Serum IL18 is associated with hemophagocytosis and poor survival in extranodal natural killer/T-cell lymphoma

Extranodal natural killer/T-cell lymphoma (ENKTL) is associated with Epstein–Barr virus (EBV) infection, a common cause of hemophagocytosis. As interleukin-18 (IL18) is related with hemophagocytosis, we measured serum IL18 and IL18-related cytokines of newly diagnosed patients with ENKTL (N = 114) to investigate the role as a biomarker for hemophagocytosis and determine the prognosis of ENKTL. The median value of serum IL18 was 20.5 pg/mL (1.23–2021.81 pg/mL). The high IL18 group (≥20.5 pg/mL) was associated with stage III/IV, the presence of hemophagocytosis and poor treatment outcome. Serum IL18 showed significant positive correlations with TNFα, IFNγ, and IP10. Overall survival was significantly different between the high and low IL18 groups (p <.001), and high serum IL18 was independently prognostic for survival in the multivariate analysis. In conclusion, serum IL18 levels may be associated with the hemophagocytosis and poor survival outcomes in patients with ENKTL.