(80 days)
Good Biotech Corp. Duet hs-CRP LIT Assay is intended to be used as a high sensitive assay for the quantitative determination of C-reactive protein in serum by latex particle enhanced immunoturbidimetry (LIT). Highly sensitive measurement of C-reactive protein is useful for the detection and evaluation of infection, tissue injury, inflammatory disorders and associated diseases.
Good Biotech Corp. Duet hs-CRP Calibrator Set is intended to be used with Duet hs-CRP LIT Assay for the quantitative determination of C-reactive protein in serum samples.
For In Vitro Diagnostic Use.
Duet hs-CRP LIT kit is the ready-to-use reagent suitable for quantification of C-reactive protein by latex particle enhanced immunoturbidimetry (LIT). Duck anti-CRP IgY (ΔFc) is coupled to polystyrene microparticles, which greatly increased the analytical sensitivity. When CRP of the sample encounters with the latex microparticles sensitized with duck anti-CRP IgY (ΔFc), agglutination among the latex microparticles occurs based on the antigen-antibody reaction. The agglutination increases the turbidity of the sample and the degree of agglutination is detected by the absorbance change at 570 nm. The value of the absorbance change is proportional to the CRP concentration of the sample and is recorded by a general chemistry autoanalyzer. Then, the actual CRP concentration of the sample is determined by interpolation of the calibration curve obtained by standard samples with known CRP concentrations.
Here's a breakdown of the acceptance criteria and the study details for the Duet hs-CRP LIT Assay:
1. Table of Acceptance Criteria and Reported Device Performance
The submission frames its acceptance criteria through demonstrating "substantial equivalence" to a predicate device, the K-ASSAY CRP (3). The primary performance metric presented to establish this equivalence is correlation. While explicit numerical acceptance criteria (e.g., R² > 0.95) are not stated, the high R² values achieved are presented as evidence of equivalence.
| Acceptance Criteria (Implied) | Reported Device Performance (Duet hs-CRP LIT Assay vs. K-ASSAY CRP (3)) |
|---|---|
| Correlation to Predicate Device: The device should show a strong correlation with the legally marketed predicate device across the relevant analytical range to demonstrate equivalent performance. | Regression Equation (0-200 mg/L): y = 0.955x + 0.938 mg/L |
| Correlation Coefficient (R²): 0.998 |
Regression Equation (0-10 mg/L): y = 1.075x + 0.226 mg/L
Correlation Coefficient (R²): 0.996 |
| Intended Use Equivalence: The device should have comparable intended use to the predicate device. | Duet hs-CRP LIT Assay: Intended for quantitative determination of C-reactive protein in serum by latex particle enhanced immunoturbidimetry (LIT) as a high-sensitive assay, useful for detection and evaluation of infection, tissue injury, inflammatory disorders, and associated diseases.
K-ASSAY CRP (3) (Predicate): Intended for quantitative determination of CRP in serum and plasma by immunoturbidimetric assay as a high-sensitive assay, aiding in detection and evaluation of tissue injury, inflammatory disorders, and related diseases. (Both uses are highly similar.) |
| Methodology Equivalence: The test principles and components should be similar to the predicate. | Methodology: Both use Latex particle enhanced immunoturbidimetry.
Reagent Composition: Both have Reagent 1 (Reactive buffer solution) and Reagent 2 (Latex suspension). |
| Analytical Performance Characteristics: Similar analytical range, interference profiles, and calibrator properties. | Assay Range:
Duet hs-CRP LIT Assay: 0.3-200 mg/L
K-ASSAY CRP (3): 0.1-320 mg/L (Predicate has a slightly wider range)
Interference (Bilirubin C/F, Hemoglobin, Lipemia/Lipid):
Duet hs-CRP LIT Assay generally shows tolerance equal to or greater than the predicate in mg/dl thresholds for Bilirubin and Hemoglobin (e.g., Bilirubin C: 45 mg/dl vs 30 mg/dl for predicate; Hemoglobin: 805 mg/dl vs 500 mg/dl for predicate). Lipemia tolerance is different units but comparable.
Calibrator Traceability: Both traceable to IFCC CRM470.
Calibrator Matrix: Both use Human serum. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Sizes:
- N = 93 for CRP concentrations ranging from 0 to 200 mg/L.
- N = 64 for CRP concentrations ranging from 0 to 10 mg/L (likely a subset focusing on the high-sensitivity range).
- Data Provenance: Not explicitly stated in the provided text. It is common for such clinical correlation studies to use patient samples, but details like country of origin or whether they were retrospectively collected or prospectively gathered are not available here. The submission is from a Taiwanese company, so it's plausible the samples originated there. The study appears to be a retrospective comparative study as it involves comparing the new device's measurements against a predicate device's measurements on the same samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts
This type of in-vitro diagnostic (IVD) device does not typically involve expert review for "ground truth" in the same way an imaging or pathology device would. For CRP assays, the "ground truth" is established by the predicate device's measurement itself, which is considered the reference method for establishing substantial equivalence. No human experts are involved in creating a "ground truth" label for each sample; rather, the predicate device provides the comparative value.
4. Adjudication Method for the Test Set
Not applicable for this type of IVD device. The comparison is objective, based on direct numerical outputs from the new device versus the predicate device, not subjective interpretation requiring adjudication.
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 assay, not an imaging or interpretive device that would involve human "readers" or AI assistance in interpretation. The output is a quantitative CRP concentration.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, this is essentially what was performed. The Duet hs-CRP LIT Assay is a standalone automated assay. Its performance was evaluated by directly comparing its quantitative results against those obtained from the predicate device on the same samples, without human intervention in the result generation or comparison process (beyond operating the instruments).
7. The Type of Ground Truth Used
The "ground truth" for the test set was the measurements obtained from the predicate device (K-ASSAY CRP (3)). For IVD devices seeking substantial equivalence, the performance of the legally marketed predicate device often serves as the de facto "ground truth" or reference for comparison.
8. The Sample Size for the Training Set
The provided documentation does not mention a "training set" in the context of machine learning or algorithm development. For IVD assays like this, the development process involves reagent formulation and optimization, calibration curve fitting, and then analytical validation (as presented here). There isn't typically a separate "training set" of patient data for an algorithm as there would be for AI-based diagnostic tools.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as a "training set" as commonly understood in AI/ML contexts is not mentioned or relevant for this type of IVD device submission. The device's calibration curve is established using known CRP standards, as mentioned in the description, and this is part of the manufacturing process, not a "training set" of unknown patient samples.
§ 866.5270 C-reactive protein immunological test system.
(a)
Identification. A C-reactive protein immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the C-reactive protein in serum and other body fluids. Measurement of C-reactive protein aids in evaluation of the amount of injury to body tissues.(b)
Classification. Class II (performance standards).