ABSTRACT
<p><b>OBJECTIVE</b>To explore the characteristics of cellular immunity in drug abusers with pulmonary tuberculosis.</p><p><b>METHODS</b>Sixty drug abusers with pulmonary tuberculosis and 60 non-drug abusers with pulmonary tuberculosis (control) were enrolled in this study. Three days after establishment of a definite diagnosis, peripheral blood was taken from the patients for lymphocyte subgroup (CD3(+), CD3(+)/CD4(+), CD3(+)/CD8(+) T lymphocyte subgroups and NK cells) examination by flow cytometry, and the CD4(+)/CD8+(+) ratio was calculated. The difference of cellular immunity between the drug abusers and control group was analyzed statistically.</p><p><b>RESULTS</b>CD3(+) and CD3(+)/CD4(+) T lymphocytes subgroups and NK cells of the drug abusers were significantly lower than those of the control patients (P=0.037, 0.028 and 0.015), and the former patients had also significantly lower CD4(+)/CD8(+) ratio (P=0.021). The pulmonary tuberculosis types and CD3(+)/CD8(+) T lymphocyte subgroup were not significant different between the two groups (P=0.053 and 0.85).</p><p><b>CONCLUSION</b>Drug abuse might depress cellular immunity in patients with pulmonary tuberculosis, which further complicate the treatment of this disease.</p>