Abstract:ObjectiveTo evaluate the significance of change in T help cell 17(Th17) and regulatory T cell (Treg) in HIVinfected patients. Methods106 HIVinfected patients and 30 healthy volunteers were selected. Flow cytometry was used to detect the CD4+ T ,Th17 and Treg cells in peripheral blood. HIV RNA levels in serum were tested by RTPCR.ResultsCD4+ T cells were 13-702/uL, 19 patients were ≤200/uL (group A), 32 were 201-350/uL( group B), 26 were 351-500/uL(group C), 29 were >500/uL(group D); All were significantly lower than (798-1 130/uL) in healthy control group(P<0.05). The percentage of Th17 cells in CD4+ T cells were (0.73±0.21)%,(1.52±0.33)%, (2.92±0.46)% , and (3.74±0.58)% in group A, B ,C and D, respectively, which were all lower than (4.90±1.43)% of control group(P<0.05); The percentage of Treg cells in CD4+ T cells were (9.78±2.15)%, (7.23±1.72)%, (5.69±1.67)% , and (4.62±0.97)% in group A, B,C and D,respectively, group A, B and C were higher than (4.43±0.97)% of control group(P<0.05), but group D had no significant difference compared with control group(P>0.05). HIV RNA levels were (0-5.36)×107copies/mL in HIVinfected patients, the average levels of HIV RNA were (5.36±1.21)×106copies/mL ; HIV RNA levels in group A,B,C and D were(6.24±1.36)×107copies/mL,(4.36±1.02) ×106 copies/mL,(5.78±1.67)×104copies/mL,and (3.54±1.25) ×103copies/mL ,respectively,there was significant difference between each group(P<0.05), HIV RNA levels were negatively correlated with CD4 +T cells count. ConclusionHIV infection can result in the decrease of Th17 and CD4+T cells, imbalance of Th17/Treg cells, and negative correlation with HIV RNA levels.