Coping with TB immune reconstitution inflammatory syndrome

Abstract

The TB immune reconstitution inflammatory syndrome (IRIS) is a relatively frequent complication in HIV–TB-coinfected patients after they start highly active antiretroviral therapy (HAART). There are two forms of TB IRIS: the ‘paradoxical’ type (clinical worsening of a patient on TB treatment) and the ‘unmasking’ type (undiagnosed TB becoming apparent after starting HAART). Their pathogeneses are not fully understood, although, as the name suggests, IRIS following initiation of HAART is accompanied by an increase in immune responses to Mycobacterium tuberculosis. The diagnosis of TB IRIS is mainly clinical; so far there are no laboratory tests able to diagnose or predict TB IRIS. Risk factors for TB IRIS include a low CD4+ lymphocyte count, disseminated TB infection at HAART initiation and a short interval between TB treatment and HAART initiation. TB IRIS complicates the treatment and care for HIV–TB-coinfected patients. In this paper, we discuss some aspects of pathogenesis and options for the treatment and prevention of TB IRIS.