A cross-standardized flow cytometry platform to assess phenotypic stability in precursor B-cell acute lymphoblastic leukemia (B-ALL) xenografts.

With the continued poor outcome of relapsed acute lymphoblastic leukemia (ALL), new patient-specific approaches for disease progression monitoring and therapeutic intervention are urgently needed. Patient-derived xenografts (PDX) of primary ALL in immune-deficient mice have become a powerful tool for studying leukemia biology and therapy response. In PDX mice, the immunophenotype of the patient's leukemia is commonly believed to be stably propagated. In patients, however, the surface marker expression profile of the leukemic population often displays poorly understood immunophenotypic shifts during chemotherapy and ALL progression. We therefore developed a translational flow cytometry platform to study whether the patient-specific immunophenotype is faithfully recapitulated in PDX mice. To enable valid assessment of immunophenotypic stability and subpopulation complexity of the patient's leukemia after xenotransplantation, we comprehensively immunophenotyped diagnostic B-ALL from children and their matched PDX using identical, clinically standardized flow protocols and instrument settings. This cross-standardized approach ensured longitudinal stability and cross-platform comparability of marker expression intensity at high phenotyping depth. This analysis revealed readily detectable changes to the patient leukemia-associated immunophenotype (LAIP) after xenotransplantation. To further investigate the mechanism underlying these complex immunophenotypic shifts, we applied an integrated analytical approach that combined clinical phenotyping depth and high analytical sensitivity with unbiased high-dimensional algorithm-based analysis. This high-resolution analysis revealed that xenotransplantation achieves patient-specific propagation of phenotypically stable B-ALL subpopulations and that the immunophenotypic shifts observed at the level of bulk leukemia were consistent with changes in underlying subpopulation abundance. By incorporating the immunophenotypic complexity of leukemic populations, this novel cross-standardized analytical platform could greatly expand the utility of PDX for investigating ALL progression biology and assessing therapies directed at eliminating relapse-driving leukemic subpopulations.

Baseline Hemoglobin, Hepcidin, Ferritin, and Total Body Iron Stores are Equally Strong Diagnostic Predictors of a Hemoglobin Response to 12 Weeks of Daily Iron Supplementation in Cambodian Women.

BACKGROUND: The WHO recommends daily iron supplementation for all women in areas where the population-level anemia prevalence is ≥40%, despite the fact that hemoglobin (Hb) concentration is generally considered to be a poor prognostic indicator of iron status. OBJECTIVES: In this secondary analysis, we investigated the predictive power of ten baseline hematological biomarkers towards a 12-week Hb response to iron supplementation. METHODS: Data were obtained from a randomized controlled trial of daily iron supplementation in 407 nonpregnant Cambodian women (18-45 years) who received 60 mg elemental iron as ferrous sulfate for 12 weeks. Ten baseline biomarkers were included: Hb, measured with both a hematology analyzer and a HemoCue; inflammation-adjusted ferritin; soluble transferrin receptor; reticulocyte Hb; hepcidin; mean corpuscular volume; inflammation-adjusted total body iron stores (TBIS); total iron binding capacity; and transferrin saturation. Receiver operating characteristic (ROC) curves from fitted logistic regression models were used to make discrimination comparisons and variable selection methods were used to construct a multibiomarker prognostic model. RESULTS: Only 25% (n = 95/383) of women who completed the trial experienced a 12-week Hb response ≥10 g/L. The strongest univariate predictors of a Hb response were Hb as measured with a hematology analyzer, inflammation-adjusted ferritin, hepcidin, and inflammation-adjusted TBIS (AUCROC = 0.81, 0.83, 0.82, and 0.82, respectively), and the optimal cutoffs to identify women who were likely to experience a Hb response were 117 g/L, 17.3 µg/L, 1.98 nmol/L, and 1.95 mg/kg, respectively. Hb as measured with a hematology analyzer, inflammation-adjusted ferritin, and hepcidin had the best combined predictive ability (AUCROC=0.86). Hb measured with the HemoCue had poor discrimination ability (AUCROC = 0.65). CONCLUSIONS: Baseline Hb as measured with a hematology analyzer was as strong a predictor of Hb response to iron supplementation as inflammation-adjusted ferritin, hepcidin, and inflammation-adjusted TBIS. This is positive given that the WHO currently uses the population-level anemia prevalence to guide recommendations for untargeted iron supplementation.

