Hematogones with light chain restriction: A potential diagnostic pitfall when using flow cytometry analysis to assess bone marrow specimens.

Light-chain restricted hematogones (LCR HGs) detected by flow cytometry analysis can mimic bone marrow involvement by B-cell lymphoma. This phenomenon can present a diagnostic pitfall and negatively impact patient management, as misinterpretation may upgrade disease stage. In this study, we characterized the immunophenotype of LCR HGs with an aim to differentiate them from B-cell lymphoma.

Establishment and characterization of a novel MYC/BCL2 "double-hit" diffuse large B cell lymphoma cell line, RC.

Background: Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoid malignancy worldwide. Approximately 5 % of cases of DLBCL are so-called double-hit lymphomas (DHL), defined by a chromosomal translocation or rearrangement involving MYC/8q24.2 in combination with another recurrent breakpoint, usually BCL2/18q21.

Phase 1/2 study of mogamulizumab, a defucosylated anti-CCR4 antibody, in previously treated patients with cutaneous T-cell lymphoma.

This phase 1/2 study evaluated the efficacy of mogamulizumab, a defucosylated, humanized, anti-CC chemokine receptor 4 monoclonal antibody, in 41 pretreated patients with cutaneous T-cell lymphoma. No dose-limiting toxicity was observed and the maximum tolerated dose was not reached in phase 1 after IV infusion of mogamulizumab (0.1, 0.

Differential expression of CD200 in B-cell neoplasms by flow cytometry can assist in diagnosis, subclassification, and bone marrow staging.

Objectives: To analyze CD200 expression by flow cytometry in a large series of B-cell neoplasms in a variety of tissue types in comparison with benign B-lineage cells.

Methods: We measured CD200 expression levels in 505 peripheral blood (PB), bone marrow (BM), and lymphoid tissue biopsy specimens, including 364 cases positive for B-cell leukemias and lymphomas.

Results: CD200 expression in chronic lymphocytic leukemia cases was as bright as or brighter than normal PB B cells in nearly all cases, while mantle cell lymphoma (MCL) cases were usually dim or negative.

Reduction of regulatory T cells by Mogamulizumab, a defucosylated anti-CC chemokine receptor 4 antibody, in patients with aggressive/refractory mycosis fungoides and Sézary syndrome.

Purpose: The CC chemokine receptor 4 (CCR4) is expressed on malignant T cells in cutaneous T-cell lymphoma (CTCL) as well as on regulatory T cells (Treg). When mogamulizumab, a defucosylated monoclonal antibody, binds to CCR4, it induces antibody-dependent cellular cytotoxicity against CCR4(+) malignant T cells. The goal of this study was to determine the effect of mogamulizumab on CCR4(+) Tregs in patients with CTCL.

Utility of quantitative flow cytometry immunophenotypic analysis of CD5 expression in small B-cell neoplasms.

Context: The value of assessing CD5 expression in the differential diagnosis of small B-cell neoplasms is well established. Assessment is usually done qualitatively.

Objectives: To assess CD5 expression levels by quantitative flow cytometry immunophenotyping and to determine possible differences among various small B-cell neoplasms.

Eradication of bone marrow minimal residual disease may prompt early treatment discontinuation in CLL.

The high complete remission rate with first-line combined fludarabine, cyclophosphamide, and rituximab (FCR) begs the question of the value of minimal residual disease (MRD)-negative status as a treatment end point. We report on 237 patients with chronic lymphocytic leukemia who received first-line FCR. MRD was prospectively assessed by 4-color flow cytometry in bone marrow after course 3 and at final response assessment.

Involvement of tumor-associated macrophage activation in vitro during development of a novel mantle cell lymphoma cell line, PF-1, derived from a typical patient with relapsed disease.

Human mantle cell lymphoma (MCL) cell lines are scarce and have been only sporadically described and validated, and only a few have been thoroughly molecularly or genetically characterized. We describe here the successful establishment of a new MCL line, PF-1, with typical MCL characteristics. Culturing primary MCL cells in vitro initially gave rise to an essential generative microenvironment "niche" involving macrophages required for MCL growth, and eventually produced the PF-1 MCL cell line.

Detection of MRD may predict the outcome of patients with Philadelphia chromosome-positive ALL treated with tyrosine kinase inhibitors plus chemotherapy.

From 2001 to 2011, 122 patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia were treated with chemotherapy + imatinib (n = 54) or + dasatinib (n = 68). One hundred fifteen (94%) achieved complete remission (CR) including 101 patients who achieved it with only 1 induction course and had at least 1 minimal residual disease (MRD) assessment; 25 patients underwent an allogeneic stem cell transplant in first CR and were excluded, leaving 76 patients as the subject of this report. MRD monitoring by multiparameter flow cytometry (MFC) and real-time quantitative polymerase chain reaction (PCR) was performed at the end of induction and at ~3-month intervals thereafter.

Phase 2 study of cladribine followed by rituximab in patients with hairy cell leukemia.

We conducted this study to determine the feasibility and safety of cladribine followed by rituximab in patients with hairy cell leukemia including the vari-ant form (HCLv). Cladribine 5.6 mg/m² given IV over 2 hours daily for 5 days was followed ∼ 1 month later with rituximab 375 mg/m² IV weekly for 8 weeks.

Utility of CD26 in flow cytometric immunophenotyping of T-cell lymphomas in tissue and body fluid specimens.

Background: CD26 is expressed by most CD4+ T cells in normal peripheral blood specimens. Neoplastic T cells are frequently CD26- in mycosis fungoides/Sezary syndrome involving the peripheral blood. However, CD26 expression by reactive and neoplastic T cells in solid tissues and body fluids has not been fully characterized by flow cytometry (FC).