AIDS; nieuwe ontwikkelingen. III. Voorspellende waarde van de hoeveelheid HIV-RNA voor het beloop van de HIV-infectie en het effect van de behandeling

– Standardized tests to measure the quantity of HIV-RNA in blood have been available since early 1995. Individual differences in quantity of HIV-RNA in blood are determined mainly by differences in virus production. Most of the HIV production takes place in infected and activated CD4 T lymphocytes.

– The concentration of HIV-RNA in plasma or serum is an important predictor of AIDS and death, in the early stage of the infection even the only one. High concentrations (≥ 10⁴ HIV-RNA copiesml) in the early stage of the infection increase the probability of AIDS from 2.5 to 5 times that with concentrations < 10⁴ HIV-RNA copiesml.

– The degree of reduction of the HIV-RNA concentration during anti-HIV therapy is of great predictive value for the clinical course. The percentage of persons in whom the amount of HIV-RNA decreases to below the limit of detectibility is a good second indicator of a favourable prognosis.

– Consequently, anti-HIV treatment should be started as early as possible in the infection, and not postponed until the first symptoms of immunodeficiency occur; only then can the virus production be kept at a minimal level as early and as long as possible.

– The current guideline reads: determination of HIV-RNA concentrations in serum or plasma should be part of the standard clinical practice in monitoring HIV-infected persons. Treatment is started as soon as occasioned by the quantity of HIV-RNA (limit: 10,000 copiesml), the CD4 cell count (limit: 500 x 10⁶l) or the onset of HIV-related symptoms. The quantity of HIV-RNA should diminish substantially during the first three months of treatment. If this is the case, one checkup every three months will suffice. If the HIV-RNA concentration does not decrease sufficiently, resistance or poor compliance may be involved.