Transfusion-related Epstein-Barr virus (EBV) infection: A multicenter prospective cohort study among pediatric recipients of hematopoietic stem cell transplants (TREASuRE study).

BACKGROUND: Epstein-Barr virus (EBV) is carried in the blood of most adults, and transfusion-related infections have been reported. EBV is particularly deleterious in immunosuppressed transplant patients. The aim was to determine if EBV transmission occurred through leukodepleted blood product transfusion in pediatric recipients of hematopoietic stem cell transplants (HSCT). STUDY DESIGN AND METHODS: This prospective Canadian multi-center cohort study includes 156 allogeneic HSCT pediatric recipients. The association between EBV and transfusion was analyzed using Cox regressions. EBV infection, defined by a PCR+ test in the blood of seronegative recipients of an EBV-negative graft, was monitored in order to correlate the recipient EBV strain with that of the blood donors. EBV genotypes were determined by PCR amplification followed by DNA sequencing at two loci (EBNA3b and LMP1). RESULTS: No statistically significant associations were found between transfusions and EBV. One case of post-transplant EBV infection was identified among the 21 EBV-seronegative recipients receiving an EBV-negative graft. A total of 22 blood donors were retraced to determine whether the recipient's EBV strain matched that of a donor. One donor strain showed 100% sequence homology at the EBNA3b locus, but differed by one or two point mutations and by a 132-bp deletion at the LMP1 locus. The blood donor in question was alone among the 22 donors to show amplifiable virus in plasma. Blood from this donor readily produced an immortalized lymphoblastoid cell line in culture. CONCLUSION: While considered a rare event, EBV transmission through transfusion may occur in the context of severe immunosuppression.

Risk factors for post-transplant Epstein-Barr virus events in pediatric recipients of hematopoietic stem cell transplants.

BACKGROUND: Epstein-Barr virus (EBV) can cause severe disease following hematopoietic stem cell transplant (HSCT), including post-transplant lymphoproliferative disorder (PTLD). The objective was to analyze risk factors associated with post-transplant EBV outcomes among pediatric allogeneic HSCT recipients. METHODS: We used data from 156 pediatric allogeneic HSCT recipients enrolled in the Canadian multicenter TREASuRE study. Cox and Prentice-Williams-Petersen models were used to analyze risk factors for post-transplant EBV events including occurrence and recurrence of EBV DNAemia, increase in EBV viral load (EBV-VL), and preemptive use of rituximab, an effective therapy against PTLD. RESULTS: Females were at higher risk for increasing EBV-VL (adjusted hazard ratio (HR) = 2.83 [95% confidence intervals (CI): 1.33-6.03]) and rituximab use (HR = 3.08 [1.14-8.30]), but had the same EBV DNAemia occurrence (HR = 1.21 [0.74-1.99]) and recurrence risks (HR=1.05 [0.70-1.58]) compared to males. EBV DNAemia was associated with recipient pre-transplant EBV seropositivity (HR = 2.47 [1.17-5.21]) and with graft from an EBV-positive donor (HR = 3.53 [1.95-6.38]). Anti-thymocyte globulin (ATG) was strongly associated with all EBV outcomes, including the use of rituximab (HR = 5.33 [1.47-19.40]). Mycophenolate mofetil (MMF) significantly decreased the risk of all EBV events including the rituximab use (HR = 0.13 [0.03-0.63]). CONCLUSION: This study in pediatric allogeneic HSCT patients reveals a reduced risk of all EBV outcomes with the use of MMF. Risk factors for EBV events such as EBV-VL occurrence and recurrence include EBV positivity in the donor and recipient, and use of ATG, whereas risk factors for the most severe forms of EBV outcome (EBV-VL and the use of rituximab) include female sex and ATG use.

Prolonged granulocyte colony stimulating factor use in glycogen storage disease type 1b associated with acute myeloid leukemia and with shortened telomere length.

