[Effect of IL-8 on the Immune Function of Patients with Acute -Lymphoblastic Leukemia and Its Mechanism]. 
To investigate the effect of interleukin -8 (IL-8) on immune function in acute lymphoblastic leukemia patients and its related mechanisms.  Forty-five ALL patients were selected from January 2014 to September 2017 in our hospital.  Out of them, 32 relieved patients were included in group A, 13 patients did not relieved patients after treatment and were included in the group B. The serum IL-8 level was detected by ELISA.Th1 and Th2 cells were measured by flow cytometry.  After Th cells were treated with different concentration of IL-8, the Western blot was used to detect the translation levels of p-STAT3 and JAK in cells.  The difference of white blood cell count and clinical risk level between the 2 groups was statistically significant (P<0.05).  The serum IL-8 levels in group A and B were significantly higher than that in control group (P<0.05).  The serum IL-8 level in group B was significantly higher than that in group A (P<0.05).  After treatment, the level of Th1 cells in group B was 6.15%±1.22%, significantly lower than that in group A (P<0.05), and Th2 cell level in group B was 2.76%±0.24%, significantly higher than that in group A (P<0.05); Th1/Th2 in group B was 2.23%±0.09, significantly lower than that in group A (P<0.05).  The protein level of p-STAT3 and JAK in the Th cells was lower than that in control group at different levels of IL-8 after treatment (P<0.05).  After stimulating Th cells with 20 ng/ml IL-8, the levels of p-STAT3 and JAK protein in cells were lower than those after 10 ng/ml IL-8 treatment (P<0.05).  IL-8 level had no significant effect on the protein expression of STAT3 in Th cells (P>0.05).  IL-8 can interfere the balance of Th1/Th2 through STAT3 signaling pathway, and has effect on the immune function of ALL patients.