Fusion Harboring Mast Cells Can Explain Molecular Positivity in Flow Cytometric MRD Negative Core Binding Factor AML.

Molecular measurable residual disease (MRD) can persist in core binding factor acute myeloid leukemia (AML) in otherwise disease-free patients. Utilizing cell sorting followed by fluorescent in situ hybridization, we show that detection is due to mast cells.

Assessment for 11q and other chromosomal aberrations in large B-cell/high-grade B cell lymphomas of germinal center phenotype lacking BCL2 expression.

The WHO classifications of hematolymphoid malignancies have recognized several distinct entities within the large B cell lymphomas, including the more recently described high-grade B cell lymphoma with 11q aberration (HGBCL-11q). We utilized genomic array to assess for chromosome 11q abnormalities in a broad set of aggressive B cell lymphomas from 27 patients with a focus on younger adults. The findings suggest more frequent alterations of 11q in diffuse large B cell lymphoma (DLBCL)/HGBCL-GC BCL2-, in comparison to cases of Burkitt lymphoma (BL) or DLBCL-GC BCL2+, and confirm a low genomic complexity score of BL. Variability identified in patterns of 11q alterations suggests genomic array studies may afford value over FISH testing as we continue to understand HGBCL-11q as a distinct entity, and interrogate cases of DLBCL/HGBCL-GC BCL2-.

Application of Health Technology Assessment (HTA) to Evaluate New Laboratory Tests in a Health System: A Case Study of Bladder Cancer Testing.

We describe the methods and decision from a health technology assessment of a new molecular test for bladder cancer (Cxbladder), which was proposed for adoption to our send-out test menu by urology providers. The Cxbladder health technology assessment report contained mixed evidence; predominant concerns were related to the test's low specificity and high cost. The low specificity indicated a high false-positive rate, which our laboratory formulary committee concluded would result in unnecessary confirmatory testing and follow-up. Our committee voted unanimously to not adopt the test system-wide for use for the initial diagnosis of bladder cancer but supported a pilot study for bladder cancer recurrence surveillance. The pilot study used real-world data from patient management in the scenario in which a patient is evaluated for possible recurrent bladder cancer after a finding of atypical cytopathology in the urine. We evaluated the type and number of follow-up tests conducted including urine cytopathology, imaging studies, repeat cystoscopy evaluation, biopsy, and repeat Cxbladder and their test results. The pilot identified ordering challenges and suggested potential use cases in which the results of Cxbladder affected a change in management. Our health technology assessment provided an objective process to efficiently review test performance and guide new test adoption. Based on our pilot, there were real-world data indicating improved clinician decision-making among select patients who underwent Cxbladder testing.

Silver Lining: Reduced Relapse with Chronic GVHD after Transplant for MDS.

Chronic GVHD following hematopoietic cell transplantation is associated with reduced relapse incidence in patients with leukemias. This impact has been investigated in myelodysplastic syndrome, showing a beneficial impact of limited chronic GVHD on transplant outcomes in a cohort of more than 3,000 patients.See related article by Konuma et al., p. 6483.

CD33 expression on natural killer cells is a potential confounder for residual disease detection in acute myeloid leukemia by flow cytometry.

Detection of minimal/measurable residual disease (MRD) in acute myeloid leukemia (AML) is important for guiding patient-specific clinical management. Natural killer (NK) cells can express various markers not typically associated with NK lineage, potentially confounding the detection of MRD by flow cytometry. We have observed CD33 expression on NK cells when evaluating for AML MRD in routine clinical practice in multiple patient samples. To characterize CD33 expression on NK cells, 40 peripheral blood or bone marrow samples with NK cells present at >5% of lymphocytes were selected for further assessment of NK cell phenotype and CD33 expression. Seven of the 40 samples (17.5%) were found to have CD33 expression on at least 5% of the NK cells. The CD33-positive NK cell population accounted for an average of 11.4% of NK cells (median 11.9%, range 8.0-15.3%) and 2.2% of total white cells (median 1.1%, range 0.1-10.1%). This NK cell subset expressed bright CD2, bright CD56, and dim CD16. On average, CD33 expression on NK cells was dimmer than on monocytes (mean median fluorescence intensity ratio 0.4; range 0.1-1.0). This study characterizes expression of CD33 on NK cells. Recognition of this pattern of antigen expression is critical in evaluating samples for MRD in patients with myeloid neoplasms, particularly AML.

A Paradigm Shift: Considerations in Prenatal Cell-Free DNA Screening.

BACKGROUND: Testing to determine the health of a fetus has undergone multiple iterations since the widespread adoption of amniocentesis in the 1970s, including several combinations of ultrasound and/or maternal serum screening. The clinical paradigm for prenatal screening for fetal chromosome aneuploidies was transformed by the introduction of cell-free DNA (cfDNA) screening or noninvasive prenatal screening in 2011. CONTENT: The clinical performance of cfDNA screening is well-established for the most common autosomal and sex chromosome aneuploidies with a detection rate exceeding 90% for all aneuploidies. One of the most significant advantages of cfDNA screening relative to maternal serum screening is the markedly reduced false-positive rate, which is <0.5%. The clinical implementation of cfDNA screening is discussed at length, including key biological, preanalytical, and analytical factors that affect test performance. SUMMARY: cfDNA prenatal screening for whole chromosome aneuploidies has become routine in high-risk obstetric populations. There is tremendous interest in expanding cfDNA screening to the general obstetric population. Early studies suggest that routine application of cfDNA screening is both feasible and effective, although significant economic and quality control considerations remain.

Transfusion Practice in Trauma Resuscitation.

Recognition of the acute coagulopathy of trauma and the limits of reconstituting whole blood with conventional blood components has led to a radical change in the way trauma patients with severe injuries are resuscitated. Massive transfusion protocols (MTP) have evolved toward the administration of conventional blood components in fixed ratios. Administration of a 1:1:1 unit ratio of fresh frozen plasma to whole-blood-derived platelets to packed red blood cells is now the most common strategy and the stated goal of directors of >80% of the level I trauma centers in the United States. Various physiologic scoring systems exist to guide early activation of an MTP. After activation of an MTP, more goal-directed therapy follows as soon as laboratory results are available. Hemostatic resuscitation using defined blood component ratios modified by early laboratory results can lead to more efficient blood product usage and improved patient outcomes.