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Immunophenotypic characteristics of juvenile myelomonocytic leukaemia and their relation with the molecular subgroups of the disease
Author(s) -
Frisanco Oliveira Anita,
Tansini Aline,
Toledo Thais Regina,
Balceiro Rafael,
Onofre Vidal Daniel,
de Martino Lee Maria Lucia,
LorandMetze Irene,
Lopes Luiz Fernando
Publication year - 2021
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/bjh.17098
Subject(s) - monocytosis , immunophenotyping , cd34 , medicine , pathology , ptpn11 , myelodysplastic syndromes , population , myeloid , bone marrow , juvenile myelomonocytic leukemia , immunology , flow cytometry , biology , haematopoiesis , stem cell , cancer , colorectal cancer , environmental health , kras , genetics
The diagnosis of juvenile myelomonocytic leukaemia (JMML) is based on clinical, laboratory and molecular features but immunophenotyping [multiparametric flow cytometry (MFC)] has not been used routinely. In the present study, we describe the flow cytometric features at diagnosis with special attention to the distribution of monocytic subsets and the relation between MFC and molecular subgroups. MFC was performed with an eight‐colour platform based on Euroflow. We studied 33 JMML cases. CD34 + /CD117 + /CD13 + cells >2% was found in 25 cases, and 51·5% presented an aberrant expression of CD7. A decrease of CD34 + /CD19 + /CD10 + cells was seen in eight cases and in four they were absent. The granulocytic population had a decreased side scatter in 29 cases. Bone marrow monocytic precursors were increased in 28 patients, with a decrease in classical monocytes (median 80·7%) and increase in CD16 + (intermediate and non‐classical). A more pronounced increase in myeloid CD34 + cells was seen in patients with Neurofibromatosis type 1 ( NF1 ) and tyrosine‐protein phosphatase non‐receptor type 11 ( PTPN11 ), with aberrant CD7 expression in four of six and 10/12 patients respectively. Thus, JMML shows an immunophenotypic profile similar to myelodysplastic syndromes, and a different monocyte subset distribution when compared with chronic MML. MFC proved to be an important diagnostic tool that can help in differential diagnosis with other clonal diseases with monocytosis.