(351 days)
The Helicobacter pylori (H. pylori) ELISA IgG test kit is intended for the qualitative detection of IgG antibodies to H. pylori in human serum in the adult population. This test is intended to aid in the diagnosis of H. pylori in patients suspected of having H. pylori infection, and in patients with gastrointestinal symptoms, and is to be used in conjunction with clinical findings.
The assay requires a total of 90 minutes incubation time. The test uses purified antigen coated on microtiter wells. Serum is added to each well and incubated for 30 minutes at 37°C. If H. pylori IgG antibodies are present they will bind to the antigen in the well. Unbound serum is removed by washing the wells three times. An HRP-conjugated anti-human IgG is then added to each well and incubated for 30 minutes at 37℃. If H. pylori antibody is present, it will bind to the antibody attached to the antigen on the wells are again washed three times to remove any unbound coniugate. A TMB substrate is added to each well and incubated for 30 minutes at 37°C. If enzyme is present, it will react with the substrate to generate a colored product. After the incubation period, the reaction is stopped with a Stop Solution and the color intensity is measured spectrophotometrically.
Here's an analysis of the provided text regarding the Gold Standard Diagnostics Helicobacter pylori ELISA IgG Test Kit, focusing on the acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document does not explicitly state pre-defined acceptance criteria values for the clinical performance metrics (Positive Agreement, Negative Agreement, Overall Agreement). Instead, it compares the device's performance to a legally marketed predicate device (Micro Detect, Inc. Pylori Detect IgG kit) and argues for substantial equivalence based on the observed agreement percentages.
However, based on the context of 510(k) submissions, the implicit "acceptance criteria" are that the device's performance should be comparable to or not worse than the predicate device, demonstrating substantial equivalence. The reported device performance is as follows:
| Performance Metric | Acceptance Criteria (Implied: Comparable to Predicate Device) | Reported Device Performance | Comments |
|---|---|---|---|
| % Positive Agreement | Comparable to Predicate Device (Micro Detect IgG ELISA) | 92.7% (with 95% CI: 88.5% to 95.5%) | This indicates a high level of agreement between the new device and the predicate device for positive H. pylori cases. The 95% CI suggests reasonable precision for this estimate. |
| % Negative Agreement | Comparable to Predicate Device (Micro Detect IgG ELISA) | 94.7% (with 95% CI: 92.0% to 96.5%) | This indicates a high level of agreement between the new device and the predicate device for negative H. pylori cases. The 95% CI suggests reasonable precision for this estimate. |
| % Equivocal Agreement | Comparable to Predicate Device (Micro Detect IgG ELISA) | 20% (with 95% CI: 5.7% to 51.0%) | This agreement is significantly lower than positive and negative agreement. However, equivocal results often require further testing or clinical correlation, so a lower agreement for this category might be acceptable given the overall high positive and negative agreements. The wide CI suggests uncertainty in this estimate due to the small number of equivocal cases. |
| Overall Agreement | Comparable to Predicate Device (Micro Detect IgG ELISA) | 92.8% | This metric provides an overall measure of concordance between the two devices. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 625 samples.
- Data Provenance: The samples were "routinely tested for H." at multiple sites. The document implies these were human serum samples collected as part of routine clinical practice. There is no specific mention of the country of origin, but given the submitter and review body (US FDA), it's highly probable the data is from the US. The study appears to be retrospective, as it used "samples being routinely tested."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The concept of "experts establishing ground truth" as it applies to image-based diagnostics with radiologists is not directly applicable here. For this type of serological assay (ELISA for H. pylori IgG antibodies), the "ground truth" for the comparative study was established by a legally marketed predicate device (Micro Detect, Inc. Pylori Detect IgG assay, K973508).
For discrepant samples, a "third assay, the DiaMedix H. pylori IgG assay (which is also commercially available)" was used for further testing. These commercially available assays themselves have their own validated performance characteristics, so they serve as the reference standard in this context rather than individual human experts adjudicating cases.
4. Adjudication Method for the Test Set
The adjudication method for the clinical comparison was a "third assay" (DiaMedix H. pylori IgG assay) for discrepant results between the new device and the predicate device.
- For the 11 samples where the Gold Standard Diagnostics device was negative and the Micro Detect Inc. device was positive, the third assay called: 9 positive, 2 negative.
- For the 13 samples where the Gold Standard Diagnostics device was positive and the Micro Detect Inc. device was negative, the third assay called: 1 borderline, 2 negative, 10 positive.
This acts as a tie-breaker or further confirmatory test for discordant results, though the final calculation of agreement percentages is primarily based on the direct comparison between the new device and the predicate.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This type of study typically involves multiple human readers interpreting cases with and without AI assistance, which is not relevant for a laboratory-based serological assay like the one described.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance evaluation was done for the Gold Standard Diagnostics H. pylori ELISA IgG Test Kit. The clinical comparison study directly measures the performance of the device itself (the "algorithm only") against a predicate device. The results (Positive Agreement, Negative Agreement, Overall Agreement) represent the direct output of the assay for each sample.
7. The Type of Ground Truth Used
The primary "ground truth" or reference standard for the clinical comparison was the predicate device (Micro Detect, Inc. Pylori Detect IgG ELISA). For discrepant samples, a secondary commercially available assay (DiaMedix H. pylori IgG assay) was used for further analysis. This is a common approach for establishing substantial equivalence for in vitro diagnostic devices when a definitive "gold standard" (like pathology for cancer) is not directly applicable or available for all samples.
8. The Sample Size for the Training Set
The document does not mention a training set or its sample size. This is expected because the device is an ELISA kit, which is a laboratory assay with fixed chemical and biological reagents and protocols, not a machine learning algorithm that requires a training set for model development. The performance characteristics are inherent to the assay's design and are evaluated through analytical and clinical validation studies.
9. How the Ground Truth for the Training Set Was Established
As no training set is mentioned or applicable for this type of device, this point is not relevant.
§ 866.3110
Campylobacter fetus serological reagents.(a)
Identification. Campylobacter fetus serological reagents are devices that consist of antisera conjugated with a fluorescent dye used to identifyCampylobacter fetus from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by this bacterium and provides epidemiological information on these diseases.Campylobacter fetus is a frequent cause of abortion in sheep and cattle and is sometimes responsible for endocarditis (inflammation of certain membranes of the heart) and enteritis (inflammation of the intestines) in humans.(b)
Classification. Class I (general controls).