Abstract: Objective To analyze the clinical characteristics and treatment regimens of drug-resistant tuberculosis containingisoniazid-resistance (Hr)DR-TB patients, and provide evidence for clinical practice and further research. Methods We retrospectively enrolled patients with (Hr)DR-TB, including Hr-TB and multidrug-resistant tuberculosis (MDR-TB) during January 2011 to December 2016 in Shenzhen Third People's Hospital, collected the demographic data, history of anti-tuberculosis treatment, phenotypic drug susceptibility testing (pDST) results of Mycobacterium tuberculosis and the changes of pDST, treatment regimens and adjustment strategy, treatment outcomes, and divided these data into new cases and retreated cases for comparative analysis. Results ①There are 37.5% (232/619) of Hr-TB and 62.5% (387/619) of MDR-TB in total, 49.7% and 50.3% in new cases, and 22.8% and 77.2% in retreated cases. Some patients experienced changes in the drug resistance spectrum during anti-tuberculosis treatment or after TB recurrence. 10.8% (67/619) of anti-tuberculosis drugs changed from drug-susceptible to drug-resistant.7.4% (46/619) changed from drug-resistant to drug-susceptible. ②Among 235 cases of Hr-TB, according to the pDST results, 8.5% (20/235) of patients with levofloxacin resistance and 8.9% (21/235) of patients with ethambutol resistance were found. Among the retreated cases, levofloxacin-resistant patients accounted for 20.9% (14/67), which was more than that in new cases (20.9% vs 3.6%, P>0.05). Among those who were sensitive to levofloxacin, 80.5% (167/215) used isoniazid in the initial regimen. Among those resistant to levofloxacin, 70% (14/20) used levofloxacin. After the pDST was reported, most cases (86.4%, 203/235) ignored the results and did not adjust their regimens. In terms of treatment outcome, 71.5% (168/235) were lost to follow-up, and 26.4% (62/235) maintained in the cohort. The treatment success rate of newly cases was higher than that of retreated cases (29.8%, 50/168 vs 16.4%, 11/67, P<0.01). Conclusion The most of (Hr)DR-TB patients were young and middle-aged men, and most of them were combined with rifampicin resistance. The drug resistance spectrum was easy to change during treatment. During the treatment of HR-TB, the treatment was rarely adjusted according to drug sensitivity, and more than 70% of cases were lost to follow-up. Attention should be paid to the standardized diagnosis and treatment of (HR) Dr-TB, especially Hr-TB.

Key words: Tuberculosis, Isoniazid-resistant tuberculosis, Treatment, Drug susceptibility testing, Characteristics