[Diffuse interstitial pneumopathies caused by lentivirus (HIV-1) in humans and animals]

Lentiviruses belong to the retroviruses family (ie RNA viruses with reverse transcriptase activity); they induce inflammatory and/or degenerative slowly progressive diseases, affecting various organs. Some lentiviruses preferentially infect lymphocytes (HIV-1 and HIV-2, SIV and FIV) and are associated with infectious and tumoral disorders. Most lentiviruses induce a pulmonary disease, typically diffuse interstitial pneumonia. The visna/maedi-virus of sheep infects monocyte macrophage cells and the pulmonary lesions are macrophagic and neutrophilic alveolitis, lymphoid infiltration, myomatosis and interstitial fibrosis. Such pulmonary lesions are also induced by the goat and equine lentiviruses. In humans infected by HIV-1 or HIV-2, a diffuse interstitial lung disease also occurs; the histological findings are of alveolitis associated with lymphoid peribronchovascular infiltrates. The mechanism of formation of the lesions involves complex cellular interactions (especially between macrophage and lymphocyte, via cytokine production). These interactions are well modelled by small ruminant lentivirus induction of interstitial pneumonia.