(146 days)
The Roche Elecsys HSV-1 IgG immunoassay is a test for the in vitro qualitative determination of IgG class antibodies to HSV-1 in human serum and lithium-heparin plasma, K2—EDTA plasma, and K3—EDTA plasma. The test is intended for sexually active individuals and expectant mothers as an aid in the presumptive diagnosis of HSV-1 infection. The predictive value of positive and negative results depends on the population's prevalence and the pretest likelihood of HSV-1. The electrochemiluminescence immunoassay "ECLIA" is intended for use on Elecsys and cobas e immunoassay analyzers. The test is not FDA cleared for screening blood or plasma donors. The performance of this assay has not been established for use in a pediatric population, neonates, immunocompromised patients, or for use at point of care facilities.
PreciControl HSV is used for quality control of the Elecsys HSV-1 IgG immunoassay on the Elecsys and cobas e immunoassay analyzers.
(1) The Elecsys HSV-1 IgG immunoassay is a two-step sandwich immunoassay with streptavidin microparticles, biotinylated recombinant HSV-1-specific antigen labeled with a ruthenium complex and electrochemiluminescence detection. This assay is a qualitative test based on a cut-off formula dependent on the negative and positive calibrators. Cut-off index (COI) is based on the ratio of assay signal to cut-off signal (also abbreviated s/co). COI values greater than or equal to 1.0 are considered positive for the presence of anti-HSV-1 IgG antibody. Results are determined using a two-point calibration. The test system contains the human serum-based calibrators intended for use with the system. (2) PreciControl HSV contains lyophilized control serum based on human serum. The controls are used for monitoring the accuracy of the Elecsys HSV-1 IgG immunoassay.
Here's an analysis of the acceptance criteria and study details for the Elecsys HSV-1 IgG Immunoassay, extracted from the provided 510(k) summary:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the Elecsys HSV-1 IgG Immunoassay are demonstrated through its agreement with a Western Blot (WB) assay within different cohorts. The performance is reported as Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA).
| Performance Metric | Cohort | Acceptance Criteria (Implicit, based on reported performance) | Reported Device Performance (95% CI) |
|---|---|---|---|
| Positive Percent Agreement (PPA) | Expectant Mother Cohort | Not explicitly stated as a numerical criterion, but demonstrated by achieving the reported value. | 91.0% (82.4-96.3%) |
| Sexually Active Cohort | Not explicitly stated as a numerical criterion, but demonstrated by achieving the reported value. | 94.2% (91.3-96.4%) | |
| Low Prevalence Cohort | Not explicitly stated as a numerical criterion, but demonstrated by achieving the reported value. | 94.9% (87.4-98.6%) | |
| Negative Percent Agreement (NPA) | Expectant Mother Cohort | Not explicitly stated as a numerical criterion, but demonstrated by achieving the reported value. | 95.7% (85.5-99.5%) |
| Sexually Active Cohort | Not explicitly stated as a numerical criterion, but demonstrated by achieving the reported value. | 90.3% (85.9-93.8%) | |
| Low Prevalence Cohort | Not explicitly stated as a numerical criterion, but demonstrated by achieving the reported value. | 96.7% (91.8-99.1%) | |
| Agreement with CDC Panel | (General) | 100% agreement. | 100% |
Note: The document implicitly establishes the reported performance as meeting acceptance criteria by presenting it in the context of substantial equivalence.
2. Sample Sizes Used for the Test Set and Data Provenance
- Expectant Mother Cohort: n=125
- Sexually Active Cohort: n=600
- Low Prevalence Cohort: n=200
- CDC Panel: Not explicitly stated, but 100% agreement indicates a comparison against a reference standard panel.
Data Provenance: The document does not explicitly state the country of origin for the data or whether it was retrospective or prospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The ground truth for the device's performance comparison was established using a Western Blot (WB) assay as the comparator (predicate device: Focus HerpeSelect 1 and 2 Immunoblot IgG (K000238)). This is a laboratory test, not an interpretation by human experts.
For the "Agreement with CDC Panel," the CDC panel itself represents a reference standard, implying established truth without direct mention of human experts in this section.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method involving multiple human readers for the test set. The direct comparison is between the candidate device (Elecsys HSV-1 IgG Immunoassay) and a predicate Western Blot assay.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. The study compares the performance of the device against a predicate laboratory assay (Western Blot), not against human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, the performance study performed appears to be a standalone assessment of the Elecsys HSV-1 IgG Immunoassay. The assay produces a quantitative result (Cut-off Index, COI) that is interpreted as reactive (≥ 1.0 COI) or non-reactive (
§ 866.3305 Herpes simplex virus serological assays.
(a)
Identification. Herpes simplex virus serological assays are devices that consist of antigens and antisera used in various serological tests to identify antibodies to herpes simplex virus in serum. Additionally, some of the assays consist of herpes simplex virus antisera conjugated with a fluorescent dye (immunofluorescent assays) used to identify herpes simplex virus directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by herpes simplex viruses and provides epidemiological information on these diseases. Herpes simplex viral infections range from common and mild lesions of the skin and mucous membranes to a severe form of encephalitis (inflammation of the brain). Neonatal herpes virus infections range from a mild infection to a severe generalized disease with a fatal outcome.(b)
Classification. Class II (special controls). The device is classified as class II (special controls). The special control for the device is FDA's revised guidance document entitled “Class II Special Controls Guidance Document: Herpes Simplex Virus Types 1 and 2 Serological Assays.” For availability of the guidance revised document, see § 866.1(e).