Flow Cytometric Assessment of Malignant Hematologic Disorders.

Multiparameter flow cytometry (MPF) is an essential component of the diagnostic workup of hematologic malignancies. Recently developed tools have expanded the utility of MPF in detecting T-cell clonality and myelomonocytic dysplasia. Minimal/measurable residual disease analysis has long been established as critical in the management of B-lymphoblastic leukemia and is emerging as a useful tool in myeloid malignancies.

Molecular signature incorporating the immune microenvironment enhances thyroid cancer outcome prediction.

Genomic and transcriptomic analysis has furthered our understanding of many tumors. Yet, thyroid cancer management is largely guided by staging and histology, with few molecular prognostic and treatment biomarkers. Here, we utilize a large cohort of 251 patients with 312 samples from two tertiary medical centers and perform DNA/RNA sequencing, spatial transcriptomics, and multiplex immunofluorescence to identify biomarkers of aggressive thyroid malignancy.

Neutrophil trafficking to the site of infection requires Cpt1a-dependent fatty acid β-oxidation.

Cellular metabolism influences immune cell function, with mitochondrial fatty acid β-oxidation and oxidative phosphorylation required for multiple immune cell phenotypes. Carnitine palmitoyltransferase 1a (Cpt1a) is considered the rate-limiting enzyme for mitochondrial metabolism of long-chain fatty acids, and Cpt1a deficiency is associated with infant mortality and infection risk. This study was undertaken to test the hypothesis that impairment in Cpt1a-dependent fatty acid oxidation results in increased susceptibility to infection.

Educational Case: AA Amyloidosis Complicating Common Variable Immunodeficiency.

http://journals.sagepub.com/doi/10.

Lymphoma and the Kidney: A Kidney Biopsy Teaching Case.

Lymphomatous infiltration of kidney parenchyma is a frequent complication of systemic hematologic malignancies and often shows subtle clinical presentation. Diffuse large B-cell lymphoma represents the most frequent form involving the kidney, with advanced stage at diagnosis, poor outcome, and risk for central nervous system relapse if not adequately treated. Kidney biopsy can provide specific and early detection of these cases, helping in the differential diagnosis with more frequent entities.

Venetoclax response is enhanced by selective inhibitor of nuclear export compounds in hematologic malignancies.

The selective inhibitor of nuclear export (SINE) compounds selinexor (KPT-330) and eltanexor (KPT-8602) are from a novel class of small molecules that target exportin-1 (XPO1 [CRM1]), an essential nucleo-cytoplasmic transport protein responsible for the nuclear export of major tumor suppressor proteins and growth regulators such as p53, p21, and p27. XPO1 also affects the translation of messenger RNAs for critical oncogenes, including MYC, BCL2, MCL1, and BCL6, by blocking the export of the translation initiation factor eIF4E. Early trials with venetoclax (ABT-199), a potent, selective inhibitor of BCL2, have revealed responses across a variety of hematologic malignancies.

Limited Utility of Fluorescence In Situ Hybridization for Recurrent Abnormalities in Acute Myeloid Leukemia at Diagnosis and Follow-up.

Objectives: Acute myeloid leukemia (AML) is classified in part by recurrent cytogenetic abnormalities, often detected by both fluorescent in situ hybridization (FISH) and karyotype. The goal of this study was to assess the utility of FISH and karyotyping at diagnosis and follow-up.

Methods: Adult AML samples at diagnosis or follow-up with karyotype and FISH were identified.

Genotypic and clinical heterogeneity within NCCN favorable-risk acute myeloid leukemia.

The National Comprehensive Cancer Network (NCCN) defines the following types of acute myeloid leukemia (AML) as favorable-risk: acute promyelocytic leukemia with t(15;17) (APL); AML with core-binding factor (CBF) rearrangements, including t(8;21) and inv(16) or t(16;16) without mutations in KIT (CBF-KIT); and AML with normal cytogenetics and mutations in NPM1 (NPM1); or biallelic mutations in CEBPA (CEBPA), without FLT3-ITD. Although these AMLs are categorized as favorable risk by NCCN, clinical experience suggests that there are differences in clinical outcome amongst these cytogenetically and molecularly distinct leukemias. This study compared clinical and genotypic characteristics of 60 patients with favorable-risk AML, excluding APL, and demonstrated significant differences between them.

B Lymphoblastic Leukemia Minimal Residual Disease Assessment by Flow Cytometric Analysis.

Among the most thoroughly evaluated modalities for assessment of minimal residual disease (MRD) in B acute lymphoblastic leukemia is multiparameter flow cytometry. Flow cytometric evaluation of MRD for B-ALL requires complete understanding of the immunophenotype of hematogones, the normal counterpart of leukemic B lymphoblasts. Assessment of multiple flow cytometry markers, in concert with each other in multidimensional histograms, is necessary to distinguish hematogones from malignant blasts.

Nuances of Morphology in Myelodysplastic Diseases in the Age of Molecular Diagnostics.

Morphologic dysplasia is an important factor in diagnosis of myelodysplastic syndrome (MDS). However, the role of dysplasia is changing as new molecular genetic and genomic technologies take a more prominent place in diagnosis. This review discusses the role of morphology in the diagnosis of MDS and its interactions with cytogenetic and molecular testing.

A QA Program for MRD Testing Demonstrates That Systematic Education Can Reduce Discordance Among Experienced Interpreters.

Background: Minimal residual disease (MRD) in B lymphoblastic leukemia (B-ALL) by flow cytometry is an established prognostic factor used to adjust treatment in most pediatric therapeutic protocols. MRD in B-ALL has been standardized by the Children's Oncology Group (COG) in North America, but not routine clinical labs. The Foundation for National Institutes of Health sought to harmonize MRD measurement among COG, oncology groups, academic, community and government, laboratories.

