A Multichannel Portable Platform With Embedded Thermal Management for Miniaturized Dielectric Blood Coagulometry.

This article presents a standalone, multichannel, miniaturized impedance analyzer (MIA) system for dielectric blood coagulometry measurements with a microfluidic sensor termed ClotChip. The system incorporates a front-end interface board for 4-channel impedance measurements at an excitation frequency of 1 MHz, an integrated resistive heater formed by a pair of printed-circuit board (PCB) traces to keep the blood sample near a physiologic temperature of 37 °C, a software-defined instrument module for signal generation and data acquisition, and a Raspberry Pi-based embedded computer with 7-inch touchscreen display for signal processing and user interface. When measuring fixed test impedances across all four channels, the MIA system exhibits an excellent agreement with a benchtop impedance analyzer, with rms errors of ≤0.30% over a capacitance range of 47-330 pF and ≤0.35% over a conductance range of 2.13-10 mS. Using in vitro-modified human whole blood samples, the two ClotChip output parameters, namely, the time to reach a permittivity peak (Tpeak) and maximum change in permittivity after the peak (Δϵr,max) are assessed by the MIA system and benchmarked against the corresponding parameters of a rotational thromboelastometry (ROTEM) assay. Tpeak exhibits a very strong positive correlation (r = 0.98, p < 10-6, n = 20) with the ROTEM clotting time (CT) parameter, while Δϵr,max exhibits a very strong positive correlation (r = 0.92, p < 10-6, n = 20) with the ROTEM maximum clot firmness (MCF) parameter. This work shows the potential of the MIA system as a standalone, multichannel, portable platform for comprehensive assessment of hemostasis at the point-of-care/point-of-injury (POC/POI).

Switching from Sucrose-Formulated rFVIII to Octocog Alfa (BAY 81-8973) Prophylaxis Improves Bleed Outcomes in the LEOPOLD Clinical Trials.

Introduction: Previous clinical trials established the efficacy and safety of sucrose-formulated recombinant factor (F) VIII (rFVIII-FS/Kogenate FS®/Helixate FS®) and octocog alfa (BAY 81-8973/Kovaltry®; LEOPOLD trials). Aim: To report the results of a post hoc subgroup analysis assessing efficacy and safety outcomes in patients with hemophilia A who were receiving rFVIII-FS prior to enrolling into the LEOPOLD I Part B and LEOPOLD Kids Part A clinical trials and switching to octocog alfa. Methods: LEOPOLD I Part B (NCT01029340) and LEOPOLD Kids Part A (NCT01311648) were octocog alfa Phase 3, multinational, open-label studies in patients with severe hemophilia A aged 12-65 years and ≤12 years, respectively. Annualized bleeding rate (ABR) was the efficacy endpoint for both studies. Safety endpoints included adverse events (AEs) and development of FVIII inhibitors. Results: Of the 113 patients in both LEOPOLD trials, 40 (35.4%) patients received rFVIII-FS prophylaxis pre-study and had data available for pre-study total ABR. In LEOPOLD I Part B (n = 22, 35.5%), median (Q1; Q3) total ABR decreased from 2.5 (0.0; 9.0) pre-study to 1.0 (0.0; 6.8), and from 1.0 (0.0; 6.0) pre-study to 0.0 (0.0; 6.02) in LEOPOLD Kids Part A (n = 18, 35.3%). Octocog alfa was well tolerated, and no patients had drug-related serious AEs or inhibitors. Conclusion: Treatment with octocog alfa prophylaxis appeared to have a favorable risk-benefit profile compared with rFVIII-FS and thus could be an effective and improved alternative strategy for individualized treatment for children, adolescent and adult patients with severe hemophilia A currently on rFVIII-FS treatment.

Massage therapy for children, adolescents, and young adults: Clinical delivery and effectiveness in hematology and oncology.

