Dataset Information

Hepatitis C virus RNA quantitation in venous and capillary small-volume whole-blood samples.

ABSTRACT: Quantitation of hepatitis C virus (HCV) RNA in plasma and serum samples is a costly procedure in both time and reagents. Additionally, cell-associated viral RNA may not be detected. This study evaluated the accuracy of HCV RNA quantitation in small-volume whole-blood (WB) samples, which would be appropriate for point-of-care diagnostic devices. HCV RNA was extracted from 222 clinical plasma and WB samples of 82 patients with chronic hepatitis C by a specific locked nucleic acid-mediated capture method and quantified by real-time reverse transcription-PCR. The results were compared to the reference plasma viral load determined with the COBAS AmpliPrep/TaqMan (CAP/CTM) HCV test. This assay had an analytical sensitivity of 9 IU per 10-microl sample (95% limit of detection [95% LOD]), a linearity range of 500 to 5 x 10(6) IU/ml, and was accurate in testing 10 HCV subtypes (<0.22 log10 unit) in plasma. The assay was matrix equivalent for plasma and WB samples (coefficient of determination [R2] of 0.943) and had a specificity of 100% (n = 20) in WB samples. The HCV RNA concentration in clinical WB samples exceeded the estimated hematocrit-corrected plasma viral loads by 0.22 log10 unit, but absolute quantitation results in plasma and WB samples were identical (95% confidence interval, -0.06 to 0.04 log10 unit). The sensitivity in WB samples was 100% (n = 141) for plasma concentrations above the 95% LOD. Quantitation results in 10-microl WB samples correlated linearly with the CAP/CTM HCV plasma test results (R2 = 0.919; n = 140) and did not differ between capillary and venous samples (R2 = 0.960; n = 40). This study shows that HCV RNA quantitation in 10-microl WB samples is appropriate for monitoring viral loads of >900 IU/ml, although the use of WB does not increase the diagnostic sensitivity.

SUBMITTER: Bruns T

PROVIDER: S-EPMC2756920 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Hepatitis C virus RNA quantitation in venous and capillary small-volume whole-blood samples.

Bruns Tony T Steinmetzer Katrin K Ermantraut Eugen E Stallmach Andreas A

Journal of clinical microbiology 20090819 10

Quantitation of hepatitis C virus (HCV) RNA in plasma and serum samples is a costly procedure in both time and reagents. Additionally, cell-associated viral RNA may not be detected. This study evaluated the accuracy of HCV RNA quantitation in small-volume whole-blood (WB) samples, which would be appropriate for point-of-care diagnostic devices. HCV RNA was extracted from 222 clinical plasma and WB samples of 82 patients with chronic hepatitis C by a specific locked nucleic acid-mediated capture ...[more]

PMID: 19692560

Similar Datasets

Project description:BackgroundGuidelines for the emergency management of mild traumatic brain injury have been used for over a decade and are considered safe. However, they recommend computerized tomography for at least half of these patients. The Scandinavian Neurotrauma Committee guideline uses serum S100B protein level to rule out intracranial hemorrhage. Analysis of capillary serum S100B protein level has not yet been employed for this purpose. The primary aim of this study was to investigate the correlation and agreement of capillary and venous serum S100B protein level over a spectrum of concentrations typical for mild traumatic brain injury.MethodsEighteen patients with traumatic intracranial hemorrhage and 39 volunteers without trauma to the head within the past 7 days were recruited. Blood was sampled from patients with intracranial hemorrhage daily up to four consecutive days and healthy volunteers were sampled once during the study. One venous and two capillary samples were drawn at each sampling event. Samples were analyzed using the Cobas e411 S100 electrochemiluminescence assay.ResultsMedian serum S100B protein level of capillary sampling 1 was 0.12 (IQR 0.075-0.21) μg/l and median serum S100B protein level of capillary sampling 2 was 0.13 (IQR 0.08-0.22) μg/l. Median serum S100B protein level of all venous samples was 0.05 (IQR 0.03-0.07) μg/l. Correlation plots of capillary and venous samples showed poor correlation and Bland-Altman plots showed a large dispersion of samples and wide limits of agreement.ConclusionThe results of this study indicate that correlation and agreement between capillary and venous samples are low, and because of this, we cannot recommend studies on capillary serum S100B protein level to rule out intracranial hemorrhage in mild traumatic brain injury. Given the limitations of the current sampling and analysis methods of capillary protein S100B protein level, we conclude that evaluating its predictive ability to rule out intracranial hemorrhage should be withheld until more reliable methods can be incorporated into the study design.

Project description:BackgroundLoa loa and Mansonella perstans-the causative agents of loiasis and mansonellosis-are vector-borne filarial parasites co-endemic in sub-Saharan Africa. Diagnosis of both infections is usually established by microscopic analysis of blood samples. It was recently established that the odds for detecting Plasmodium spp. is higher in capillary (CAP) blood than in venous (VEN) blood. In analogy to this finding this analysis evaluates potential differences in microfilaraemia of L. loa and M. perstans in samples of CAP and VEN blood.MethodsRecruitment took place between 2015 and 2019 at the CERMEL in Lambaréné, Gabon and its surrounding villages. Persons of all ages presenting to diagnostic services of the research center around noon were invited to participate in the study. A thick smear of each 10 microliters of CAP and VEN blood was prepared and analysed by a minimum of two independent microscopists. Differences of log2-transformed CAP and VEN microfilaraemia were computed and expressed as percentages. Furthermore, odds ratios for paired data were computed to quantify the odds to detect microfilariae in CAP blood versus in VEN blood.ResultsA total of 713 participants were recruited among whom 52% were below 30 years of age, 27% between 30-59 years of age and 21% above 60 years of age. Male-female ratio was 0.84. Among 152 participants with microscopically-confirmed L. loa infection median (IQR) microfilaraemia was 3,650 (275-11,100) per milliliter blood in CAP blood and 2,775 (200-8,875) in VEN blood (p<0.0001), while among 102 participants with M. perstans this was 100 (0-200) and 100 (0-200), respectively (p = 0.44). Differences in linear models amount up to an average of +34.5% (95% CI: +11.0 to +63.0) higher L. loa microfilaria quantity in CAP blood versus VEN blood and for M. perstans it was on average higher by +24.8% (95% CI: +0.0 to +60.5). Concordantly, the odds for detection of microfilaraemia in CAP samples versus VEN samples was 1.24 (95% CI: 0.65-2.34) and 1.65 (95% CI: 1.0-2.68) for infections with L. loa and M. perstans, respectively.ConclusionThis analysis indicates that average levels of microfilaraemia of L. loa are higher in CAP blood samples than in VEN blood samples. This might have implications for treatment algorithms of onchocerciasis and loiasis, in which exact quantification of L. loa microfilaraemia is of importance. Furthermore, the odds for detection of M. perstans microfilariae was higher in CAP than in VEN blood which may pre-dispose CAP blood for detection of M. perstans infection in large epidemiological studies when sampling of large blood quantities is not feasible. No solid evidence for a higher odds of L. loa microfilariae detection in CAP blood was revealed, which might be explained by generally high levels of L. loa microfilaraemia in CAP and VEN blood above the limit of detection of 100 microfilariae/ml. Yet, it cannot be excluded that the study was underpowered to detect a moderate difference.

Dataset Information

Hepatitis C virus RNA quantitation in venous and capillary small-volume whole-blood samples.

Publications

Hepatitis C virus RNA quantitation in venous and capillary small-volume whole-blood samples.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets