(52 days)
An enzyme-linked immunosorbent assay (ELISA) designed for the detection and measurement of circulating IgM rheumatoid factor. When used according to instructions, the kit is useful in establishing the presence of rheumatoid factor and as an aid in the diagnosis and management of rheumatic diseases.
An enzvme-linked immunosorbent assay (ELISA) designed for the detection and measurement of IgM rheumatoid factor in human serum and plasma.
The ELISA methodology is commonly used for antibody evaluations. Purified IgG has been attached to the inner surfaces of the microwell plate. During the initial incubation step, rheumatoid factor in patient serum or plasma binds specifically to the immobilized IgG and remains in place after a wash step.
A second antibody which is conjugated to horseradish peroxidase (HRP) is used to recognize the "u" chain regions of the patient's IgM rheumatoid factor remaining after the wash step. In the wells where the second antibody remains bound. the coniugated HRP catalyzes a color change in the substrate. After the reaction is stopped, the color is read in an EIA Plate reader.
Here's an analysis of the provided text, focusing on the acceptance criteria and the supporting study, structured as requested:
Acceptance Criteria and Study Details for Hemagen® Rheumatoid Factor Kit
1. Table of Acceptance Criteria and Reported Device Performance
Based on the provided text, the acceptance criteria are largely implied by the performance metrics reported. The study aimed to demonstrate substantial equivalence to a predicate device.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Precision (Inter-assay) | Low %CV (indicating acceptable variability between runs) | Mean %CV for IU/mL: Range from 7.2% to 11.7% (for positive samples). |
| Mean %CV for O.D.: Range from 11.6% to 15.6%. | ||
| Precision (Intra-assay) | Low %CV (indicating acceptable variability within a single run) | Mean %CV for IU/mL: Range from 2.6% to 10.8% (for positive samples). |
| Mean %CV for O.D.: Range from 2.3% to 8.4%. | ||
| Correlation with WHO Standard (Calibrators) | High degree of correlation with WHO International Reference Preparation | A study was conducted to demonstrate a "high degree of correlation" (specific numerical criteria not provided). |
| Relative Analytical Sensitivity | Acceptable sensitivity compared to the predicate device | 94.8% (95% CI: 87.3% to 97.9%) compared to the predicate device in the RF panels. |
| Relative Analytical Specificity | Acceptable specificity compared to the predicate device | 93.1% (95% CI: 78.0% to 98.1%) compared to the predicate device in the RF panels. |
| Performance with Normal Blood Donors | Low false positive rate compared to predicate device | In a panel of normal blood donors (N=82): 4 positives by proposed device, 4 positives by predicate, 78 negatives by both. No false positives/negatives detected by either device compared to the other. |
| Assay Performance with Serum and Plasma | Accurate estimates of IgM RF in both serum and plasma | Results indicate the kit "can provide accurate estimates of IgM rheumatoid factor in both human serum and plasma." (Specific quantitative equivalence not provided). |
| Interfering Substances (Hemoglobin) |
§ 866.5775 Rheumatoid factor immunological test system.
(a)
Identification. A rheumatoid factor immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the rheumatoid factor (antibodies to immunoglobulins) in serum, other body fluids, and tissues. Measurement of rheumatoid factor may aid in the diagnosis of rheumatoid arthritis.(b)
Classification. Class II (performance standards).