(192 days)
for the qualitative detection of total antibodies (IgG and IgM) 10 Legionella pneumophila serogroups 1-6 in serum from patients with clinical suspicion of Legionella Disease.
The Legionella pneumophila IgG/IgM ELISA kit is an Enzyme-Linked Immunosorbent Assay (ELISA) for the qualitative detection of total antibodies (IgG and IgM) 10 Legionella pneumophila serogroups 1-6 in serum from patients with clinical suspicion of Legionella Disease.
The Legionella pneumophila IgG/IgM ELISA test is an enzyme linked immunosorbent assay to detect IgG/IgM antibodies to Legionella. Purified Legionella pneumopilla antigen (serogroups 1, 2, 3, 4, 5, 6) is attached to a solid phase microtiter well. Diluted test sera is added to each well. If the antibodies are present that recognize the antigen, they will bind to the antigen in the well. After incubation the wells are washed to remove unbound antibody. An enzyme labeled anti-human IgG/IgM is added to each well. If antibody is present it will bind to the antibody attached to the antigen on the well. After incubation the wells are washed to remove unbound conjugate. A substrate solution is added to each well. If enzyme is present the substrate will undergo a color change. After an incubation period the reaction is stopped and the color intensity is measured photometrically, producing an indirect measurement of specific antibody in the patient specimen.
Here's a breakdown of the acceptance criteria and study information for the Legionella pneumophila IgG/IgM ELISA Test Kit, based on the provided text:
1. Acceptance Criteria and Reported Device Performance
The provided document doesn't explicitly state numerical "acceptance criteria" in the typical sense (e.g., a pre-defined threshold that must be met for approval). Instead, it presents "Performance Characteristics" and compares the device's performance to a predicate device (BioWhitttaker's Legionella STAT test) and a reference method (IFA). The reported performance values are those observed in these comparative studies.
Table of Acceptance Criteria (Implied) and Reported Device Performance:
| Performance Metric | Implied Acceptance Criterion (from predicate comparison) | Reported Device Performance |
|---|---|---|
| Relative Sensitivity (Vs IFA) | Comparable to predicate or reference method | 90.00% (95% CI: 79.0% - 100%) |
| Relative Specificity (Vs IFA) | Comparable to predicate or reference method | 98.53% (95% CI: 95.6% - 100%) |
| Relative Agreement (Vs IFA) | Comparable to predicate or reference method | 98.57% (95% CI: 95.7% - 100%) |
| Seroconversion Sensitivity (CDC Panel) | Demonstrate ability to detect seroconversion | 93.5% (29/31 seroconversions detected) |
| Precision (Intra-assay CV) | Not explicitly stated, but generally 1:256." |
The document does not explicitly state the number of human experts involved in interpreting the IFA results or their specific qualifications (e.g., medical technologists, clinical pathologists). However, IFA is a standardized laboratory test, and its results are generally considered objective.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method in the context of human readers interpreting data. The comparisons are made against established laboratory test results (IFA). Equivocal results from the ELISA device were "not included in the above calculations" for sensitivity and specificity, which acts as a form of handling ambiguous results rather than human adjudication of ground truth.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not done. This study focuses on the performance of a diagnostic kit (ELISA) compared to another diagnostic kit (IFA), not on human reader performance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, the studies presented are standalone performance evaluations of the Legionella pneumophila IgG/IgM ELISA Test Kit. The results (Relative Sensitivity, Specificity, Agreement, Seroconversion Sensitivity, and Precision) reflect the performance of the assay itself, without any human-in-the-loop interaction influencing the calculation of these metrics.
7. The Type of Ground Truth Used
The primary ground truth used for performance evaluation was:
- Legionella IFA (Immunofluorescence Assay) results: This is a laboratory-based method for detecting Legionella antibodies and is used as the reference standard in the comparative studies.
- CDC-confirmed IFNA titer changes: For the seroconversion study, the ground truth was a confirmed greater than 4-fold increase in IFA titer from the CDC.
The document explicitly states: "There was not an attempt to correlate the assay's results with disease presence or absence. No judgment can be made on the comparison assay's accuracy to predict disease." This means the ground truth is based on a serological reference method, not clinical disease outcomes (e.g., pathology confirmation or patient follow-up).
8. The Sample Size for the Training Set
The document does not mention a training set or machine learning/AI development. This is a traditional in vitro diagnostic (IVD) device, and its performance is evaluated through clinical laboratory studies comparing it to established methods, rather than through a machine learning development pipeline involving training and test sets in the AI sense.
9. How the Ground Truth for the Training Set was Established
As there is no mention of a training set for an AI/ML algorithm, this question is not applicable to the provided document.
§ 866.3300
Haemophilus spp. serological reagents.(a)
Identification. Haemophilus spp. serological reagents are devices that consist of antigens and antisera, including antisera conjugated with a fluorescent dye, that are used in serological tests to identifyHaemophilus spp. directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by bacteria belonging to the genusHaemophilus and provides epidemiological information on diseases cause by these microorganisms. Diseases most often caused byHaemophilus spp. include pneumonia, pharyngitis, sinusitis, vaginitis, chancroid venereal disease, and a contagious form of conjunctivitis (inflammation of eyelid membranes).(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.