In addition, the ANRS EP47 VISCONTI study identified 14 patients who had been able to maintain plasmatic viral loads below 400 copies/ml for more than 7 years in the absence of antiretroviral treatment. Differently from HIV controllers, naïve of antiretroviral treatment, the patients from the VISCONTI study started therapy within ten weeks of primary infection and kept it for a median of three years before treatment discontinuation (Post-Treatment Controllers or PTC). The initial analyses revealed important clinical and immunogenetic differences between post-treatment and natural controllers, suggesting that PTC were not naturally predispose to control infection and that they succeeded thanks to initial therapeutic intervention. The mechanisms associated with long-term control in post-treatment controllers also appear different from the main mechanisms identified in HIV controllers. The main objective now is to gather in a common cohort patients with a particular resistance to HIV infection, either with an immunological control (ALT) or a natural (HIV Controllers) or induced virological control (PTC). The enrolled patients will be the patients already enrolled in the cohorts CO15 and CO18, the ANRSEP47 VISCONTI study, and new patients. This will allow common physiopathological studies to precise the mechanisms leading to the virus control and CD4 homeostasy. A better knowledge of the mechanisms of viral control and immune response preservation is very important in the setting of vaccine perspectives and in the perspective of implementing new therapeutic interventions to induce remission of HIV infection. This cohort will allow common research projects with common funding, a better visibility both for clinicians who see patients with unusual phenotypes and for international research. Such a cohort will be unique in the world by its size and the presence of these three complementary groups of patients. The two main objectives for the " Extreme " cohort (ANRS CO21 CODEX) are clinical and immunovirological. We wish to precise the impact of a prolonged untreated HIV infection, to describe the frequency of the "immunological escapes" (CD4 T cell decrease) or "virological escapes" (permanent or transient viral load increase), and to identify predictive markers of HIV control. We wish to study the genetic characteristics of the patients and those of their viruses, the innate and adaptative immune responses directed against HIV and other viruses, the consequences of inflammation, and the characteristics of the loss of control.