CHEMMATE L26 (CD20)

• K Number: K973390
• Device Name: CHEMMATE L26 (CD20)
• Manufacturer: VENTANA MEDICAL SYSTEMS, INC.
• Date Cleared: 1997-10-03 ( 85 days)
• Product Code: DEM
• Regulation Number: 866.5130

Intended Use

To qualitative aid in the identification by light microscopy of human cells of B-cell lineage, by recognizing CD20 antigen in normal and pathologic paraffin embedded tissues processed in neutral buffered formalin, B5, or Bouin's fixative. Positive results aid in the classification of lymphomas of B-cell origin and must be interpreted by a pathologist within the context of clinical data, gross and microscopic morphologic criteria and multiple chemical and immunohistochemical stains.

Device Description

The ChemMate™ L26 (CD20) is comprised of a mouse monoclonal antibody, clone L26. and is of the IgG2a / Kappa light chain class of immunoglobulins. The antibody reacts with two non-covalently associated components (33kD and 30kD) present in the majority of B-cells. Positive staining occurs on the cells' plasma membrane. Recent studies demonstrated that the L26 antibody positively stained COS-1 cells transfected with CDNA encoding for the CD20 antigen (a pan B-cell marker). L26 has been classified as a CD20 antibody by the Fifth International Workshop on Human Leukocyte Differentiation Antigens. A unique feature of the ChemMate™ L26 (CD20) is the antibody's ability to recognize epitopes on Ivmphocvtes that survive the rigors of processing and fixation. The resultant advantage in the use of this antibody is its applicability with formalin-fixed specimens. The CD20 antigen is expressed in most B-cells present in peripheral blood and lymphoid tissue including germinal center blasts, mantle zone lymphocytes and scattered interfollicular lymphocytes. Staining also occurs in most non-Hodgkin's lymphomas of B-cell lineage.

Predicate Devices

Not Found

Reference Devices

Not Found

AI/ML (Artificial Intelligence / Machine Learning)

No
The device is an antibody-based immunohistochemical stain for light microscopy, and the summary describes its biological properties and performance in staining tissues, with no mention of computational analysis, image processing, AI, or ML.

Therapeutic

No
This device is an in-vitro diagnostic (IVD) tool used to aid in the identification and classification of B-cell lymphomas by staining specific cellular components; it does not directly treat or alleviate disease.

Diagnostic

Yes
The device is described as a "qualitative aid in the identification by light microscopy of human cells of B-cell lineage" and "positive results aid in the classification of lymphomas of B-cell origin." This indicates its use in aiding medical professionals in diagnosing specific conditions.

SaMD (Software as a Medical Device)

No

The device description clearly states it is comprised of a mouse monoclonal antibody, which is a biological reagent, not software. The intended use is for identifying cells by light microscopy using this antibody.

IVD (In Vitro Diagnostic)

Based on the provided information, this device is an IVD (In Vitro Diagnostic).

Here's why:

• Intended Use: The intended use clearly states that the device is used "to qualitative aid in the identification by light microscopy of human cells of B-cell lineage, by recognizing CD20 antigen in normal and pathologic paraffin embedded tissues". This is a diagnostic purpose, aiming to identify specific cellular components in patient samples.
• Sample Type: The device is used on "human cells of B-cell lineage in normal and pathologic paraffin embedded tissues", which are biological specimens taken from a human body.
• Diagnostic Aid: The device is described as an "aid in the identification" and "aid in the classification of lymphomas of B-cell origin". This indicates its role in the diagnostic process.
• Interpretation by a Pathologist: The results "must be interpreted by a pathologist within the context of clinical data, gross and microscopic morphologic criteria and multiple chemical and immunohistochemical stains". This confirms its use in a clinical laboratory setting for diagnostic purposes.
• Device Description: The description details a "mouse monoclonal antibody" that reacts with a specific antigen (CD20) in B-cells. Antibodies used to identify specific markers in biological samples are a common component of IVDs.

The definition of an IVD generally includes reagents, instruments, and systems intended for use in the diagnosis of disease or other conditions, including a determination of the state of health, in order to cure, mitigate, treat, or prevent disease or its sequelae. This device fits this description by aiding in the identification and classification of lymphomas, which are diseases.

PCCP (Predetermined Change Control Plan) Authorized

N/A

Overview

Intended Use / Indications for Use

FOR IN VITRO DIAGNOSTIC USE.

The ChemMate™ L26 (CD20) is intended for laboratory use to qualitatively identify by light microscopy human lymphocytes of B-cell lineage in normal and pathological paraffin embedded tissues processed in zinc formalin, neutral buffered formalin, Bouin's or B5 fixative. 8. 12, 19 Positive results aid in the classification of lymphomas as B-cell in origin and must be interpreted by a pathologist within the context of clinical data, gross and microscopic morphological criteria and multiple chemical and immunohistochemical stains.

This mouse monoclonal antibody has been optimally prediluted for use with the ChemMate™ SDK605 or SDK305 Secondary Detection - Peroxidase/DAB kit. Additionally, the prediluted ChemMate™ L26 (CD20) antibody as well as the ChemMate™ SDK605 or SDK305 Secondary Detection -Peroxidase/DAB kit has been optimized for use with the TechMate™ for automated immunohistochemical staining.

