Delayed Recovery of Normal Hematopoiesis in Arsenic Trioxide Treatment of Acute Promyelocytic Leukemia: A Comparison to All-trans Retinoic Acid Treatment

Abstract

Objective To examine laboratory data including total blood cell count, leukocyte morphology and coagulation parameters during treatment for acute promyelocytic leukemia (APL) at a single institute, and compare the precise differences between all-trans retinoic acid (ATRA) and arsenic trioxide (As₂O₃) treatment.
Patients and Methods Sixteen patients with APL who were treated with ATRA or As₂O₃ alone and achieved complete remission (CR) were analyzed. ATRA 45 mg/m²/day was given orally until CR. As₂O₃ 0.15 mg/kg/day was given intravenously until leukemic blasts and promyelocytes were eliminated from the bone marrow.
Results All 7 patients in the ATRA-treated group were primary cases and all 9 patients in the As₂O₃-treated group were relapsed cases after the achievement of CR with the ATRA. There was no difference in the data before treatment between these two groups. The duration of leukocytopenia and neutropenia during As₂O₃ treatment was significantly longer than those of ATRA treatment. The nadir of leukocyte and neutrophil counts was observed later in the As₂O₃-treated group. Terminal neutrophil differentiation was observed more obviously in the ATRA-treated group. The red blood cell count and hemoglobin concentration decreased significantly at the end of As₂O₃ treatment and were lower than those of ATRA treatment. Platelets recovered earlier in the ATRA-treated group. Coagulation parameters were not significantly changed between the two groups.
Conclusion In comparison with ATRA treatment, the recovery of several components in the peripheral blood cells was delayed in As₂O₃ treatment. Therefore we should pay more and longer attention in As₂O₃ treatment.