[AIDS: biological aspects].

In June 1981 a new clinical syndrome, now called acquired immunodeficiency syndrome (AIDS) was first reported by the CDC. This entity has grown to be a pandemic disease with major socioeconomics, political and medical consequences. HIV-induced immunodeficiency infection typically occurs gradually over several years and leads to secondary opportunistic infections and malignancies. Similar features are observed in transplant recipients; the same clinical and diagnostic management is mandatory, but only in transplant complications an effective cure is possible.