Expression of type 2 innate lymphoid cell and related cytokines in chronic lymphocytic leukemia

Objective To explore the difference of type 2 innate lymphoid cell(ILC2s) and related cytokines between chronic lymphocytic leukemia(CLL) patients and controls，to investigate the correlation between ILC2s and IL-9 in CLL patientsMethods Flow cytometry was used to detect the expression of ILC2s and regulatory T cells(Treg) in peripheral blood of 26 CLL patients at initial diagnosis and 10 healthy controls.QRT-PCR was used to detected mRNA of TGF-β,IL-9 and IL-10 in peripheral blood mononuclear cell（PBMC）.ELISA was used to detect serum TGF-β, IL-9, IL-4, IL-6 and IL-10. Bivariate Pearson test was used to analyze the correlation between peripheral blood ILC2s and serum IL-9 in CLL patients.ILC2s were observed in the cervical lymph node of 12 CLL patients at initial diagnosis and 12 patients with reactive lymphoid hyperplasias by indirect immunofluorescence staining.Results Compared with control group, in CLL group,the proportions of ILC2s and Treg were significantly increased(both P<0.05); the mRNA expressions of IL-9,IL-10 and TGF-βin PBMCs were significantly increased(both P<0.05);the expressions of IL-9,IL-6,IL-10 and TGF-βin serum were significantly increased(both P<0.05). The peripheral blood level of ILC2s in CLL patients was positively related to the serum level of IL-9(r=0.56,P<0.01).Compared with reactive lymphoid hyperplasias patients, the mean fluorescence intensities of GATA3 and CRTH2 in cervical lymph nodes representing ILC2s were significantly increased in the CLL group(both P<0.001).Conclusion In CLL patients,the proportion of ILC2s in peripheral blood and lymph nodes increased, Treg in peripheral blood increased,and cytokines such as IL-9 increased,in CLL patients,the peripheral blood level of ILC2s was positively related to the serum level of IL-9.