BACKGROUND: Children, adolescents, and young adults with hematologic and/or oncologic conditions experience multiple, significant symptoms (e.g., pain, stress, and anxiety), which may be addressed by nonpharmacologic approaches such as massage therapy (MT). The purpose of this study was to describe the clinical delivery of MT provided by a certified pediatric massage therapist and assess effectiveness in two patient groups: those with sickle cell disease (SCD) or hematologic and/or oncologic conditions excluding SCD (HemOnc). METHODS: Investigators conducted a retrospective review of MT sessions provided to patients 0-39 years with hematologic and/or oncologic conditions at a large pediatric academic medical center. RESULTS: Between October 2019 and December 2021, 3015 MT sessions were provided to 243 patients (171 HemOnc; 72 SCD) and documented in the electronic health record. Patients (mean age: 12.21 ± 7.19 years) were generally White (49.4%) or Black/African American (43.2%), non-Hispanic (94.2%), and 52.3% female. Patients in the SCD group (vs. patients in the HemOnc group) reported significantly higher (p < .05) pretreatment pain (6.95 vs. 4.46), stress (6.47 vs. 4.58), and anxiety (6.67 vs. 4.59). All patients reported clinically and statistically significant (p < .001) mean reductions in pain (-2.25 ± 1.87), stress (-2.50 ± 1.73), and anxiety (-2.52 ± 1.69), with patients in the HemOnc group reporting greater mean pain change (-2.54 vs. -1.87) than patients in the SCD group. CONCLUSIONS: This study supports the clinical effectiveness of MT for addressing acute pain, stress, and anxiety among youth with hematologic and/or oncologic conditions. Future research is needed to identify optimal MT utilization.

Assessment of fibrinolytic status in whole blood using a dielectric coagulometry microsensor.

Rapid assessment of the fibrinolytic status in whole blood at the point-of-care/point-of-injury (POC/POI) is clinically important to guide timely management of uncontrolled bleeding in patients suffering from hyperfibrinolysis after a traumatic injury. In this work, we present a three-dimensional, parallel-plate, capacitive sensor - termed ClotChip - that measures the temporal variation in the real part of blood dielectric permittivity at 1 MHz as the sample undergoes coagulation within a microfluidic channel with <10 µL of total volume. The ClotChip sensor features two distinct readout parameters, namely, lysis time (LT) and maximum lysis rate (MLR) that are shown to be sensitive to the fibrinolytic status in whole blood. Specifically, LT identifies the time that it takes from the onset of coagulation for the fibrin clot to mostly dissolve in the blood sample during fibrinolysis, whereas MLR captures the rate of fibrin clot lysis. Our findings are validated through correlative measurements with a rotational thromboelastometry (ROTEM) assay of clot viscoelasticity, qualitative/quantitative assessments of clot stability, and scanning electron microscope imaging of clot ultrastructural changes, all in a tissue plasminogen activator (tPA)-induced fibrinolytic environment. Moreover, we demonstrate the ClotChip sensor ability to detect the hemostatic rescue that occurs when the tPA-induced upregulated fibrinolysis is inhibited by addition of tranexamic acid (TXA) - a potent antifibrinolytic drug. This work demonstrates the potential of ClotChip as a diagnostic platform for rapid POC/POI assessment of fibrinolysis-related hemostatic abnormalities in whole blood to guide therapy.

Bone health in haemophilia carriers and persons with von Willebrand disease: A large database analysis.

INTRODUCTION: Persons with haemophilia(PWH) have been shown to have low bone mineral density likely the result of prolonged immobility, recurrent hemarthrosis, decreased weight bearing, lower physical activity level and obesity. Bone health has been poorly characterized in haemophilia carriers (HC) and persons with von Willebrand disease (PWvWD). AIM: To estimate the prevalence of osteoporosis, osteoarthritis and bone fractures in HC and PWvWD and identify risk factors for poor bone health. METHODS: This is a retrospective study using a population level, commercial database - Explorys (IBM Watson Health, Cleveland, USA). We compared prevalence rates of osteoporosis, osteoarthritis and fractures among cases (HC or PWvWD) and controls (general population without an underlying bleeding disorder) from 1999 to 2020. Prevalence of common risk factors for poor bone health were compared among cases and controls. RESULTS: Among 72,917,850 active persons in the database, we identified 940 women with the diagnosis of HC and 19,580 PWvWD. Among HC and PWvWD, prevalence of osteoporosis, osteoarthritis and fractures were significantly higher in cases, when compared to controls. In HC, the prevalence of vitamin D deficiency, obesity, hypothyroidism, smoking, diabetes mellitus, hypocalcaemia, corticosteroid use, malignancy, renal failure and Nonsteroidal anti-inflammatory drugs (NSAID) use were significantly higher among the cases. In PWvWD, the prevalence of risk factors was significantly higher in cases when compared to controls. CONCLUSION: The prevalence of osteoporosis, osteoarthritis and fractures is significantly higher among HC and PWvWD. This data highlights the importance of screening patients for risk factors for poor bone health and provide education to prevent these complications.

