Evaluation of the Abbott Real-Time HIV-1 quantitative assay with dried blood spot specimens

Marconi, A.; Balestrieri, M; Comastri, G.; Pulvirenti, F. Renato; Gennari, William; Tagliazucchi, Sara; Pecorari, Monica; Borghi, Vanni; Marri, D.; Zazzi, Maurizio

doi:10.1111/j.1469-0691.2008.02116.x

Cited by 63 publications

(62 citation statements)

References 21 publications

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“…In addition, we demonstrated good sensitivity for the assay, with a corresponding lower limit of detection of 550 copies/ml in plasma, which may be considered enough for early detection of virological treatment failure in most instances during longitudinal follow-up of patients on ART. Marconi and colleagues have recently published similar results, although the sensitivity of their assay was slightly lower (14). For early detection of virological failure with low-level viremia, it is clear that the VL sensitivity on DBS must improve (18).…”

Section: Discussionsupporting

confidence: 51%

Comparison of HIV-1 RNA Measurements Obtained by Using Plasma and Dried Blood Spots in the Automated Abbott Real-Time Viral Load Assay

Arredondo¹,

Garrido²,

Parkin

et al. 2012

J Clin Microbiol

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c Dried blood spots (DBS) may be a promising alternative specimen type to plasma for measuring the viral load (VL) in HIVinfected individuals in resource-limited settings. However, characterization of assay performance using DBS is incomplete. In this prospective study, the VL was measured in parallel using plasma and DBS specimens collected at the same time from 157 HIV-1-infected individuals. DBS were prepared by dispensing 50 l of blood onto filter paper cards and were stored desiccated at ؊20°C. Nucleic acid extraction from plasma and DBS was performed automatically using the Abbott m2000sp instrument, and the VL was measured using the RealTime HIV-1 VL assay, which has a lower limit of detection of 40 HIV RNA copies/ml. The correlation between plasma and DBS results was good (R ‫؍‬ 0.91; P < 0.001). The mean difference in the VL (DBS minus plasma) was 0.35 log copies (standard deviation [SD], 0.47 log copies). A total of 40 (26%) paired specimens had a difference of >0.5 log copy, and in 12 (7.8%) it was >1 log copy. the VL from DBS was measurable in 95.7% of specimens with a plasma VL of >2.74 log copies (550 HIV RNA copies/ml). In summary, the VL can reliably be measured using DBS with the Abbott RealTime HIV-1 assay. The estimated lower limit of detection of this automated methodology on DBS is 550 copies/ml, a threshold that may be acceptable for periodic VL monitoring in patients on antiretroviral therapy in resource-limited settings, where early detection of virologic treatment failure is often problematic. P eriodic measurement of the viral load (VL) in plasma remains a key parameter in the follow-up of HIV-infected individuals, especially those on antiretroviral therapy (ART) (21). However, reliable VL testing in plasma requires specialized facilities that often are not available in resource-poor settings. Dried blood spots (DBS) may be an interesting alternative to plasma for periodic VL testing (1,5,7,9,12,23). DBS can be easily collected and stored without being frozen or refrigerated (2,17,22). Several studies have demonstrated the feasibility of DBS as a specimen type for VL testing using different methodologies, although limitations in terms of sensitivity and stability have been noted (3,5,9,10,12,16). In addition, the recognition of distinct subtypes is an important problem in countries where HIV variability is high, and some VL assays occasionally underquantify some variants (19,24).In a previous study, we reported the results of VL testing on DBS using the Abbott mSample preparation system, a manual RNA isolation method. Although the correlation with plasma values was acceptable, the sensitivity was significantly lower on DBS (ϳ3.5 log copies) (11). Improvements in the detection limit (similar to plasma values of ϳ400 copies/ml) are important for early recognition of virological failure in patients on antiretroviral treatment. Here, we evaluate the feasibility of using an automated RNA isolation method, m2000sp, and the Abbott RealTime HIV-1 VL assay to quantify HIV-1 RNA on DBS and compar...

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Section: Discussionsupporting

confidence: 51%

Comparison of HIV-1 RNA Measurements Obtained by Using Plasma and Dried Blood Spots in the Automated Abbott Real-Time Viral Load Assay

Arredondo¹,

Garrido²,

Parkin

et al. 2012

J Clin Microbiol

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“…Similar observations were recently made by Vidya and colleagues (23) and they reported the same threshold of 3,000 copies/ml. Other reports have also mentioned the reduced performance of the m2000rt assay on DBS for a plasma VL of Ͻ3,000 copies/ml (18,24). The generic G2 assay developed by the ANRS Working Group on HIV Quantification is used in many laboratories in developing countries because of its lower cost than the costs of commercial assays.…”

Section: Discussionmentioning

confidence: 99%

Field Evaluation of Dried Blood Spots for Routine HIV-1 Viral Load and Drug Resistance Monitoring in Patients Receiving Antiretroviral Therapy in Africa and Asia

