Utility Of POC Xpert HIV-1 Tests For Detection-Quantification Of Complex HIV Recombinants Using Dried Blood Spots From Kinshasa, D. R. Congo

Abstract

Point-of-Care (POC) molecular assays improve HIV infant diagnosis and viral load (VL) quantification in resource-limited settings. We evaluated POC performance in Kinshasa (Democratic Republic of Congo), with high diversity of HIV-1 recombinants. In 2016, 160 dried blood samples (DBS) were collected from 85 children (60 HIV−, 18 HIV+, 7 HIV-exposed) and 75 HIV+ adults (65 treated, 10 naive) at Monkole Hospital (Kinshasa). We compared viraemia with Cepheid-POC-Xpert-HIV-1VL and the non-POC-COBAS ® AmpliPrep/COBAS ® TaqMan ® HIV-1-Testv2 in all HIV+, carrying 72.4%/7.2% HIV-1 unique/complex recombinant forms (URF/CRF). HIV-1 infection was confirmed in 14 HIV+ children by Cepheid-POC-Xpert-HIV-1Qual and in 70 HIV+ adults by both Xpert-VL and Roche-VL, identifying 8 false HIV+ diagnosis performed in DRC (4 adults, 4 children). HIV-1 was detected in 95.2% and 97.6% of 84 HIV+ samples by Xpert-VL and Roche-VL, respectively. Most (92.9%) HIV+ children presented detectable viraemia by both VL assays and 74.3% or 72.8% of 70 HIV+ adults by Xpert or Roche, respectively. Both VL assays presented high correlation (R 2 = 0.89), but showing clinical relevant ≥0.5 log VL differences in 15.4% of 78 cases with VL within quantification range by both assays. This is the first study confirming the utility of Xpert HIV-1 tests for detection-quantification of complex recombinants currently circulating in Kinshasa.

Current and historic HIV-1 molecular epidemiology in paediatric and adult population from Kinshasa in the Democratic Republic of Congo

“…Our study reinforces the use of dried blood as a field-friendly, useful, convenient and alternative specimen type to whole blood or plasma in HIV molecular epidemiology surveillance studies in developing countries or settings with limitations as regards the collection, storing, transportation of plasma or when low blood volume is available 68 . Only 3 of 27 studies reporting variants in the DRC 48 , 50 , 51 had used DBS for HIV-1 variant characterization (Sup. Table 1 ).…”

“…From 2016 to 2018, 2 DBS cards were collected from 340 patients under clinical follow up at Monkole and Kalembelembe Hospitals (Kinshasa, DRC), 71 HIV-infected children (0–14 years) and adolescents (15–21 years) and 269 HIV-infected adults (more than 22 years). DBS preparation and viral load quantification was performed using Cobas Ampliprep/Cobas Taqman HIV-1 test v2.0 (Roche) as previously reported 50 considering hematocrit 70 , 71 .…”

HCV Diagnosis and Sequencing Using Dried Blood Spots from Patients in Kinshasa (DRC): A Tool to Achieve WHO 2030 Targets

“…Nine positive samples from our series were tested through Xpert ® HCV (data not shown) and correctly detected as expected. This new technique could be an alternative for HCV RNA quantification for samples collected on DBS in SSA, as recently reported for HIV viral load testing [18].…”

“…Twenty-six samples were tested using 1000 µL of eluted DBS (1 spot eluted in 1000 µL of PBS during 60 min at 37 • C). The adjusted HCV viral load in plasma was calculated as previously described [17,18], taking into account the dilution factor of the elution process, the usual hematocrit values (42% for women and 47% for men), and considering that 70 µL of blood was collected per spot. The lower limit of RNA quantification following this methodology was estimated at 860 IU/mL of eluted DBS.…”

Dried Blood Specimens as an Alternative Specimen for Immune Response Monitoring During HIV Infection: A Proof of Concept and Simple Method in a Pediatric Cohort

“…In this sense, the use of DBS has emerged as a great specimen due to its easier sampling, transport, and storage ( 20 ), being extensively used in many countries. In the DRC, DBS have been used for HIV diagnosis, viral load quantification, drug levels and resistance monitoring, HIV subtyping, and seroprevalence studies, among others ( 41 ).…”