Evaluation of dried blood spot specimens for HIV-1 drug-resistance testing using the Trugene HIV-1 genotyping assay.
BACKGROUND
Efforts to simplify the collection and shipping of specimens for HIV drug-resistance testing in resource-limited settings are needed as antiretroviral therapy increases worldwide.


OBJECTIVE
To evaluate the reliability and practicality of using dried blood spots (DBS) for HIV-1 drug-resistance testing with the Trugene HIV-1 genotyping assay.


METHODS
Nucleic acids from 33 DBS and counterpart plasma specimens were extracted using the Nuclisens MiniMAG system and genotyped using the Trugene HIV-1 genotyping assay. Results were evaluated for sensitivity, accuracy, and reproducibility.


RESULTS
A genotype was obtained for 33 (100%) plasma specimens and 26 (78.8%) DBS specimens, including 19 of 21 (90.5%) DBS specimens with a viral load greater than 6000 copies/mL. The mean nucleotide sequence concordance for the 940-nucleotide region evaluated was 99.3% for 26 DBS and plasma pairs, and 99.2% for 15 replicate DBS pairs. All 58 resistance-associated mutations detected in plasma specimens were detected in the corresponding DBS specimens.


CONCLUSIONS
We show that DBS can be reliably and accurately genotyped using standard clinical assay methods, offering a practical alternative to plasma. This method is well suited for pre-treatment resistance testing and has potential for use in monitoring drug resistance in ART-treated individuals.
Hallack
Renee
R
Wadsworth Center, New York State Department of Health, David Axelrod Institute, P.O. Box 22002, Albany, NY 12201-2002, United States.
Doherty
Lauren E
LE
Wethers
Judith A
JA
Parker
Monica M
MM
D019943:Amino Acid Substitution / Q000235:genetics; D001769:Blood / Q000821:virology*; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D020125:Mutation, Missense; D010949:Plasma / Q000821:virology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*