IMMUNE ACTIVATION: Edited by Irini Sereti and Marcus AltfeldHIV infection and immune activation the role of coinfectionsBoulougoura, Afroditi; Sereti, IriniAuthor Information HIV Pathogenesis Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA Correspondence to Irini Sereti, HIV Pathogenesis Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 11B07A, Bethesda, MD 20892, USA. E-mail: email@example.com Current Opinion in HIV and AIDS: March 2016 - Volume 11 - Issue 2 - p 191-200 doi: 10.1097/COH.0000000000000241 Buy Metrics Abstract Purpose of review This article explores new data from recent studies addressing the role of coinfections in immune activation in HIV-1-infected patients, with a focus on immune reconstitution inflammatory syndrome (IRIS), an aberrant inflammatory response occurring shortly after antiretroviral therapy (ART) initiation. Recent findings Chronic HIV infection is associated with several coinfections that contribute to immune activation in various settings including early after ART initiation in the most noticeable form of IRIS and also in chronic-treated infection, with chronic viral infections like cytomegalovirus and hepatitis C or hepatitis B virus contributing to immune activation and also morbidity and mortality. Expanding on older studies, the role of T cells in IRIS has been further elucidated with evidence of more pronounced effector activity in patients with IRIS that may be leading to excessive tissue disorder. Newer studies are also continuing to shed light on the role of myeloid cells as well as the contribution of antigen load in IRIS. In addition, preliminary data are beginning to suggest a possible role of inflammasome formation in IRIS. In cryptococcal IRIS, the role of activated immune cells (T cell and myeloid) and biomarkers were evaluated in more detail at the site of infection (cerebrospinal fluid). Finally, important differences of patients developing IRIS versus those who die from tuberculosis despite ART initiation were reported, a distinction that may have important implications for participant selection in studies aiming to prevent IRIS with immunosuppressive agents. Summary Better understanding of the role of opportunistic infections at ART initiation and IRIS pathogenesis will assist in improved strategies for prevention and treatment. The long-term consequences of IRIS remain unclear. Chronic viral coinfections with herpesviruses and hepatitis C virus are important factors in persistent immune activation in chronic-treated HIV. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.