Point-of-care microchip electrophoresis for integrated anemia and hemoglobin variant testing.

Anemia affects over 25% of the world's population with the heaviest burden borne by women and children. Genetic hemoglobin (Hb) variants, such as sickle cell disease, are among the major causes of anemia. Anemia and Hb variant are pathologically interrelated and have an overlapping geographical distribution. We present the first point-of-care (POC) platform to perform both anemia detection and Hb variant identification, using a single paper-based electrophoresis test. Feasibility of this new integrated diagnostic approach is demonstrated via testing individuals with anemia and/or sickle cell disease. Hemoglobin level determination is performed by an artificial neural network (ANN) based machine learning algorithm, which achieves a mean absolute error of 0.55 g dL-1 and a bias of -0.10 g dL-1 against the gold standard (95% limits of agreement: 1.5 g dL-1) from Bland-Altman analysis on the test set. Resultant anemia detection is achieved with 100% sensitivity and 92.3% specificity. With the same tests, subjects with sickle cell disease were identified with 100% sensitivity and specificity. Overall, the presented platform enabled, for the first time, integrated anemia detection and hemoglobin variant identification using a single point-of-care test.

Microfluidic electrical impedance assessment of red blood cell-mediated microvascular occlusion.

Alterations in the deformability of red blood cells (RBCs), occurring in hemolytic blood disorders such as sickle cell disease (SCD), contribute to vaso-occlusion and disease pathophysiology. There are few functional in vitro assays for standardized assessment of RBC-mediated microvascular occlusion. Here, we present the design, fabrication, and clinical testing of the Microfluidic Impedance Red Cell Assay (MIRCA) with embedded capillary network-based micropillar arrays and integrated electrical impedance measurement electrodes to address this need. The micropillar arrays consist of microcapillaries ranging from 12 µm to 3 µm, with each array paired with two sputtered gold electrodes to measure the impedance change of the array before and after sample perfusion through the microfluidic device. We define RBC occlusion index (ROI) and RBC electrical impedance index (REI), which represent the cumulative percentage occlusion and cumulative percentage impedance change, respectively. We demonstrate the promise of MIRCA in two common red cell disorders, SCD and hereditary spherocytosis. We show that the electrical impedance measurement reflects the microvascular occlusion, where REI significantly correlates with ROI that is obtained via high-resolution microscopy imaging of the microcapillary arrays. Further, we show that RBC-mediated microvascular occlusion, represented by ROI and REI, associates with clinical treatment outcomes and correlates with in vivo hemolytic biomarkers, lactate dehydrogenase (LDH) level and absolute reticulocyte count (ARC) in SCD. Impedance measurement obviates the need for high-resolution imaging, enabling future translation of this technology for widespread access, portable and point-of-care use. Our findings suggest that the presented microfluidic design and the integrated electrical impedance measurement provide a reproducible functional test for standardized assessment of RBC-mediated microvascular occlusion. MIRCA and the newly defined REI may serve as an in vitro therapeutic efficacy benchmark for assessing the clinical outcome of emerging RBC-modifying targeted and curative therapies.

Increased Toxicity Among Adolescents and Young Adults Compared with Children Hospitalized with Acute Lymphoblastic Leukemia at Children's Hospitals in the United States.

Purpose: Adolescent and young adult (AYA) patients (15-39 years old) with acute lymphoblastic leukemia (ALL) have less favorable outcomes and higher treatment-related mortality as compared with older children with ALL. Minimal data exist regarding how well AYA patients tolerate the intensity of chemotherapy at doses and regimens designed for children, and the toxicities suffered by this population at children's hospitals have not been thoroughly characterized. Methods: Pediatric Health Information Systems database was queried to analyze health care outcomes in pediatric (ages 10-14) and AYA patients (ages 15-39) with ALL hospitalized between January 1999 and December 2014. We extracted relevant ICD-9 data for each patient related to grades 3 or 4 toxicities as outlined by the NCI. Results: A total of 5345 hospital admissions met inclusion criteria, representing 4046 unique patients. Of these admissions, 2195 (41.1%) were in the AYA age group, and the remainder were in the 10-14-year-old group. AYA patients had a significantly higher incidence of intensive care unit stay but no difference in median hospital stay nor mortality. AYA patients had increased toxicities in almost every organ system as compared with older children. Conclusions: In this large multicenter US database study, we found an overall increased number of toxicities among AYA patients with ALL in children's hospitals. Compared with children between the ages of 10 and 15, AYA patients developed disproportionately higher toxicities from drugs commonly used in pediatric protocols for ALL. Prospective studies are needed to assess whether dose modifications for certain chemotherapeutics may improve the toxicity profile and health care burden of AYA patients with ALL treated in children's hospitals.

