Combined immunophenotyping and fluorescence in situ hybridization with chromosome-specific DNA probes allows quantification and differentiation of ex vivo generated dendritic cells, leukemia-derived dendritic cells and clonal leukemic cells in patients with acute myeloid leukemia

Antileukemic T-cell responses induced by leukemia-derived dendritic cells (DCleu) are variable, due to varying DC/DCleu composition/quality. We studied DC/DCleu composition/quality after blast culture in four DC media by flow cytometry (FC) and combined fluorescence in situ hybridization/immunophenotyping analysis (FISH-IPA). Both methods showed that DC methods produce variable proportions of DC subtypes. FISH-IPA is an elaborate method to study clonal aberrations in blast/DC cells on slides, however without preselection of distinct cell populations for FISH analysis. FISH-IPA data proved previous FC data: not every clonal/blast cell is converted to DCleu (resulting in various proportions of DCleu) and not every detectable DC is of clonal/leukemic origin. Preselection of the best of four DC methods for "best" DC/DCleu generation is necessary. DCleu proportions correlate with the antileukemic functionality of DC/DCleu-stimulated T-cells, thereby proving the necessity of studying the quality of DC/DCleu after culture. FC is the superior method to quantify DC/DCleu, since a blast phenotype is available in every given patient, even with low/no proportions of clonal aberrations, and can easily be used to study cellular compositions after DC culture.