Improved Fluoroquinolone-Resistant and Extensively Drug-Resistant Tuberculosis Treatment Outcomes.

BACKGROUND

Treatment outcomes of multidrug-resistant tuberculosis (MDR TB) remain poor, particularly for fluoroquinolone-resistant (FQ-R) MDR TB. The aim of this study was to determine treatment outcomes and factors associated with failure of MDR TB treatment, focusing on FQ resistance.

METHODS

Medical records were retrospectively reviewed of patients diagnosed and treated for MDR TB from January 2005 through December 2017 at Severance Hospital, South Korea.

RESULTS

Of a total of 129 patients with MDR TB, 90 (69.8%) cases were FQ-sensitive (FQ-S) and 39 (30.2%) were FQ-R. FQ-R MDR TB was associated with more severe clinical symptoms, including cavitary lesions and bilateral disease, and tended to require treatment with a greater number of drugs for a longer period of time than FQ-S MDR TB. Linezolid (51.3% vs 7.8%, < .001), bedaquiline (20.5% vs 8.9%, = .083), and delamanid (10.3% vs 5.6%, = .452) were more frequently used in FQ-R cases. Overall, 95/124 patients (76.6%) had favorable treatment outcomes, and we did not detect a significant difference between FQ-R and FQ-S (FQ-S 65/87, 74.7%, vs FQ-R 30/37, 81.1%; = .443). Old age, low body mass index, smoking, and malignancy-but not FQ resistance or extensively drug-resistant (XDR) TB-were associated with poor clinical outcomes.

CONCLUSIONS

Overall, 76.6% of MDR TB patients had successful treatment outcomes. Effective drug combinations and appropriate use of new drugs may improve treatment outcomes of FQ-R MDR and XDR TB. Poor clinical outcomes were more related to the patients' general condition rather than FQ resistance or XDR.