[A "primitive" variant of the blast crisis in chronic myeloleukemia].

While immunotyping blast cells from 45 patients with CML blast crisis, we detected 5 cases with immunologically primitive blast cells. The immunological phenotype of these cells corresponded to that of primitive stem cells which are characterized by expression of CD34 and HLA-DR antigens in the absence of other immunological markers. We suggest that blast cells from these patients may undergo differentiation similar to that of primitive stem cells that implies the existence of a new immunological variant of CML blast crisis, a primitive variant.

[The clinical significance of the expression of the multiple-drug resistance protein P-glycoprotein in chronic myeloleukemia].

Cell resistance to pharmaceutical agents arises among other causes because of multiple drug resistance induced by P-glycoprotein (P-gp). The analysis of expression of P-gp and differentiation antigens of hemopoietic cells has been made on myeloid cells from 14 patients in CML chronic phase and 25 with CML acceleration and in blast crisis. Surface antigen expression was evaluated at flow cytofluorimetry (FACScan unit).