Glycogen storage disease (GSD) type 1 is a rare autosomal recessive inherited condition. The 1b subtype comprises the minority of cases, with an estimated prevalence of 1 in 500,000 children. Patients with glycogen storage disease type 1b are often treated with granulocyte colony stimulating factor (G-CSF) for prolonged periods to improve symptoms of inflammatory bowel disease (IBD) and in the face of severe neutropenia to decrease risk of infection. Long-term G-CSF treatment may result in an increased risk of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) possibly due to increased marrow stress resulting in telomere shortening. To our knowledge, there have been two published cases of AML in GSD type 1b patients following long-term G-CSF exposure. Here, we report two further cases of AML/MDS-related changes in patients GSD type 1b treated with G-CSF. One patient developed AML with complex karyotype after 20 years of G-CSF treatment. The second patient was found to have short telomeres after 10 years of G-CSF exposure, but no evidence of acute leukemia at present. The third patient developed AML/MDS after 25 years of G-CSF use, with short telomeres prior to bone marrow transplant. Together these cases suggest that GSD type 1b patients with prolonged G-CSF exposure may be at an increased risk of MDS/AML states associated with G-CSF-induced shortened telomeres. We recommend that any GSD1b patients with prolonged G-CSF should have routine telomere assessments with monitoring for MDS if telomere shortening is observed, and with particular attention warranted if there is unexplained loss of G-CSF responsiveness.

Serum Soluble Transferrin Receptor Concentrations Are Elevated in Congolese Children with Glucose-6-Phosphate Dehydrogenase Variants, but Not Sickle Cell Variants or α-Thalassemia.

Background: Anemia is common in Congolese children, and inherited blood disorders may be a contributing cause. The presence of sickle cell variants, X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency and α-thalassemia, has been previously reported. G6PD A- deficiency is characterized by the co-inheritance of G6PD 376 and 202 variants and is common in sub-Saharan Africa.Objective: We aimed to measure the associations between inherited blood disorders and hemoglobin, ferritin, and soluble transferrin receptor (sTfR) concentrations in Congolese children.Methods: Venous blood was collected from 744 children aged 6-59 mo from 2 provinces. We measured biomarkers of nutritional and inflammation status and malaria. Pyrosequencing was used to detect sickle cell variants. Polymerase chain reaction was used to detect G6PD variants and α-thalassemia deletions.Results: Overall, 11% of children had a sickle cell variant, 19% of boys were G6PD A- hemizygotes, 12% and 10% of girls were G6PD A- hetero- or homozygotes, respectively, and 12% of children had α-thalassemia. Multivariable linear regression models (adjusted for age, province, altitude, malaria, and biomarkers of nutritional and inflammation status) showed that G6PD A- hemizygous boys and G6PD 376 homozygous girls had higher sTfR concentrations [geometric mean ratios (95% CIs): 1.20 (1.03, 1.39) and 1.25 (1.02, 1.53), respectively] than children with no G6PD variants. Hemoglobin and ferritin concentrations were not independently associated with any of the inherited blood disorder genotypes.Conclusions: We found that 2 G6PD variant genotypes were associated with elevated sTfR concentrations, which limits the accuracy of sTfR as a biomarker of iron status in this population.

Comparison of four immunoassays to measure serum ferritin concentrations and iron deficiency prevalence among non-pregnant Cambodian women and Congolese children.

BACKGROUND: Global standardization of ferritin assays is lacking, which could have direct implications on the accurate measurement and comparability of ferritin concentration and iron deficiency (ID) prevalence rates in at-risk populations. METHODS: We measured serum ferritin concentrations using four immunoassays: the s-ELISA and the AxSYM™ analyzer were compared among 420 non-pregnant Cambodian women; the Centaur® XP analyzer, s-ELISA, and AxSYM™ analyzer were compared among a subset of 100 Cambodian women; and the s-ELISA and the Elecsys® 2010 analyzer were compared among 226 Congolese children aged 6-59 months. RESULTS: Median ferritin concentrations (adjusted for inflammation) ranged between 48 and 91 µg/L among Cambodian women and between 54 and 55 µg/L among Congolese children. ID prevalence ranged from 2% to 10% among Cambodian women and 5% to 7% among Congolese children. Bias between methods varied widely (-9 to 45 µg/L) among women, and was 43 µg/L among children. Bias was lower when ferritin values outside of the s-ELISA measurement range (>250 µg/L) were excluded. CONCLUSIONS: The observed differences in ferritin concentrations likely reflect different ferritin isoforms, antibodies, and calibrators used across assays and by different laboratories. However, despite differences in ferritin concentrations, ID prevalence was relatively similar and low across all methods.

