Stability of Human Immunodeficiency Virus RNA in Blood Specimens as Measured by a Commercial PCR-Based Assay

We investigated the effects of conditions often encountered during handling, transit, and storage of blood specimens on the quantity of detectable human immunodeficiency virus (HIV) RNA in plasma. HIV RNA copy numbers were measured with a commercially available assay (the Amplicor HIV-1 Monitor test kit). Variables examined were the time to processing of blood and plasma, the holding temperature of blood and plasma prior to processing, the effect of freezing and thawing of plasma, and the use of different anticoagulants. The relationship between the HIV RNA copy number and the HIV isolation rate by peripheral blood mononuclear cell (PBMC) coculture was also examined. We found that RNA copy numbers were maintained to within 0.5 log(10) (approximately threefold) in blood and plasma samples held at room temperature or 4°C for up to 3 days and remained stable despite (limited) freezing and thawing of the plasma. HIV RNA copy numbers were also maintained after long-term storage of plasma at −70°C. The ability to isolate HIV from PBMCs was directly proportional to the HIV RNA copy number.