Acute monocytic leukemia diagnosed by flow cytometry includes acute myeloid leukemias with weakly or faintly positive non-specific esterase staining

Abstract

A diagnosis of acute monocytic leukemia (AML-M5) based on α-naphthyl butyrate esterase (α-NB) staining has some problems, because AML-M5 leukemic cells often show weak or faint positivity on α-NB staining. In these situations, some cases of AML-M5 tend to be misdiagnosed as AML-M0. Therefore, we evaluated the significance of weak or faint α-NB staining in AML-M5 diagnosed by flow cytometry (FCM). Nineteen AML cases in which leukemic cells were negative for naphthol AS-D chloroacetate esterase staining were studied. For FCM, we defined leukemic cells as having a monocytic nature when more than 10% of the leukemic cells were positive for at least one of the following antigens: CD4, CD11c, CD14, and CD64. The monocytic nature determined by FCM was consistent with positive or weak positivity on α-NB staining. Five of 6 cases in which leukemic cells exhibited faint positivity for α-NB staining could be diagnosed as AML-M5 by FCM, while negative α-NB staining was consistent with a diagnosis of AML-M0. These results suggest that AML-M5 should be taken into consideration even when leukemic cells are faintly positive for α-NB staining.

Preclinical Evaluation of CD64 As a Potential Target For CAR-T-cell Therapy For Acute Myeloid Leukemia

“…33 As a typical marker of acute monoblastic leukemia, CD64 expression can be detected on most of the M5 patients with high site density. 33,40,41 Nevertheless, it is less common in other types of AML, with 80% in M3,…”

“…CD64 is expressed in around 46.8% of AML patients 33. As a typical marker of acute monoblastic leukemia, CD64 expression can be detected on most of the M5 patients with high site density 33,40,41. Nevertheless, it is less common in other types of AML, with 80% in M3, 58% in M2, 20% expression in M4, and rare expression in M0, M1, M6, and M7 patients 30,40.…”

Morphologic and immunophenotypic features of a case of acute monoblastic leukemia with unusual positivity for Glycophorin-A

“…2,9,11-15 Therefore, by using MFC and a wide MoAb panel, it is possible to identify leukemic monoblasts and diagnose AMoL, even in cases negative for ANAE and/or ANBE. 16…”

Chloroacetate esterase reaction combined with immunohistochemical characterization of the specific tissue microenvironment of mast cells

“…The enzyme is found in much greater amounts in MC granules (Wong et al 1982 ; Atiakshin et al 2017 ). High resistance to formalin fixation, as well as to other fixatives, has led to the widespread use of ChAE as a MC marker in histological and pathomorphological studies (Michova and Fakan 1980 ; Hahn von Dorsche et al 1981 ; Lam et al 1985 ; Kashima et al 2015 ; Atiakshin et al 2017 ; Zushi et al 2018 ; Uchihara et al 2019 ). The efficiency of MC detection by detecting ChAE activity can be comparable or even exceed other methods for MC detection, including immunohistochemical methods (Atiakshin et al 2017 ; Wong et al 1982 ).…”