Increased serum levels of sIL-15Rα in patients with T-LGL leukemia. (A) sIL-15Rα concentrations were determined using the ELISA assay described in “sIL15-Rα ELISA” in serum samples from T-LGL leukemic patients (n = 43). Twenty-nine serum samples from healthy normal donors were included as controls (P < .0001). (B) The serum levels of IL-18 in patients with T-LGL leukemia (n = 43) compared with that of normal donors (n = 29). (C) The distribution sIL-15Rα serum levels in patients with T-LGL leukemia with different grades of neutropenia (P < .001). (D) The distribution sIL-15Rα serum levels in patients with T-LGL leukemia with different grades of anemia (P < .05).