Clinical implications of high-risk mutations in drug resistant tuberculosis (DR-TB): An observational cohort study

Abstract

Genotype MTBDRsl [SL-LPA] was endorsed as a tool for early diagnosis of fluoroquinolones (FQ) and injectable second-line TB drugs (SLID) resistance in DR-TB. Correlation between specific genetic mutations using this tool and clinical outcome has not hitherto been studied in India. We conducted a observational cohort study to evaluate the predictive value of specific mutations for bad outcome. Our study identified 15 different types of gyrA mutations, commonest being A90V and D94G. Poor outcome was associated with mutations D94G and D94N/D94Y.Most XDR-TB patients harbored the high risk mutation of A1401G. Hence information of specific mutations using SL-LPA can help prognosticate and design appropriate treatment regimens.

Keywords: Line probe assay; MDR TB; XDR TB; mutations,Pre-XDR TB.