The study aims to evaluate 13 different HCV RDTs (10 on-market, 3 under development) for their diagnostic performance and operational characteristics in archived EDTA plasma samples, originating from patients from different geographical regions (Nigeria, Georgia, Cambodia, Belgium) and with or without HIV co-infection.

Background and rationale:

Screening of past exposure to Hepatitis C Virus (HCV) infection is done by detection of HCV specific antibodies. In Low and Middle Income Countries (LMICs), where equipped laboratories and trained staff are limited, Rapid Diagnostic Tests (RDTs) are widely used for HCV screening. Although many RDTs are available on the market, only some of them received CE-IVD marking and only two have been validated by WHO Pre-Qualification (PQ). More quality-assured tests are needed to establish effective screening programmes in LMICs.

Furthermore, an important research gap is the lack of studies on the impact of HIV positivity on RDT performance, as it is estimated that 2-15% of people living with HIV are co-infected with HCV.

The evaluation of RDT performance on clinical samples collected in different geographic regions as well as from HIV co-infected individuals, would allow to identify tests with a performance meeting or having the potential to meet WHO quality standards.

Concept:

This is a multicenter laboratory evaluation study using archived, frozen plasma samples.

Sensitivity and specificity of RDTs will be measured against a composite reference standard that consists of two WHO prequalified Enzyme Immunoassays (EIAs) (Murex Anti-HCV EIA version 4.0, Fujirebio Innotest HCV Ab IV) and a Line Immunoassay (LIA) (MP Diagnostics HCV blot 3.0). Samples are assigned as anti-HCV negative or anti-HCV positive based on the results of all three assays.

RDT results will be read by three independent readers to evaluate inter-reader variability (differences in visual interpretation, i.e. presence or absence of test and control line).

For each RDT, two independently produced lots will be tested for each sample to assess lot-to-lot variability (differences in RDT result for the same sample). Furthermore, rate of invalid runs will be assessed and a technical appraisal is completed for each RDT.

Primary objective:

1.1 Evaluation of sensitivity and specificity of anti-HCV RDTs in archived plasma samples, collected from HCV-infected and HCV-uninfected individuals not co-infected with HIV, measured against the composite reference standard composed of two Enzyme Immunoassays (EIAs) and a Line Immunoassay (LIA).

1.2 Evaluation of sensitivity and specificity of anti-HCV RDTs in archived plasma samples, collected from HCV-infected and HCV-uninfected individuals who are all co-infected with HIV, measured against the composite reference standard composed of two EIAs and a LIA.

Secondary objectives:

2.1 Evaluation of sensitivity and specificity of anti-HCV RDTs in archived plasma samples, collected from HCV-infected and HCV-uninfected individuals, both co-infected and not with HIV, measured against the composite reference standard composed of two EIAs and a LIA.

2.2 Evaluation of operational characteristics of anti-HCV RDTs: inter-reader variability; lot-to-lot variability; rate of invalid runs 2.3 Technical appraisal of each RDT product per manufacturer

Inclusion Criteria of archived samples:

• Non-hemolytic plasma samples with EDTA used as anticoagulant
• Sample were frozen at -20°C or lower on the day of processing and stored at -20°C or lower until they are used in this study
• Samples pre-characterized for, HCV, HIV serology status using assays routinely used at the sites and approved for diagnostic use by a local health authority. If available, samples should also be characterized for HBV status.
• Samples taken from subjects aged ≥18 years
• Availability of informed consent to use the sample in future research

Exclusion Criteria:

- Samples not stored correctly

Samples tested in Belgium originate from Cambodia (80%) and Belgium (20%). Cambodian samples are leftovers from samples collected during a cross-sectional study of hepatitis C among people living with HIV (De Weggheleire, A. 2017); samples in Belgium were collected and archived during routine patient care visits to the HIV clinic.

Samples in Nigeria originate from routine diagnostic activities at NIMR as well as the AIDS Prevention Initiative Nigeria (APIN) PEPFAR Program Sample/Data Bank setup at NIMR and the Lagos University Teaching Hospital.

Samples tested in Georgia are leftover samples from a previous FIND HCV study (Reipold, E.I., 2019), as well as archived routine diagnostic samples from the site.

Percent sample distribution per site:

Belgium: 38% Nigeria: 41% Georgia: 21%