There is clear clinical evidence that effective antiretroviral therapy (ART) can result in beneficial immune reconstitution for patients with advanced HIV disease. Examples include the decreased incidence of AIDS-defining opportunistic infections (OIs), the dramatic decline in mortality rates from AIDS, and the clinical resolution of OIs (eg, cryptosporidiosis and progressive multifocal leukoencephalopathy) without specific antimicrobial therapy that has been reported in areas where ART has become widely available. However, laboratory studies suggest that, in spite of the normalization of absolute CD4 T-cell counts that can result from long-term, virologically effective ART, immune reconstitution may not be complete, at least with the follow-up data available to date. In addition, among patients with advanced HIV disease who initiate ART, some have exuberant inflammatory responses to opportunistic pathogens that can lead to troublesome immune reconstitution disease (IRD) syndromes.