Central venous catheter-related thrombosis in children and adults.

Central venous catheters (CVC) have revolutionized the care of patients requiring long-term venous access. With increasing use of CVCs, the incidence of catheter-related thrombosis (CRT) has been on the rise. CRT constitutes 10% of all deep venous thromboses (DVT) in adults and 50-80% of all DVTs among children. The incidence of CRT varies significantly based on patient characteristics, catheter-related factors and the steps involved in the process of catheter insertion. Multiple risk factors have been associated with a higher risk of CRT, including older age, hospitalization, CVC insertion in the subclavian vein, left-sided CVC insertion, longer duration of catheter, catheter-to-vein ratio > 0.45, and type of CVC. A majority of patients with CRT are asymptomatic. Duplex ultrasound is the initial diagnostic modality of choice, though other modalities like CT angiography and MRV may be necessary for certain CRT locations. Current guidelines recommend maintaining a catheter unless nonfunctional or unneeded, in addition to systemic anticoagulation. Data guiding anticoagulant management specific to upper extremity VTE is lacking, and practice is mostly extrapolated from data on lower extremities. Further studies are required to establish evidence-based guidelines in the management of adults and children with CRT, and in particular the role of direct oral anticoagulants. In this review, we describe the knowledge gaps that exist in multiple aspects of CRT and the need for large collaborative studies to improve the care of patients with CRT.

A novel, point-of-care, whole-blood assay utilizing dielectric spectroscopy is sensitive to coagulation factor replacement therapy in haemophilia A patients.

BACKGROUND: Reliable monitoring of coagulation factor replacement therapy in patients with severe haemophilia, especially those with inhibitors, is an unmet clinical need. While useful, global assays, eg thromboelastography (TEG), rotational thromboelastometry (ROTEM) and thrombin generation assay (TGA), are cumbersome to use and not widely available. OBJECTIVE: To assess the utility of a novel, point-of-care, dielectric microsensor - ClotChip - to monitor coagulation factor replacement therapy in patients with haemophilia A, with and without inhibitors. METHODS: The ClotChip Tpeak parameter was assessed using whole-blood samples from children with severe haemophilia A, with (n = 6) and without (n = 12) inhibitors, collected pre- and postcoagulation factor replacement therapy. ROTEM, TGA and chromogenic FVIII assays were also performed. Healthy children (n = 50) served as controls. RESULTS: ClotChip Tpeak values exhibited a significant decrease for samples collected postcoagulation factor replacement therapy as compared to baseline (pretherapy) samples in patients with and without inhibitors. A difference in Tpeak values was also noted at baseline among severe haemophilia A patients with inhibitors as compared to those without inhibitors. ClotChip Tpeak parameter exhibited a very strong correlation with clotting time (CT) of ROTEM, endogenous thrombin potential (ETP) and peak thrombin of TGA, and FVIII clotting activity. CONCLUSIONS: ClotChip is sensitive to coagulation factor replacement therapy in patients with severe haemophilia A, with and without inhibitors. ClotChip Tpeak values correlate very well with ROTEM, TGA and FVIII assays, opening up possibilities for its use in personalized coagulation factor replacement therapy in haemophilia.

Utility of a screening tool for haemostatic defects in a multicentre cohort of adolescents with heavy menstrual bleeding.

