(219 days)
The Zeus Scientific, Inc. AtheNA Multi-Lyte® ToRCH IgG Plus Test System is intended for the qualitative detection of specific human IgG class antibodies to Toxoplasma gondii (T.gondii), Rubella, Cytomegalovirus (CMV) and HSV 1 & 2 in human serum. The results of this assay are intended to be used as an aid in the assessment of serological status to Toxoplasma gondii, Rubella and CMV. For HSV 1 and HSV 2, the test is indicated for sexually active adults and expectant mothers, as an aid for presumptively diagnosing Herpes Simplex 1 and Herpes Simplex 2.
The test is not intended for use in screening blood or plasma donors.
The performance of this assay has not been established for use in a pediatric population, neonatal screening, immunocompromised or immunosuppressed patients or for use at point of care facilities.
The Zeus Scientific, Inc. AtheNA Multi-Lyte® ToRCH IgG Plus Test System is a multiplex immunoassav intended for the simultaneous qualitative detection and differentiation of specific human IgG class antibodies to Toxoplasma gondii, Rubella, Cytomegalovirus (CMV), Herpes Simplex 1 (HSV-1) and Herpes Simplex 2 (HSV-2) in human serum. The results of this assay are intended to be used as an aid in the assessment of a patient's serological status to infection with Toxoplasma gondii, Rubella, CMV, HSV 1 and HSV 2 and in the determination of immune status of individuals including pregnant women. The test system is comprised of the AtheNA Multi-Lyte test kit, software and the Luminex Corp instrument.
The AtheNA Multi-Lyte ToRCH IgG Plus Test System provides the following components:
Reactive Reagents:
All reactive reagents contain sodium azide as a preservative at a concentration of 0.1% (w/v).
- Multiplexed bead suspension 1. Ready to use, 5.5 mL bottle. The suspension contains separate distinguishable 5.6 micron polystyrene beads that are conjugated with:
. Toxo grade 2 antigen
. Rubella K2S grade antigen
CMV grade 2
. HSV-1 type-specific recombinant gG-1 protein antigen
. HSV-2 gG-2 type-specific recombinant gG-2 protein antigen
The bead mix also contains one bead set designed to detect non-specific antibodies in the patient sample (if present) and four separate bead sets used for assay calibration.
- Conjugate: Phycoerythrin conjugated goat anti-human IgG (y chain specific). Ready to use, 15 mL amber bottle.
- Human positive serum control 1. One, 0.2 mL vial.
- Human positive serum control 2. One, 0.2 mL vial.
- Human negative serum control. One, 0.2 mL vial.
- SAVe Diluent®. One 50 mL bottle containing phosphate-buffered-saline. Ready to use. NOTE, the sample diluent will change color in the presence of serum.
- Wash Buffer Concentrate: dilute 1 part concentrate + 9 parts deionized or distilled water. One bottle containing 10 X concentrate of phosphate buffered saline.
Non-Reactive Reagents
- One, 96-well filtration plate for rinsing the microspheres
- Data Labels: One label is adhered to the inside lid of the kit box and a second label is inside the kit box.
- Package Insert providing instructions for use
- Calibration CD: a compact disc that includes all lot-specific kit calibration values required for specimen analysis and assay quality control
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device: AtheNA Multi-Lyte® ToRCH IgG Plus Test System
Submission Purpose: Simultaneous qualitative detection and differentiation of specific human IgG class antibodies to Toxoplasma gondii (Toxo), Rubella, Cytomegalovirus (CMV), and Herpes Simplex 1 (HSV-1) and Herpes Simplex 2 (HSV-2). The results aid in assessing serological status for Toxo, Rubella, and CMV, and for presumptively diagnosing HSV-1 and HSV-2 in sexually active adults and expectant mothers.
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" as a single, consolidated list with numerical targets for each performance metric (e.g., "Sensitivity must be >95%"). Instead, it presents the results of comparative studies against predicate devices and CDC panels. The implicit acceptance criterion is that the device demonstrates performance substantially equivalent to or in agreement with these established methods.
