Defining use cases for biomarkers and tests across tuberculosis infection, disease and treatment: An international consensus and prioritisation exercise

Background Translation of tuberculosis (TB) biomarker and diagnostic research into tools that improve patient and public health outcomes has been slow, partly because no internationally agreed framework exists defining the use cases that new biomarkers and tests should address. We aimed to identify, validate, and prioritise use cases for TB biomarkers and tests across Mycobacterium tuberculosis (Mtb) infection, TB disease, TB treatment, and post-TB care, through an international consensus process. Methods and Findings We conducted a scoping review of the literature, guidelines, and target product profiles (24 documents; 69 candidate use cases consolidated to 13), followed by a hybrid RAND/UCLA modified Delphi consensus process involving 185 identified interest-holders, including clinicians, researchers, diagnostic developers, industry, funders, civil society, national TB programmes, and policymakers (including WHO representatives). Interest-holders completed an online survey rating agreement with each use case, and attended a consensus meeting to discuss use cases with less than 80% agreement, followed by a further validation meeting. Eleven use cases were retained across four TB care pathway stages: three for Mtb infection, four for disease detection, three for treatment optimisation, and one for post-TB care. Highest-priority use cases were detection of drug-resistant TB, prediction of progression from infection to disease, identification of current Mtb infection, and improved diagnosis of active TB disease. Conclusions This consensus exercise provides the first comprehensive, prioritised framework of use cases for TB biomarkers and tests, spanning the full care pathway. These eleven priority use cases can guide investment, focus biomarker discovery, and inform future target product profiles, funding calls, and policy development. Applying the framework to the current biomarker pipeline is a key next step to address gaps between innovation and priority needs.