(153 days)
Monoclonal Mouse Anti-Human B-cell, CD19, Clone HD37, RPE-Cy5 conjugated, has been developed for use in flow cytometry for the analysis of B-cells. This reagent allows simultaneous detection and quantification of CD19-positive cells (B-cells) in normal and pathological conditions such as immunodeficiency disorders. It is one component of the suggested monoclonal antibody (MAb) combinations for routine immunophenotyping of lymphocytes in peripheral blood.
Immunophenotyping of lymphocytes is widely applied for detection and classification of hematovojetic malignancies, and for diagnosis of immunodeficiencies. DAKO Anti-CD19/Cy5 is one of the reagents utilized when performing immunophenotyping of lymphocytes.
Monoclonal Mouse Anti-Human B-cell, CD19, RPE-Cy5-conjugated, Clone HD37 is specific for B-lymphocyte cluster determinants as evaluated by the International Workshop on Human Leukocyte Differentiation Antigens. HD37 CD19-specific monoclonal antibody was designated B28 antibody at the Second Workshop (Reinherz, EL, Haynes, BF, Nadler, LM, Bernstein, ID, Leukocyte Typing II, Vol. 2. New York-Berlin-Heidelberg-Tokyo: eds. Springer Verlag, 1986.) Purified monoclonal mouse anti-human CD19 is produced in tissue culture, dialyzed and conjugated with R-phycoerythrin (RPE) covalently coupled to cyanin 5 (Cy5). One ml (1,0 ml) containing the conjugated antibody is supplied in 0.05M Tris-HCI buffer, pH 7.2, 15mM NaN3, 0.1M NaCl, stabilized with 1% carrier protein.
This document describes the DAKO® Mouse Anti-Human B-cell, CD19/RPE-Cy5, Clone HD37 (Product Code No. C7066), a monoclonal antibody reagent intended for flow cytometry analysis of B-cells in peripheral blood.
Acceptance Criteria and Device Performance Study Summary
The acceptance criteria for this device are not explicitly stated in a quantitative manner as "acceptance criteria" but are implied through the performance characteristics presented. The study demonstrates the device's linearity, reproducibility, specificity, and correlation with a predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Characteristic | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Binding Linearity | $R^2$ value close to 1 for the linear fit of antigen dilution vs. signal. | $y = 0.01% + 0.98x$, $R^2 = 0.999$ (for Anti-CD19/Cy5, HD37) |
| Reproducibility | Low Coefficient of Variation (%CV) across different concentrations and machines. | FACScan: High Level (90.87 ± 1.24, 1.37%CV); Medium Level (51.28 ± 1.47, 2.87%CV); Low Level (26.77 ± 1.02, 3.81%CV). |
| Profile II: High Level (87.16 ± 2.09, 2.40%CV); Medium Level (49.75 ± 1.54, 3.09%CV); Low Level (26.13 ± 1.08, 4.11%CV). | ||
| Specificity | Minimal non-specific binding, particularly to non-lymphocyte populations; specific binding to B-cells (lymphocytes). | Specific for lymphocytes (average 13.0% binding, representative of B-cell population). Minimal binding to RBCs (0.04%), granulocytes (1.10%), and platelets (0.22%). Some binding to monocytes (7.66%), but can be excluded by proper gating. |
| Predicate Equivalence (Normal) | Strong linear correlation ($R^2$ close to 1) with the predicate device. | $y_{\text{(DAKO CD19/Cy5+ Lymphocytes)}} = 2.27 + 0.77 x_{\text{(DAKO CD19/RPE + Lymphocytes)}}$. $R^2 = 0.6743$. |
| Predicate Equivalence (Total) | Strong linear correlation ($R^2$ close to 1) with the predicate device across a broader range of samples, ideally a 1:1 relationship (slope near 1, intercept near 0). | $y_{\text{(DAKO CD19/Cy5+ Lymphocytes)}} = 0.45 + 0.98 x_{\text{(DAKO CD19/RPE + Lymphocytes)}}$. $R^2 = 0.8832$. This indicates comparability on a 1:1 basis (slope 0.98, intercept 0.45). |
2. Sample Size Used for the Test Set and Data Provenance
- Linearity: 5 dilutions of Raji cells (antigen-positive) diluted with JM cells (antigen-negative). Data provenance is internal (DAKO Corporation, implicitly).
- Reproducibility: 10 replicates from peripheral blood of 3 donors. Data provenance is internal (DAKO Corporation, implicitly).
- Specificity: 5 apparently healthy adult donors of various races. Data provenance is internal (DAKO Corporation, implicitly).
- Predicate Equivalence:
- 153 normal, apparently healthy individuals. Data provenance: prospective, from three geographically separate laboratories.
- An additional 27 samples from patients with illnesses. Data provenance: not explicitly stated if prospective or retrospective, but added to the overall dataset for correlation.
- Total for correlation: 180 samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
The document does not mention the use of experts to establish a "ground truth" in the traditional sense for the performance studies. The measurements (e.g., %CD19+ cells) are direct measurements from flow cytometry, which is an objective measurement technique rather than interpretive.
4. Adjudication Method for the Test Set
Not applicable. The measurements are objective laboratory results and do not require 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 device is a monoclonal antibody reagent used in flow cytometry, not an AI or imaging diagnostic tool that involves human "readers" or subjective interpretation.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This refers to the performance of the device itself (the antibody reagent) in binding to target cells and being detected by a flow cytometer. The entire testing described (linearity, reproducibility, specificity, predicate comparison) represents the standalone performance of the reagent. Human involvement is in operating the flow cytometer and analyzing the raw data, but the performance metrics directly pertain to the reagent's characteristics.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" for the performance studies is rooted in the intrinsic properties of the cells and the flow cytometry method itself:
- Linearity: Based on known concentrations of antigen-expressing cells.
- Reproducibility: Based on repeated measurements of the same samples.
- Specificity: Verified by testing binding to different known cell populations (RBCs, granulocytes, monocytes, lymphocytes, platelets) and observing the expected pattern of strong binding to lymphocytes (B-cells) and minimal binding to others.
- Predicate Equivalence: The predicate device (DAKO Anti-CD19/RPE, HD37 reagent) serves as the "reference standard" or "ground truth" for comparative purposes, implicitly having its own established performance.
8. The sample size for the training set
The document does not mention a "training set" in the context of machine learning or AI algorithms. This device is a biochemical reagent, and its development would typically involve empirical optimization and validation rather than a formal machine learning training phase.
9. How the ground truth for the training set was established
Not applicable, as there is no "training set" in the context of the type of device described.
§ 864.5220 Automated differential cell counter.
(a)
Identification. An automated differential cell counter is a device used to identify one or more of the formed elements of the blood. The device may also have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the blood, bone marrow, or other body fluids. These devices may combine an electronic particle counting method, optical method, or a flow cytometric method utilizing monoclonal CD (cluster designation) markers. The device includes accessory CD markers.(b)
Classification. Class II (special controls). The special control for this device is the FDA document entitled “Class II Special Controls Guidance Document: Premarket Notifications for Automated Differential Cell Counters for Immature or Abnormal Blood Cells; Final Guidance for Industry and FDA.”