(458 days)
Immunoassay for the in vitro quantitative determination of thyroglobulin in human serum and plasma. Determination of Tg is used as an aid in monitoring for the presence of persistent or recurrent/metastatic disease in patients who have differentiated thyroid cancer (DTC) and have had thyroid surgery (with or without ablative therapy). The electrochemiluminescence immunoassay "ECLIA" is intended for use on cobas e immunoassay analyzers.
The Tg II immunoassay makes use of a two-step, double antigen sandwich principle using a biotinylated monoclonal Tg-specific antibody and monoclonal Tg-specific antibodies labeled with a ruthenium complex. The Tg II immunoassay is intended for the in vitro quantitative determination of thyroglobulin in human serum and plasma. Determination of Tg is used to aid in monitoring for the presence of persistent or recurrent/metastatic disease in patients who have differentiated thyroid cancer (DTC) and have had thyroid surgery (with or without ablative therapy). It is intended for use on the cobas e immunoassay analyzers. Results are determined via a calibration curve which is instrument-specifically generated by 2-point calibration and a master curve provided via the reagent barcode or e-barcode.
The Elecsys Tg II device is an immunoassay intended for the in vitro quantitative determination of thyroglobulin in human serum and plasma, used as an aid in monitoring for the presence of persistent or recurrent/metastatic disease in patients who have differentiated thyroid cancer (DTC) and have had thyroid surgery.
Here's an analysis of its acceptance criteria and the study that proves the device meets them:
1. Table of Acceptance Criteria and Reported Device Performance
The provided document doesn't explicitly list "acceptance criteria" for all performance measures in a comparative table against the reported performance. However, based on the studies conducted and their results, one can infer the implicit acceptance criteria by observing the measured performance and statements like "All deviations from linearity met the specification" or "Non-significant interferences were defined as %interferences within ± 10 %".
Below is a table summarizing the reported device performance, with inferred acceptance criteria where direct ones are not explicitly stated, but are implied by the reported "met specifications" or similar statements.
| Performance Characteristic | Inferred Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Clinical Performance | ||
| Sensitivity | High sensitivity required for monitoring recurrent/metastatic disease (e.g., >90%). | 98.91% (91/92) with 95% CI: (94.10%; 99.81%) |
| Specificity | Acceptable specificity for the intended use (the exact value is not explicitly stated as an initial acceptance criterion, but the reported value is presented as performance). | 53.42% (234/438) with 95% CI: (48.74%; 58.05%) |
| Negative Predictive Value (NPV) | High NPV desired for ruling out disease (-ve result, truly -ve). | 99.89% with 95% CI: (99.42%; 99.98%) (calculated at 4.99% prevalence) |
| Positive Predictive Value (PPV) | Acceptable PPV for the intended use. | 10.03% with 95% CI: (9.16%; 11.03%) (calculated at 4.99% prevalence) |
| Analytical Performance | ||
| Limit of Blank (LoB) | Must be very low (e.g., in the picogram/mL range) to detect low levels of Tg. No explicit criterion given, but the reported value is the outcome of the study designed to determine it. | 0.02 ng/mL (Determined according to CLSI EP17-A2) |
| Limit of Detection (LoD) | Must be very low, enabling early detection of disease recurrence. No explicit criterion given, but the reported value is the outcome of the study designed to determine it. | 0.04 ng/mL (Determined according to CLSI EP17-A2) |
| Limit of Quantitation (LoQ) | %CV of within-laboratory precision ≤ 20% and %bias within ±15%. | 0.1 ng/mL (%CV for samples around this level ranged from 7.56% to 4.00% for repeatability, and within-laboratory CVs were 9.34%, 8.75%, 5.67% for HS1, HS2, HS3 respectively, all below 20%. Bias not explicitly shown in summary table but met criteria.) |
| Linearity | Deviations from linearity ≤ ±10% for values ≥0.3 ng/mL and within ±0.03 ng/mL for values |
§ 866.6010 Tumor-associated antigen immunological test system.
(a)
Identification. A tumor-associated antigen immunological test system is a device that consists of reagents used to qualitatively or quantitatively measure, by immunochemical techniques, tumor-associated antigens in serum, plasma, urine, or other body fluids. This device is intended as an aid in monitoring patients for disease progress or response to therapy or for the detection of recurrent or residual disease.(b)
Classification. Class II (special controls). Tumor markers must comply with the following special controls: (1) A guidance document entitled “Guidance Document for the Submission of Tumor Associated Antigen Premarket Notifications (510(k)s) to FDA,” and (2) voluntary assay performance standards issued by the National Committee on Clinical Laboratory Standards.