(468 days)
MarDx Lyme Disease (IgG) Marblot Strip Test System is a Western blot assay for the qualitative detection of human IgG antibody to B. burgdorferi. The MarDx Lyme Disease (1gG) Marblot Strip Test System is intended for use in testing human serum samples which have been found positive or equivocal using an EIA or IFA test procedure.
The MarDx Lyme Disease (IgG) Marblot Strip Test System is a Western blot device for the detection of human IgG antibodies directed to the organism Borrelia burgdorferi. The device is similar in function to other solid phase enzyme immunoassays (EIA), but differs in its ability to discriminate the individual antibody specificities directed against the organism.
This document describes the MarDx Lyme Disease (IgG) Marblot Strip Test System, a Western blot device for detecting human IgG antibodies to Borrelia burgdorferi.
Here's an analysis of the provided information regarding acceptance criteria and the study:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document doesn't explicitly state quantitative acceptance criteria (e.g., "sensitivity must be >90%"). Instead, it sets a qualitative acceptance criterion: "performs at least as well as the predicate devices." The predicate devices are:
- MarDx Lyme Disease IgG EIA Test System (K894224)
- The Lyme Western blot procedure developed and utilized by Dr. Allen Steere, MD, Tufts Medical Center, Boston, MA.
- The physicians' diagnosis of the Academic Reference Centers (ARCs) panel maintained by the CDC, Fort Collins, CO.
The reported device performance is: "The data indicates that the MarDx Marblot Lyme IgG Test has a high sensitivity and specificity relative to the Steere Western blot and the MarDx Lyme Disease IgG EIA Test System reference procedure."
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Performs at least as well as predicate devices (MarDx Lyme Disease IgG EIA, Steere Western blot, CDC ARCs panel physician diagnosis) in terms of agreement, sensitivity, and specificity. | "Has a high sensitivity and specificity relative to the Steere Western blot and the MarDx Lyme Disease IgG EIA Test System reference procedure." (Implying it meets or exceeds the performance of predicates) |
2. Sample Size Used for the Test Set and Data Provenance
The study used 1268 sera for the test set.
- Data Provenance: Not explicitly stated regarding country of origin. The reference devices and associated experts/organizations are from the USA (Tufts Medical Center, CDC Fort Collins). It is a retrospective study as it involved testing collected sera using established methodologies.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document refers to three types of reference/ground truth:
- Dr. Allen Steere, MD, Tufts Medical Center, Boston, MA: His "Lyme Western blot procedure" was used as a reference. While not explicitly stated as an expert establishing ground truth for the test set, his established method serves as a strong reference, implying expert consensus or standardization. His qualifications are "MD." The document references a publication (Dressler et al. Journal of Infectious Diseases, 1993; 167:392-400), suggesting his method is a recognized standard.
- Academic Reference Centers (ARCs) panel maintained by the CDC, Fort Collins, CO: "The physicians diagnosis" from this panel was used as a reference. This implies multiple physicians were involved, establishing a form of expert consensus or clinically adjudicated ground truth. The number of physicians/experts is not specified, but they are qualified as "physicians."
4. Adjudication Method for the Test Set
The document does not explicitly state a specific adjudication method like "2+1" or "3+1" among experts for the test set. Instead, it refers to established external references:
- The "reference Western blot" (Steere's procedure) implies a standardized, expert-driven interpretation of Western blot results.
- "EIA methodologies" (MarDx Lyme Disease IgG EIA Test System) are an existing commercial test.
- "Physicians diagnosis of the Academic Reference Centers (ARCS) panel maintained by the CDC" suggests a clinical diagnosis by multiple physicians, implying a consensus or a decision by an expert panel.
Therefore, the adjudication relies on pre-established expert-defined criteria from recognized institutions/experts rather than a real-time adjudication process for the specific test set cases.
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 explicitly described. The study compared the new device's performance (sensitivity, specificity, agreement) against established reference methods and a commercial EIA, not against varying human interpretations of the new device with or without AI assistance. This device is a diagnostic test (Western blot), not an AI-powered image analysis tool for human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, implicitly. The MarDx Marblot Strip Test System is a Western blot device. When it states "Twelve hundred and sixty eight sera were tested by reference Western blot and EIA methodologies to determine the agreement, sensitivity, specificity of the MarDx Lyme Disease (IgG) Marblot Strip Test System," it describes the performance of the device itself (analogous to "algorithm only" if considering it as a standalone diagnostic tool) in producing a result, which is then compared to other references. There's no mention of human-in-the-loop for interpreting the new device's results and comparing that hybrid performance.
7. The Type of Ground Truth Used
There are effectively three types of "ground truth" or reference standards used:
- Expert-defined laboratory procedure: The "Lyne Western blot procedure developed and utilized by Dr. Allen Steere, MD."
- Established commercial diagnostic test: The "MarDx Lyme Disease IgG EIA Test System."
- Clinical expert consensus/diagnosis: "The physicians diagnosis of the Academic Reference Centers (ARCS) panel maintained by the CDC."
These represent a combination of expert consensus (clinical and laboratory) and established diagnostic standards.
8. The Sample Size for the Training Set
Not provided. The document describes a clinical study for validation (test set) but does not mention any specific training set for the development of the MarDx Lyme Disease (IgG) Marblot Strip Test System. As this is a traditional diagnostic kit (Western blot) and not an AI/machine learning algorithm, the concept of a "training set" in the context of machine learning is not directly applicable. The device's development would involve reagent optimization and protocol establishment rather than algorithm training.
9. How the Ground Truth for the Training Set Was Established
Not applicable/Not provided. As stated above, this is a traditional diagnostic kit where the concept of a training set as understood in AI/ML is not relevant. The "ground truth" for developing such a kit would likely stem from extensive research into Borrelia burgdorferi antigens, antibody responses, and established clinical correlations, rather than a discrete "training set" with established ground truth.
§ 866.3830
Treponema pallidum treponemal test reagents.(a)
Identification. Treponema pallidum treponemal test reagents are devices that consist of the antigens, antisera and all control reagents (standardized reagents with which test results are compared) which are derived from treponemal sources and that are used in the fluorescent treponemal antibody absorption test (FTA-ABS), theTreponema pallidum immobilization test (T.P.I.), and other treponemal tests used to identify antibodies toTreponema pallidum directly from infecting treponemal organisms in serum. The identification aids in the diagnosis of syphilis caused by bacteria belonging to the genusTreponema and provides epidemiological information on syphilis.(b)
Classification. Class II (performance standards).