Unmasking tuberculosis in the era of antiretroviral treatment

Tuberculosis (TB) can develop soon after antiretroviral treatment initiation, as the result of restoration of the anti-TB specific immune response. This form of the disease is often defined as "unmasked TB", and it represents a major challenge for severely immune-suppressed HIV-infected subjects initiating treatment. Emergence of previously unrecognised TB disease occurs frequently in countries where TB/HIV co-infection is common, and where antiretroviral treatment has become increasingly accessible. The challenges posed by unmasked TB, such as its high incidence, the lack of reliable diagnostic tools and the uncertainties on its optimal management, may hamper our ability to face the TB/HIV epidemic. Therefore, unmasked TB appears a major threat to global health and poses additional barriers to successful HIV/AIDS care and treatment programmes. This review focuses on the epidemiology, immunopathogenesis and clinical manifestations of unmasked TB, and provides evidence-based recommendations for management and care of the disease.