INTRODUCTION: Heavy menstrual bleeding (HMB) may be expected for many adolescents after menarche. Accurate assessment of HMB, a key component in the diagnosis of a haemostatic defect (HD), is a well-recognized challenge. AIM: Our objective was to determine the diagnostic accuracy of an HMB-specific screening tool for HDs in adolescents with HMB, presenting to a secondary care setting. METHODS: Adolescents with HMB were evaluated for a HD at 4 US centres. A screening tool, the Philipp Tool, developed and validated in adult women with HMB, was administered. We modified the tool by assigning a score based on the number of affirmative responses. Sensitivity, specificity and likelihood ratios (LRs) of a positive tool, modified tool, with a pictorial blood assessment chart (PBAC) score >185, and with serum ferritin ≤20 ng/mL were calculated for HDs. RESULTS: Among 248 adolescents with HMB, 29% were diagnosed with HDs. Sensitivity, specificity and LR of a positive screening tool for HDs were 95% (range 88-99), 14% (9-21) and 1.1 (1-1.2), respectively. A score of ≥2, addition of a PBAC score >185 and ferritin ≤20 ng/mL changed the sensitivity, specificity and LR of the tool to 72% (61-81), 94% (83-99), 76% (65-85); 60% (53-68), 24% (16-34) and 39% (31-47) and 1.8 (1.4-2.2), 1.2 (1.1-1.4) and 1.2 (1-1.4), respectively. CONCLUSION: Although sensitive, the discriminative ability of the tool to identify adolescents with HDs from those without, who presented with HMB, was low. Further research is needed to optimize or develop an adolescent-specific HMB tool for secondary care settings.

BAY 81-8973, a full-length recombinant factor VIII for the treatment of hemophilia A: product review.

BAY 81-8973 (Kovaltry®) is an unmodified, full-length recombinant factor VIII (rFVIII) approved for the prevention and treatment of bleeding episodes in patients with hemophilia A. The amino acid sequence for BAY 81-8973 is identical to that of sucrose-formulated rFVIII (rFVIII-FS; Kogenate® FS/KOGENATE®, Bayer), but the two products differ in their manufacturing approaches. The manufacture of BAY 81-8973 includes several modifications and enhancements, such as the introduction of the gene for human heat shock protein 70, a molecular chaperone protein that facilitates folding of proteins; no addition of human- or animal-derived proteins in the cell culture, purification process, or final formulation; and use of a 20-nm filter to remove any potential aggregates and pathogens. BAY 81-8973 was extensively studied in the LEOPOLD clinical development program, which enrolled participants of all age groups (children, adolescents, and adults) with severe hemophilia A. The pharmacokinetic profile of BAY 81-8973 was shown to be noninferior to, and for some variables more favorable than, rFVIII-FS and another commercial full-length rFVIII product. BAY 81-8973 was shown to be efficacious when used for prophylaxis, on-demand treatment, and perioperative hemostasis. The efficacious prophylaxis dose of BAY 81-8973 was approximately 20-40 IU/kg given two or three times per week, which achieved low annualized bleeding rates. Either the one-stage or the chromogenic assay provides accurate measurements for postinfusion monitoring of BAY 81-8973 levels, with no product-specific calibration standard needed. The incidence of treatment-related adverse events was ⩽7% across all LEOPOLD studies, and no previously treated patient developed anti-BAY 81-8973 inhibitors in the completed primary studies.

Identification of a "VTE-rich" population in pediatrics - Critically ill children with central venous catheters.

BACKGROUND: The incidence of venous thromboembolism (VTE) is rising among inpatients in US hospitals, especially among kids with central venous catheters (CVCs) in the pediatric intensive care unit (PICU). OBJECTIVES: To identify a sub-group of "VTE-rich" population among PICU children, and to assess the effect of VTE on morbidity and mortality. METHODS: Data was extracted from a multicenter Virtual PICU Database, or VPS, for children with a CVC and presence of a VTE. The primary outcome variable was all cause mortality and secondary outcome measure was prolonged mechanical ventilation. Primary diagnoses and Pediatric risk of mortality 2 (PIM 2) score were also recorded. RESULTS: The database identified 158,299 PICU patients who had a CVC. A total of 1602 patients had VTE (103 per 10,000 PICU patients). Multivariate analysis showed increased risk of VTE in patients who were <1year old (OR 1.48; 1.30-1.68), mechanically ventilated (OR 2.48; 2.07-2.98), had either a diagnostic (OR 2.32; 1.94-2.78) or therapeutic cardiac catheterization (OR 2.06; 1.66-2.55), PICC (OR 3.91; 3.50-4.37), and percutaneous CVC (OR 3.99; 3.48-4.61). Primary diagnoses associated with VTE were endocrinologic, immunologic, and gastrointestinal disorders. PICU patients with CVC and VTE had increased odds of mortality (OR 1.71; 1.47-2.00) after adjusting for factors associated with mortality, and fewer Ventilator Free Days (VFD) than patients without VTE. CONCLUSIONS: Critically ill children with CVC have a significant risk of developing VTE. Identification of the above "VTE-rich" population may aid in design of clinical trials aimed at prevention of VTE among hospitalized PICU children.

