Impact of line probe assay-based molecular testing on individualized treatment in patients with rifampicin-resistant tuberculosis: data from the prospective INNOVA4TB cohort study in Ukraine.

Background: Ukraine remains a high World Health Organization priority country for drug-resistant tuberculosis (TB). Rifampicin-resistant TB (RR-TB) has a more protracted, more complicated, and more expensive treatment. In 2021, Ukraine reported 4025 RR-TB cases – 5.4 times more (751) than all 30 European Union/ European Economic Area countries together. Objectives: The objective of the study was to determine the diagnostic accuracy of line probe assay (LPA), AID Autoimmun Diagnostika GmbH, for detecting resistance to anti-TB drugs and its clinical application for selecting treatment regimens. Design: A prospective observational cohort study. Methods: From May 2019 to June 2020, we consecutively enrolled patients with active TB hospitalized at the Regional Phthisiopulmonology Center (Vinnytsia, Ukraine), aged between 18 and 82 years. The LPA was performed in the Genetic Research Laboratory at National Pirogov Memorial Medical University, Vinnytsia, Ukraine. Results: A total of 84 clinical specimens and 97 culture isolates from 126 TB patients were tested during the study. Accuracy (95% confidence interval) of LPA for clinical samples in comparison with phenotypic drug susceptibility test (DST) was 80.1 (68.5–89.0) for isoniazid (H), 74.7 (62.4–84.6) for rifampicin (R), 74.4 (62.5–84.1) for ethambutol, 71.4 (41.9–91.6) for streptomycin, 84.6 (62.4–96.5) for prothionamide/ethionamide, and 84.6 (73.6–92.3) for levofloxacin (Lfx), respectively. We found a significantly higher sensitivity of LPA for H, R, and Lfx for the culture isolates compared to clinical specimens (p < 0.05). LPA detected different mutations in 6 out of 17 (35.5%) patients susceptible to R by Xpert. A shorter treatment regimen with an injectable agent demonstrated a low suitability rate of 5% (8/156) in a cohort of RR-TB patients from Ukraine. Conclusion: Initial LPA testing accurately identifies resistance to anti-TB drugs and facilitates the selection of an appropriate treatment regimen, minimizing exposure to empirical therapy. Plain language summary: Study about the impact of rapid resistance detection on the treatment of patients with tuberculosis in Ukraine written by healthcare and biomedical professionals to better understand how we can improve the results of treatment and to prevent spreading of resistant bacteria Why was the study done? Ukraine has over 4000 patients with tuberculosis (TB) resistant to at least one drug (rifampicin) - five times that of all 30 European Union/European Economic Area countries combined. Unfortunately, only about 60% of such patients have been successfully treated in 2019. At that time, the majority of people suffering from tuberculosis in Ukraine, after checking resistance to rifampicin, initially received standard combinations of the first-line or second-line anti-TB medicines before the result of traditionally used tests (usually few weeks later) became available to individualize the treatment. Alternatively, the sputum could be transported to some overloaded reference laboratories located hundreds of km away from the treatment places. What did the researchers do? The INNOVA4TB team implemented rapid diagnostics of drug resistance in routine practice, guiding key antibiotics use in TB patients. A total of 181 samples from 126 individuals were tested during 2019-2020. What did the researchers find? This new diagnostic technology accurately detected resistance to 9 anti-TB drugs in sputum samples. It could be helpful to select appropriate TB treatment regimens, reducing time for decision from 1 month up to 2 days. Recommended at the study time 9-month shorter standardized treatment regimen with injectable agent was suitable only for 5% of patients for whom it was indicated in Vinnytsia region of Ukraine. What do the findings mean? The study has demonstrated successful implementation of the new molecular diagnostic technology from scratch in a country with restricted resources and limited TB laboratory capacity. This test can facilitate optimal distribution of available wards among patients with different profiles of resistance and correct choice between treatment options. [ABSTRACT FROM AUTHOR]