scholarly journals Leukodepletion as a Point-of-Care Method for Monitoring HIV-1 Viral Load in Whole Blood

2014 ◽  
Vol 53 (4) ◽  
pp. 1080-1086 ◽  
Author(s):  
Logan Titchmarsh ◽  
Clement Zeh ◽  
Thierry Verpoort ◽  
Jean-Pierre Allain ◽  
Helen Lee
Keyword(s):  
Viral Load ◽  
Whole Blood ◽  
Clinical Performance ◽  
Point Of Care ◽  
White Blood Cells ◽  
Cell Content ◽  
Loss To Follow Up ◽  
Resource Limited ◽  
Virus Retention ◽  
Hiv 1

In order to limit the interference of HIV-1 cellular nucleic acids in estimating viral load (VL), the feasibility of leukodepletion of a small whole-blood (WB) volume to eliminate only leukocyte cell content was investigated, using a selection of filters. The efficacy of leukocyte filtration was evaluated by counting, CD45 quantitative PCR, and HIV-1 DNA quantification. Plasma HIV-1 was tested by real-time reverse transcription (RT)-PCR. A specific, miniaturized filter was developed and tested for leukocyte and plasma virus retention, WB sample dilution, and filtration parameters in HIV-1-spiked WB samples. This device proved effective to retain >99.9% of white blood cells in 100 μl of WB without affecting plasma VL. The Samba sample preparation chemistry was adapted to use a leukodepleted WB sample for VL monitoring using the point-of-care Samba-1 semiautomated system. The clinical performance of the assay was evaluated by testing 207 consecutive venous EDTA WB samples from HIV-1-infected patients attending a CD4 testing clinic. Most patients were on antiretroviral treatment (ART), but their VL status was unknown. Compared to the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test, the new Samba assay had a concordance of 96.5%. The use of the Samba system with a VL test for WB might contribute to HIV-1 ART management and reduce loss-to-follow-up rates in resource-limited settings.

scholarly journals Study to evaluate the performance of a point-of-care whole blood HIV viral load test (SAMBA II HIV-1 Semi-Q Whole Blood).

2020 ◽  
Author(s):  
Gary Brook ◽  
Tetiana Stepchenkova ◽  
Innocent M. Ali ◽  
Sandra Chipuka ◽  
Neha Goel ◽  
...  
Keyword(s):  
Viral Load ◽  
Whole Blood ◽  
Point Of Care ◽  
Venous Blood ◽  
Load Test ◽  
Hiv Viral Load ◽  
Percent Agreement ◽  
Finger Prick ◽  
Hiv 1 ◽  
Point Of Care Assay

Remote areas of many low and middle income (LMI) countries have poor access to HIV viral load (HIV VL) testing. The SAMBA-II (Simple Amplification-based Assay) Semi-Q Whole Blood Test (Diagnostics for the Real World (DRW), Cambridge, UK) is a point of care assay which uses leucodepletion technology to allow whole blood testing in remote settings. 1540 consecutive HIV-positive clinic patients in Cameroon (250), UK (633), Ukraine (412) and Zimbabwe (245) donated venous blood (all countries) and finger-prick blood (all except UK) for testing on SAMBA-II. SAMBA II results were compared with simultaneous plasma results on the Abbott RealTime HIV-1 (Abbott Molecular, Des Plaines, IL) viral load assay and interpreted as either <1000 RNA copies/ml or ≥1000 RNA copies/ml. For 1528 venous whole-blood samples tested on SAMBA II, overall percent agreement with the reference test at a cut-off of HIV VL ≥1000 cps/ml was 96.9% (1480/1528 95% CI 95.9-97.7), negative percent agreement 97.7% (1259/1289 95% CI 96.7-98.4), positive percent agreement 92.5% (221/239 95% CI 88.4-95.5). For 854 finger-prick samples there was 95.0% (811/854 95% CI 93.3-96.3) overall percent agreement; negative percent agreement 98.0% (625/638, 95% CI 96.5-98.9); positive percent agreement 86.1% (186/216 95% CI 80.8-90.4). These rose to 93.5% (82.1, 98.6), 97.6% (95.6, 98.8) and 95.6% (93.3, 97.3) after exclusion of aberrant results from the Ukraine centre. These results show a high level of agreement between SAMBA-II and a laboratory-based assay. SAMBA-II has a performance that is suitable to use as a VL point of care assay in remote settings

scholarly journals Human Neutrophil Lipocalin as a Superior Diagnostic Means To Distinguish between Acute Bacterial and Viral Infections

2015 ◽  
Vol 22 (9) ◽  
pp. 1025-1032 ◽  
Author(s):  
Per Venge ◽  
Lena Douhan-Håkansson ◽  
Daniel Garwicz ◽  
Christer Peterson ◽  
Shengyuan Xu ◽  
...  
Keyword(s):  
Whole Blood ◽  
Human Neutrophil ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Response Times ◽  
Clinical Performance ◽  
Point Of Care ◽  
Signs And Symptoms ◽  
Healthy Controls ◽  
Acute Infections