The table below summarizes the reported device performance from the clinical studies for various analytes and populations, indicating successful agreement or high percentage agreement where applicable. For Toxoplasma, Rubella, and CMV in the "Individuals Undergoing ToRCH Antibody Assessment," the columns refer to "Positive Percent Agreement (PPA)" which represents sensitivity and "Negative Percent Agreement (NPA)" which represents specificity. For HSV-1 and HSV-2 in "Sexually Active Adults", it uses "Sensitivity" and "Specificity." For the CDC panels, it also uses "PPA" and "NPA" against the CDC results.
| Analyte (Population) | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Individuals Undergoing ToRCH Antibody Assessment | ||
| Toxoplasma (Positive) | High agreement with predicate device for positive samples | PPA = 99.3% (136/137) (95% CI: 96.0% - 100%) |
| Toxoplasma (Negative) | High agreement with predicate device for negative samples | NPA = 98.0% (450/514) (95% CI: 98.0% - 99.9%) (Typo in original doc for 95.7%) |
| Rubella (Positive) | High agreement with predicate device for positive samples | PPA = 98.5% (533/541) (95% CI: 97.1% - 99.4%) |
| Rubella (Negative) | High agreement with predicate device for negative samples | NPA = 87% (60/69) (95% CI: 76.7% - 93.9%) |
| CMV (Positive) | High agreement with predicate device for positive samples | PPA = 99.6% (450/452) (95% CI: 98.4% - 100%) |
| CMV (Negative) | High agreement with predicate device for negative samples | NPA = 91.3% (181/197) (95% CI: 87.2% - 95.3%) |
| Sexually Active Adults | ||
| HSV-1 (Positive) | High sensitivity | Sensitivity = 98.6% (418/424) (95% CI: 97.0% - 99.5%) |
| HSV-1 (Negative) | High specificity | Specificity = 94.6% (163/172) (95% CI: 90.3% - 97.6%) |
| HSV-2 (Positive) | High sensitivity | Sensitivity = 96.9% (127/131) (95% CI: 92.4% - 98.8%) |
| HSV-2 (Negative) | High specificity | Specificity = 93.5% (433/463) (95% CI: 90.9% - 95.6%) |
| Pregnant Women | ||
| Toxoplasma (Positive) | High agreement with predicate device for positive samples | PPA = 91.3% (21/23) (95% CI: 72.0% - 98.9%) |
| Toxoplasma (Negative) | High agreement with predicate device for negative samples | NPA = 95.3% (170/178) (95% CI: 91.3% - 98.0%) |
| Rubella (Positive) | High agreement with predicate device for positive samples | PPA = 99.0% (194/196) (95% CI: 96.4% - 99.9%) |
| Rubella (Negative) | High agreement with predicate device for negative samples | NPA = 100.0% (4/4) (95% CI: 47.3% - 100%) |
| CMV (Positive) | High agreement with predicate device for positive samples | PPA = 98.1% (151/154) (95% CI: 94.4% - 99.6%) |
| CMV (Negative) | High agreement with predicate device for negative samples | NPA = 100.0% (46/46) (95% CI: 93.7% - 100%) |
| HSV-1 (Positive) | High agreement with predicate device for positive samples | PPA = 99.3% (137/138) (95% CI: 96.1% - 100%) |
| HSV-1 (Negative) | High agreement with predicate device for negative samples | NPA = 85.2% (46/54) (95% CI: 72.3% - 93.4%) |
| HSV-2 (Positive) | High agreement with predicate device for positive samples | PPA = 97.1% (68/70) (95% CI: 90.1% - 99.7%) |
| HSV-2 (Negative) | High agreement with predicate device for negative samples | NPA = 92.6% (113/122) (95% CI: 86.5% - 96.6%) |
| Agreement with CDC Panel | ||
| Toxoplasma (Positive) | 100% agreement with CDC panel positives | PPA = 100.0% (70/70) (95% CI: 95.8% - 100.0%) |
| Toxoplasma (Negative) | 100% agreement with CDC panel negatives | NPA = 100.0% (30/30) (95% CI: 90.5% - 100.0%) |
| Rubella (Positive) | 100% agreement with CDC panel positives | PPA = 100.0% (80/80) (95% CI: 96.3% - 100.0%) |
