The term "immune reconstitution inflammatory syndrome" (IRIS) describes a collection of inflammatory disorders associated with paradoxical worsening of preexisting infectious processes following the initiation of highly active antiretroviral therapy (HAART) in HIV-infected individuals [1-6]. Preexisting infections in individuals with IRIS may have been previously diagnosed and treated or they may be subclinical and later unmasked by the host's regained capacity to mount an inflammatory response .
If immune function improves rapidly following the commencement of HAART, systemic or local inflammatory reactions may occur at the site or sites of the preexisting infection. This inflammatory reaction is usually self-limited, especially if the preexisting infection is effectively treated. However, long-term sequelae and fatal outcomes may rarely occur, particularly when neurologic structures are involved.
This topic reviews the immunobiology, pathogenesis, clinical features, and management of IRIS. Since the clinical features are strongly linked with type and location of preexisting infection, IRIS associated with preexisting mycobacterial, cryptococcal, cytomegalovirus, Pneumocystis jirovecii, and JC virus infection will be discussed as separate entities even though the basic mechanism of illness is similar. In the absence of well-performed clinical trials, our recommendations for managing IRIS are based on clinical experience, case reports, case series, and expert opinion.
Initiation of HAART is discussed separately. (See "Selecting antiretroviral regimens for the treatment naive HIV-infected patient".)
Many synonyms exist for IRIS [2,8,9]: