Immune Reconstitution Inflammatory Syndrome

Human immunodeficiency virus (HIV) targets the immune system by depleting CD4+ T lymphocytes and predisposing patients to an increased risk of opportunistic infections. Highly active antiretroviral therapy (HAART) leads to restoring CD4+ T lymphocytes and normalizing an immune response against pathogens. This improvement in immunity has resulted in significant improvement in the quality of life and health care outcomes in HIV patients. Although the introduction of HAART has been a landmark in preventing HIV-related deaths, there are still issues with HAART therapy. Since its inception, there have been several reported side effects of HAART and its possible interactions with other medications. Side effects can range from mild-severe allergic reactions, idiosyncratic reactions, and hematological disorders to altered drug metabolism. Additionally, using HAART therapy, the serum levels of certain medications can increase due to drug interaction, causing significant side effects. Another potential complication that may arise with HAART therapy is immune reconstitution inflammatory syndrome (IRIS). IRIS is a poorly understood disease whose exact mechanism is not yet fully known. It is a state of dysregulated, hyper-inflammatory response against opportunistic infections that usually occurs in the first 6 months of treatment of HIV/AIDS patients. IRIS is a potential complication of highly active antiretroviral therapy (HAART) and was first reported in the 1990s. It can lead to poor adherence and compliance with HAART in HIV/AIDS patients. It can also increase the risk of drug resistance with HAART, worsen HIV progression to AIDS, and decrease the quality of life in the infected population. Overall, the IRIS has been associated with significant morbidity and mortality in HIV/ AIDS patients. This topic provides a comprehensive review of the risk factors, pathophysiology, associated microorganisms, clinical presentations, and treatment of IRIS in HIV patients following the initiation of HAART.