Genetic hemoglobin disorders rather than iron deficiency are a major predictor of hemoglobin concentration in women of reproductive age in rural prey Veng, Cambodia.

BACKGROUND: Anemia is common in Cambodian women. Potential causes include micronutrient deficiencies, genetic hemoglobin disorders, inflammation, and disease. OBJECTIVES: We aimed to investigate factors associated with anemia (low hemoglobin concentration) in rural Cambodian women (18-45 y) and to investigate the relations between hemoglobin disorders and other iron biomarkers. METHODS: Blood samples were obtained from 450 women. A complete blood count was conducted, and serum and plasma were analyzed for ferritin, soluble transferrin receptor (sTfR), folate, vitamin B-12, retinol binding protein (RBP), C-reactive protein (CRP), and α1 acid glycoprotein (AGP). Hemoglobin electrophoresis and multiplex polymerase chain reaction were used to determine the prevalence and type of genetic hemoglobin disorders. RESULTS: Overall, 54% of women had a genetic hemoglobin disorder, which included 25 different genotypes (most commonly, hemoglobin E variants and α(3.7)-thalassemia). Of the 420 nonpregnant women, 29.5% had anemia (hemoglobin <120 g/L), 2% had depleted iron stores (ferritin <15 µg/L), 19% had tissue iron deficiency (sTfR >8.3 mg/L), <3% had folate deficiency (<3 µg/L), and 1% had vitamin B-12 deficiency (<150 pmol/L). Prevalences of iron deficiency anemia (IDA) were 14.2% and 1.5% in those with and without hemoglobin disorders, respectively. There was no biochemical evidence of vitamin A deficiency (RBP <0.7 µmol/L). Acute and chronic inflammation were prevalent among 8% (CRP >5 mg/L) and 26% (AGP >1 g/L) of nonpregnant women, respectively. By using an adjusted linear regression model, the strongest predictors of hemoglobin concentration were hemoglobin E homozygous disorder and pregnancy status. Other predictors were 2 other heterozygous traits (hemoglobin E and Constant Spring), parity, RBP, log ferritin, and vitamin B-12. CONCLUSIONS: Multiple biomarkers for anemia and iron deficiency were significantly influenced by the presence of hemoglobin disorders, hence reducing their diagnostic sensitivity. Further investigation of the unexpectedly low prevalence of IDA in Cambodian women is warranted.

The Homozygous Hemoglobin EE Genotype and Chronic Inflammation Are Associated with High Serum Ferritin and Soluble Transferrin Receptor Concentrations among Women in Rural Cambodia.

BACKGROUND: Ferritin and soluble transferrin receptor (sTfR) concentrations are commonly used to assess iron deficiency (ID); however, they are influenced by multiple factors. OBJECTIVES: We assessed associations between numerous variables and both ferritin and sTfR concentrations in Cambodian women and compared ID prevalence through the use of study-generated correction factors (CFs) for ferritin with those from a published meta-analysis. METHODS: Venous blood from 450 women (aged 18-45 y) was assessed for hemoglobin (Hb), ferritin, sTfR, retinol binding protein, folate, vitamin B-12, C-reactive protein, α-1 acid glycoprotein (AGP), and genetic Hb disorders. Linear regression was used to calculate geometric mean ratios (95% CIs) for ferritin and sTfR concentrations. RESULTS: The variant Hb EE genotype was associated with 50% (14%, 96%) and 51% (37%, 66%) higher geometric mean ferritin and sTfR concentrations, respectively, than was the normal Hb AA genotype; a 1-g/L increase in AGP was associated with 99% (50%, 162%) and 48% (33%, 64%) higher concentrations in the same variables, respectively. ID prevalence in nonpregnant women (n = 420) was 2% (n = 9) with the use of ferritin <15 µg/L and 18% (n = 79) with the use of sTfR >8.3 mg/L as criteria. ID prevalence with the use of sTfR was higher in women with the Hb EE genotype (n = 17; 55%) than in those with the Hb AA genotype (n = 20; 10%); and in women with the Hb AA genotype and chronic inflammation (n = 10; 18%) than in that group of women without chronic inflammation (n = 10; 7%) (P < 0.05). No differences in ID prevalence were found with the use of ferritin between women with Hb EE and AA genotypes (P = 1.0) or by chronic inflammation status (P = 0.32). There were no differences in mean ferritin concentrations among all 450 women when study-generated CFs were compared with those from the meta-analysis (P = 0.87). CONCLUSIONS: Compared with sTfR, ferritin concentrations appear to reflect more accurately true ID in rural Cambodian women. The CFs from a published meta-analysis were appropriate for use in this population with a high prevalence of Hb disorders and inflammation.

