Quantitation of HIV-1 RNA in dried blood and plasma spots

Dried blood spots (DBSs) and dried plasma spots (DPSs) are an attractive method for serological and molecular diagnosis of HIV infection. Recently, Youngpairoj et al. [Youngpairoj, A.S., Masciotra, S., Garrido, C., Zahonero, N., de Mendoza, C., Garcia-Lerma, J.G., 2008. HIV-1 drug resistance genotyping from dried blood spots stored for 1 year at 4 degrees C. J. Antimicrob. Chemother. 61, 1217-1220] showed that HIV-1 can be genotyped efficiently from DBS specimens stored at 4 degrees C for 1 year. The viral load obtained from DBS and DPS samples was compared with that obtained from plasma samples. A total of 86 samples was prepared from people infected with HIV subtype B or non-B and spotted on 903 filter papers stored with desiccant at 4 degrees C. RNA was extracted using the QIAamp Viral RNA mini kit (Qiagen, Courtaboeuf, France). RNA from DBS or DPS samples was quantified in accordance with the Agence Nationale de Recherche sur le SIDA (ANRS, AC11, Paris, France) assay for HIV-1 quantitation. When the mean viral load of plasma samples and DPS samples or plasma samples and DBS samples were compared, there were no significant differences. The overall data showed that although the sensitivity threshold of the assays was different, there was a correlation between the three specimen types and that DBS and DPS samples can be routinely used for viral load quantification particularly in resource-limited settings.