To qualitative aid in the identification by light microscopy of human cells of B-cell lineage, by recognizing CD20 antigen in normal and pathologic paraffin embedded tissues processed in neutral buffered formalin, B5, or Bouin's fixative. Positive results aid in the classification of lymphomas of B-cell origin and must be interpreted by a pathologist within the context of clinical data, gross and microscopic morphologic criteria and multiple chemical and immunohistochemical stains.

Product codes (comma separated list FDA assigned to the subject device)

DEM

Device Description

The ChemMate™ L26 (CD20) is comprised of a mouse monoclonal antibody, clone L26. and is of the IgG2a / Kappa light chain class of immunoglobulins. 123 The antibody reacts with two non-covalently associated components (33kD and 30kD) present in the majority of B-cells. 12 Positive staining occurs on the cells' plasma membrane. Recent studies demonstrated that the L26 antibody positively stained COS-1 cells transfected with CDNA encoding for the CD20 antigen (a pan B-cell marker).4 L26 has been classified as a CD20 antibody by the Fifth International Workshop on Human Leukocyte Differentiation Antigens.5

A unique feature of the ChemMate™ L26 (CD20) is the antibody's ability to recognize epitopes on Ivmphocvtes that survive the rigors of processing and fixation. 23.6 The resultant advantage in the use of this antibody is its applicability with formalin-fixed specimens.

The CD20 antigen is expressed in most B-cells present in peripheral blood and lymphoid tissue including germinal center blasts, mantle zone lymphocytes and scattered interfollicular lymphocytes. 13 Staining also occurs in most non-Hodgkin's lymphomas of B-cell lineage.3,10

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

Light Microscopy

Anatomical Site

human lymphocytes of B-cell lineage in normal and pathological paraffin embedded tissues

Indicated Patient Age Range

Not Found

Intended User / Care Setting

Laboratory use. Interpreted by a pathologist.

Description of the training set, sample size, data source, and annotation protocol

Not Found

Description of the test set, sample size, data source, and annotation protocol

Not Found

Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

Reproducibility: ChemMate™ L26 (CD20), and Negative Control Reagent have been tested on serial sections of 281 tissue specimens (both normal and tumor specimens were included in the study). Runs were performed a total of three times, with each run being performed on a different day. Consistent staining results have been obtained with run-to-run and withinrun antibody testing.

Immunoreactivity: The following immunoreactivities have been demonstrated in paraffin-embedded tissues. The list provided below is not exhaustive but characterizes the types of immunoreactivity reported in the literature for the L26 clone contained in ChemMate™ L26 (CD20).

