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The Ig plex Celiac DGP Panel is an in vitro diagnostic test for the semi-quantitative detection of the IgA and IgG immunoglobulin classes of antibodies to deamidated gliadin peptide (DGP) and tissue transglutaminase (TG) in human serum. The test is intended for use in clinical laboratories as an aid in the disease in conjunction with other laboratory and clinical findings, and requires the sqid-X system.

The Ig plex Celiac DGP Panel is a consumable reagent kit. It is designed to run on the sqid-X system. The kit includes a microarray plate, reporter mix, standards, controls, sample diluents, wash buffer concentrates and a CD-ROM.

The assay detects the presences of the IgA and IgG classes of antibody, and the IgA and lgG classes of anti-tissue transglutaminase antibody. This is performed in an integrated fashion on the sqid-X system that reports all analytes simultaneously to aid in the diagnosis of celiac disease.

The system is a multiplex immunoassay analyzer that semi-automates the protocol of a specific lg plex assay from plate washing to reporting of all assay markers for each individual patient sample. The system combines manual liquid handling (samples and reagents) with automated steps for washing, scanning, data analyses and reporting. Results for each patient sample are obtained simultaneously for each of the four markers using the results from one well containing one aliquot of the patient's serum. Results are reported independently.

Here's a summary of the acceptance criteria and study findings for the Ig plex Celiac DGP Panel, based on the provided document:

1. Table of Acceptance Criteria & Reported Device Performance

The document does not explicitly state formal "acceptance criteria" in a go/no-go fashion with numerical targets for all performance metrics. However, it presents various performance results without indicating that they failed to meet any internal or regulatory thresholds. The following table summarizes what can be inferred as the expected performance based on the reported study results:

The concluding statement, "the lg_plex Celiac DGP Panel demonstrated performance, safety and effectiveness equivalent or superior to its predicates," implies that the reported performance met or exceeded the expected standards set by the predicate devices.

2. Sample Size and Data Provenance

• Sensitivity and Specificity (Test Set): 378 samples
  • 128 celiac biopsy-confirmed samples.
  • 250 samples from other autoimmune diseases (rheumatic and infectious diseases).
  • No specific country of origin is mentioned, nor is it explicitly stated whether the data is retrospective or prospective. Given the nature of these studies, it's highly likely to be retrospective, utilizing banked samples.
• Method Comparison: 379 samples
  • 229 positive celiac patient samples.
  • 132 presumptively normal samples.
  • 18 other autoimmune disease samples.
• Expected Values/Cut-off Determination: 292 specimens
  • 126 presumed normal.
  • 56 other autoimmune disease.
  • 110 celiac patient specimens.
• Reference Range Determination: 328 presumptively normal donors.
  • 167 males (age 19-90 years).
  • 161 females (age 18-66 years).
• Analytical Interference: 3 samples (2 celiac diagnosed, 1 negative).
• Precision and Reproducibility: Various replicates (e.g., replicates of two for 20 days for inter-assay, replicates of five per kit for lot-to-lot and multi-instrument studies). The total number of unique samples for these studies is not clearly aggregated but involves multiple runs and sites.

3. Number of Experts and Qualifications for Ground Truth

• The document does not mention the use of experts to establish ground truth for the test set.
• For the "celiac biopsy confirmed samples," the ground truth is implied to be established by the biopsy itself, which would typically be interpreted by pathologists. No number or specific qualifications of these pathologists are provided.
• For "other autoimmune diseases," the diagnosis is implied as existing, but the means of diagnosis or qualifications of those who made the diagnoses are not described.

4. Adjudication Method

• No adjudication method (e.g., 2+1, 3+1) is described for establishing the ground truth of the test set. The ground truth seems to be based on pre-existing diagnoses (biopsy, clinical diagnosis).

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• No MRMC comparative effectiveness study is mentioned. This device is an in vitro diagnostic (IVD) assay designed for laboratory use, not typically requiring human reader interpretation in the same way as an imaging AI device would. It provides numerical results for analytes.

6. Standalone Performance

• Yes, the studies described are standalone performance studies. The device (Ig plex Celiac DGP Panel on the sqid-X system) is evaluated on its own ability to accurately measure the target analytes and to classify samples as positive or negative for celiac disease markers based on objective cut-off values. There is no human-in-the-loop component for the performance metrics measured here (sensitivity, specificity, agreement, precision).

7. Type of Ground Truth Used

• The primary ground truth used is biopsy confirmation for celiac disease (specifically, "celiac biopsy confirmed samples").
• For other conditions, it relies on existing clinical diagnoses of "other autoimmune diseases."

8. Sample Size for the Training Set

• The document does not explicitly state a separate "training set" for the algorithm. For IVD diagnostic tests, the "training" equivalent often involves the development and optimization of the assay itself, selection of reagents, and establishment of cut-off values using reference populations.
• The "Expected Values" section mentions that 126 presumed normal, 56 other autoimmune disease, and 110 celiac patient specimens (total 292 samples) were "evaluated for accurate determination of each analyte's cut-off." This process is analogous to defining thresholds, which could be considered part of the development/training phase for the diagnostic interpretation.

9. How the Ground Truth for the Training Set was Established

• As mentioned above, if the "Expected Values" samples were used for cut-off determination (a form of "training" or optimization), the ground truth for these samples would likely be established in the same way as the test set: through biopsy confirmation for celiac patients and clinical diagnosis for other conditions/normal individuals. However, the document does not elaborate further on the process for these specific sets of samples beyond their use for cut-off determination.

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