Absolute circulating leukemic cells as a risk factor for early bleeding events in patients with non-high-risk acute promyelocytic leukemia

Abstract

Background: Hemorrhagic complications are the most common cause of early death in patients with APL and remain a major challenge in the management of APL. Early fatal bleeding events occur not only in high-risk but also in non-high-risk acute promyelocytic leukemia (APL) patients with normal or low WBC counts. Objectives and Methods: To demonstrate the role of the absolute number of circulating leukemic cells in early bleeding events in APL patients. Clinical and laboratory character-istics of 149 patients newly diagnosed with APL were obtained from medical records and retrospectively investigated. Results: In this study, circulating absolute leukemic cells were positively correlated with the WBC count (r=0.9813, p<0.001) in all patients with APL, and importantly, they were strongly associated with significant bleeding events in non-high-risk patients. Multivariate logistic regression analysis showed that the absolute number of leukemia cells was an independent risk factor for significant bleeding events in APL patients. A cut-off value of 2.59×109/L for circulating leukemic cells to predict significant bleeding events in APL patients was obtained by ROC curve analysis. We further confirmed that the significant bleeding rate of patients with non-high-risk APL was statistically increased when the absolute number of circulating leukemic cells was ≥2.59×109/L. Conclusion: Circulating leukemic cell content has great clinical value for predicting early bleeding events in APL patients, especially in non-high-risk APL.