A retrospective study on primary anti-tuberculosis drug resistance in patients with acquired immunodeficiency syndrome and tuberculosis

Objective To investigate primary anti-tuberculosis drug resistance in patients with acquired immunodeficiency syndrome (AIDS) and tuberculosis in Chongqing area. Methods Clinical data of 119 patients with AIDS and tuberculosis were retrospectively collected. Anti-tuberculosis drug resistance rates were analyzed according to drug susceptibility testing, and their correlations with CD4+ T lymphocytes counts, initially treatment or retreatment and clinical forms of tuberculosis were also analyzed. Comparison between groups was analyzed by χ2 test. Results Thirty-eight patients (31.9%) showed anti-tuberculosis drug resistance among the 119 patients with completed results of drug susceptibility testing results. The percentages of mono-resistance, poly-resistance, multi-drug resistance (MDR) and extensive drug resistance (XDR) were 11.7%, 7.6%, 6.7% and 5.9%, respectively. The resistance rate of isoniazid (22.7%, 28/119) was the highest among first-line anti-tuberculosis drugs and that of pasiniazide (11.0%, 14/119) was the highest among second-line drugs. Drug resistance rates among patients with different levels of CD4+ T lymphocytes counts did not differ significantly (the cut-off of CD4+ T lymphocytes count was 50/μL: χ2=0.545, P=0.461; cut-off value was 100/μL: χ2=0.652, P=0.420). Patents with milliary pulmonary tuberculosis had a significantly higher drug resistance rate (64.0%) than those with secondary pulmonary tuberculosis (27.6%). Conclusions The prevalence of anti-tuberculosis drug resistance prior to anti-tuberculosis treatment initiation is high among AIDS patients with tuberculosis in Chongqing area. Patients with milliary pulmonary tuberculosis tend to have higher anti-tuberculosis drug resistance, but drug resistance does not appear to correlate with CD4+ T lymphocytes counts. Key words: Acquired immunodeficiency syndrome; Tuberculosis; Coinfection; Anti-tuberculosis drug resistance