Predictors of Unfavorable Outcomes in Lesotho MDR-TB Cohort
Adults treated for multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB) using shortened, all-oral regimens experience high rates of culture conversion, yet baseline radiographic and microbiologic features can identify patients at a significantly higher risk of unfavorable outcomes, according to a prospective cohort study published in Nature.
The research (NCT05871489), conducted in Lesotho, tracked 238 participants with bacteriologically confirmed pulmonary MDR/RR-TB to evaluate how baseline clinical features correlate with treatment success. Researchers recorded a median participant age of 41 years, with 29 percent female and 62 percent living with HIV. Among the cohort, 27 participants experienced unfavorable outcomes, comprising 20 deaths, three treatment failures, and four recurrences.
Culture Conversion Rates and High-Risk Baseline Features
Out of 148 participants who had positive baseline cultures, 142 experienced culture conversion within four months, translating to a 95.9 percent conversion rate. Despite this rapid early response, specific baseline markers strongly impaired treatment success and delayed culture conversion. Fibrosis, cavitation, bilateral disease, and high smear grade all correlated with poorer prognoses.
The predictive value of these features shifted depending on the patient’s HIV status. Bilateral disease showed a stronger association with unfavorable outcomes in participants without HIV, whereas fibrosis and high smear grade demonstrated stronger associations among participants living with HIV.
Impact of Severe Fibrocavitary Disease on Final Treatment Results
Combinations of baseline sputum and radiographic indicators proved particularly detrimental to final treatment outcomes. Cavitation paired with a high smear grade showed a negative association with favorable final outcomes, yielding an unadjusted odds ratio of 0.29 and an adjusted odds ratio of 0.39.
Similarly, severe fibrocavitary disease—defined as multi-lobar fibrosis accompanied by at least one cavity measuring 5 centimeters or larger—was negatively associated with favorable final outcomes. This condition registered an unadjusted odds ratio of 0.20 and an adjusted odds ratio of 0.26.
These combined baseline factors allow clinicians to pinpoint higher-risk patients early in the treatment cycle. Consequently, public health programs can deploy risk-adapted treatment strategies to manage shortened all-oral regimens for MDR/RR-TB more effectively.