BACKGROUND: HIV type-1 (HIV-1) drug resistance testing is rarely available in resource-limited settings because of high costs and stringent requirements for storage and transport of plasma. Dried blood spots (DBS) can be a convenient alternative to plasma, but the use of DBS needs validation under field conditions. We assessed the performance of DBS in genotypic resistance testing of patients who failed first-line antiretroviral therapy (ART) in rural Tanzania. METHODS: A total of 36 ART-experienced patients with viral loads >1,000 copies/ml (median 15,180 copies/ml [range 1,350-3,683,000]) and with various HIV-1 subtypes were selected for resistance testing. DBS were stored with desiccant at ambient temperature for a median of 29 days (range 8-89). Samples were amplified using an in-house reverse transcriptase-nested PCR method and sequenced using the ViroSeq™ assay (Abbott Molecular, Des Plaines, IL, USA). DBS-derived genotypes were compared with genotypes from plasma. RESULTS: Overall, 34 of 36 (94%) DBS specimens were successfully genotyped. In the protease region, of 142 polymorphisms found in plasma, 132 (93%) were also detected in DBS. In the reverse transcriptase region, of 57 clinically relevant mutations present in plasma, 51 (89%) were also detected in DBS. A total of 30 of 34 (88%) patients had identical resistance profiles to antiretroviral drugs in plasma and DBS. CONCLUSIONS: Genotyping was successful in the vast majority of DBS specimens stored at ambient temperature for up to 3 months, and there was high concordance between mutations found in DBS and plasma. Our study suggests that DBS can be a feasible and reliable tool to monitor HIV-1 drug resistance in patients on ART in resource-limited settings.
BACKGROUND:HIV type-1 (HIV-1) drug resistance testing is rarely available in resource-limited settings because of high costs and stringent requirements for storage and transport of plasma. Dried blood spots (DBS) can be a convenient alternative to plasma, but the use of DBS needs validation under field conditions. We assessed the performance of DBS in genotypic resistance testing of patients who failed first-line antiretroviral therapy (ART) in rural Tanzania. METHODS: A total of 36 ART-experienced patients with viral loads >1,000 copies/ml (median 15,180 copies/ml [range 1,350-3,683,000]) and with various HIV-1 subtypes were selected for resistance testing. DBS were stored with desiccant at ambient temperature for a median of 29 days (range 8-89). Samples were amplified using an in-house reverse transcriptase-nested PCR method and sequenced using the ViroSeq™ assay (Abbott Molecular, Des Plaines, IL, USA). DBS-derived genotypes were compared with genotypes from plasma. RESULTS: Overall, 34 of 36 (94%) DBS specimens were successfully genotyped. In the protease region, of 142 polymorphisms found in plasma, 132 (93%) were also detected in DBS. In the reverse transcriptase region, of 57 clinically relevant mutations present in plasma, 51 (89%) were also detected in DBS. A total of 30 of 34 (88%) patients had identical resistance profiles to antiretroviral drugs in plasma and DBS. CONCLUSIONS: Genotyping was successful in the vast majority of DBS specimens stored at ambient temperature for up to 3 months, and there was high concordance between mutations found in DBS and plasma. Our study suggests that DBS can be a feasible and reliable tool to monitor HIV-1 drug resistance in patients on ART in resource-limited settings.
Authors: Dorothy E Dow; Werner Schimana; Balthazar M Nyombi; Blandina T Mmbaga; Aisa M Shayo; John A Bartlett; Charles G Massambu; Emmanuel G Kifaro; Elizabeth L Turner; Todd DeMarco; Fangping Cai; Coleen K Cunningham; Ann M Buchanan Journal: AIDS Res Hum Retroviruses Date: 2017-10-05 Impact factor: 2.205
Authors: Hezhao Ji; Yang Li; Binhua Liang; Richard Pilon; Paul MacPherson; Michèle Bergeron; John Kim; Morag Graham; Gary Van Domselaar; Paul Sandstrom; James Brooks Journal: PLoS One Date: 2013-02-07 Impact factor: 3.240
Authors: Dana N Raugi; Robert S Nixon; Sally Leong; Khadim Faye; Jean Phillipe Diatta; Fatima Sall; Robert A Smith; ElHadji Ibrahima Sall; Jean Jacques Malomar; Moussa Seydi; Geoffrey S Gottlieb Journal: J Clin Microbiol Date: 2020-12-17 Impact factor: 5.948