Elevated levels of iron in groundwater in Prey Veng province in Cambodia: a possible factor contributing to high iron stores in women.

Iron is a natural element found in food, water and soil and is essential for human health. Our aim was to determine the levels of iron and 25 other metals and trace elements in groundwater from 22 households in Prey Veng, Cambodia. Water analyses were conducted using inductively coupled plasma-mass spectrometry and optical emission spectrometry. Compared to the 2011 World Health Organization guidelines for drinking water quality, aluminum, iron and manganese exceeded maximum levels (in 4.5, 72.7 and 40.9% of samples, respectively). Compared to the 2004 Cambodian drinking water quality standards, iron and manganese exceeded maximum levels (in 59.1 and 36.4% of samples, respectively). We found no evidence of arsenic contamination. Guidelines for iron were established primarily for esthetic reasons (e.g. taste), whereas other metals and elements have adverse effects associated with toxicity. Iron in groundwater ranged from 134 to 5,200 µg/L (mean ∼1,422 µg/L). Based on a daily consumption of 3 L groundwater, this equates to ∼0.4-15.6 mg iron (mean ∼4.3 mg/day), which may be contributing to high iron stores and the low prevalence of iron deficiency anemia in Prey Veng women. Elevated levels of manganese in groundwater are a concern and warrant further investigation.

Policy recommendations for addressing privacy challenges associated with cell-based research and interventions.

BACKGROUND: The increased use of human biological material for cell-based research and clinical interventions poses risks to the privacy of patients and donors, including the possibility of re-identification of individuals from anonymized cell lines and associated genetic data. These risks will increase as technologies and databases used for re-identification become affordable and more sophisticated. Policies that require ongoing linkage of cell lines to donors' clinical information for research and regulatory purposes, and existing practices that limit research participants' ability to control what is done with their genetic data, amplify the privacy concerns. DISCUSSION: To date, the privacy issues associated with cell-based research and interventions have not received much attention in the academic and policymaking contexts. This paper, arising out of a multi-disciplinary workshop, aims to rectify this by outlining the issues, proposing novel governance strategies and policy recommendations, and identifying areas where further evidence is required to make sound policy decisions. The authors of this paper take the position that existing rules and norms can be reasonably extended to address privacy risks in this context without compromising emerging developments in the research environment, and that exceptions from such rules should be justified using a case-by-case approach. In developing new policies, the broader framework of regulations governing cell-based research and related areas must be taken into account, as well as the views of impacted groups, including scientists, research participants and the general public. SUMMARY: This paper outlines deliberations at a policy development workshop focusing on privacy challenges associated with cell-based research and interventions. The paper provides an overview of these challenges, followed by a discussion of key themes and recommendations that emerged from discussions at the workshop. The paper concludes that privacy risks associated with cell-based research and interventions should be addressed through evidence-based policy reforms that account for both well-established legal and ethical norms and current knowledge about actual or anticipated harms. The authors also call for research studies that identify and address gaps in understanding of privacy risks.

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.

A longitudinal single-cell atlas of treatment response in pediatric AML.

Pediatric acute myeloid leukemia (pAML) is characterized by heterogeneous cellular composition, driver alterations and prognosis. Characterization of this heterogeneity and how it affects treatment response remains understudied in pediatric patients. We used single-cell RNA sequencing and single-cell ATAC sequencing to profile 28 patients representing different pAML subtypes at diagnosis, remission and relapse. At diagnosis, cellular composition differed between genetic subgroups. Upon relapse, cellular hierarchies transitioned toward a more primitive state regardless of subtype. Primitive cells in the relapsed tumor were distinct compared to cells at diagnosis, with under-representation of myeloid transcriptional programs and over-representation of other lineage programs. In some patients, this was accompanied by the appearance of a B-lymphoid-like hierarchy. Our data thus reveal the emergence of apparent subtype-specific plasticity upon treatment and inform on potentially targetable processes.

