(232 days)
The Theranos™ HSV-1 IgG Assay is a chemiluminescent immunoassay intended for the qualitative detection of IgG antibodies to herpes simplex virus type 1 (HSV-1) in human serum, in K2-EDTA anticoagulated human plasma from venous blood, and in human fingerstick K2-EDTA anticoagulated whole blood obtained with the Theranos Capillary Tubes and Nanotainer Tubes. The test is indicated 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 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 and immunocompromised patients.
The Theranos HSV-1 IgG Assay is for use with the Theranos System which performs automated sample processing steps and result analysis.
The Theranos HSV-1 IgG Assay is for use with the Theranos System. The Theranos System performs automated sample processing steps and analysis to produce the test results.
The Theranos HSV-1 IgG Assay is a three-step sandwich immunoassav with an HSV-1 glycoprotein G (gG) recombinant antigen coated surface, an anti-human IgG detection reagent conjugated to alkaline phosphatase (AP) and chemiluminescent substrate. During the first incubation step, the HSV-1 IgG antibodies present in the positive control and sample bind to the gG recombinant antigen on the coated surface. Following the first incubation step, unbound materials are removed with a wash cycle. Then the detection reagent-AP conjugate is added and during the second incubation step, the detection reagent-AP conjugate reacts with the HSV-1 IgG antibodies already bound to the capture surface. Following the second incubation, unbound materials are removed with a wash cycle. The chemiluminescent substrate is added to the capture-analyte-detection complex during the third incubation step to initiate the chemiluminescence reaction. Light generated by this reaction is detected and analyzed by the Theranos System using a calibration function to determine the cut-off index (COI) values for the sample and controls. The results for the Positive and Negative controls must be within specified limits for a run to be considered valid.
The Theranos Herpes Simplex Virus-1 (HSV-1) IgG Assay is a chemiluminescent immunoassay for the qualitative detection of IgG antibodies to HSV-1 in human serum, K2-EDTA anticoagulated human plasma from venous blood, and human fingerstick K2-EDTA anticoagulated whole blood. It is intended to aid in the presumptive diagnosis of HSV-1 infection in sexually active individuals and expectant mothers.
Here's an analysis of the acceptance criteria and supporting study details:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state a consolidated table of acceptance criteria for all performance aspects. However, based on the studies described, we can infer some key criteria and the reported performance. The most critical performance metrics for a diagnostic assay like this are Sensitivity and Specificity in the intended use populations.
| Performance Metric | Acceptance Criteria (Inferred from Study Design & Conclusions) | Reported Device Performance (Sexually Active Adults) | Reported Device Performance (Pregnant Women) | Reported Device Performance (Low Prevalence Population) |
|---|---|---|---|---|
| Sensitivity | Not explicitly stated but expected to be high for diagnostic aid. Implied acceptable range is within 95% Confidence Interval established by the study. | 95.1% (90.3-97.6% CI) | 97.9% (94.8-99.2% CI) | 97.0% (84.7-99.5% CI) |
| Specificity | Not explicitly stated but expected to be high for diagnostic aid. Implied acceptable range is within 95% Confidence Interval established by the study. | 97.4% (92.7-99.1% CI) | 95.2% (89.3-98.0% CI) | 100% (92.7-100% CI) |
| Precision (Venous Serum) | Max %CV of 14.2% across different conditions (inferred from study conclusion). | 10.2% to 14.2% | N/A | N/A |
| Precision (Fingerstick Whole Blood) | Max %CV of 12.2% across different conditions (inferred from study conclusion). | N/A | 10.9% to 12.2% | N/A |
| Reproducibility (Total Imprecision) | %CV of 11.4% for COI >= 0.5, SD of 0.022 for COI 0.5)** | 0.5)** |
§ 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).