Expression of HLA-DR antigens and cell proliferation in acute lymphoblastic leukemia of children.

Non-T, non-B acute lymphoblastic leukemia (ALL) in children can be further subdivided into common, null/undifferentiated and pre-B ALL. The overall labelling indices (LI) showed comparable values for these 3 subtypes of ALL. By sequential immunological, cytochemical and cytokinetic studies on single bone marrow cells, combined with morphological evaluation, blast cells could be attributed to the compartments of E-Ia+sIgM- and E-Ia-sIgM- cells, in pre-B/B ALL also to the compartment of E-Ia+sIgM+ cells. In all 30 patients investigated, the LI of Ia+ blast cells was higher than the LI of Ia- blast cells (p less than 0.001). However, no correlation between the percentage of Ia+ blast cells and the overall LI could be found in these patients (r = 0.284; p greater than 0.1).