Interleukin-8 is not a predictive biomarker for the development of the acute promyelocytic leukemia differentiation syndrome

Differentiation syndrome (DS) is the main life-threatening adverse event that occurs in acute promyelocytic leukemia (APL) patients treated with all-trans retinoic acid (ATRA). Cytokine imbalances have been reported to play role during the developing of acute promyelocytic leukemia differentiation syndrome (APL-DS). However, the relationship between the plasma cytokine levels and their prognostic value for the prediction of DS developing in patients with APL during the treatment with ATRA and anthracyclines has not been previously reported. In this study, we followed an APL cohort (n = 17) over 7 days of ATRA therapy in DS (n = 6) and non-DS groups (n = 11). Interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α were measured in the peripheral blood plasma from 17 patients with APL and 11 healthy adult controls by using the cytometric bead array method. In non-DS patients, IL-8 plasma levels were significantly reduced in the seventh day of ATRA treatment (34.16; 6.99 to 147.11 pg mL in D0 vs. 10.9; 0 to 26.81 pg mL in D7; p = 0.02) whereas their levels did not discriminate between DS and non-DS development during the entire induction period (all p > 0.05 in D0, D3, and D7). No significant differences were found in IL-6 levels between groups (p > 0.05 in D0-D7). Other cytokines tested were all undetectable in patients with APL or healthy controls. We demonstrated that the modulation of IL-8 following ATRA treatment may occur regardless of the development of DS and, therefore, does not appear to be a predictive biomarker to monitor the APL-DS.