ANTI-TG IGG ELISA TEST SYSTEM

• K Number: K983553
• Device Name: ANTI-TG IGG ELISA TEST SYSTEM
• Manufacturer: COLUMBIA BIOSCIENCE, INC.
• Date Cleared: 1998-12-07 ( 59 days)
• Product Code: JZO
• Regulation Number: 866.5870
• Type: Traditional
• Panel: IM
• Reference & Predicate Devices: N/A

Intended Use

The TG IgG kit is an Enzyme-Linked Immunosorbent Assay (ELISA) for the qualitative detection and quantitation of antibodies against the Thyroglobulin (TG) antigen in serum as an aid in the diagnosis of thyroid autoimmune disease. The test can be performed either manually or in conjunction with the Mago Plus automated ETA processor.

Device Description

The TG IgG ELISA Kit is an enzyme-linked immunosorbent assay (ELISA) for the detection of IgG to Thyroglobulin in human serum.

AI/ML Overview

Here's a breakdown of the acceptance criteria and the study details for the anti-TG IgG ELISA Kit, based on the provided 510k summary:

1. Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state "acceptance criteria" as a set of pre-defined thresholds that the device must meet in a table. Instead, it presents performance characteristics from studies that demonstrate its capabilities. I will infer the implied acceptance criteria from the reported values, particularly in comparison to a commercially available ELISA kit mentioned in the "Relative Sensitivity and Specificity" section.

Performance Characteristic	Implied Acceptance Criteria (Inferred)	Reported Device Performance (anti-TG IgG ELISA Kit)
Relative Sensitivity	High sensitivity to detect positive cases (implied: comparable to

                           | a benchmark kit, with a lower bound within the 95% CI that indicates acceptable detection)                                                                                                                                              | 83.3% (95% CI: 67.2-93.0)                                                                            |

| Relative Specificity | High specificity to correctly identify negative cases (implied: comparable to a benchmark kit, with a lower bound within the 95% CI that indicates acceptable rejection of negatives) | 97.2% (95% CI: 93.5-99.1) |
| Overall Agreement | High overall agreement with a benchmark kit (implied: overall performance nearing 90% or above, with a lower bound within the 95% CI that indicates acceptable consistency) | 94.8% (95% CI: 90.9-97.4) |
| Clinical Specificity (Normals) | High specificity in a normal population. Specific numerical criteria are not specified, but a high percentage is expected to avoid false positives in healthy individuals. | 97.7% (95% CI: 94.3-99.4) |
| Clinical Sensitivity (Grave's Disease) | Moderate to high sensitivity in Grave's Disease patients; while not an explicit threshold, the reported value (38.5%) should be considered clinically acceptable for an aid in diagnosis based on the device's role. | 38.5% (95% CI: 13.9-68.4) |
| Clinical Sensitivity (Hashimoto's Disease) | Moderate to high sensitivity in Hashimoto's Disease patients; similar to Grave's, the reported value (64.3%) should be acceptable for diagnostic aid. | 64.3% (95% CI: 35.1-87.2) |
| Precision (Intra-assay & Inter-assay CV%) | Low Coefficient of Variation (CV%) for both positive and negative samples across different runs and sites. Although no explicit threshold is given, typically CVs below 15-20% are considered acceptable, especially for quantitative assays. | Max Intra-assay CV%: 61.85% (F, NEG, Site 1, Run 1)
Max Inter-assay CV%: 98.47% (F, NEG, Site 1)

(Values for positive samples generally much lower, e.g., ~10-15%) |
| Correlation (Manual vs. MAGO Plus) | High correlation between manual and automated methods. The Pearson Correlation Coefficient (r) should be close to 1. | 0.988 (Pearson Correlation Coefficient) |

