Close resemblance between chemokine receptor expression profiles of lymphoproliferative disease of granular lymphocytes and their normal counterparts in association with elevated serum concentrations of IP-10 and MIG

Abstract

T-cell large granular lymphocyte (T-LGL) leukemia and chronic natural killer (NK) cell lymphocytosis (CNKL) are major subtypes of lymphoproliferative disease of granular lymphocytes (LDGL). To clarify the mechanism of LGL proliferation and the relationship with the chemokine system in LDGL, we enrolled 22 T-LGL leukemia patients and 8 CNKL cases, analyzed the expression profiles of chemokine receptors, and measured the serum concentrations of the corresponding chemokines. There were no significant differences in chemokine receptor expression profiles between T-LGL leukemia patients and healthy donors. An association of CCR5 and CXCR3 expression levels on LGLs was recognized in T-LGL leukemia patients (r = 0.84; P < .001). Among the chemokines, serum IP-10 and MIG levels were significantly higher in LDGL patients than in healthy donors (P < .05, and P < .001, respectively), and MIG expression was associated with the number of circulating LGLs (r = 0.73; P < .01). The chemokine receptor phenotypes of LDGL cells are essentially similar to those of normal T-cells and NK cells. The roles of IP-10 and MIG in the pathophysiology of LDGL need further examination.