White Blood Cell Count Nadir and Duration of Aplasia Do Not Associate with Treatment Outcome in Adult Patients with Acute Myeloid Leukemia Undergoing Intensive Chemotherapy

Abstract

<b><i>Introduction:</i></b> Adult patients with acute myeloid leukemia (AML) are usually treated with intensive chemotherapy, leading to prolonged bone marrow aplasia. It is usually assumed that a short duration of aplasia could be a surrogate marker of poor therapeutic efficacy in clearing bone marrow blasts, especially in older patients. No studies have evaluated the usefulness of such a surrogate marker in younger AML patients treated with intensive chemotherapy. <b><i>Materials and Methods:</i></b> In the present study, we retrospectively assessed the role of white blood cell (WBC) count nadir and duration of aplasia in 68 patients with AML treated with intensive chemotherapy and potentially candidate to stem cell transplantation. <b><i>Results:</i></b> The median (interquartile range) bone marrow aplasia was 25 days, and the mean WBC count nadir from chemotherapy start was at day +12, whereas the median neutrophil recovery occurred at day +24. No significant differences were found between responders and nonresponders for mean aplasia duration (25 vs. 26 days, <i>p</i> value = 0.76), mean WBC count nadir (12 vs. 12 days, <i>p</i> value = 0.86), and median neutrophil recovery (24 vs. 24, <i>p</i> value = 0.67). <b><i>Discussion:</i></b> The present study evaluated the potential prognostic role of WBC count nadir and duration of aplasia, demonstrating that they are not associated with treatment outcomes in adult patients with AML treated with intensive chemotherapy. Therefore, a short duration of aplasia seems not linked to poor therapeutic efficacy in clearing bone marrow blasts. Our findings, although needing validation in larger and more homogeneous cohorts, may offer helpful clues in the management of aplasia of AML patients.

Association of leukocyte nadir with complete remission in Indonesian acute myeloid leukemia patients undergoing 7+3 remission induction chemotherapy

“… 9 This result is similar to that reported by Marras where the time required for nadir leukocyte level to be reached was also 12 days for both responder and non-responder groups. 29 This reinforces the premise that the nadir pattern of leukocytes in the peripheral blood is similar to the pattern of hypoplasia in the bone marrow.…”

“…Kinetics of leukocyte has long been used as an indicator of bone marrow recovery, which is characterized by absolute neutrophil count (ANC) levels reaching above 500/mcl after nadir. 29 This shows that the concept of low nadir leukocyte levels as a surrogate marker of the degree of bone marrow hypoplasia associated with CR does not conflict with existing knowledge about AML.…”

Targeting SAMHD1 with hydroxyurea in first‐line cytarabine‐based therapy of newly diagnosed acute myeloid leukaemia: Results from the HEAT‐AML trial

“…It is conceivable that the addition of hydroxyurea potentiates the risk of ara-C-related adverse events. However, the observed toxicities and time to haematopoietic recovery were in line with expected outcomes for patients undergoing inten-sive chemotherapy for AML [47] and did not delay subsequent cycles of chemotherapy or time to allo-HSCT. This might at least partially be explained by the low expression levels of SAMHD1 in healthy bone marrow progenitors including HSPC.…”