Expression of the myeloid-associated marker CD33 is not an exclusive factor for leukemic plasmacytoid dendritic cells.

A new entity of acute leukemia coexpressing CD4(+)CD56(+) markers without any other lineage-specific markers has been identified recently as arising from lymphoid-related plasmacytoid dendritic cells (pDCs). In our laboratory, cells from a patient with such CD4(+)CD56(+) lineage-negative leukemia were unexpectedly found to also express the myeloid marker CD33. To confirm the diagnosis of pDC leukemia despite the CD33 expression, we demonstrated that the leukemic cells indeed exhibited pDC phenotypic and functional properties.

Allogenic bone marrow transplantation with a donor presenting with an acute hepatitis A.

We report the unique occurrence of an allogenic bone marrow transplantation performed as the donor was suffering from an acute hepatitis A. The bone marrow was contaminated at the time of collection, as demonstrated by hepatitis A virus (HAV) RNA detected by RT-PCR. Hepatitis A virus infection in such a situation could have resulted in a severe liver disease in the recipient.

[Contribution of in vitro models to the management of hematologic risk in pharmacovigilance].

The decisions of health authorities concerning adverse effects of drugs are usually notified following clinical observations, but are rarely associated to experimental data. The haematopoietic tissue is one of the most sensitive to these effects. In order to anticipate and to explain adverse effects, it becomes necessary to carry out in vitro assays on normal human haematopoietic progenitors.