Processing and Cryopreservation of Blood, Cancer Tissues, and Cancer Cells for Viable Biobanking.

Biorepositories of fresh frozen and formalin-fixed paraffin-embedded tissues have been foundational to many molecular cancer research studies. Collections of these materials, however, do not enable the establishment of short-term cultures, cell lines, or patient-derived xenograft models for functional studies. Also, intact dissociated cells that are required for some single-cell analyses cannot be obtained from these material types. Adding viable tumor banking to the repertoire of routine cancer biobanking would increase the value of samples collected. This chapter outlines procedures for processing and storing blood and tissue specimens viably in order to expand the future utility of the samples collected. We provide practical tips that can be used by banks and other researchers seeking to incorporate the cryopreservation of viable materials as part of their overall biobanking strategies.

Machine learning optimized multiparameter radar plots for B-cell acute lymphoblastic leukemia minimal residual disease analysis.

BACKGROUND: Flow cytometry is widely used for B-ALL minimal residual disease (MRD) analysis given its speed, availability, and sensitivity; however, distinguishing B-lymphoblasts from regenerative B-cells is not always straightforward. Radar plots, which project multiple markers onto a single plot, have been applied to other MRD analyses. Here we aimed to develop optimized radar plots for B-ALL MRD analysis. METHODS: We compiled Children's Oncology Group (COG) flow data from 20 MRD-positive and 9 MRD-negative B-ALL cases (enriched for hematogones) to create labeled training and test data sets with equal numbers of B-lymphoblasts, hematogones, and mature B-cells. We used an automated approach to create hundreds of radar plots and ranked them based on the ability of support vector machine (SVM) models to separate blasts from normal B-cells in the training data set. Top-performing radar plots were compared with PCA, t-SNE, and UMAP plots, evaluated with the test data set, and integrated into clinical workflows. RESULTS: SVM area under the ROC curve (AUC) for COG tube 1/2 radar plots improved from 0.949/0.921 to 0.989/0.968 after optimization. Performance was superior to PCA plots and comparable to UMAP, but with better generalizability to new data. When integrated into an MRD workflow, optimized radar plots distinguished B-lymphoblasts from other CD19-positive populations. MRD quantified by radar plots and serial gating were strongly correlated. DISCUSSION: Radar plots were successfully optimized to discriminate between diverse B-lymphoblast populations and non-malignant CD19-positive populations in B-ALL MRD analysis. Our novel radar plot optimization strategy could be adapted to other MRD panels and clinical scenarios.

Finding the Value in Biobanks: Enhancing the CTRNet Locator.

Biobanks are a critical piece of Research Infrastructure (RI). However, biobanks need to accept the reality of a life cycle for RIs. Until recently, strategies to sustain biobanks have been commonly focused on ways to maintain current operational models. However, sustaining biobanks as they exist today may be increasingly challenging in the face of the disruption in health and research priorities caused by the COVID-19 pandemic. In this opinion article, we review the current and emerging future drivers of biobank value for their researchers, institutions, and funders, highlighting utilization and impact of research performed using the biobank as key measures of future value. While biobanks can only indirectly influence the specific impact of the research performed, they can transform themselves to more actively redefine utilization to their advantage. Utilization means more than the balance of samples and data in versus out. Utilization means redirecting expertise to best support end users, and importantly, closing the operating gap between biobanks and their end users who seek to find the right biospecimens and data to pursue their research. We discuss the specific role of locators (those created by public investment) in closing this gap and the need for additional tools for researchers, before and subsequent to connecting with locators. For the former, we specifically propose that more support is needed to assist researchers in the decision as to how to best obtain biospecimens and navigate the options as to whether finding existing biospecimens and data held by a biobank is the optimal solution for a given project, or whether the optimal solution is either contracting with a biobank to collect samples or creating a new biobank. We believe this type of biospecimen navigator platform will help to maximize utilization of current biobank resources, and also promote the services and expertise in biobanks to better serve researchers' needs.