OBJECTIVE: To probe into the dynamic changes and clinical significance of peripheral blood T lymphocyte subsets in patients with non-drug-resistant and multi-drug-resistant pulmonary tuberculosis. METHODS: Totally 97 patients with pulmonary tuberculosis admitted into the hospital from Jan. 2020 to Jun. 2021 were extracted as the research objects. All patients were tested for drug resistance. According to the results

all patients were divided into multi-drug resistance group and non-drug resistance group. Peripheral blood T lymphocyte CD3

+

CD4

+

CD8

+

CD4

+

/CD8

+

ratio and peripheral blood Th1

Th2

Th17 cell subsets were detected and compared between two groups. Both the multi-drug-resistance group and the non-drug-resistance group received anti-tuberculosis treatment for 3 months

and the anti-tuberculosis treatment effect was evaluated and the levels of peripheral blood T lymphocyte subsets were re-examined. RESULTS: Before treatment

the peripheral blood T lymphocyte CD3

+

CD4

+

CD8

+

CD4

+

/CD8

+

ratio in the multi-drug-resistance group was significantly lower than that in the non-drug-resistance group

with statistically significant difference（P

<

0.05）

and there was no significant difference in the level of CD8

+

between two groups（P

>

0.05）. Peripheral blood Th1 and Th2 in the multi-drug-resistance group were significantly lower than those in the non-drug-resistance group

and peripheral blood Th17 was significantly higher than that in the non-drug-resistance group

with statistically significant difference（P

<

0.05）. The good prognosis rate of non-drug-resistance group was 77.59%（45/58）

significantly higher than that of multi-drug-resistance group（35.90%

14/39）

the difference was statistically significant（P

<

0.05）. Compared with before treatment

CD3

+

CD4

+

CD4

+

/CD8

+

ratio in non-drug-resistance group increased significantly after treatment

with statistically significant difference（P

<

0.05）. There were no significant differences in CD3

+

CD4

+

CD4

+

/CD8

+

ratio in the multi-drug-resistance group after treatment compared with those before treatment（P

>

0.05）. Compared with before treatment

Th1 and Th2 in non-drug-resistance group increased significantly and Th17 decreased significantly after treatment

with statistically significant difference（P

<

0.05）. However

there were no significant differences in Th1

Th2 and Th17 in the multi-drug-resistance group after treatment compared with those before treatment（P

>

0.05）. CONCLUSIONS: Patients with pulmonary tuberculosis have significantly impaired immune status

which is more severe in patients with multi-drug-resistant pulmonary tuberculosis; drug resistance of Mycobacterium tuberculosis affects the immune status and the efficacy of anti-tuberculosis treatment in patients with pulmonary tuberculosis.