(35 days)
The MESACUP-2 Test CENP-B is a semi-quantitative enzyme-linked immunosorbent assay (ELISA) for the detection of anti-CENP-B antibodies in human serum. The MESACUP-2 Test CENP-B is intended for in vitro diagnostic use as an aid in the diagnosis of CREST syndrome and related connective tissue diseases.
The MESACUP-2 Test CENP-B is an enzyme-linked immunosorbent assay (ELISA), utilizing the 96microwell plate format, similar to the predicate device. Diluted serum samples, calibrator sera, and controls are incubated in microwells coated with CENP-B antigen. Incubation allows the anti-CENP-B antibodies present in the samples to react with the immobilized antigen. After the removal of unbound serum proteins by washing, antibodies specific for human immunoglobulins (IgG, IgM and IgA), labeled with horseradish peroxidase (HRP), are added forming complexes with the CENP-B bound antibodies. Following another washing step, the bound enzyme-antibody conjugate is assayed by the addition of a single solution containing tetramethlybenzidine (TMB) and hydrogen peroxide (H2O2) as the chromogenic substrate. The intensity of the color generated is proportional to the serum concentration of anti-Jo-1 antibodies. Optical density is read spectrophotometrically at 450nm. The total incubation time (at room temperature) of the assay is 150 minutes. The assay makes use of two calibrators to measure the amount of anti-CENP-B antibody in patient samples.
The MESACUP-2 Test CENP-B is an in vitro diagnostic device intended to detect anti-CENP-B antibodies in human serum.
Here's an analysis of its acceptance criteria and the supporting study:
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance (%) |
|---|---|
| Specificity (healthy donors) | 95% (MESACUP-2 Test) |
| Specificity (healthy donors) | 100% (Predicate Device) |
| Sensitivity (CREST Syndrome) | 90% (MESACUP-2 Test) |
| Sensitivity (CREST Syndrome) | 95% (Predicate Device) |
| Relative Agreement | 95% (between MESACUP-2 and Predicate) |
Note: The document implies that the performance of the MESACUP-2 Test CENP-B is considered equivalent to the predicate device, thereby meeting the acceptance criteria for market clearance. The specific numerical thresholds for "acceptance" beyond establishing equivalence are not explicitly stated as strict cut-offs, but rather demonstrated through comparable performance.
2. Sample Size Used for the Test Set and Data Provenance
The document states that in-house studies were conducted.
- Healthy Donor Population: The sample size for healthy donors is not specified.
- CREST Syndrome Population: The sample size for the CREST Syndrome population is not specified.
- Data Provenance: The studies were "in-house," suggesting the data was collected and analyzed by the manufacturer. The country of origin is not specified, but the submission is to the U.S. FDA, implying relevance to a U.S. context. The studies appear to be retrospective as they are described as "in-house studies" and "additional studies" rather than a prospective clinical trial.
3. Number of Experts and Qualifications for Ground Truth
The document does not provide information on the number of experts used or their qualifications for establishing the ground truth for the test sets.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method used for the test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. The device is an ELISA assay; therefore, a human-in-the-loop scenario, as typically seen in image interpretation or diagnostic aid, does not apply in the same way. The comparison is between two analytical methods (the MESACUP-2 Test and the predicate device).
6. Standalone Performance Study
Yes, a standalone performance study was conducted. The "in-house studies" and "additional studies" of the MESACUP-2 Test CENP-B's specificity and sensitivity directly report the algorithm's (or device's) performance without human intervention in the interpretation of the output. The MESACUP-2 Test CENP-B is a laboratory assay that produces a quantitative result (optical density) which is then interpreted against established cut-offs by the device's design, not by a human reader's subjective assessment.
7. Type of Ground Truth Used
- For Specificity (Healthy Donor Population): The ground truth was based on a "healthy donor serum population," implying that these individuals were confirmed not to have anti-CENP-B antibodies or the associated conditions.
- For Sensitivity (CREST Syndrome Population): The ground truth was established using a "CREST Syndrome population on both assay respectively for anti-CENP-B antibodies previously also found positive by double immunodiffusion (DID)." This indicates that Double Immunodiffusion (DID) was used as the reference standard (ground truth) to independently confirm the presence of anti-CENP-B antibodies in the CREST Syndrome patients.
8. Sample Size for the Training Set
The document does not provide information about a separate training set or its sample size. For an ELISA assay, the "training" equivalent might involve optimizing assay parameters and cut-offs using a set of known samples, but this is not explicitly detailed.
9. How Ground Truth for the Training Set Was Established
As no specific training set is mentioned, information on how its ground truth was established is not available in the provided text.
§ 866.5100 Antinuclear antibody immunological test system.
(a)
Identification. An antinuclear antibody immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the autoimmune antibodies in serum, other body fluids, and tissues that react with cellular nuclear constituents (molecules present in the nucleus of a cell, such as ribonucleic acid, deoxyribonucleic acid, or nuclear proteins). The measurements aid in the diagnosis of systemic lupus erythematosus (a multisystem autoimmune disease in which antibodies attack the victim's own tissues), hepatitis (a liver disease), rheumatoid arthritis, Sjögren's syndrome (arthritis with inflammation of the eye, eyelid, and salivary glands), and systemic sclerosis (chronic hardening and shrinking of many body tissues).(b)
Classification. Class II (performance standards).