Killer cell immunoglobulin-like receptors in Thai patients with leukemia and diffuse large B-cell lymphoma

Natural killer (NK) cells are key components of the innate immune system that have been implicated in the immune response against tumor cells. Killer cell immunoglobulin-like receptors (KIR) regulate NK cell activity by interaction with specific human leukocyte antigen (HLA) class I. In this study, KIR gene polymorphisms and their HLA ligands were investigated in Thai patients with chronic myelogenous leukemia (CML) (n = 60), acute myelogenous leukemia (AML) (n = 60), acute lymphoblastic leukemia (ALL) (n = 55), and diffuse large B-cell lymphoma (DLBCL) (n = 60) compared with 150 healthy controls. The frequency of KIR3DL1 with HLA-Bw4 was significantly lower in DLBCL patients than in controls (P = 0.0006, Pc = 0.02), whereas no significant differences were seen in KIR gene frequencies and their ligands between leukemia patients and controls. This study suggest a role of inhibitory KIR with its ligand in the protection against DLBCL.