Inclusion Criteria:
Cohort 1: short-term ART cohort
* Documented HIV-1 infection
* Able and willing to provide written informed consent
* Age = or \>18 years and \< 80 years
* ART started during a documented recent HIV-1 infection (acute HIV infection, defined as:
* Clinical symptoms of acute seroconversion and incomplete Western Blot, or
* Negative screening test within the past 6 months and incomplete Western Blot, or
* Risk contact within the \<3 months and presumable primo-infection with or without clinical symptoms and incomplete Western Blot.
* Being on ART since minimum 2 years and maximum 10 years
* Participants should have had a routine plasma viral load measurement at least once a year.
* Viral load \< 40 or \<50 copies/ml determined by the assay (used in the local centers) for at least 3 years (one blip \< 200 copies/ml is allowed)
* Ability and willingness to have blood samples collected and stored for 20 years and used for various research purposes.
* Patients with HIV-1 subtype B are preferred for inclusion (as most of the complex assays are subtype B specific). However, if the investigators do not reach our target of 10 participants, patients infected with other subtypes will be allowed to enter the study. (Primers will subsequently be adapted to the patient-specific proviral sequences).
Cohort 2: long-term ART cohort
* Documented HIV-1 infection
* Able and willing to provide written informed consent
* Age = or \>18 years and \< 80 years
* Being on ART since at least 20 years
* ART should not have been started during a documented recent HIV-1 infection (acute HIV infection), defined as:
* Clinical symptoms of acute seroconversion and incomplete Western Blot or
* Negative screening test within the past 6 months and incomplete Western Blot or
* Risk contact within \<3 months and presumable primo-infection with or without clinical symptoms and incomplete Western Blot.
* Patients should have had a routine plasma viral load measurement at least once a year.
* Routine plasma viral load \< 40 or \<50 copies/ml determined by the assay used in the local centres for at least 20 years (one blip \< 200 copies/ml is allowed if it occurred \>10 years ago)
* Ability and willingness to have blood samples collected and stored for 20 years and used for various research purposes.
* Participants with HIV-1 subtype B are preferred for inclusion (as most of the complex assays are subtype B specific). However, if the investigators do not reach our target of 10 participants, patients infected with other subtypes will be allowed to enter the study. (Primers will subsequently be adapted to the patient-specific proviral sequences).
Exclusion Criteria:
* Previous or current history of opportunistic infection (AIDS defining events as defined in category C of the Centers for Disease Control and Prevention (CDC) clinical classification), consisting of chronic HIV-1 infection.
* Evidence of active Hepatitis B-virus (HBV) infection (Hepatitis B surface antigen positive or HBV viral load positive in the past and no evidence of subsequent seroconversion (= HBV antigen or viral load negative and positive HBV surface antibody).
* Evidence of active HCV infection (HCV antibody positive result within 60 days prior to study entry with positive HCV viral load or, if the HCV antibody result is negative, a positive HCV RNA result within 60 days prior to study entry).
* Current or known history of cardiomyopathy or significant ischemic or cerebrovascular disease.
* Current cancer.
* History of HIV-related thrombocytopenia.
* Pregnancy or breastfeeding.
* Any condition, including preexisting psychiatric and psychological disorders, which will in the opinion of the investigator interfere with the trial conduct or safety of the participant.
* Abnormal results of standard of care laboratory tests:
1. Confirmed haemoglobin \<11g/dl for women and \<12 g/dl for men
2. Confirmed platelet count \<100 000/µl \*
3. Confirmed neutrophil count \<1000/μl
4. Confirmed Aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT)\>10x upper limit of normal (ULN)
* Active drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements.
* Acute or serious illness, in the opinion of the site investigator, requiring systemic treatment and/or hospitalization within 60 days prior to entry.