Abstract: OBJECTIVE To investigate the expression of interferon-alpha（IFN-alpha）, interferon-stimulated gene 56（ISG56）, myxovirus resistance protein A（MxA）, programmed cell death protein-1（PD-1） and T cell immunoglobulin and ITIM domain（TIGIT） in patients with human immunodeficiency virus（HIV） complicated with the lung infection.METHODS Totally 52 HIV patients with pulmonary infection treated in Yuyao People’s Hospital from Dec. 2016 to Dec. 2017 were selected as the study group. Another 48 HIV patients without pulmonary infection were selected as the control group. The levels of IFN-α, ISG56, MxA, PD-1 and TIGIT on the surface of CD₃⁺CD₄⁺-T cells in peripheral blood were measured.RESULTS The percentage of CD₃⁺CD₄⁺-T cells in the study group was significantly higher than that in the control group（P＜0.05）. The levels of IFN-a, ISG56 and MxA in the study group was（15.82±5.31）,（0.74±0.22）,（0.83±0.14）pg/ml, significantly lower than those in the control group（P＜0.05）. The percentages of TIGIT and PD1 CD₃⁺CD₄⁺-T cells in the study group were（23.61±12.83） and（51.32±13.74）, significantly higher than those in the control group（P＜0.05）. The percentage of TIGIT and PD-1 CD₃⁺CD₄⁺-T cells in the study group was negatively correlated with the absolute number of CD₄⁺-T cells（P=0.027）, and positively correlated with viral load（P=0.001）. The percentage of PD1 CD₃⁺CD₄⁺-T cells in the study group was negatively correlated with the absolute number of CD₄⁺-T cells（P=0.026） and not correlated with viral load（P=0.711）.CONCLUSION In patients with HIV combined with pulmonary infection, the proportion of CD₃⁺CD₄⁺-T cells increased, IFN-α, ISG56, MxA decreased, TIGIT and PD-1 increased obviously. The changes of related indexes showed that the immune function of the body became disordered when infected, and it had some correlation with the progression of HIV disease, with certain clinical value.