• Reactive Normal Tissues/Cells:
  • Lymph Node: germinal center cells, mantle zone lymphocytes (most cells)
  • Spleen: white pulp (B-cell) areas
  • Tonsil: germinal center cells, mantle zone lymphocytes (most cells)
  • Thymus: medulla (some scattered areas)* - *L26 positive dendritic cells have also been identified
  • Whole Blood (Peripheral): circulating B lymphocytes
• Nonreactive Normal Tissues/Cells:
  • Lymphoid Tissues: Lymph Node (Interfollicular & Medullary Areas, Histiocytes (Interdigitating Reticulum Cells), Dendritic Reticulum Cells, Sinus Histiocytes), Spleen (Red pulp areas), Tonsil (Interfollicular & Medullary Areas, Histiocytes (Interdigitating Reticulum Cells), Dendritic Reticulum Cells, Sinus Histiocytes), Thymus (Cortex), Bone Marrow (Erythroid Cells, Myeloid Cells, Megakaryocytes). *Scattered positive B-cells identified
  • Non-Lymphoid Tissues: Skin (Epidermis, Sebacious Glands, Eccrine Glands, Hair Follicles), Thyroid (Follicular Epithelium), Lung (Pneumocytes, Bronchial Epithelium), Brain (Neurons, Glial Cells), Pancreas (Acini, Intercalated & Interlobular Ducts, Islets), Liver (Hepatocytes, Bile Duct Epithelium), Prostate (Epithelial Glands, Stroma), Kidney (Proximal Convoluted Tubules, Distal Convoluted Tubules, Glomeruli, Collecting Ducts), Uterus (Endometrium, Myometrium, Ectocervix, Endocervix), Muscle (Cardiac, Smooth, Skeletal), Placenta, Other (Fibroblasts, Mesothelium), Peripheral Blood (Erythrocytes, Granulocytes, Monocytes, Platelets).
• Non-Lymphoid Pathological Negative Tissues/Cells (0/139 reactive):
  • Epithelial (0/90): Adenoma, Parathyroid (0/1); Adenocarcinoma (0/49) - Breast (0/11), Colon (0/7), Liver, hepatocellular (0/5), Lung (0/10), Metastatic (0/4), Ovary (0/1), Ovary, cystadenocarcinoma (0/2), Pancreas (0/1), Stomach (0/3), Thyroid (0/3), Thyroid, papillary (0/2); Ameloblastoma (0/1); Carcinoma (0/20) - Bladder, transitional cell (0/5), Nasopharyngeal (0/1), Squamous cell (0/10), Small cell (0/3), Thyroid, anaplastic (0/1); Mesothelioma (0/5); Melanoma (0/14) - Amelanotic (0/10), Unspecified (0/4).
  • Mesenchymal (0/25): Angiosarcoma (0/3), Chordoma (0/1), Chondrosarcoma, extraskeletal myxoid (0/1), Endometrial Stromal Sarcoma (0/3), Fibrosarcoma (0/1), Leiomyosarcoma (0/3), Malignant Fibrous Histiocytoma (0/6), Rhabdomyosarcoma (0/7).
  • Embryonal (0/2), Unspecified (0/5).
  • Endocrine (0/24): Neuroendocrine (0/21) - Carcinoid (0/5), Lung, small cell undifferentiated (0/5), Merkel cell tumor (0/4), Pancreas (0/3), Thyroid, medullary carcinoma (0/4), Other (0/3); Pituitary adenoma (0/1), Prolactinoma (0/2).
  • Mixed (0/5): Carcinoma, Salivary Gland (0/1), Fibroadenoma, breast (0/3), Uterus (0/1).
  • Neuro/Glial (0/9): Astrocytoma (0/5), Glioma, malignant (0/2), Ganglioneuroma (0/1), Neurofibroma (0/1).
  • Small Cell Tumors (0/9): Ewing's Sarcoma (0/4), Neuroblastoma (0/4), Wilms (0/1).
• Non-Hodgkin's Lymphomas and Other Lymphoproliferative Disorders:
  • Non-Hodgkin's Lymphoma: 397/430 (92% B-Cell), 1/89 (1.1% T-Cell).
    • Low Grade: 176/184 (96% B-Cell).
      • Small Lymphocytic: 26/32 (81%).
      • Small cleaved, follicular & diffuse: 47/47 (100% B-Cell), 0/5 T-Cell.
      • Mixed small and large: 7/7 (100% B-Cell), 1/22 (4.5% T-Cell).
      • Large cleaved: 2/2 (100%).
      • Large diffuse: 94/96 (98% B-Cell), 0/13 T-Cell.
    • Intermediate: 25/25 (100% B-Cell).
      • Larger cell: 25/25 (100%).
    • High Grade: 102/106 (96% B-Cell).
      • Small non-cleaved: 4/4 (100%).
      • Large immunoblastic: 26/27 (96% B-Cell), 0/2 T-Cell.
      • Large lymphoblastic (pre B): 1/1 (100% B-Cell), 0/2 T-Cell.
      • Malignant: 71/74 (96%).
    • Miscellaneous: 21/21 (95% B-Cell).
      • Immunoblastic Sarcoma: 2/2 (100%).
      • Marginal Zone Lymphoma: 1/1 (100%).
      • Sinonasal Large-Cell Lymphoma: 0/1.
      • Monocytoid Lymphoma: 17/17 (100%).
      • T-cell Lymphoma: 0/44.
      • High Grade Lymphoblastic Lymphoma: 0/1.
  • Other Lymphoproliferative Disorders: 74/94 (79% B-Cell).
    • Hairy Cell Leukemia: 40/46 (87%).
    • Plasmacytoma/Plasma Cell Myeloma: 1/11 (10%).
    • Lymph nodules/Bone marrow biopsies 27:
      • Polycythemia Vera: 4/4 (100%).
      • Idiopathic Thrombocythaemia: 7/7 (100%).
      • Chronic Myeloid Leukemia: 0/4.
    • Myelofibrosis/Osteomyelosclerosis: 17/17 (100%).
    • Borderline: 5/5 (100%).
• Hodgkin's Lymphoma:
  • Lymphocyte Depleted: 1/9 (11%).
  • Lymphocyte Predominant: 49/51 (96%).
  • Mixed Cellularity: 8/44 (18%).
  • Nodular Sclerosing: 2/33 (6%).
  • Inconspicuous Nodularity: 5/5 (100%).
  • Diffuse: 4/4 (100%).
  • Interfollicular: 0/1.
  • Unclassified: 0/3.
  • Total: 69/150 (46%).

Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)

Not Found. Reactivity percentages and confidence intervals are provided for different tissue types.

Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.

Not Found

Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.

Not Found

Predetermined Change Control Plan (PCCP) - All Relevant Information

Not Found

Regulation Number and Section

§ 866.5130

Alpha -1-antitrypsin immunological test system.(a)
Identification. Analpha -1-antitrypsin immunological test system is a device that consists of the reagents used to measure by immunochemical techniques thealpha -1-antitrypsin (a plasma protein) in serum, other body fluids, and tissues. The measurements aid in the diagnosis of several conditions including juvenile and adult cirrhosis of the liver. In addition,alpha -1-antitrypsin deficiency has been associated with pulmonary emphysema.(b)
Classification. Class II (performance standards).

