(107 days)
The Factor VIII Antibody Screen is a qualitative solid phase enzyme linked immunosorbent assay (ELISA) designed to detect IgG antibodies reactive with recombinant human factor VIII (FVII) in human serum and plasma.
The Factor VIII Antibody Screen is designed as a solid phase enzyme-linked immunosorbent assay (ELISA) with a colorimetric endpoint. This product is intended to be used as an in vitro diagnostic kit by hemostasis and other laboratories to screen patient samples for the presence of IgG antibodies reactive with human Factor VIII.
The Factor VIII Antibody Screen is an Enzyme Linked Immunosorbent Assay with a colorimetric endpoint. The Factor VIII Antibody Screen is designed to detect IgG antibodies reactive with recombinant human Factor VIII in human serum and plasma. The Factor VIII Antibody Screen kit contains all of the reagents necessary to perform the assay.
The Factor VIII Antibody Screen solid phase ELISA microwells provide immobilized recombinant human FVIII as target molecules for the detection of anti-Factor VIII IgG antibodies.
Diluted patient serum or plasma is added to microwells coated with recombinant FVIII molecules allowing antibody, if present, to bind. Unbound material is then washed away. An alkaline phosphatase labeled anti-human immunoglobulin reagent (Anti-IgG) is added to the wells and incubated. The unbound Anti-IgG is washed away and the substrate PNPP (p-nitrophenyl phosphate) is added. After a 30 minute incubation period, the reaction is stopped by a sodium hydroxide solution. The optical density of the color that develops is measured in a spectrophotometer at 405 nm with no reference filter.
Here's an analysis of the provided text to extract the acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly define a list of "acceptance criteria" with specific thresholds in a standardized table format. Instead, it discusses the performance against a predicate device and a "gold standard" (Bethesda assay), and establishes internal precision and reproducibility standards. Based on the "Conclusions" sections of the performance studies, here's a reconstructed table:
| Performance Characteristic | Acceptance Criteria (Implied/Derived from Conclusions) | Reported Device Performance (Factor VIII Antibody Screen) |
|---|---|---|
| Accuracy (vs. Predicate: FVIII Inhibitor Assay) | "Excellent sensitivity (co-positivity), specificity (co-negativity), and overall agreement" | Co-positivity: 92.7% (95% CI: 85.7 - 96.4%) |
| Co-negativity: 97.6% (95% CI: 87.4 - 99.6%) | ||
| Overall Agreement: 94.2% | ||
| Accuracy (vs. Gold Standard: Bethesda Assay) | "Excellent sensitivity (co-positivity), specificity (co-negativity), and overall agreement" | Co-positivity: 95.8% (95% CI: 89.8 - 98.4%) |
| Co-negativity: 89.1% (95% CI: 81.9 - 93.6%) | ||
| Overall Agreement: 92.2% | ||
| Precision (OD Values) | Imprecision 0.600; ≤ 24% CV for OD 0.600 | |
| ≤ 24% CV total imprecision for OD values 98% of the normal samples must be negative. This iterative process established the "ground truth" for setting the kit's operational cutoff. |
§ 864.7290 Factor deficiency test.
(a)
Identification. A factor deficiency test is a device used to diagnose specific coagulation defects, to monitor certain types of therapy, to detect coagulation inhibitors, and to detect a carrier state (a person carrying both a recessive gene for a coagulation factor deficiency such as hemophilia and the corresponding normal gene).(b)
Classification. Class II (performance standards).