Serum Levels of Cytokines and Cytokine Receptors Are Associated with Outcome in Newly Diagnosed AML Patients

Background: Cytokines, cytokine receptors and adhesion molecules have been studied as markers of immune system activation in various diseases including AML/MDS. These factors form a dynamic network which affects AML cell susceptibility to chemotherapy. To provide more evidence of these interactions, we analyzed the serum levels of a broad panel of cytokines, cytokine receptors, matrix metalloproteinase-9 and soluble adhesion molecules.

Aims: The aim of our study was to evaluate hypothesis that baseline serum levels of these factors are associated with relapse and overall survival (OS).

Methods: A total of 65 AML patients (27 males, 38 females, mean age 53.7 ± 12.8, median 57.1 years) newly diagnosed in the period 2011 - 2014 were analyzed. All patients were Caucasian. Of these, 14 had better risk, 10 intermediate-1 risk, 13 intermediate-2 risk and 28 high risk AML according to ELN risk stratification (Döhner et al., Blood 2010). The NPM-1 was mutated in 16 cases, the FLT3-ITD was present in 15 cases. The secondary disease was present in 26 cases, 3 patients were BCR/ABL positive. Five patients with APL were treated with the PETHEMA regimen combining Idarubicin and All-trans retinoic acid (ATRA). All other patients were induced with "3+7" induction chemotherapy consisting of Cytarabin 100mg/m² per day for 7 consecutive days and Daunorubicin 90mg/m² for the first 3 days of therapy in younger patients. In patients aged ≥ 65 years, Daunorubicin 45-60mg/m² was administered, depending on patient WHO performance status.

We evaluated baseline circulating levels of the following factors: interleukins (IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-15), epidermal growth factor (EGF), granulocyte-macrophage colony stimulating factor (GM-CSF), interferon-gamma (IFN-γ), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α), matrix-metalloproteinase-9 (MMP-9), tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), soluble IL-2 receptor-α (sIL-2Rα) and soluble receptors for IL-6 (sIL-6R) and TNF-α type I and II (TNFR-1,2), E-selectin (E-SEL), P-selectin (P-SEL), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). All biomarkers were measured by biochip array technology on Evidence Investigator analyzer (Randox). Statistical analysis was performed in R 3.1.2. Probability values (P) < 0.05 were considered statistically significant.

Results: All evaluated analytes were independent of age, disease origin and ELN risk stratification. Relapse occurred in 34 cases with median of 516 days. Median follow-up was 627 days. Primary AML, normal karyotype and achieving of complete remission (CR) after induction therapy were associated with better relapse free survival (RFS), whereas higher TNFR-1, VEGF, IL-3, TNFR-2, NPM-1 and BCR/ABL were associated with inferior RFS. OS correlated with levels of IFN-γ, GM-CSF and TNFR-1. In multivariate analysis, primary AML, higher IL-10 and IL-15 were associated longer OS. Higher age, higher ELN risk and higher levels of TNFR-1, IL-3, IL-6, IL-8 and TNFR-2 were associated with inferior OS.

Conclusions: Cytokines are an important part of cancer environment. In AML, some cytokines or their receptors may be informative for individual prognosis. The literature suggests association of IL-6 and IL-10 levels and OS (Correa et al., Cytokine 2013). Our data are in agreement with this finding, but revealed more cytokines and their receptors, especially TNFR-1, which were independently associated with relapse and OS. To confirm these findings, analysis in a larger cohort with longer follow-up should be performed.

Acknowledgment:

The work was supported by a specific research project "Analysis of defined prognostic factors in acute myeloid leukemia" (FMHS Hradec Kralove), by a long-term organization development plan 1011 (FMHS Hradec Kralove) and by MH CZ - DRO (UHHK, 00179906).