ABSTRACTThe distinction between causes of acute infections is a major clinical challenge. Current biomarkers, however, are not sufficiently accurate. Human neutrophil lipocalin (HNL) concentrations in serum or whole blood activated by formyl-methionine-leucine-phenylalanine (fMLP) were shown to distinguish acute infections of bacterial or viral cause with high accuracy. The aim was therefore to compare the clinical performance of HNL with currently used biomarkers. Seven hundred twenty-five subjects (144 healthy controls and 581 patients with signs and symptoms of acute infections) were included in the study. C-reactive protein (CRP), the expression of CD64 on neutrophils, procalcitonin (PCT), and blood neutrophil counts were measured by established techniques, and HNL concentrations were measured in whole-blood samples after activation with fMLP. All tested biomarkers were elevated in bacterial as opposed to viral infections (P< 0.001). CRP, PCT, and CD64 expression in neutrophils was elevated in viral infections compared to healthy controls (P< 0.001). In the distinction between healthy controls and patients with bacterial infections, the areas under the receiver operating characteristic (ROC) curves were >0.85 for all biomarkers, whereas for the distinction between bacterial and viral infections, only HNL concentration in fMLP-activated whole blood showed an area under the ROC curve (AUROC) of >0.90 and superior clinical performance. The clinical performance of HNL in fMLP-activated whole blood was superior to current biomarkers and similar to previous results of HNL in serum. The procedure can be adopted for point-of-care testing with response times of <15 min.

scholarly journals Clinical performance evaluation of SARS-CoV-2 rapid antigen testing in point of care usage in comparison to RT-qPCR

2021 ◽  
Author(s):  
Isabell Wagenhaeuser ◽  
Kerstin Knies ◽  
Vera Rauschenberger ◽  
Michael Eisenmann ◽  
Miriam McDonogh ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Viral Load ◽  
Clinical Performance ◽  
Point Of Care ◽  
Hospital Setting ◽  
High Viral Load ◽  
Evaluation Study ◽  
Study Cohort ◽  
Protein Variant ◽  
Atypical Symptoms

Background Antigen rapid diagnostic tests (RDT) for SARS-CoV-2 are fast, broadly available, and inexpensive. Despite this, reliable clinical performance data is sparse. Methods In a prospective performance evaluation study, RDT from three manufacturers (NADAL, Panbio, MEDsan) were compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) in 5 068 oropharyngeal swabs for detection of SARS-CoV-2 in a hospital setting. Viral load was derived from standardized RT-qPCR Cycle threshold (Ct) values. The data collection period ranged from November 12, 2020 to February 28, 2021. Findings Overall, sensitivity of RDT compared to RT-qPCR was 42.57% (95% CI 33.38%-52.31%), and specificity 99.68% (95% CI 99.48%-99.80%). Sensitivity declined with decreasing viral load from 100% in samples with a deduced viral load of 10^8 SARS-CoV-2 RNA copies per ml to 8.82% in samples with a viral load lower than 104 SARS-CoV-2 RNA copies per ml. No significant differences in sensitivity or specificity could be observed between the three manufacturers, or between samples with and without spike protein variant B.1.1.7. The NPV in the study cohort was 98.84%; the PPV in persons with typical COVID-19 symptoms was 97.37%, and 28.57% in persons without or with atypical symptoms. Interpretation RDT are a reliable method to diagnose SARS-CoV-2 infection in persons with high viral load. RDT are a valuable addition to RT-qPCR testing, as they reliably detect infectious persons with high viral loads before RT-qPCR results are available. Funding German Federal Ministry for Education and Science (BMBF), Free State of Bavaria

scholarly journals Performance of a True Point-of-Care Assay for HIV-1/2 Viral Load Measurement at Antenatal and Postpartum Services

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
B. Meggi ◽  
T. Bollinger ◽  
A. Zitha ◽  
C. Mudenyanga ◽  
A. Vubil ◽  
...  
Keyword(s):  
Viral Load ◽  
Point Of Care ◽  
Viral Load Measurement ◽  
Load Measurement ◽  
Hiv 1 ◽  
True Point ◽  
Point Of Care Assay

Performance and usability of mPIMA™ HIV 1/2 viral load test in point of care settings in Kenya

2019 ◽  
Vol 121 ◽  
pp. 104202
Author(s):  
Priska Bwana ◽  
Joshua Ageng’o ◽  
Jeff Danda ◽  
Joseph Mbugua ◽  
Allan Handa ◽  
...  
Keyword(s):  
Viral Load ◽  
Point Of Care ◽  
Load Test ◽  
Viral Load Test ◽  
Hiv 1
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