Data-Driven Iterative Refinement of Bone Marrow Testing Protocols Leads to Progressive Improvement in Cytogenetic and Molecular Test Utilization.

Objectives: To determine the effect of iterative refinement of standard ordering protocols on test utilization and results for bone marrow biopsy specimens.

Methods: Eighteen months of test utilization and result data were used to revise the protocols that determine cytogenetic and molecular test selection on bone marrow specimens and then compared with data obtained following protocol revision.

Results: Revision of protocols resulted in reduction in total tests and associated charges, due to a decrease in tests both concordant and discordant with the protocols.

Concurrent and Clonally Related Pediatric Follicular Lymphoma and Burkitt Lymphoma in a 5-Year-Old Boy.

Pediatric follicular lymphoma shares morphologic similarities with the adult form of the disease but lacks other classic features of adult lymphoma, including t(14;18) translocation, BCL2 overexpression, and transformation to aggressive higher-grade lymphoma. Herein, we report a novel case in which a 5-year-old boy (ethnicity unknown) had follicular lymphoma, along with concurrent high-grade and clonally related disease that fulfilled all of the morphologic, immunophenotypic, and genetic criteria for Burkitt lymphoma, including a t(8;14) translocation involving the MYC gene. To our knowledge, this case is the first reported instance of transformation of follicular lymphoma of any sort into true Burkitt lymphoma and the first reported instance of acquisition of MYC abnormalities in pediatric follicular lymphoma.

Case study interpretation: Report from the ICCS Annual Meeting, Seattle, 2014.

The Case Study Interpretation (CSI) cases presented at the 2014 International Clinical Cytometry Society (ICCS) meeting in Seattle illustrate the utility of state-of-the art multiparameter flow cytometry in the diagnosis of hematolymphoid neoplasms. Download the listmode files (Supporting Information) and test your analysis skills before reading the case reports, keeping in mind the following questions. How many separate abnormal mature B-cell populations can you identify, and how many of these represent different subtypes of B-cell neoplasm? How many separate abnormal mature T-cell populations can you identify, and do these represent different subtypes of T-cell neoplasm or phenotypic heterogeneity in one neoplasm? How many separate immature/blastic cell populations can you identify, and do they meet criteria for mixed phenotype leukemia? Is there a population of blasts that lacks T-cell, B-cell, and myeloid lineage defining antigens and if so, what entities should you consider and what additional antigens should you assess for?

B-ALL minimal residual disease flow cytometry: an application of a novel method for optimization of a single-tube model.

Objectives: Optimizing a clinical flow cytometry panel can be a subjective process dependent on experience. We develop a quantitative method to make this process more rigorous and apply it to B lymphoblastic leukemia/lymphoma (B-ALL) minimal residual disease (MRD) testing.

Methods: We retrospectively analyzed our existing three-tube, seven-color B-ALL MRD panel and used our novel method to develop an optimized one-tube, eight-color panel, which was tested prospectively.

Contribution of Beta-HPV Infection and UV Damage to Rapid-Onset Cutaneous Squamous Cell Carcinoma during BRAF-Inhibition Therapy.

Purpose: BRAF-inhibition (BRAFi) therapy for advanced melanoma carries a high rate of secondary cutaneous squamous cell carcinoma (cSCC) and risk of other cancers. UV radiation and α-genus human papillomavirus (HPV) are highly associated with SCC, but a novel role for β-genus HPV is suspected in BRAFi-cSCC. Cutaneous β-HPV may act in concert with host and environmental factors in BRAFi-cSCC.

Transformation of small B-cell lymphoma into large cell CD30⁺, CD4⁺, Epstein-Barr virus-negative lymphoma.

We report here 2 separate cases in which patients with known low-grade B-cell lymphomas presented with transformed lesions that were CD30⁺, CD4⁺, Epstein-Barr virus negative, and negative or focally weak for a wide range of B-cell, T-cell, and histiocytic/dendritic cell markers. In each case the transformed lymphoma possessed an identical pattern of immunoglobulin heavy chain and/or BCL2 rearrangement to the corresponding original low-grade B-cell lymphoma, confirming their identity as transformed B-cell lymphoma. A review of the relevant literature reveals that, to our knowledge, no transformed B-cell lymphomas with this immunophenotype have been previously reported, which creates the opportunity for potential errors of diagnosis.

Spontaneously arising mutL mutators in evolving Escherichia coli populations are the result of changes in repeat length.

Over the course of thousands of generations of growth in a glucose-limited environment, 3 of 12 experimental populations of Escherichia coli spontaneously and independently evolved greatly increased mutation rates. In two of the populations, the mutations responsible for this increased mutation rate lie in the same region of the mismatch repair gene mutL. In this region, a 6-bp repeat is present in three copies in the gene of the wild-type ancestor of the experimental populations but is present in four copies in one of the experimental populations and two copies in the other.

Fitness evolution and the rise of mutator alleles in experimental Escherichia coli populations.

We studied the evolution of high mutation rates and the evolution of fitness in three experimental populations of Escherichia coli adapting to a glucose-limited environment. We identified the mutations responsible for the high mutation rates and show that their rate of substitution in all three populations was too rapid to be accounted for simply by genetic drift. In two of the populations, large gains in fitness relative to the ancestor occurred as the mutator alleles rose to fixation, strongly supporting the conclusion that mutator alleles fixed by hitchhiking with beneficial mutations at other loci.