Performance evaluation of the Aptima® HCV Quant Dx assay for hepatitis C virus (HCV) RNA detection and quantification in comparison to the Abbott RealTime HCV assay

Evaluation of the Aptima HCV Quant Dx Assay Using Serum and Dried Blood Spots

Hepatitis C virus (HCV) RNA quantitation is the primary method by which active HCV infections are identified and the response to direct-acting antiviral therapy is monitored. This study describes the evaluation of the Aptima HCV Quant Dx assay (Aptima HCV) performed on the Panther system. The clinical performance of Aptima HCV was compared to that of the Cobas AmpliPrep/Cobas TaqMan HCV test v2.0 (CAP/CTM). Overall agreement was 84.9% (186/219) with a kappa statistic of 0.755 (standard error, 0.037; 95% confidence interval [CI], 0.682 to 0.828). Passing-Bablok regression of log₁₀ IU/ml values revealed a regression line of Y = 1.163 × X - 0.991 (95% CI of the slope, 1.103 to 1.221, and intercept, -1.341 to -0.642). The 95% lower limit of detection (LLOD) for Aptima HCV on dried blood spot (DBS) samples was calculated to be 2.43 log₁₀ IU/ml (267 IU/ml; 95% CI, 2.31 to 2.73 log₁₀ IU/ml [204 to 540 IU/ml]). A comparison of Aptima HCV testing on paired DBS and serum specimens collected from patients at the time of routine blood collection for CAP/CTM demonstrated an overall agreement of 90.1% (82/91) with a kappa statistic of 0.657 (standard error, 0.101; 95% CI, 0.458 to 0.855). In conclusion, Aptima HCV provides a suitable alternative for HCV RNA testing on serum and DBS samples.

Performance evaluation of the Hologic Aptima HCV Quant Dx assay for detection of HCV RNA from dried blood spots

BACKGROUND

The availability of effective direct-acting antiviral therapy for hepatitis C virus (HCV) has led to a need for simplified diagnostic pathways. Barriers to treatment uptake, specifically in people who inject drugs and in remote and resource limited settings, may be overcome by utilizing novel collection methods, such as dried blood spots (DBS). However, there are currently no registered assays for HCV RNA testing from DBS samples.

OBJECTIVES

To evaluate the sensitivity and specificity of the Aptima HCV Dx Quant assay for HCV RNA detection in DBS samples STUDY DESIGN: 107 paired venepuncture and DBS samples from HCV antibody positive individuals were analyzed for HCV RNA on the Aptima HCV Dx Quant and Roche CAP/CTM (gold standard) HCV assays.

RESULTS

78% (n=83) had detectable HCV RNA in plasma. Sensitivity of the Aptima assay for HCV RNA detection in DBS was 96.4% (95% CI 89.8-99.3%) and specificity was 95.8% (95% CI 78.8-99.9%). Sensitivity for HCV RNA detection in DBS using a quantitative threshold of ≥15 IU/mL in plasma was 95.1% (95% CI 88%-98.7%) and specificity was 96.0% (95% CI 79.7%-99.9%). The sensitivity of HCV RNA detection in DBS using a quantitative threshold of ≥1000 IU/mL (based on a clinically relevant threshold) was 100% (95% CI 95.3-100%) and specificity was 100% (95% CI 88.4-100%).

CONCLUSIONS

Our data indicates that the Aptima HCV Dx Quant can detect active HCV infection from a DBS sample with good sensitivity and specificity, particularly when using a threshold of ≥1000 IU/mL.

Evaluating the aptima HIV-1 quant Dx, HCV quant Dx and HBV quant assays against the Abbott HIV-1, HCV and HBV RealTime assays

BACKGROUND

Viral load measurement is routine for the management of patients infected with HIV, HCV or HBV, using sensitive, quantitative, nucleic acid amplification tests (NAATs). However, platforms are not equivalent in terms of turnaround time, random access capability and operator hands-on time.

OBJECTIVES AND STUDY DESIGN

We compared the performance of the Hologic Panther transcription-mediated amplification based Aptima assays for HIV, HBV and HCV viral load measurement with the corresponding Abbott m2000 RealTime assays. All Aptima assays were run according to the manufacturer's instructions, on archived patient samples for HIV (n = 251 including subtypes 01_AE, A (A1), B, BG recombinant, C CRF02_AG and G), HBV (n = 117 including genotypes A, B, C and D) and HCV (n = 82 including genotypes 1, 2, 3 and 4). Additional testing was performed with WHO international standards and expanded HIV-1 subtype and HCV NIBSC genotype panels.

RESULTS

The Hologic Panther Aptima assays for HIV-1 RNA, HBV DNA and HCV RNA viral load measurements performed equivalently to the Abbott m2000 RealTime assays. The performance of the Aptima assays was also acceptable on the WHO and NIBSC standards and subtype/genotype panels.

CONCLUSIONS

The Aptima Panther platform offers equivalent clinical performance for the viral load measurement of these three viruses, with the added benefits of reduced turnaround time, random access capability and reduced 'hands-on time' for staff, resulting in a potentially superior workflow for diagnostic laboratories.

Analytical and clinical performance of the Hologic Aptima HCV Quant Dx Assay for the quantification of HCV RNA in plasma samples

BACKGROUND

Chronic hepatitis C virus (HCV) infection can be effectively treated with directly acting antiviral (DAA) therapy. Measurement of HCV RNA is used to evaluate patient compliance and virological response during and after treatment.

OBJECTIVES

To compare the analytical performance of the Aptima HCV Quant Dx Assay (Aptima) and the COBAS Ampliprep/COBAS TaqMan HCV Test v2.0 (CAPCTMv2) for the quantification of HCV RNA in plasma samples, and compare the clinical utility of the two tests in patients undergoing treatment with DAA therapy.

STUDY DESIGN

Analytical performance was evaluated on two sets of plasma samples: 125 genotyped samples and 172 samples referred for quantification of HCV RNA. Furthermore, performance was evaluated using dilutions series of four samples containing HCV genotype 1a, 2b, 3a, and 4a, respectively. Clinical utility was evaluated on 118 plasma samples obtained from 13 patients undergoing treatment with DAAs.

RESULTS

Deming regression of results from 187 plasma samples with HCV RNA >2 Log IU/mL indicated that the Aptima assay quantified higher than the CAPCTMv2 test for HCV RNA >4.9 Log IU/mL. The linearity of the Aptima assay was excellent across dilution series of four HCV genotypes (slope of the regression line: 1.00-1.02). The Aptima assay detected significantly more replicates below targeted 2 Log IU/mL than the CAPCTMv2 test, and yielded clearly interpretable results when used to analyze samples from patients treated with DAAs.

CONCLUSIONS

The analytical performance of the Aptima assay makes it well suited for monitoring patients with chronic HCV infection undergoing antiviral treatment.