| Rubella (Negative) | 100% agreement with CDC panel negatives | NPA = 100.0% (20/20) (95% CI: 86.1% - 100.0%) |
| CMV (Positive) | 100% agreement with CDC panel positives | PPA = 100.0% (52/52) (95% CI: 94.4% - 100.0%) |
| CMV (Negative) | High agreement with CDC panel negatives | NPA = 95.8% (46/48) (95% CI: 90.2% - 100.0%) |
| HSV-1 (Positive) | 100% agreement with CDC panel positives | PPA = 100.0% (50/50) (95% CI: 94.2% - 100.0%) |
| HSV-1 (Negative) | 100% agreement with CDC panel negatives | NPA = 100.0% (50/50) (95% CI: 94.2% - 100.0%) |
| HSV-2 (Positive) | 100% agreement with CDC panel positives | PPA = 100.0% (48/48) (95% CI: 94.0% - 100.0%) |
| HSV-2 (Negative) | High agreement with CDC panel negatives | NPA = 98.1% (51/52) (95% CI: 94.3% - 100.0%) |
2. Sample Size Used for the Test Set and Data Provenance
The evaluation of the AtheNA Multi-Lyte ToRCH IgG Plus Test System involved several studies:
- Comparative testing of Intended Use Populations (651 samples):
- Sample Size: 651 unselected samples.
- Data Provenance:
- 300 samples from a hospital laboratory in the Mid-Atlantic region (United States).
- 351 samples from a hospital laboratory in the Northeast (United States).
- The samples were "prospectively collected" individuals undergoing ToRCH antibody assessment. They were described as "frozen remnant serum samples" which suggests they might have been collected over a period and then accessed retrospectively for this study. The phrasing "prospectively collected frozen remnant serum samples" can be ambiguous, but generally, "prospectively collected" refers to data collected specifically for the study. However, using "remnant" suggests they were left over from routine testing.
- Data was gathered concurrently with the AtheNA Multi-Lyte test system and predicate assays.
- Pregnant Women Population (200 samples):
- Sample Size: 200 samples.
- Data Provenance: From expectant mothers, sourced from two serum vendors. The samples were "prospectively collected" and were "frozen remnant serum samples". Tested internally at the manufacturer's lab.
- CDC Reference Panels:
- Sample Size:
- Toxo: 100 samples (70 positive, 30 negative)
- Rubella: 100 samples (80 positive, 20 negative)
- CMV: 100 samples (54 positive, 46 negative)
- HSV-1: 100 samples (50 positive, 50 negative)
- HSV-2: 100 samples (48 positive, 52 negative)
- Data Provenance: Masked, well-characterized serum panels from the CDC (Centers for Disease Control and Prevention), a US government agency.
- Sample Size:
- HSV-1 & HSV-2 Low Prevalence Population:
- Sample Size: 67 samples.
- Data Provenance: Serum samples from 18 and 19-year-old subjects previously tested for non-sexual infections. Assessed internally at Zeus. Retrospective.
- Rubella Retrospective Negative Sample Study:
- Sample Size: 100 samples.
- Data Provenance: Pre-selected banked samples of sera previously tested negative for Rubella antibody by the predicate device. Assessed internally at Zeus. Retrospective.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not explicitly mention the number or qualifications of experts used to establish the ground truth for the test sets. Instead, the "ground truth" was established by:
- Predicate assays: The results of FDA-cleared predicate ELISA test systems (Toxo IgG ELISA, Rubella IgG ELISA, CMV IgG ELISA, HerpeSelect 1 and 2 Immunoblot IgG for HSV-1/2) were used as the reference standard for the clinical performance studies in general populations and pregnant women. These predicate devices are themselves validated diagnostic tools.
