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To qualitatively aid in the identification by light microscopy of human cells of lymphoid orgin, by recognizing Leukocyte Common Antigen (LCA) in normal and pathologic paraffin embedded tissues processed in neutral buffered formalin, B5, or Bouin's fixative.

The ChemMate™ LCA (CD45) is comprised of a mixture of two mouse monoclonal antibodies, clones PD7/26/16 and 2B11; each is of the IgG1 class of immunoglobulins. Each clone reacts with a different epitope of a family of membrane glycoproteins present on most human leukocytes known as the leukocyte common antigen (LCA).

This submission pertains to the ChemMate™ LCA (CD45) antibody, intended for the qualitative identification of human cells of lymphoid origin in paraffin-embedded tissues via light microscopy. The document provides detailed performance characteristics regarding the immunoreactivity and reproducibility of the device.

Here's an analysis of the acceptance criteria and the study that proves the device meets them:

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state quantitative acceptance criteria (e.g., "sensitivity must be >90%"). Instead, it describes the expected immunoreactivity profiles (reactive, variably reactive, nonreactive) for various tissue and cell types, both normal and pathological. The reported performance is then presented as the percentage of cases showing reactivity or non-reactivity within these categories, often accompanied by 95% confidence intervals where the sample size was sufficient.

Given the qualitative nature of the intended use (aid in identification by light microscopy), the acceptance criteria appear to be the demonstration of consistent and expected reactivity patterns as described in the literature and confirmed by the studies. The device “meets” acceptance criteria by demonstrating these expected immunoreactivity profiles.

2. Sample Sizes Used for the Test Set and Data Provenance:

The document describes two main types of studies:

• Reproducibility Study:

  • Sample size: 271 tissue specimens (both normal and tumor, as referenced in Tables IB and V).
  • Data Provenance: Not explicitly stated by country, but conducted by Ventana Medical Systems, Inc. (the manufacturer). Retrospective, as these are "serial sections" from existing tissue banks.

• Immunoreactivity Studies (Various tables refer to different data sources):

  • Table IA (Reactive and Nonreactive Normal Tissues/Cells - Literature Review): A total of 45 tissues were examined.
    • Data Provenance: This table largely synthesizes data from published literature (references 1, 7, 17, 18, 21), implying multicentric and retrospective data collection.
  • Table IB (Reactive and Nonreactive Normal Tissues/Cells - BioTek Solutions Study): 126 normal tissues.
    • Data Provenance: Conducted by BioTek Solutions (a company, likely related to Ventana) using the ChemMate™ LCA-CD45 and TechMate™ Automated Staining System. Retrospective.
  • Table II (Reactive B- and T- Cell Non-Hodgkin's Lymphoma - Literature Review): 80 specimens.
    • Data Provenance: Predominantly literature-based, with some fixed in multiple fixatives. Retrospective.
  • Table III (Other Hematopoietic Neoplasms - Literature Review): Not a single sample size for the entire table, but individual counts for each disease type (e.g., 3/3 for CLL, 5/5 for Hairy Cell Leukemia). Total reactive/non-reactive cases shown in the table: (70 reactive + 115 non-reactive) = 185 unique cases across various tumor types. However, this is also a compilation of literature.
    • Data Provenance: Literature-based. Retrospective.
  • Table IV (Nonreactive Non-Lymphoid Pathological Tissues - Literature Review): A total of 162 tissues.
    • Data Provenance: Literature-based. Retrospective.
  • Table V (Reactive and Nonreactive Pathological Tissues/Cells - BioTek Solutions Study): 145 pathological tissues.
    • Data Provenance: Conducted by BioTek Solutions using the ChemMate™ LCA-CD45 and TechMate™ Automated Staining System. Retrospective.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:

The document implicitly relies on consensus from pathologists and researchers who published the referenced literature, as well as pathologists involved in internal studies (BioTek Solutions).

• For the literature-based data (Tables IA, II, III, IV): The ground truth for diagnosis and reactivity was established by the original authors/pathologists of the cited publications. While specific numbers and qualifications of these experts aren't given in this 510(k) summary, it's assumed they are qualified pathologists and researchers in the field of immunohistochemistry and hematopathology.
• For the BioTek Solutions studies (Tables IB, V): The studies state "All tissues were stained using the TechMate™ Automated Staining System." and the intent is for interpretation "by a pathologist within the context of clinical data, gross and microscopic morphological data and multiple chemical and immunohistochemical stains." It is implied that qualified pathologists made the assessments, but the specific number of experts or their years of experience are not mentioned.

4. Adjudication Method for the Test Set:

No specific adjudication method (e.g., 2+1, 3+1) is described for the ground truth establishment in either the literature-based data or the BioTek Solutions studies. The reported findings are presented as observations or consensus from the respective studies.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No MRMC study comparing human readers with AI assistance versus without AI assistance was done. This device is an antibody reagent, not an AI-powered diagnostic tool. The performance is assessed in terms of its biological reactivity and reproducibility, not human interpretive improvement.

6. Standalone Performance Study:

Yes, the studies described are essentially "standalone" in nature for the device (the antibody). The performance refers to the antibody's ability to consistently stain specific cell populations. The outcomes (e.g., positive or negative staining) are then interpreted by human pathologists, but the study itself (immunoreactivity and reproducibility) focuses on the consistent behavior of the reagent. The "Performance Characteristics" section directly addresses this.

7. Type of Ground Truth Used:

The ground truth used is primarily expert consensus (pathology/histopathology). The tissue diagnoses (e.g., specific types of lymphomas, carcinomas, normal tissues) were established by qualified pathologists based on morphological, clinical, and often other immunohistochemical markers, as is standard practice in surgical pathology. The reactivity of the LCA (CD45) antibody was then assessed against these established diagnoses.

8. Sample Size for the Training Set:

This product is an antibody reagent, not a machine learning algorithm. Therefore, there is no "training set" in the computational sense. The product's development and optimization involved empirical testing to ensure optimal predilution and performance with specific detection kits and automated staining systems. The "training" in this context would be the iterative development and formulation of the antibody cocktail and its associated staining protocols.

9. How the Ground Truth for the Training Set Was Established:

As there is no "training set" in the AI sense, this question is not applicable. The development of the antibody involved standard laboratory and histopathological methods to characterize its specificity and sensitivity, likely using well-characterized tissue samples from disease banks, with ground truth established by expert pathologists as described above.

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