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 characteristics 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.
Keywords: circulating leukemic cells, early fatal bleeding events, non-high-risk acute promyelocytic leukemia