Objective: To explore the mechanism of leukocytosis.
Methods: Enzyme linked immunosorbent assay (ELISA) method was used for detecting levels of serum granulocyte colony-stimulating factor (G-CSF) in 47 cases of acute promyelocytic leukemia (APL) during the treatment with all-trans retinoic acid (ATRA).
Results: The peak of increased serum G-CSF level occurred on the 9th day, and WBC number was the highest on the 11th day. After ATRA treatment, both serum G-CSF level and WBC number increased in 68.1% of the cases. In 19.2% of the cases treated, serum G-CSF level was increased but without obvious change in WBC number, and the reverse was true in 12.7% of the cases.
Conclusion: Serum G-CSF level was statistically correlated to the number of WBC, promyelocytes and its late stage by Spearman's rank-order correlation coefficient.