10 mL blood in plain tube (for serum) or lithium heparin tube (for lymphocytes).


HIV-1 RNA is amplified and then measured by immunoassay. The result is derived by comparison with standard curves and expressed as viral equivalents (copies)/mL.

Reference Interval:

Method dependent.


Monitoring the course of HIV infection, including prognosis and response to treatment. CD4 counts are also used to monitor HIV infection; see Lymphocyte immunophenotyping. In neonates, to assess whether HIV antibody is maternally derived or indicates infection.


The test measures viral load and provides a predictor of disease course and prognosis, independent of CD4 counts. High viral load is associated with a poor prognosis if detected early in the course of the disease. Decreased viral load in response to treatment is associated with an improved long term outcome.


Holodniy M. Clin Lab Med. 1994; 14: 335-349.