The Impact of Antiretroviral Therapy on Lung Immunology

Despite the introduction of antiretroviral therapy (ART), human immunodeficiency virus-1 (HIV) continues to cause a major impact worldwide. HIV-induced lung disease continues to represent a significant source of morbidity and mortality, although the spectrum of pulmonary diseases has changed. HIV significantly affects the lung, causing acute and chronic cellular changes in the alveolar space. The impact of ART on lung immunology still needs to be fully elucidated. Similar to the periphery, ART affects HIV viral load and reconstitutes CD4(+) T cells in the lung. ART has been associated with significant decreases in bronchoalveolar lavage lymphocytes and increases in B-cell numbers and functionality, resulting in improved immune responses to vaccinations. There are substantial clinical implications of these ART-induced alterations, including the emergence of immune reconstitution inflammatory syndrome and the increased incidences of noninfectious lung diseases, such as lung cancer and chronic obstructive lung disease. There continues to be many unanswered questions regarding the effects of ART on lung health and, in particular, the immune system. Growing knowledge in this area will hopefully diminish the incidence of these noninfectious lung diseases and further improve the health of individuals living with HIV.