2. Sample Size and Data Provenance:

• Relative Sensitivity and Specificity:
  • Test Set Sample Size: 227 (Frozen retrospective sera). The table provided specifies N=213 for calculation after excluding equivocal results.
  • Data Provenance: Retrospective sera. Country of origin is not specified but is implied to be relevant to the market the device is seeking approval for, likely the US.
• Clinical Sensitivity and Specificity:
  • Test Set Sample Size: 207 (Frozen retrospective, clinically characterized sera). The table breaks this down into:
    • Normals: 176 (175 used for calculation)
    • Grave's Disease: 12 (13 used for calculation)
    • Hashimoto's Disease: 16 (14 used for calculation)
  • Data Provenance: Retrospective sera. Clinically characterized. Country of origin not specified.
• Precision:
  • Test Set Sample Size: 6 sera (4 positive, 2 negative) tested 10 times in 3 different runs at 2 different sites.
  • Data Provenance: Not specified; likely laboratory samples.
• Correlation of Manual and MAGO Plus Results:
  • Test Set Sample Size: 91 serum samples.
  • Data Provenance: Not specified; likely laboratory samples.
• MAGO Plus Precision:
  • Test Set Sample Size: 6 sera (implied same a precision study data set).
  • Data Provenance: Not specified; likely laboratory samples.

3. Number of Experts and Qualifications for Ground Truth:

• The document does not specify the number of experts used to establish the ground truth or their qualifications for any of the studies.
• For the "Relative Sensitivity and Specificity" study, the comparison is made to "a commercially available ELISA KIT." The "ground truth" here is essentially the results of this comparator kit.
• For the "Clinical Sensitivity and Specificity" study, the "ground truth" for patient groups (Normals, Grave's Disease, Hashimoto's Disease) is established through "clinically characterized sera." How this clinical characterization was performed (e.g., by a panel of endocrinologists, by a single specialist for each patient, based on a gold standard diagnostic) is not detailed.

4. Adjudication Method for the Test Set:

• The document does not explicitly describe an adjudication method for the test set in the context of expert review.
• For the "Relative Sensitivity and Specificity" study, "Equivocal results were excluded from calculations." This acts as a form of exclusion, but not a multi-expert adjudication to reconcile discrepant results.
• For "Clinical Sensitivity and Specificity," "Equivocal results were excluded from calculations" as well.

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

• No, an MRMC comparative effectiveness study was not done. This device is an in-vitro diagnostic (IVD) ELISA kit, not an imaging or interpretation device that would involve multiple human readers. The studies focus on the analytical and clinical performance of the assay itself.

6. Standalone Performance Study:

• Yes, standalone performance was done for the algorithm (the ELISA kit). The primary studies (Relative Sensitivity and Specificity, Clinical Sensitivity and Specificity, Precision) all evaluate the performance of the anti-TG IgG ELISA Kit in isolation. The "Correlation of Manual and MAGO Plus Results" and "MAGO Plus Precision" evaluate its performance when integrated with an automated system, but the core analytical performance is still inherent to the kit itself.

7. Type of Ground Truth Used:

• For Relative Sensitivity and Specificity: The "ground truth" was established by comparison to a "commercially available ELISA KIT" designed for detecting anti-TG IgG antibodies. This is a comparator device ground truth.
• For Clinical Sensitivity and Specificity: The "ground truth" was based on clinical characterization of the patient sera (categorized as Normals, Grave's Disease, Hashimoto's Disease). This can be considered clinical diagnosis/outcomes data ground truth, although the specific diagnostic criteria and methods for this characterization are not elaborated upon.
• For Precision, Correlation, and MAGO Plus Precision: The ground truth is the inherent concentration or presence/absence of the analyte in the tested sera, with consistency and correlation being the metrics of interest against established values or the manual method.

8. Sample Size for the Training Set:

• The document does not specify a separate "training set" for the ELISA kit. ELISA kits are typically developed and optimized through iterative R&D processes, but the performance studies described here are for validation rather than training a machine learning model. If any optimization involved specific sample sets, it is not detailed as a formal "training set" in this summary.

9. How Ground Truth for the Training Set Was Established:

• As a formal "training set" is not described, the method for establishing its ground truth is not applicable/not provided in this summary.

Regulation Number and Section

§ 866.5870 Thyroid autoantibody immunological test system.

(a)
Identification. A thyroid autoantibody immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the thyroid autoantibodies (antibodies produced against the body's own tissues). Measurement of thyroid autoantibodies may aid in the diagnosis of certain thyroid disorders, such as Hashimoto's disease (chronic lymphocytic thyroiditis), nontoxic goiter (enlargement of thyroid gland), Grave's disease (enlargement of the thyroid gland with protrusion of the eyeballs), and cancer of the thyroid.(b)
Classification. Class II (performance standards).