Summary

0

KU 13340

510(k) Summary

OCT - 3 1997

Date: September 29, 1997

VENTANA MEDICAL SYSTEMS, INC. 3865 North Business Center Drive Tucson, Arizona 85705

[phone] Telephone: [phone] Facsimile:

Stephen A. Tillson, Ph.D. Contact: Vice President Scientific Affairs/ Quality Assurance

Registration #: 2028492

ChemMate™ L26 (CD20) Trade Name:

Class II

FOR IN VITRO DIAGNOSTIC USE. Intended Use:

The ChemMate™ L26 (CD20) is intended for laboratory use to qualitatively identify by light microscopy human lymphocytes of B-cell lineage in normal and pathological paraffin embedded tissues processed in zinc formalin, neutral buffered formalin, Bouin's or B5 fixative. 8. 12, 19 Positive results aid in the classification of lymphomas as B-cell in origin and must be interpreted by a pathologist within the context of clinical data, gross and microscopic morphological criteria and multiple chemical and immunohistochemical stains.

This mouse monoclonal antibody has been optimally prediluted for use with the ChemMate™ SDK605 or SDK305 Secondary Detection - Peroxidase/DAB kit. Additionally, the prediluted ChemMate™ L26 (CD20) antibody as well as the ChemMate™ SDK605 or SDK305 Secondary Detection -Peroxidase/DAB kit has been optimized for use with the TechMate™ for automated immunohistochemical staining.

1

510K SUMMARY OF SAFETY AND EFFECTIVENESS

Summary And Explanation

The ChemMate™ L26 (CD20) is comprised of a mouse monoclonal antibody, clone L26. and is of the IgG2a / Kappa light chain class of immunoglobulins. 123 The antibody reacts with two non-covalently associated components (33kD and 30kD) present in the majority of B-cells. 12 Positive staining occurs on the cells' plasma membrane. Recent studies demonstrated that the L26 antibody positively stained COS-1 cells transfected with CDNA encoding for the CD20 antigen (a pan B-cell marker).4 L26 has been classified as a CD20 antibody by the Fifth International Workshop on Human Leukocyte Differentiation Antigens.5

A unique feature of the ChemMate™ L26 (CD20) is the antibody's ability to recognize epitopes on Ivmphocvtes that survive the rigors of processing and fixation. 23.6 The resultant advantage in the use of this antibody is its applicability with formalin-fixed specimens.

The CD20 antigen is expressed in most B-cells present in peripheral blood and lymphoid tissue including germinal center blasts, mantle zone lymphocytes and scattered interfollicular lymphocytes. 13 Staining also occurs in most non-Hodgkin's lymphomas of B-cell lineage.3,10

In a study encompassing benign lymphoid tissues. Cartun et. al. demonstrated that L26 was reactive in known B-cell rich regions; i.e. germinal centers, mantle zone lymphocytes of lymph node and tonsil and white pulp of spleen. Thymus and bone marrow were unreactive for L26 with only scattered positive cells in the medulla regions of thymus. L26 was unreactive in all normal non-lymphoid tissues testedand negative in 124 non-lymphoid tumors with L26 reactivity confined to immunoreactive lymphocytes infiltrated within the tumors. Among non-Hodgkin's lymphoma cases, L26 was shown to be reactive in 73 out of 74 B-cell lymphomas, including 44 out of 44 cases of diffuse large cell and immunoblastic B-cell lymphoma. Only 37 of 44 of these B cell Lymphomas were positive with leukocyte Common Antigen (LCA). This finding suggests that a panel of antibodies including L26 should be used to exclude B-cell pathogenesis. No T-cell tumors (0/8) were reactive. Four of four hairy cell leukemias were positive for L26.7

The majority of non-Hodgkin's lymphomas will stain positively for L26. Elghetany, et al. reported on 44 cases of paraffin-embedded non-Hodgkin's lymphomas stained with a panel of monoclonal antibodies to T and B cells. Results revealed that immunophenotyping was the same as genotypic analysis in 37 of the 39 cases. Five could not be assigned a specific B or T-

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cell lineage. L26 labeled 32 out of 33 B-cell Ivmphomas and one of the six Tcell lymphomas.8 In a study on 13 diffuse mixed cell non-Hodgkin's lymphomas. Katzin et al. emploved immunohistochemical and gene rearrangement analyses to determine whether these mixed cell lymphomas were of monoclonal, oligoclonal or dual lineage. Large lymphoid cells were L26 positive in 12 of 13 cases and in no cases were the small Ivmphoid cells positive for L26.11

And in studies conducted by Wolf et al. in which thyroid neoplasms were reevaluated, immunophenotyping results showed that 65 of the 68 neoplasms assessed were non-Hodgkin's lymphomas (60 out of 65 were immunoreactive with L26). Of these lymphomas, 63 out of 65 were determined to be of B-cell origin and two were not able to be determined. The remaining three cases were characterized as epithelial in origin (carcinomas) and negative for L26. Immunohistochemical results converted a preliminary diagnosis of small cell carcinoma to a non-Hodgkin's lymphoma in many cases. Small cell carcinomas are rare in the thyroid with most thyroid neoplasms being Ivmphomas of B-cell origin. 12

Additionally, Hodgkin's disease that has been classified as lymphocyte predominance stained positively for L26. Nicholas, et al re-evaluated archival cases previously diagnosed as lymphocyte predominance Hodgkin's disease (LPHD) using a panel of antibodies, including L26. Immunostaining revealed that of the 30 cases all were positive for L26. These cases were further subdivided as LPHD with nodular architecture (21 cases), diffuse LPHD (four cases) and LPHD with inconspicuous nodularity. Mixed cellularity Hodakin's (13 cases), nodular sclerosing Hodgkin's (two cases), and interfollicular Hodgkin's (one case) were all negative for L26. Additionally, the LPHD biopsies all contained polylobated Reed-Sternberg cell variants that were positive for L26.13

