(45 days)
The MESACUP-2 TEST Jo-1 is a semi-quantitative enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Jo-1 antibodies in human serum as an aid in the diagnosis of polymyositis and/or dermatomyositis, or other related connective tissue diseases.
The MESACUP-2 Test Jo-1 is an enzyme-linked immunosorbent assay (ELISA), utilizing the 96-microwell plate format, similar to the predicate device. Diluted serum samples, calibrator sera, and controls are incubated in microwells coated with Jo-1 (histidyl-tRNA synthetase) antigen. Incubation allows the anti-Jo-1 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 Jo-1 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 antibodics. Optical density is read spectrophotometrically at 450mm. 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-Jo-1 antibodies in patient samples.
Here's a breakdown of the acceptance criteria and study information for the MESACUP-2 Test Jo-1, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Clinical Specificity for anti-Jo-1 antibodies in a healthy donor serum population | 98% (MESACUP-2 Test Jo-1) |
| 100% (Predicate Device) | |
| Clinical Sensitivity for anti-Jo-1 antibodies in a polymyositis/dermatomyositis population (previously positive by double immunodiffusion - DID) | 100% (MESACUP-2 Test Jo-1) |
| 85% (Predicate Device) | |
| General performance characteristics comparability | Comparable between the two methods |
| Compliance with published literature for anti-Jo-1 detection | In compliance |
Study Information
2. Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size:
- Healthy donor serum population: Not explicitly stated, but "in-house studies" are mentioned for specificity.
- Polymyositis/dermatomyositis population: Not explicitly stated, but "additional studies" are mentioned for sensitivity.
- Data Provenance: Retrospective ("in-house studies" and "additional studies"). Country of origin is not specified, but the submission is from a US company (Corgenix Inc.).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
Not specified. The ground truth for the sensitivity study was based on antibodies "previously also found positive by double immunodiffusion (DID)," which implies a prior established diagnosis, but the expert involvement in that initial diagnosis is not detailed.
4. Adjudication Method for the Test Set:
Not applicable. This is an ELISA assay detecting antibodies, not a diagnostic imaging or clinical assessment where adjudication between readers would typically occur.
5. 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:
Not applicable. This is an in-vitro diagnostic (IVD) device, specifically an ELISA. It does not involve human readers interpreting images or data with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
Yes. The performance data (specificity and sensitivity) are for the device itself, the MESACUP-2 Test Jo-1, as a standalone diagnostic tool. The "human-in-the-loop" component in an ELISA is a laboratory technician performing the assay and reading the spectrophotometer, but the output (optical density and subsequent antibody concentration) is determined by the assay itself, not human interpretation in the sense of an AI-assisted diagnostic.
7. The Type of Ground Truth Used:
- For Specificity: Healthy donor serum population (absence of disease/antibodies).
- For Sensitivity: Polymyositis/dermatomyositis population with antibodies "previously also found positive by double immunodiffusion (DID)." This indicates a reference method (DID) was used to confirm the presence of anti-Jo-1 antibodies, serving as the ground truth for that cohort.
8. The Sample Size for the Training Set:
Not applicable. ELISA assays are not typically "trained" in the machine learning sense. Their performance is determined by their chemical and biological design, optimization, and validation against known samples.
9. How the Ground Truth for the Training Set Was Established:
Not applicable, as there isn't a training set in the machine learning context for this type of device. The ground truth for the validation/test sets was established as described in point 7.
§ 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).