(281 days)
The intended use of the device is for the qualitative and/ or quantitative determination of serum IgG antibodies to Entamoeba histolytica using an Enzyme-Linked Immunosorbent Assay (ELISA) technique.
The device is an Enzyme Linked Immunosorbent Assay (ELISA). The antigen capture takes place in microwells. During the first incubation, antibodies in the patient's serum binds to antigen attached to the test wells. After washing the excess antibodies away, an enzyme complex binds to the antigen-antibody complex. After washings that remove unbound enzyme, a substrate is added which develops a blue color in the presence of the enzyme complex and peroxide. The stop solution ends the reaction and turns the The blue color to yellow. results read may be be spectrophotometrically with a microplate reader or visually.
Here's an analysis of the provided text, focusing on the acceptance criteria and the study details:
Acceptance Criteria and Device Performance
| Criterion | Acceptance Criteria (Original 510(k) Kit) | Reported Device Performance (Modified Test Kit) |
|---|---|---|
| Sensitivity | 95% | 100% |
| Specificity | 97% | 92% |
| Visual Interpretation | Not explicitly stated, but assumed to be acceptable for original kit. | "Testing for 'visual' interpretation was performed" (validated substantial equivalency) |
| Intra-assay (Within-Run) Precision | Not explicitly stated, but assumed to be acceptable for original kit. | "Testing for Intra-assay (Within-in) Run Precision was performed." (validated substantial equivalency) |
| Run-to-Run Precision | Not explicitly stated, but assumed to be acceptable for original kit. | "Testing for Run-to-Run Precision was performed." (validated substantial equivalency) |
| Cross-reactivity | Not explicitly stated, but assumed to be acceptable for original kit. | "Testing for Cross-reactivity" (validated substantial equivalency) |
Study Details
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Sample size used for the test set and the data provenance:
- Test set size: The text provides conflicting numbers within the table structure.
- For the "Original 510(k) Test Kit ASK Abstract C 38 Data", it states "Pos. (64) Neg. (104) 168". This implies a total of 168 samples.
- For the "Modified Test Kit Comparison Data for Bench Study", it shows "Pos. (8) Neg. (49) 57". This implies a total of 57 samples.
- It is unclear if the "Modified Test Kit" used a subset of the "Original 510(k)" samples or an entirely different set. The wording "Comparison Data for Bench Study" suggests a new, smaller set was used to validate the modified kit against the original.
- Data provenance: Not explicitly stated. Given the context of a 510(k) submission for a diagnostic test for Entamoeba histolytica, it is likely that the samples were collected from individuals in regions where the disease is prevalent, which would include "endemic third world countries" and "immigration centers in industrialized countries" as mentioned in the "Intended Use". The data is retrospective, as it refers to "samples confirmed as positive or negative".
- Test set size: The text provides conflicting numbers within the table structure.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- This information is not provided in the text. The ground truth is stated as "Serum samples confirmed as positive or negative for antibodies to E. histolytica", but the method of confirmation (e.g., through culture, PCR, or expert serological evaluation) and the number/qualifications of individuals who made these confirmations are not detailed.
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Adjudication method for the test set:
- None described. The text simply states that samples were "confirmed as positive or negative." There is no mention of a process involving multiple experts or an adjudication decision rule.
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If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No, an MRMC study was not done. This device is an ELISA test system, a laboratory diagnostic kit, not an AI-assisted diagnostic tool. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone study was done. The performance data (Sensitivity/Specificity) for the "Modified Test Kit" reflects the performance of the assay itself, independent of human interpretation beyond potential visual reading (which was assessed separately as "visual interpretation" and found to be substantially equivalent). The ELISA kit is the "algorithm" here, and its output (color change leading to a positive/negative result) is what was evaluated.
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The type of ground truth used:
- The ground truth was based on "Serum samples confirmed as positive or negative for antibodies to E. histolytica". This implies a reference standard based on confirmation of the presence or absence of E. histolytica antibodies, likely through a combination of other established diagnostic methods (e.g., culture, PCR, or a consensus of multiple serological tests or clinical presentations), but the specific method is not detailed. It is not pathology or direct outcomes data in the sense of patient recovery, but rather an established diagnostic classification for the samples.
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The sample size for the training set:
- Not applicable / not provided. As an ELISA test kit modification, this submission focuses on validating the performance of the modified kit against a predicate device. There is no mention of a "training set" in the context of machine learning, as the device is not based on AI/machine learning. The "testing" referred to is for validation against known samples.
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How the ground truth for the training set was established:
- Not applicable / not provided for the same reason as point 7.
§ 866.3220
Entamoeba histolytica serological reagents.(a)
Identification. Entamoeba histolytica serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies toEntamoeba histolytica in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identifyEntamoeba histolytica directly from clinical specimens. The identification aids in the diagnosis of amebiasis caused by the microscopic protozoan parasiteEntamoeba histolytica and provides epidemiological information on diseases caused by this parasite. The parasite may invade the skin, liver, intestines, lungs, and diaphragm, causing disease conditions such as indolent ulcers, an amebic hepatitis, amebic dysentery, and pulmonary lesions.(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.