HIV-1 Plasma RNA Quantitation by

Polymerase Chain Reaction (PCR) INDICATIONS

For the quantitative determination of HIV-1 RNA in human plasma as an aid in the prognosis of HIV disease and in assessing the efficacy of anti-retroviral therapy and vaccines.

DESCRIPTION

The human immunodeficiency virus (HIV) is recognized as the etiologic agent of acquired immune deficiency syndrome (AIDS). Until recently, monitoring of disease progression and assessment of clinical response to therapy have relied on a number of immunologic and virologic surrogate markers. Such markers have included CD4 lymphocyte cell count, serum HIV-1 p24 antigen (with and without immune complex dissociation), beta-2 microglobulin, neopterin, and quantitative microculture of peripheral blood mononuclear cells (PBMCs) and plasma. However, experience has shown limitations to the clinical application of these markers and has emphasized the need for more direct quantitation of viral load.

Recent studies have shown that viral RNA in plasma of HIV-1 infected individuals can be accurately and reproducibly quantitated by polymerase chain reaction (PCR) assay. Current methods are of sufficient sensitivity with the ability to detect as few or fewer than 20 RNA copies/ml thus enhancing the ability to more sensitively assess clinical samples.

Quantitative determination of plasma HIV-1 RNA levels are reported to be a more significant predictor of disease stage and clinical progression than other virologic surrogate markers, including CD4+ lymphocyte cell count, p24 antigen or neopterin, which reflect distal, later occurring consequences of HIV infection. Patients with higher levels of plasma HIV-1 RNA progress more rapidly to AIDS defining illnesses than patients with lower levels.

Plasma HIV-1 RNA levels decrease rapidly in patients beginning anti-retroviral therapies and rise again when therapy is discontinued or drug resistance develops; thus signaling disease progression even in some patients whose CD4 cell counts remain unchanged.

Quantitation of HIV-1 plasma RNA should be considered in the prognostic evaluation and serial monitoring of viral load in assessment of anti-retroviral drug therapy. This may be particularly significant in view of recent reports that rapid turnover of virus results in increasing viral diversity over time. This suggests that plasma viral monitoring be early and frequent if clinical impact is to be more significant.

TEST CODE/TEST NAME

2407  HIV-1 Plasma RNA Quantitation by Polymerase Chain Reaction (PCR)

METHOD

Polymerase Chain Reaction (PCR)