Characteristics of the phenotypic abnormalities of bone marrow cells in childhood myelodysplastic syndromes and juvenile myelomonocytic leukemia

Abstract

Phenotypic abnormalities were similar to those found in adult MDS. A decrease in B-cell precursors was observed especially in RAEB/RAEB-t. JMML and RAEB showed a similar pattern.

Mice expressing KrasG12D in hematopoietic multipotent progenitor cells develop neonatal myeloid leukemia

“…On the other hand, circulating T lymphocytes from most patients do not express the disease-initiating mutation (7,37), suggesting that JMML is initiated within a MPP that undergoes a differentiation block during T lymphocyte commitment. Consistent with this hypothesis, case reports suggest that patients with JMML have decreased T cell frequencies in the BM and spleen (38,39). These findings parallel our Flt3Cre + Kras G12D model, which has a paucity of T cells, an atrophied thymus, and abnormal T cell differentiation.…”

Normal variation of bone marrow B‐cell precursors according to age – reference ranges for studies in myelodysplastic syndromes in Brazil

“…This feature has been used in diagnostic scores and has also been recognized as a prognostic factor in these clonal disorders . Recently, we have shown that the percentage of BCPs in MDS is always decreased when compared to age‐matched normal or reactive BM in adults and children . So, it would be interesting to establish a normal reference pattern for BCPs in BM in a Brazilian population, assessed by the same strategy used for immunophenotyping in cases suspected for MDS.…”

“…Bone marrow (BM) B‐cell progenitors (BCP) quantified by flow cytometry are decreased in myelodysplastic syndromes (MDS), and this feature has been considered one of the most important diagnostic parameters in MDS immunophenotyping . Its enumeration is considered easily reproducible by different operators within the European LeukemiaNet and has been included in the so called Ogata score, defined as CD34 + /CD45 low /SSC low cells .…”

Immunophenotypic characteristics of juvenile myelomonocytic leukaemia and their relation with the molecular subgroups of the disease

“…So, we could confirm the findings of our previous pilot study. 26 An increased number of CD34 + /CD117 + is also in keeping with the proliferative character of JMML. Aberrant expression of CD7 has already been described in patients with paediatric MDS, with prognostic implications.…”

“…previous pilot study with a larger number of cases. 26 We also examined if the distinct molecular subgroups had different characteristics. Among the 33 patients with JMML diagnosed by the GCB-SMD-PED where MFC was available, the median age was 29 months, which is older than generally described in the literature.…”