First field evaluation of the optimized CE marked Abbott protocol for HIV RNA testing on dried blood spot in a routine clinical setting in Vietnam

Abstract

BackgroundViral load (VL) monitoring of HIV-infected patients in decentralized areas is limited due to logistic constraints. Dried Blood Spots (DBS) offer the opportunity to collect samples in remote area which can be easily transferred and tested at a central laboratory. The MOVIDA (Monitoring Of Viral load In Decentralized Area) project evaluated the performance of VL measurements on DBS using the new CE marked optimized Abbott protocol.MethodsHIV-1 infected adults from three outpatient clinics in Hanoi (Vietnam) were enrolled into the study between 1 March and 13 April 2017. VL was measured on DBS using the optimized protocol provided by the manufacturer and compared to plasma VL as reference method on the Abbott m2000rt RealTime HIV-1 platform. Sensitivity was defined as the ability for DBS samples to correctly identify VL failure at the threshold of 1000 copies/mL of plasma, while specificity represented the ability to identify patients with a plasma HIV-RNA VL of <1000 copies/mL.ResultsA total of 203 patients were enrolled in the study, of which 152 (75%) were male. Median age was 38 [inter quartile range: 34–43] years. Of these patients, 37 were untreated, 38 on ART for <6 months and 117 were on ART for ≥6 months. A strong correlation between VL results in plasma and from DBS was observed (ρ = 0.95; p<0.001). Plasma VL was ≥1000 copies/mL in 71 patients. The sensitivity of DBS was 90.1% (95% confidence interval [CI]: 80.7–95.9) and the specificity was 96.2% (95% CI: 91.4–98.8).ConclusionsThe new optimized Abbott DBS protocol performed well in this study, meeting the WHO performance criteria for the use of DBS for HIV VL monitoring. Scaling up VL monitoring using DBS can be used to reach the last 90 in the UNAIDS targets of 90-90-90 to help end the AIDS epidemics. However, sensitivity remains the main challenge for manufacturers to prevent maintaining patients in virological failure on inefficient ART.

HIV RNA measurement in dried blood spots of HIV-infected patients in Thailand using Abbott m2000 system

“…The higher level in plasma may also be due to the lack of hematocrit adjustment as reported in other studies [19,20]. This slightly lower average HIV RNA levels in DBS than in plasma has also been observed in other studies with average differences ranging between 0.07-0.76 log 10 copies/mL [5,12,16,21,22]. The smaller volume of blood tested in DBS might also explain that 2 DBS were undetectable while the corresponding plasma specimens had low HIV RNA VL (2.18 and 2.19 log 10 cp/mL) which were below the threshold of detection in DBS.…”

“…Routine monitoring of HIV RNA VL using DBS has been successfully implemented in resource-limited settings such as Angola, Tanzania, and Cameroon [10][11][12]. Several studies have evaluated the performances of the Abbott m2000 platform for the measurement of RNA in DBS versus plasma [5,[13][14][15][16]. Those studies were conducted among different populations (naïve or on ART) and used different DBS processing protocols.…”

Feasibility of dried blood spots for HIV viral load monitoring in decentralized area in North Vietnam in a test-and-treat era, the MOVIDA project

“…We reported a slightly lower rate of virological success than previous studies [23,24,31], and one could object that DBS use could explain this due to the proviral DNA amplification [37]. However, the technique used for viral load measurement on DBS, which is CE-marked, performed well in an evaluation in the same laboratory [14]. Of note, another evaluation in PWID in Vietnam reported a very similar virological failure rate [29].…”

“…Hence, the MOVIDA 2 project (Monitoring Of Viral load In Decentralised Area, Clinical trials ID: NCT03249493) was implemented to evaluate, in real-life conditions, the feasibility of DBS use for HIV viral load monitoring in remote provinces in North Vietnam, where no routine HIV viral load monitoring was available. Prior to this project, two laboratory evaluations were conducted establishing that, at the central laboratory in charge of viral load measurement, viral load results on DBS and plasma compared well and fulfilled WHO requirements [13,14].…”

Dried Blood Spot Tests for the Diagnosis and Therapeutic Monitoring of HIV and Viral Hepatitis B and C

“…The same scarcity situation must be noted for viral serology techniques, for which there is neither regulatory approval for use on DBS nor official application note from manufacturers. Despite these important limitations, DBS collection is recommended by WHO for diagnosis of HIV and viral hepatitis B and C in field settings to improve access to screening and management of populations with poor access to serum tests (Soulier et al, 2016;Taieb et al, 2018).…”