Eleven laboratories evaluated the use of dried blood and plasma spots for quantitation of human immunodeficiency virus (HIV) RNA by two commercially available RNA assays, the Roche Amplicor HIV-1 Monitor and the bioMerieux NucliSens HIV-1 QT assays. The recovery of HIV RNA was linear over a dynamic range extending from 4,000 to 500,000 HIV type 1 RNA copies/ml. The Monitor assay appeared to have a broader dynamic range and seemed more sensitive at lower concentrations. However, the NucliSens assay gave more consistent results and could be performed without modification of the kit. HIV RNA was stable in dried whole blood or plasma stored at room temperature or at ؊70°C for up to 1 year. Dried blood and dried plasma spots can be used as an easy and inexpensive means for the collection and storage of specimens under field conditions for the diagnosis of HIV infection and the monitoring of antiretroviral therapy.Human immunodeficiency virus (HIV) RNA levels in blood plasma are used to monitor the response to antiretroviral drug therapy in developed countries. Since the International AIDS Conference held in Durban, South Africa, in 2000, there has been a global effort to provide access to antiretroviral drugs to all infected individuals, including those in the resource-poor countries which have been hit the hardest by the AIDS pandemic. Studies have demonstrated that the provision of treatment is not enough, however. In order for the drugs to be most effective, both for an individual and for public health reasons, it will be necessary to monitor the responses to the therapy. HIV RNA assays typically use plasma, which implies access to laboratory equipment that may not be readily available in all field settings. Therefore, alternative specimens must be considered for use in these situations.Whole blood dried on filter paper (dried blood spots [DBSs]) has been used to qualitatively detect HIV antibodies (13, 15), HIV DNA (1, 3, 5-7, 9, 10, 11, 12, 16, 18) and HIV RNA (4, 14, 17; J. L. Gerstel and A. M. Comeau, Proc. 10th Natl. Neonatal Screening Symp., abstr. P-19, p. 64, 1994). In addition, dried plasma spots (DPSs) have also been used to quantitate the HIV load (8). Although the stabilities of antibodies and DNA in DBSs have been determined (2, 6, 13), there has been some question regarding the stability of the HIV RNA when it is dried and stored at room temperature (14, 17).The purpose of this study was to compare two different methods for quantitatively measuring HIV RNA in DBSs and DPSs and to assess their long-term stability at room temperature and at Ϫ70C.(This study was presented in part at the 12th World AIDS Conference, Geneva, Switzerland, 28 June to 3 July 1998 [S. Cassol, A. Comeau, S. Fiscus, G. Aldrovandi, J. Sullivan, J. Bremer, and B. Jackson, Abstr. 12th World AIDS Conf., abstr. 33166, 1998].)
MATERIALS AND METHODS
Specimens.Three different panels were prepared by the Virus Quality Assurance Laboratory by using filter paper (903; Schleicher & Schuell, Keene, N.H.) spotted with 50 l of plasma or whol...