Methods from Bone Marrow Aspirates of Pediatric Leukemia Patients.

Density gradient centrifugation is a conventional technique widely utilized to isolate bone marrow mononuclear cells (BM-MNC) from bone marrow (BM) aspirates obtained from pediatric B-cell acute lymphoblastic leukemia (B-ALL) patients. Nevertheless, this technique achieves incomplete recovery of mononuclear cells and is relatively time-consuming and expensive. Given that B-ALL is the most common childhood malignancy, alternative methods for processing B-ALL samples may be more cost-effective. In this pilot study, we use several readouts, including immune phenotype, cell viability, and leukemia-initiating capacity in immune-deficient mice, to directly compare the density gradient centrifugation and buffy coat processing methods. Our findings indicate that buffy coat isolation yields comparable BM-MNC product in terms of both immune and leukemia cell content and could provide a viable, lower cost alternative for biobanks processing pediatric leukemia samples.

Ethical Challenges for Pediatric Biobanks.

Biobank participation of children is an ethically complicated process as the vulnerability of this population is a concern throughout the entire process of biobanking. Some ethical issues are more prominent in pediatric biobanking and may not need to be considered in biobanking of adult specimens and data. These include assent, reconsent at the age of majority, capacity to consent, and consequences of genetic results on the child and family members. This article describes current processes and best practices described in the literature as well as our experience at the BC Children's Hospital BioBank, a pediatric institutional biobank in Vancouver, Canada. The focus is on processes more specific to pediatric biobanking, such as assent, as well as topics that affect the pediatric population differently compared to adult biobanking.

Antidepressant use and depressive symptomatology among older people from the Australian Longitudinal Study of Ageing.

BACKGROUND: Depression is one of the leading contributors to the burden of non-fatal diseases in Australia. Although there is an overall increasing trend in antidepressant use, the relationship between use of antidepressants and depressive symptomatology is not clear, particularly in the older population. METHODS: Data for this study were obtained from the Australian Longitudinal Study of Ageing (ALSA), a cohort of 2087 people aged over 65 years at baseline. Four waves of home interviews were conducted between 1992 and 2004 to collect information on sociodemographic and health status. Depressive symptoms were measured by the Center for Epidemiologic Studies - Depression Scale. Use of antidepressants was based on self-report, with the interviewer able to check packaging details if available. Longitudinal analysis was performed using logistic generalized estimating equations to detect if there was any trend in the use of antidepressants, adjusting for potential confounding factors. RESULTS: The prevalence of depressive symptoms was 15.2% in 1992 and 15.8% in 2004 (p > 0.05). The prevalence of antidepressant users increased from 6.5% to 10.9% (p < 0.01) over this period. Among people with depressive symptoms, less than 20% were taking antidepressants at any wave. Among people without depressive symptoms, the prevalence of antidepressant use was 5.2% in 1992 and 12.0% in 2004 (p < 0.01). Being female (OR = 1.67, 95%CI: 1.25-2.24), having poor self-perceived health status (OR = 1.17, 95%CI: 1.04-1.32), having physical impairment (OR = 1.48, 95%CI: 1.14-1.91) and having depressive symptoms (OR = 1.62, 95%CI: 1.24-2.13) significantly increased the use of antidepressants, while living in community (OR = 0.51, 95%CI: 0.37-0.71) reduced the risk of antidepressant use. CONCLUSIONS: Use of antidepressants increased, while depressive symptoms remained stable, in the ALSA over a 12-year period. Use of antidepressants was low for people with depressive symptoms.

Development and Validation of the Gene Expression Predictor of High-grade Serous Ovarian Carcinoma Molecular SubTYPE (PrOTYPE).

PURPOSE: Gene expression-based molecular subtypes of high-grade serous tubo-ovarian cancer (HGSOC), demonstrated across multiple studies, may provide improved stratification for molecularly targeted trials. However, evaluation of clinical utility has been hindered by nonstandardized methods, which are not applicable in a clinical setting. We sought to generate a clinical grade minimal gene set assay for classification of individual tumor specimens into HGSOC subtypes and confirm previously reported subtype-associated features. EXPERIMENTAL DESIGN: Adopting two independent approaches, we derived and internally validated algorithms for subtype prediction using published gene expression data from 1,650 tumors. We applied resulting models to NanoString data on 3,829 HGSOCs from the Ovarian Tumor Tissue Analysis consortium. We further developed, confirmed, and validated a reduced, minimal gene set predictor, with methods suitable for a single-patient setting. RESULTS: Gene expression data were used to derive the predictor of high-grade serous ovarian carcinoma molecular subtype (PrOTYPE) assay. We established a de facto standard as a consensus of two parallel approaches. PrOTYPE subtypes are significantly associated with age, stage, residual disease, tumor-infiltrating lymphocytes, and outcome. The locked-down clinical grade PrOTYPE test includes a model with 55 genes that predicted gene expression subtype with >95% accuracy that was maintained in all analytic and biological validations. CONCLUSIONS: We validated the PrOTYPE assay following the Institute of Medicine guidelines for the development of omics-based tests. This fully defined and locked-down clinical grade assay will enable trial design with molecular subtype stratification and allow for objective assessment of the predictive value of HGSOC molecular subtypes in precision medicine applications.See related commentary by McMullen et al., p. 5271.