L26 reactivity has been reported in several neoplastic and lymphoproliferative disorders. In a study encompassing 110 B-5 fixed, paraffin-embedded neoplastic and lymphoid proliferative disorders, Segal et. al. confirmed L26 reactivity in 73 of the 76 B-cell lymphomas and found L26 was unreactive in 5/5 T-cell lymphomas. Additionally, 11 of 12 cases positive for the T-cell marker CD43 were also positive for L26, indicating a differentiation of malignant B-cell lymphoma.14

Reactivity of L26 with hairy cell leukemias and monocytoid B-cell lymphomas was further assessed by Stroup, et al. by using a large panel of antibodies in 42 cases of hairy cell leukemia (HCL) and 24 cases of monocytoid B-cell lymphoma (MBCL). L26 was immunoreactive in 85% of the hairy cell leukemias tested. Similarly, L26 was positive in 84% of the monocytoid B-cell lymphomas tested. 15

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A panel of antibodies, including L26, were used by Wolf et al. to stain 34 paraffin-embedded cases of gastrointestinal tract lymphoma. Previous phenotyping studies through extensive frozen section immunohistochemistry revealed that 31 of the 34 cases were B-cell in origin and the remaining three T-cell in origin. 24 of the 31 paraffin sections were immunoreactive with L26 and L26 was negative in all three of the T-cell Ivmphomas. 16

Further, in studies conducted by Macon, et al. L26 labeled 33 out of 38 B-cell lymphomas tested and 0 out of 76 peripheral T-cell Ivmphomas.17

No L26 cross reactivity has been observed with normal or malignant nonlymphoid cells with the following exception7.20. L26 positive dendritic cells have been noted in the medulla of normal thymi and thymomas along with scattered B-Cells 19, 23, 24. The L26 positive dendritic cells coexpress keratin and are frequently associated with Hasall's corpuscles. It is recommended that an epithelial marker, such as keratin, be used in conjunction with the L26 antibody to aid in the differential diagnosis of mediastinal non-Hodqkin's lymphomas.

A summary of immunoreactivity in lymphoid and hematopoietic cells/tissues and neoplasms may be found in tables I-V of Performance Characteristics in this insert.

Product Specific Limitations:

• 1. A few cases of diffuse large (2/26. 7.7%) and diffuse mixed (1/12, 8.3%) non-Hodgkin's T-Cell lymphomas coexpress the CD20 antigen10,20
• 2. In poorly fixed tissue specimens, nonspecific staining of non-lymphoid tissues may be observed, particularly epithelium and smooth muscle.
• 3. In some cases of Hodgkin's disease, particularly the lymphocyte predominant type, membrane, cytoplasmic, or paranuclear staining of some Reed-Sternberg cells has been observed 5,7.
• 4. The differential diagnosis of mediastinal tumors with the L26 antibody may be compromised by the presence of L26 and keratin positive dendritic cells found in the medulla of normal thymi and some thymomas 19, 23, 24. Use a panel of antibodies to distinguish mediastinal tumors.
• 5. No L26 cross-reactivity has been observed with normal or malignant nonlymphoid cells with the following exception7.20. L26 positive dendritic cells have been noted in the medulla of normal thymi and thymomas along with

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scattered B-Cells 19, 23, 24. The L26 positive dendritic cells coexpress keratin and are frequently associated with Hassall's corpuscles. It is recommended that an epithelial marker, such as keratin, be used in conjunction with L26 antibody to aid in the differential diagnosis of mediastinal non-Hodgkin's lymphomas.

• 6. Dako® CD20, L26 positive B-Cells have been observed in granulomatous lesions of unknown significance, granulomas associated with toxoplasmosis; and sarcoid reaction affiliated with seminoma, Hodgkin's Disease. non-Hodgkin's lymphoma, and cancer of the breast, colon, and lung25.
• 7. Occasional cases of T-cell lymphoma have been reported to co-express the CD20 antigen.
• 8. In Hodgkin's disease, Reed-Sternberg cells have been reported as staining positively for L26.13,14
• 9. L26-positive B-cells may be present in tissues other than those of Ivmphoid origin. Though these reactions are positive for L26, interpretation should always be considered within the context of the predominant cell type of the tissue in question26.

Performance Characteristics:

Reproducibility: ChemMate™ L26 (CD20), and Negative Control Reagent have been tested on serial sections of 281 tissue specimens (both normal and tumor specimens were included in the study). Runs were performed a total of three times, with each run being performed on a different day. Consistent staining results have been obtained with run-to-run and withinrun antibody testing.

Immunoreactivity: The following immunoreactivities have been demonstrated in paraffin-embedded tissues.. The list provided below is not exhaustive but characterizes the types of immunoreactivity reported in the literature for the L26 clone contained in ChemMate™ L26 (CD20).