L-asparaginase in the treatment of patients with acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is a hematologic malignancy that predominantly occurs in children between 2 and 10 years of age. L-asparaginase is an integral component of treatment for patients with ALL and since its introduction into pediatric treatment protocols in the 1960s, survival rates in children have progressively risen to nearly 90%. Outcomes for adolescent and young adult (AYA) patients, aged 15-39 years and diagnosed with ALL, have historically been less favorable. However, recent reports suggest substantially increased survival in AYA patients treated on pediatric-inspired protocols that include a greater cumulative dose of asparaginase. All  currently available asparaginases share the same mechanism of action - the deamination and depletion of serum asparagine levels - yet each displays a markedly different pharmacokinetic profile. Pegylated asparaginase derived from the bacterium Escherichia coli is used as first-line therapy; however, up to 30% of patients develop a treatment-limiting hypersensitivity reaction. Patients who experience a hypersensitivity reaction to an E. coli-derived asparaginase can continue treatment with Erwinia chrysanthemi asparaginase. Erwinia asparaginase is immunologically distinct from E. coli-derived asparaginases and exhibits no cross-reactivity. Studies have shown that with adequate dosing, therapeutic levels of Erwinia asparaginase activity can be achieved, and patients switched to Erwinia asparaginase due to hypersensitivity can obtain outcomes similar to patients who do not experience a hypersensitivity reaction. Therapeutic drug monitoring may be required to ensure that therapeutic levels of asparaginase activity are maintained.

Overview of bleeding disorders in adolescent females with menorrhagia.

Women bleed with menses, during childbirth, and after childbirth. Women are more likely to manifest a bleeding disorder as they have more opportunities to experience bleeding challenges in their lifetime. Bleeding disorders such as hemophilia and von Willebrand disease affect 2.5-3 million American women. The most common inherited bleeding disorder in the population is von Willebrand disease with an estimated prevalence of 1-2%. von Willebrand factor (vWF) is required to adhere platelets to exposed subendothelium and protects factor VIII from proteolysis in the circulation. The prevalence of vWF rises in studies involving women with menorrhagia, with estimates ranging as high as 10-20% in white women, and 1-2% among African American women. Other bleeding disorders seen in adolescents with menorrhagia are disorders of inherited platelet dysfunction, clotting factor deficiencies, thrombocytopenia, and disorders of the fibrinolytic pathway. Not only are women more likely to present early in their life with a bleeding disorder, they are also more likely to have other gynecologic manifestations as a result of these disorders. This article presents an overview of the problem and touches upon the different management strategies available.

A pilot study of heel ultrasound to screen for low bone mass in children with leukemia.

The optimal method to assess pediatric bone mass remains controversial. Dual x-ray absorptiometry (DXA) is commonly used but quantitative ultrasound is less expensive, free of ionizing radiation, and predicts fractures as well as DXA does, in adults. Broadband ultrasound attenuation (BUA) was determined using a portable calcaneal ultrasonometer and, compared with DXA derived areal bone mineral density (BMD) values in 42 young patients (ages 4.5 to 20.3 y) with leukemia. Reduced BMD was defined as a DXA z score of <-1. Mean z scores for lumbar spine BMD were significantly lower than zero (-0.77+/-1.23 SD, P=0.0004). Mean z scores for whole body BMD were also significantly lower than different from 0 (-0.34+/-1.04 SD, P=0.05). Calcaneal BUA was highly correlated with DXA measurement of lumbar, whole body, and femoral neck BMD. BUA was significantly associated with the probability of having a reduced lumbar BMD z score (P=0.03) and having a reduced whole body z score of (P=0.03). Area under the receiver operator characteristic curves for model including BUA predicting reduced bone density by DXA were 0.77 and 0.86 for lumbar and whole body z score cutoffs, respectively. Our data suggest that calcaneal BUA may serve as a reliable screening tool to detect reduced bone mass in pediatric patients with leukemia.