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The LIAISON® HSV-1 Type Specific IgG assay is a chemiluminescent immunoassay (CLIA) to be used with the LIAISON® Analyzer for the qualitative determination of type specific IgG antibodies to Herpes Simplex Virus Type 1 (HSV-1) in human serum, The assay is indicated for testing sexually active adults or expectant mothers to aid in the presumptive diagnosis of HSV-1 infection.

The LIAISON® HSV-1 Type Specific IgG assay has not been established for use in the pediatrics population, for neonatal screening, or for testing immunocompromised patients. The assay is neither FDA cleared nor approved for testing blood or plasma donors.

The LIAISON® Control HSV-1 (negative and positive) are intended for use as assayed quality control samples to monitor the performance of the LIAISON® HSV-1 Type Specific IgG assay.

The method for qualitative determination of specific IgG to HSV-1 is an indirect chemiluminescence immunoassay (CLIA). HSV-1 gG1recombinant antigen is used for coating magnetic particles (solid phase) and a mouse monoclonal antibody is linked to an isoluminol derivative (isoluminol-antibody conjugate). During the first incubation. HSV-1 antibodies present in calibrators, samples or controls bind to the solid phase. During the second incubation, the antibody conjugate reacts with HSV-1 IgG already bound to the solid phase. After each incubation the unbound material is removed with a wash cycle. Subsequently, the starter reagents are added and a flash chemiluminescence reaction is thus induced. The light signal, and hence the amount of isoluminol-antibody conjugate, is measured by a photomultiplier as relative light units (RLU) and is indicative of HSV-1 IgG present in calibrators, samples or controls.

Here's a summary of the acceptance criteria and study details for the DiaSorin LIAISON® HSV-1 Type Specific IgG assay, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the comparison to the predicate device and the desired performance characteristics for diagnostic assays. While explicit acceptance thresholds (e.g., "sensitivity must be > X%") are not stated, the study aims to demonstrate equivalent performance to the FDA-cleared predicate device across various populations.

2. Sample Size Used for the Test Set and Data Provenance

• Total Sample Size for Comparative Clinical Trials: 951 samples
  • "At risk" samples (Sexually Active Adults): 401
  • Expectant Mothers: 430
  • Low Prevalence population: 120
• Data Provenance: Samples were collected in the Northeastern United States. The study was retrospective, using collected samples.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

The ground truth was primarily established using an FDA-cleared Immunoblot (Focus Diagnostics HerpeSelect® 1 and 2 Immunoblot IgG) as the reference method. For samples that were "repeat Equivocal" on the predicate device, they were sent for Western Blot testing at a Reference Laboratory.

• No specific number of human experts for interpreting the Immunoblot or Western Blot is mentioned, nor are their qualifications. It's implied that these reference methods were performed and interpreted according to their standard operating procedures at designated facilities (a reference laboratory for Western Blot).

4. Adjudication Method for the Test Set

• The primary method of determining the true status of a sample (ground truth) was through an FDA-cleared Immunoblot.
• For equivocal results on the predicate Immunoblot, samples were repeat tested. If still equivocal, they were sent for Western Blot testing. This effectively acts as an adjudication step for indeterminate results from the primary reference method.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

• No MRMC comparative effectiveness study was done. This study evaluates a laboratory assay (immunoassay) and not an imaging or interpretive AI device that assists human readers.

6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done

• Yes, a standalone study was done. The LIAISON® HSV-1 Type Specific IgG assay is an automated chemiluminescent immunoassay run on the LIAISON® Analyzer. Its performance (sensitivity, specificity, agreement) was determined directly by comparing its results to a reference method (Immunoblot/Western Blot) without human intervention in the interpretation of the LIAISON® device's raw output.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

• The primary ground truth was established by an FDA-cleared Immunoblot.
• For equivocal cases from the Immunoblot, a Western Blot was used as the confirmatory ground truth. Both are laboratory-based diagnostic tests considered highly reliable for HSV-1 type-specific IgG detection.
• Additionally, a CDC panel of characterized serum samples was used to further evaluate agreement.

8. The Sample Size for the Training Set

• The document does not provide information regarding a distinct training set. This is a traditional in vitro diagnostic device, not typically a machine learning or AI-driven system that requires a separate "training set" in the same sense. The device's parameters would have been optimized during its development, likely using internal validation samples, but this information is not detailed in the 510(k) summary.

9. How the Ground Truth for the Training Set was Established

• As no specific training set for a machine learning model is described, the method for establishing its ground truth is not applicable or provided. For a traditional immunoassay, calibration and internal validation would involve characterized samples whose status is known through established reference methods, but specifics are not mentioned here.

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