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TABLE I REACTIVE NORMAL TISSUES/CELLS '188

Tissues
Lymph Node:
germinal center cells
mantle zone lymphocytes (most cells)
Spleen:
white pulp (B-cell) areas
Tonsil:
germinal center cells
mantle zone lymphocytes (most cells)
Thymus:
medulla (some scattered areas)*
Whole Blood (Peripheral):
circulating B lymphocytes

, 24 4 L26 positive dendritic cells have also been identified

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nonreactive normal tissues/cells17 TABLE II

Lymphoid Tissues	Non-Lymphoid Tissues
Lymph Node:
Interfollicular & Medullary Areas*
Histiocytes (Interdigitating Reticulum Cells)
Dendritic Reticulum Cells, Sinus Histiocytes	Skin:
Epidermis
Sebacious Glands
Eccrine Glands
Hair Follicles
Spleen:
Red pulp areas*	Thyroid:
Follicular Epithelium
Tonsil:
Interfollicular & Medullary Areas*
Histiocytes (Interdigitating Reticulum Cells)
Dendritic Reticulum Cells, Sinus Histiocytes	Lung:
Pneumocytes
Bronchial Epithelium
Thymus:
Cortex*	Brain:
Neurons
Glial Cells
Bone Marrow:
Erythroid Cells
Myeloid Cells
Megakaryocytes	Pancreas:
Acini
Intercalated & Interlobular Ducts
Islets
	Liver:
Hepatocytes
Bile Duct Epithelium
	Prostate:
Epithelial Glands
Stroma
	Kidney:
Proximal Convoluted Tubules
Distal Convoluted Tubules
Glomeruli
Collecting Ducts
	Uterus:
Endometrium
Myometrium
Ectocervix
Endocervix
	Muscle:
Cardiac
Smooth
Skeletal
	Placenta
	Other:
Fibroblasts
Mesothelium
	Peripheral Blood:
Erythrocytes
Granulocytes
Monocytes
Platelets

*Scatted positive B-cells identified

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TABLE IIINON-LYMPHOID PATHOLOGICAL NEGATIVE TISSUES/CELLST,9,12,20

Epithelial (0/90):	Endo
Adenoma, Parathyroid (0/1)	Neuro
	Caro
Adenocarcinoma (0/49):	Lung
Breast (0/11)	Merk
Colon(0/7)	Panc
Liver, hepatocellular (0/5)	Thyro
Lung (0/10)	Othe
Metastatic (0/4)	Pitu
	Pro
Ovary (0/1)
Ovary, cystadenocarcinoma (0/2)
Pancreas (0/1)	Mixe
Stomach (0/3)	Car
Thyroid (0/3)	Fibr
Thyroid, papillary (0/2)	Uter
Ameloblastoma (0/1)	Neuro
	Astro
Carcinoma (0/20):	Glio
Bladder, transitional cell (0/5)	Gan
Nasopharyngeal (0/1)	Neuro
Squamous cell (0/10)
Small cell (0/3)	Small
Thyroid, anaplastic (0/1)	Ewir
Neuro
Mesothelioma (0/5)	Wilr
Melanoma (0/14):
Amelanotic (0/10)
Unspecified (0/4)
Mesenchymal (0/25):
Angiosarcoma (0/3)
Chordoma (0/1)
Chondrosarcoma, extraskeletal myxoid (0/1)
Endometrial Stromal Sarcoma (0/3)
Fibrosarcoma (0/1)
Leiomyosarcoma (0/3)
Malignant Fibrous Histiocytoma (0/6)
Rhabdomyosarcoma (0/7)
Embryonal (0/2)
Unspecified (0/5)

ocrine (0/24):

roendocrine (0/21) inoid (0/5) g, small cell undifferentiated (0/5) el cell tumor (0/4) creas (0/3) oid, medullary carcinoma (0/4) r (0/3) uitary adenoma (0/1) olactinoma (0/2)

d (0/5): cinoma, Salivary Gland (0/1) roadenoma, breast (0/3) rus (0/1)

• o/Glial (0/9): rocytoma (0/5) ma, malignant (0/2) glioneuroma (0/1) rofibroma (0/1)
  Cell Tumors (0/9): ng's Sarcoma (0/4) roblastoma (0/4) n's (0/1)

Note: None of the 139 non-lymphoid pathological tissues listed above were reactive for L26. The number of reactive tissues over the total number of tissues is recorded by the specimen type. Confidence Intervals have been assigned for sample values greater than 1: 0/2 = 0-84.2%, 0/3 = 0-70.8%, 0/5 = 0-52.2%, 0/7 = 0-41.0%, 0/9 = 0-33.6%, 0/10 = 0-30.8%, 0/14 = 0-23.2%, 0/17 = 0-19.5%, 0/21 = 0-16.1%, 0/24 = 0-14.2% 0/25 = 0-13.7%, 0/61 = 0-6 %, 0/99 = 0-3.5%

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TABLE IV NON-HODGKIN'S LYMPHOMAS and OTHER LYPMPHOPROLIFERATIVE DISORDERS