et al. 2014

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h Dried blood spots (DBS) can be used in developing countries to alleviate the logistic constraints of using blood plasma specimens for viral load (VL) and HIV drug resistance (HIVDR) testing, but they should be assessed under field conditions. Between 2009 and 2011, we collected paired plasma-DBS samples from treatment-experienced HIV-1-infected adults in Burkina Faso, Cameroon, Senegal, Togo, Thailand, and Vietnam. The DBS were stored at an ambient temperature for 2 to 4 weeks and subsequently at ؊20°C before testing. VL testing was performed on the plasma samples and DBS using locally available methods: the Abbott m2000rt HIV-1 test, generic G2 real-time PCR, or the NucliSENS EasyQ version 1.2 test. In the case of virological failure (VF), i.e., a plasma VL of >1,000 copies/ml, HIVDR genotyping was performed on paired plasma-DBS samples. Overall, we compared 382 plasma-DBS sample pairs for DBS VL testing accuracy. The sensitivities of the different assays in different laboratories for detecting VF using DBS varied from 75% to 100% for the m2000rt test in labs B, C, and D, 91% to 93% for generic G2 realtime PCR in labs A and F, and 85% for the NucliSENS test in lab E. The specificities varied from 82% to 97% for the m2000rt and NucliSENS tests and reached only 60% for the generic G2 test. The NucliSENS test showed good agreement between plasma and DBS VL but underestimated the DBS VL. The lowest agreement was observed for the generic G2 test. Genotyping was successful for 96/124 (77%) DBS tested, and 75/96 (78%) plasma-DBS pairs had identical HIVDR mutations. Significant discrepancies in resistance interpretations were observed in 9 cases, 6 of which were from the same laboratory. DBS can be successfully used as an alternative to blood plasma samples for routine VL and HIVDR monitoring in African and Asian settings. However, the selection of an adequate VL measurement method and the definition of the VF threshold should be considered, and laboratory performance should be monitored.T he increasing availability of antiretroviral treatment (ART) has dramatically contributed to a reduction in mortality and morbidity related to HIV/AIDS in resource-limited countries (RLC). In order to limit the emergence of resistance to antiretroviral drugs, HIV treatment should ideally be accompanied by regular virological monitoring, including viral load (VL) and genotypic drug resistance testing (1). With the recent scaling up of ART in RLC, people from semiurban and rural areas are now also receiving treatment, and recent data have shown variable levels of virological failure (VF) and drug resistance in these areas. In certain settings, VF can be Ͼ20% after 12 months of ART (2-4), stressing the urgent need for improved virological monitoring.In the majority of developing countries with limited resources, monitoring blood plasma VL poses logistical challenges since plasma preparation, storage, and/or shipment requires personnel and laboratory infrastructure that is often lacking. Today, viral load assays still require sophistic...

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“…The performance of each of these assays in measuring the VL in DBS and DPS has been evaluated in several studies, and the results have varied, especially for DBS. DBS-based VL testing has been associated with reduced sensitivity in several studies (12,20,21) but not in others (22,23,24,25), with heterogeneity of results apparently relating to the RNA extraction methods and assays used. Marconi et al found better agreement between DBS and plasma by using the Abbott mSample preparation system (m2000sp) (22), which is RNA specific, meaning that viral DNA is not coextracted and coamplified (as is done by the automated CAP/CTM extraction method that we used), which may explain the reduced difference between VL measurements in plasma and DBS using the Abbott platform.…”

Section: Discussionmentioning

confidence: 99%

“…However, additional studies suggested that the performance of DBS may be inadequate even at higher thresholds (12,13).…”

mentioning

confidence: 99%

Limited Utility of Dried-Blood- and Plasma Spot-Based Screening for Antiretroviral Treatment Failure with Cobas Ampliprep/TaqMan HIV-1 Version 2.0

Sawadogo¹,

Shiningavamwe

Chang

et al. 2014

J Clin Microbiol

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The 2013 WHO antiretroviral therapy (ART) guidelines recommend dried blood spots (DBS) as an alternative specimen type for viral load (VL) monitoring. We assessed the programmatic utility of screening for antiretroviral (ARV) treatment failure (TF) at 5,000 and 1,000 copies/ml using DBS and dried plasma spots (DPS) with a commonly used VL assay, the Roche Cobas Ampliprep/Cobas TaqMan V.2.0 (CAP/CTM). Plasma, DBS, and DPS were prepared from 839 whole-blood specimens collected from patients on ART for >6 months at three public facilities in Namibia. Using the CAP/CTM test, VL were measured in plasma, DBS, and DPS, and the results were compared using the plasma VL as the reference standard. The clinical sensitivities, specificities, and positive (PPV) and negative predictive values (NPV) of DBS at ARV TF diagnostic thresholds of 5,000 copies/ml and 1,000 copies/ml were 0.99, 0.55, 0.33, and 0.99 and 0.99, 0.26, 0.29, and 0.99, respectively, and for DPS at TF diagnostic thresholds of 5,000 copies/ml and 1,000 copies/ml, they were 0.88, 0.98, 0.92, and 0.97 and 0.91, 0.96, 0.89, and 0.97, respectively. The prevalences of TF were overestimated in DBS by 33% and 57% at these two thresholds, respectively. A high rate of false-positive results would occur if the CAP/CTM with DBS were to be used to screen for ARV TF. WHO recommendations for DBS-based VL monitoring should be specific to the VL assay version and type. Despite the better performance of DPS, the programmatic utility for TF screening may be limited by requirements for processing the whole blood at the collection site.

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Evaluation of the Abbott Real-Time HIV-1 quantitative assay with dried blood spot specimens

Cited by 63 publications

References 21 publications

Comparison of HIV-1 RNA Measurements Obtained by Using Plasma and Dried Blood Spots in the Automated Abbott Real-Time Viral Load Assay

Comparison of HIV-1 RNA Measurements Obtained by Using Plasma and Dried Blood Spots in the Automated Abbott Real-Time Viral Load Assay

Field Evaluation of Dried Blood Spots for Routine HIV-1 Viral Load and Drug Resistance Monitoring in Patients Receiving Antiretroviral Therapy in Africa and Asia

Limited Utility of Dried-Blood- and Plasma Spot-Based Screening for Antiretroviral Treatment Failure with Cobas Ampliprep/TaqMan HIV-1 Version 2.0

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