Introduction: A key reason for the failure of anti-tuberculosis (TB) treatment is missed doses (instances where medication is not taken). Adverse drug reactions (ADRs) are one cause of missed doses, but the global evidence for this, their relative contribution to missed doses versus other causes, the patterns of missed doses due to ADRs, and the specific ADRs associated with missed doses have not been appraised. We sought to address these questions through a scoping review. Methods: MEDLINE, Embase and Web of Science were searched on 3 November 2021 using terms around active TB, missed doses and treatment challenges. Studies reporting both ADR and missed dose data were examined. (PROSPERO: CRD42022295209). Results: Searches identified 108 eligible studies. 88/108 (81%) studies associated ADRs with an increase in missed doses. 33/61 (54%) studies documenting the reasons for missed doses gave ADRs as a primary reason. No studies examined patterns of missed doses due to ADRs. 41/108 (38%) studies examined associations between 68 types of ADR (across 15 organ systems) and missed doses. Nuance around ADR-missed doses relations regarding drug susceptibility testing profile and missed dose originator was found. Conclusions: There is extensive evidence that ADRs are a key driver for missed doses of anti-TB treatment. Some papers examined specific ADRs, none evaluated the patterns of missed doses due to ADRs, demonstrating a knowledge deficit. Knowing why doses both are and are not missed due to ADRs is essential in providing targeted interventions to improve treatment outcomes.

Aim Patients on anti-tuberculosis (anti-TB) therapy are at risk of drug-induced liver injury (DILI). MicroRNA-122 (miR-122) and cytokeratin-18 (K18) are exploratory DILI biomarkers. To explore their utility in this global context, circulating miR-122 and K18 concentrations were measured in UK and Ugandan populations on anti-TB therapy for mycobacterial infection. Methods European patients receiving anti-TB therapy were recruited at the Royal Infirmary of Edinburgh, UK (ALISTER-ClinicalTrials.gov Identifier: NCT03211208). African patients with HIV-TB coinfection, receiving anti-TB and anti-retroviral therapy (ART), were recruited at the Infectious Diseases Institute, Kampala, Uganda (SAEFRIF-NCT03982277). Serial blood samples, demographic and clinical data were collected. MiR-122 was quantified using PCR. K18 was quantified using the M65 ELISA. Results The study had 235 participants (healthy volunteers (n=28); ALISTER: active TB (n=30), latent TB (n=88), non-tuberculous mycobacterial infection (n=25); SAEFRIF: HIV-TB coinfection (n=64)). In the absence of DILI, there was no difference in miR-122 and K18 across the groups. Both miR-122 and K18 correlated with alanine transaminase activity (ALT) (miR-122: r=0.52, 95%CI=0.42-0.61, P<0.0001. K18: r=0.42, 95%CI=0.34-0.49, P<0.0001). There were two DILI cases: baseline ALT was 18 and 28 IU/L, peak ALT 431 and 194 IU/L; baseline K18 58 and 219 U/L, peak K18 1247 and 3490 U/L; baseline miR-122 4 and 17 fM, peak miR-122 60 and 336 fM, respectively. Conclusion In European and African patients treated with anti-TB therapy miR-122 and K18 correlated with ALT and increased with DILI. Further work should determine the diagnostic and prognostic utility of miR-122 and K18 in this global context-of-use.