Tissue	B-Cell	%	95% CI	T-Cell	%	95% CI
Non-Hodgkin's Lymphoma	397/430	92%		1/89	1.1%	0.2-4.5%
Low Grade: 7,10,11,17,21	176/184	96%	93.5
98.5%	--	--
-Small Lymphocytic	26/32	81%	63-93%	--	--
-Small cleaved, follicular &
diffuse	47/47	100%	92-100%	0/5	--	0-52%
-Mixed small and large	7/7	100%	59-100%	1/22	4.5%	0.7-27%
-Large cleaved	2/2	100%	15.8-100%	--	--
-Large diffuse	94/96	98%	93-99.8%	0/13	--	0-24.7%
Intermediate: 7.21	25/25	100%	86.3-100%	--	--
-Larger cell	25/25	100%	86.3-100%	--	--
High Grade: 7,10,12,11,14,16	102/106	96%		--	--
-Small non-cleaved	4/4	100%	39.8-100%	--	--
-Large immunoblastic	26/27	96%	81-99%	0/2	--	0-84.7%
-Large lymphoblastic (pre B)	1/1	100%	--	0/2	--	0-84.7%
-Malignant	71/74	96%	87-99%	--	--
Miscellaneous: 7,10,14,15,16,17,21,22	21/21	95%		--	--
-Immunoblastic Sarcoma	2/2	100%	15.8-100%	--	--
-Marginal Zone Lymphoma	1/1	100%	--	--	--
-Sinonasal Large-Cell
Lymphoma	0/1	--	--	--	--
-Monocytoid Lymphoma	17/17	100%		--	--
-T-cell Lymphoma				0/44	--	0-11.5%
-High Grade Lymphoblastic
Lymphoma				0/1	--
Other Lymphoproliferative
Disorders: 7,14,16,17	74/94	79%	78-95%	--	--
-Hairy Cell Leukemia	40/46	87%	73-95%	--	--
-Plasmacytoma/Plasma Cell
Myeloma	1/11	10%	0.5-42%	--	--
-Lymph nodules/Bone marrow
biopsies 27
---Polycythemia Vera	4/4	100%	39.8-100%	--	--
---Idiopathic Thrombocythaemia	7/7	100%	59-100%	--	--
---Chronic Myeloid Leukemia	0/4	--	0-60.2%	--	--
Myelofibrosis/
Osteomyelosclerosis	17/17	100%	80.5-100%	--	--
Borderline	5/5	100%	48-100%	--	--

Note: The number of reactive tissues over the total number of tissues is recorded by the specimen type. Confidence Intervals have been assigned for sample values greater than 1.

9

| TISSUE | NO. REACTIVE /
NO. TESTED | % | 95% CONFIDENCE
INTERVAL |
|-----------------------------|------------------------------|------|----------------------------|
| Lymphocyte Depleted | 1/9 | 11% | 0.3-48.2% |
| Lymphocyte
Predominant | 49/51 | 96% | 86.5-98.9% |
| Mixed Cellularity | 8/44 | 18% | 8-30% |
| Nodular Sclerosing | 2/33 | 6% | 1-20.5% |
| Inconspicuous
Nodularity | 5/5 | 100% | 48-100% |
| Diffuse | 4/4 | 100% | 39.8-100% |
| Interfollicular | 0/1 | --- | --- |
| Unclassified | 0/3 | --- | 0-70.8% |
| Total: | 69/150 | 46% | --- |

HODGKIN'S LYMPHOMA 9,10,13,19,20 TABLE V

Note: The number of reactive tissues over the total number of tissues is recorded by the specimen type. Confidence Intervals have been assigned for sample values greater than 1.

References

• 1. Ishii Y, et al. Six distinct antigen systems of human B-cells as defined by monoclonal antibodies. In: Reinherz EL, et al, eds. Leukocyte Typing II. New York. Springer Verlag 1986
• 2. Ishii Y. et al. Two distinct antigen systems in human B-lymphocytes; identification of cell surface and intercellular antigens using monoclonal antibodies. Clin Exp Immun 2.
• 3. Takami T, et al. B20.3 Reactivity and specificity of L26 (pan-B-cell mAb) on 322 cases of fresh and paraffin-embedded lymphoproliferative diseases. In Knapp W et al, eds. Leukocyte Typing IV. White Cell Differentiation Antigens. Oxford, Oxford University Press, 1989: 134
• 4. Mason DY, et al. Antibody L26 recognizes an intercellular epitope on the B-cell associated CD20 antigen. Am J Path. 1990, 136:1215
• 5. Fifth International Workshop on Leukocyte Differentiation Antigens. Boston, 1993.
• 6. Takami, et al. Three distinct antigen systems on human B cell subpopulations as defined by monoclonal antibodies. J Immun. 1985, 134:828
• 7. Cartun RW, et al. Utilization of monoclonal antibody L26 in the identification and confirmation of B-cell lymphomas: a sensitive and

10

specific marker applicable to formalin- and B5 fixed, paraffin embedded tissues. Am J Path 1987, 129: 415