- CDC Reference Panels: These are "well-characterized" serum panels which implicitly means their status (positive/negative) for the target analytes has been rigorously established, likely through expert consensus and/or a battery of highly sensitive and specific reference methods, although the details are not provided here.
4. Adjudication Method for the Test Set
The document does not describe any explicit adjudication method (like 2+1 or 3+1) for resolving discrepancies between the AtheNA Multi-Lyte system and the predicate devices or CDC panels.
The results are presented as direct comparisons, and for discrepant cases in the Rubella category, a note mentions qualitative differences (e.g., "4/4 discrepant Rubella samples which tested positive by ELISA had low positive values for AtheNA and high negative values for ELISA, 4/4 discrepant Rubella samples which tested positive by AtheNA and equivocal by ELISA had low positive values for ELISA"). This suggests discrepancy analysis was performed but no formal adjudication by an independent panel of experts is explicitly mentioned for overriding results.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This device is an automated in vitro diagnostic assay (multiplex microparticle immunoassay) that generates quantitative/qualitative results, not an imaging AI algorithm requiring human interpretation. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply in this context.
6. If a Standalone Study (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, the studies reported are essentially standalone performance studies. The AtheNA Multi-Lyte® ToRCH IgG Plus Test System is an automated immunoassay system (test kit, software, and Luminex Corp instrument) which provides qualitative detection of antibodies. Its performance is evaluated directly against predicate devices or reference panels without human interpretation influencing the device's output. The results presented (PPA, NPA, Sensitivity, Specificity) are inherent to the device's diagnostic capability.
7. The Type of Ground Truth Used
The ground truth used for the test sets was primarily based on:
- Predicate devices: Established and FDA-cleared immunoassay systems for each analyte (ELISA for Toxo, Rubella, CMV; Immunoblot IgG for HSV-1/2).
- CDC Reference Panels: Well-characterized serum panels with known positive or negative status.
- Previously tested results: For the low prevalence HSV study and retrospective Rubella study, pre-selected banked samples with known results from predicate devices were used.
These are considered established diagnostic results from reference methods or highly characterized samples, rather than pathology or direct outcomes data from patients.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" or its sample size for the AtheNA Multi-Lyte® ToRCH IgG Plus Test System. As an immunoassay, the device itself is developed and optimized through laboratory procedures, reagent formulation, and analytical validation rather than machine learning training on a dataset. The studies described are performance evaluation studies, akin to a test set, to demonstrate substantial equivalence and establish performance characteristics.
9. How the Ground Truth for the Training Set Was Established
Since a "training set" in the context of machine learning is not applicable here, the method of establishing ground truth for a training set is not provided. The development of an immunoassay involves optimizing reagents and reaction conditions, typically through analytical experiments rather than data-driven machine learning training.
§ 866.3510 Rubella virus serological reagents.
(a)
Identification. Rubella virus serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to rubella virus in serum. The identification aids in the diagnosis of rubella (German measles) or confirmation of a person's immune status from past infections or immunizations and provides epidemiological information on German measles. Newborns infected in the uterus with rubella virus may be born with multiple congenital defects (rubella syndrome).(b)
Classification. Class II. The special controls for this device are:(1) National Committee for Clinical Laboratory Standards':
(i) 1/LA6 “Detection and Quantitation of Rubella IgG Antibody: Evaluation and Performance Criteria for Multiple Component Test Products, Speciment Handling, and Use of the Test Products in the Clinical Laboratory, October 1997,”
(ii) 1/LA18 “Specifications for Immunological Testing for Infectious Diseases, December 1994,”
(iii) D13 “Agglutination Characteristics, Methodology, Limitations, and Clinical Validation, October 1993,”
(iv) EP5 “Evaluation of Precision Performance of Clinical Chemistry Devices, February 1999,” and
(v) EP10 “Preliminary Evaluation of the Linearity of Quantitive Clinical Laboratory Methods, May 1998,”
(2) Centers for Disease Control's:
(i) Low Titer Rubella Standard,
(ii) Reference Panel of Well Characterized Rubella Sera, and
(3) World Health Organization's International Rubella Standard.