Therapy-Related Changes of CD34+ Progenitor Cells in Chronic Myeloid Leukemia: A Morphometric Study on Sequential Trephine Biopsies

In chronic myeloid leukemia (CML), it has been assumed that the number of CD34+ progenitor cells (PGCs) provides useful diagnostic and prognostic information regarding the evolution of accelerated phase and blastic crisis. However, until now no information is available about changes of this peculiar precursor cell population during therapy or possible associations with the other bone marrow constituents. For this reason, a retrospective clinicopathological study was performed on 83 patients with CML including 209 sequential bone marrow biopsies (intervals ranging between 6 and 143 months) and immunohistological staining of CD34+ cells (QBEND10), megakaryocyte precursors (CD61), and erythropoiesis (Ret 40f). According to treatment modalities, three different groups of patients could be distinguished that received either monotherapy by interferon-α2b (IFN-α2b) or hydroxyurea (HU) and a combination of both. In comparison with a control group, morphometry revealed a significant increase in the quantity of CD3...