• 8. Takami T, et al. Reactivity and specificity of L26 (pan-B-cell mAb) on 322 cases of freshly and paraffin-embedded lymphoproliferative diseases. In Knapp w. et al., eds. Leukocvte Typing IV. White cell differentiation antigens. Oxford University Press., 1989: 134
• 9. Coles, FB et al. Hodgkin's disease lymphocyte predominant type: immunoreactivity with B-cell antibodies. Mod Path. 1988, 1:274
• 10. Elghteany MT et al. Immunophenotyping of non-Hodgkin's lymphomas in paraffin-embedded tissue sections. Am J Clin Path. 1991, 95:517
• 11. Katzin WE et al. Immunophenotypic and genotypic characterization of diffuse mixed non-Hodgkin's lymphomas. Am J Pathol. 1989, 135:615
• 12. Wolf, BC et al. Immunohistochemical analysis of small cell tumors of the thyroid gland. Hum Pathol. 1992, 23:1252
• 13. Nicholas DS, et al. Lymphocyte predominance Hodgkin's disease. Histopath. 1990, 16:157
• 14. Segal GH, et al. Reliable and cost-effective paraffin section immunohistology of lymphoproliferative disorders. Am J Surg Path. 1991, 15(11):1034
• 15. Stroup, R and Sheibani, K. Antigenic phenotypes of hairy cell leukemia and monocytoid B-cell lymphoma. Hum Path. 1992, 23:172
• 16. Wolf BC, et al. Non-Hodgkin's lymphomas of the gastrointestinal tract. Am J Clin Path. 1990, 93:233
• 17. Macon WR. et al. Leu-22(L60), a more sensitive marker than UCHL 1 for peripheral T-cell lymphomas particularly large-cell types. Am J Clin Path. 1991, 95:696
• 18. Taylor CR and Cote RJ. Immunomicroscopy: A diagnostic tool for the surgical pathologist. WB Saunders Company, Philadelphia. 1992, second edition. pg 42-70
• 19. Chilosi M., et al. Neoplastic epithelial cells in a subset of human thymomas express the B-Cell associated CD20 antigen. Am J Surg Path 1992; 16(10): 988
• 20. Linder J. et al. Monoclonal antibodies marking B-cell non-Hodgkin's lymphoma in paraffin-embedded tissue. Mod Path. 1988, 1:29
• 21. Norton AJ and Isaacson PG. Monoclonal antibody L26: an antibody that is reactive with normal and neoplastic B-lymphocytes in routinely fixed and paraffin wax embedded tissue. J Clin Path. 1897, 40:1405.
• 22. Franco V, et al. Immunohistochemical evaluation of bone marrow lymphoid nodules in chronic myeloproliferative disorders. Virchows Archiv A Path Anat. 1991, 419:261
• 23. Masanuga A, et al. Strong expression of L26 antigen in epithelial cells of human neonatal thymus. Thymus 1993, 21:65
• 24. Taubenberger JK, et al. Thymoma with abundant L26 positive 'asteroid' cells. Arch Path Lab Med 1991, 115:1254

11

• 25. Brincker H, and Pederson NT. Immunohistologic separation of B-cell positive granulomas from B-cell negative granulomas in paraffin embedded tissues with special reference to tumor related sarcoid reaction. APMIS 1991, 99:282
• 26. Ernst PB, et al. Immunity in mucosal tissues. Basic and Clinical Immunology, 6th edition, chapter 12. Stites, DP, et al. Editors. Norwalk, CT, Appleton & Lang Press, 1987:159
• 27. Battifora H, Alsabeh R, Jenkins KA, Gown A. Epitope Retrieval (unmasking) in immunohistochemistry. Advances in Pathology and Laboratory Medicine 1995; 8:117.

12

DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/12/Picture/1 description: The image shows the word "DEPARTMENT" in bold, black font. The word is in all capital letters and is positioned horizontally. To the left of the word is a graphic that is partially visible.

OCT - 3 1997

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Stephen A. Tillson, Ph.D. Vice President Scientific Affair/ Quality Assurance VENTANA MEDICAL SYSTEMS, INC. 3865 North Business Center Drive Tucson, Arizona 85705

Re: K973390 ChemMate™ L26 (CD20) Trade Name: Requlatory Class : II Product Code: DEM Dated: July 7, 1997 Received: July 10, 1997

Dear Dr. Tillson:

We have reviewed your Section 510 (k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual reqistration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject-to such additional controls. Existing major requlations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Reqister. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal Laws or Regulations.

13

Page 2

Under the Clinical Laboratory Improvement Amendments of 1988 (CUIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at [phone].

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at [phone]. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at [phone]. Also, please note the requlation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll free number [phone] or at [phone] or at its internet address "http://www.fda.gov/cdrh/dsmamain.html"

Sincerely yours,

Steven Autman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

14

Page 1 of 1

510(k) Number (if known): K973390

ChemMate L26(CD20) Device Name:

Antibody Reagent

Indications For Use:

ﺎﻧﺔ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍ

To qualitative aid in the identification by light microscopy of human cells of B-cell lineage, by recognizing CD20 antigen in normal and pathologic paraffin embedded tissues processed in neutral buffered formalin, B5, or Bouin's fixative. Positive results aid in the classification of lymphomas of B-cell origin and must be interpreted by a pathologist within the context of clinical data, gross and microscopic morphologic criteria and multiple chemical and immunohistochemical stains.

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Titia E. Malins

(Division Sign-Off) Division of Clinical Laboratory Devices 510(k) Number .

Prescription Use
(Per 21 CFR 801.109)

OR

Over-The-Counter. Use_

(Optional Format 1-2-96)

O