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The assay is intended for use in detecting antibodies to SSA (Ro) antigen in a single human serum sample. The results of the assay are to be used as an aid in the diagnosis of autoimmune disorders.

The Is-anti-SSA Test Kit System is an enzyme-linked immunosorbent assay (ELISA) for the detection and semi-quantitation of IgG to SSA (Ro) antigen in human serum.

Here's a breakdown of the acceptance criteria and study details based on the provided text:

Acceptance Criteria and Device Performance

The provided document describes a comparison study against a predicate device. The acceptance criteria are implicitly defined by the performance of the predicate device and the desired level of agreement, sensitivity, and specificity.

Table 1: Acceptance Criteria and Reported Device Performance (Comparison Testing)

Note: Three borderline samples were excluded from the agreement calculation.

Additional Performance Characteristics:

• Linearity: The device demonstrated a high degree of linearity throughout the testing range, both manually (R-squared = 0.9892) and with MAGO (R-squared = 0.9795).
• Precision:
  • Intra-assay CV% for Positives: Ranged from 3.1% to 6.5% (Manual) and 2.3% to 6.6% (MAGO).
  • Inter-assay CV% for Positives: Ranged from 5.0% to 8.5% (Manual) and 4.4% to 10.4% (MAGO).
  • Intra-assay CV% for Negatives: Ranged from 6.5% to 14.5% (Manual) and 11.1% to 16.3% (MAGO).
  • Inter-assay CV% for Negatives: Ranged from 20.0% to 22.2% (Manual) and 12.5% to 13.0% (MAGO).
• Cross-reactivity: Out of 24 sera positive for other autoimmune specificities, 4 anti-SSA positive and 4 anti-SSB positive sera were correctly identified as positive for SSA. One Sm positive sample was also positive for SSA (confirmed by an alternative ELISA), and one RNP positive sample was equivocal. The remaining 14 samples with other specificities (Sm, RNP, Jo-1, Scl-70) were negative for SSA, suggesting low cross-reactivity with these specificities.
• Correlation of Manual and MAGO Results: Pearson correlation of 0.85 for 165 samples.

Study Details

1. Sample Size used for the test set and the data provenance:

   • Sample Size: 165 sera (100 from normal blood donors and 65 from autoimmune patients).
   • This is the total for the comparison testing. For cross-reactivity, 24 sera were used. For precision, 6 sera, the calibrator, and controls were used. For expected values, 100 normal donor sera and 65 clinically characterized sera were used.
   • Data Provenance: The 100 normal donor sera were collected in South Florida. The provenance of the 65 autoimmune patient sera is not explicitly stated but implies a clinical setting. This indicates a retrospective evaluation of collected samples.

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • The document does not specify the number of experts or their qualifications for establishing the ground truth. The "ground truth" for the comparison study appears to be defined by the results of the "commercially available anti-SSA ELISA test kit" (predicate device) and, in some ambiguous or discrepant cases, by a "third method" or a "referee method". For the "clinically characterized sera" used in expected values, the clinical characterization would likely have been established by medical professionals, but their specific roles, number, or qualifications are not detailed.

3. Adjudication method for the test set:

   • The primary method was comparison to a predicate device.
   • In cases of disagreement between the predicate and the "Is-anti-SSA Test System", a "third method" or "referee method" was used for adjudication. For example, "Five sera negative by Is-anti-SSA (manual and MAGO) and positive by the comparative method were negative when tested by a third method." and "For manual testing, one serum positive by Is-anti-SSA and negative by the comparative method was negative when tested by a referee method." This suggests a form of discrepancy resolution with an additional method, but not necessarily by human experts.

4. 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, this was not an MRMC comparative effectiveness study involving human readers and AI assistance. This device is an immunoassay (ELISA) test kit which is typically run in a lab, either manually or using an automated instrument (MAGO). The "manual" and "MAGO" refer to the method of running the test (manual pipetting and reading vs. automated instrument), not to human reader interpretation of complex images or data that AI would typically assist with.

5. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

   • Yes, performance of the device "MAGO" (an automated instrument processing the immunoassay) can be considered a standalone performance, as it generates results without direct human interpretation of the assay reaction in the same way a human reader interprets an image. The manual method also provides standalone performance of the kit itself. The comparison to other tests (predicate, third method) establishes its diagnostic accuracy.

6. The type of ground truth used (expert consensus, pathology, outcomes data, etc):

   • The ground truth for the comparison study was largely based on the results of a commercially available predicate anti-SSA ELISA test kit and, for discrepant cases, confirmation by a "third method" or "referee method."
   • For the "Expected Values" section, 65 "clinically characterized sera" were used, implying clinical diagnosis or patient outcomes as a ground truth, but the details are sparse.
   • For the cross-reactivity study, the samples were "positive for the six autoimmune specificities," suggesting pre-established diagnostic criteria or other validated assays for these specificities.

7. The sample size for the training set:

   • The document does not specify a separate "training set" in the context of machine learning or AI models. This device is a diagnostic test kit (ELISA), and the data provided relates to its analytical and clinical performance against reference methods and established populations.

8. How the ground truth for the training set was established:

   • As there's no explicit "training set" in the AI/ML sense, this question is not directly applicable. The "training" for such an immunoassay kit would involve its internal development and optimization based on known positive and negative controls and antigen/antibody interactions, which is not detailed in this 510(k) summary.

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