PF4 ENHANCED SOLID PHASE ELISA

K053559 · Genetic Testing Institute · LCO · Jan 20, 2006 · Hematology

Device Facts

• Record ID: K053559
• Device Name: PF4 ENHANCED SOLID PHASE ELISA
• Applicant: Genetic Testing Institute
• Product Code: LCO · Hematology
• Decision Date: Jan 20, 2006
• Decision: SESE
• Submission Type: Special
• Regulation: 21 CFR 864.7695
• Device Class: Class 2

Indications for Use

PF4 ENHANCED® is a qualitative solid phase enzyme linked immunosorbent assay (ELISA) designed to detect antibodies reactive with platelet factor 4 (PF4) when it is complexed to polyanionic compounds such as Polyvinyl Sulfonate (PVS). These antibodies are found in some patients undergoing heparin therapy.

Device Story

PF4 ENHANCED® is a solid-phase ELISA kit used in clinical hematology/pathology laboratories. Input: patient serum. Process: serum added to microwells coated with PF4:PVS complexes; if heparin-associated antibodies are present, they bind to the complex. Unbound antibodies washed away; alkaline phosphatase-labeled anti-human globulin (Anti-IgG/A/M) added; unbound reagent washed away. Substrate PNPP added; reaction stopped with sodium hydroxide. Output: optical density measured via spectrophotometer. Result indicates presence of antibodies associated with Type II heparin-induced thrombocytopenia (HIT). Assists clinicians in diagnosing HIT/thrombosis in patients undergoing heparin therapy.

Clinical Evidence

Bench testing only. Performance data validated the material changes to the wash buffer and storage buffer. Studies included real-time and accelerated stability testing, assay reproducibility (within-run, lot-to-lot, and total), assay specificity (cross-reactivity), and testing with known patient samples to ensure equivalence to the predicate device.

Technological Characteristics

Solid-phase ELISA; optical density detection. Components: microwells coated with PF4:PVS complexes, alkaline phosphatase-labeled anti-human globulin (Anti-IgG/A/M), PNPP substrate, sodium hydroxide stop solution. Requires spectrophotometer for readout. Qualitative assay.

Indications for Use

Indicated for use as an in vitro diagnostic kit by hematology and pathology laboratories to assist in screening patient samples for the presence of heparin-associated antibodies in patients with heparin-induced thrombocytopenia or thrombosis.

Regulatory Classification

Identification

A platelet factor 4 radioimmunoassay is a device used to measure the level of platelet factor 4, a protein released during platelet activation by radioimmunoassay. This device measures platelet activiation, which may indicate a coagulation disorder, such as myocardial infarction or coronary artery disease.

Predicate Devices

• GTI-PF4 ELISA (K983379)

Submission Summary (Full Text)

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## 510(k) Summary

#### Submitter: I.

II.

K053559

Owner's Name: GTI 20925 Crossroads Circle. Waukesha, WI 53186 Address: Phone: [phone].754.9831 Fax: Name of Contact Person: Leigh Ann Tidey December 9, 2005 Date Summary Prepared: Name of Device: PF4 ENHANCED®Solid Phase ELISA Device Name: Proprietary Name: PF4 ENHANCED® Solid Phase ELISA

Classification Name: Anti-Platelet Factor IV complex Antibodies, Product Code: 0545

#### Name of predicate device for claiming equivalence III.

GTI-PF4 ELISA (K983379)

#### IV. Description of Device:

PF4 ENHANCED® Solid Phase ELISA microwells provide immobilized PF4:PVS complexes as a target for the detection of antibodies associated with Type II HIT which are found in some patients undergoing heparin therapy. The presence of these antibodies has been shown to be associated with heparin induced thrombocytopenia Type II (Type II HIT).

Patient serum is added to microwells coated with platelet factor 4 (PF4) complexed to polyvinyl sulfonate (PVS). If an antibody recognizing a site on PF4:PVS is present, binding will occur. Unbound antibodies are then washed away. An alkaline phosphatase labeled anti-human globulin reagent (Anti-IgG/A/M) is added to the wells and incubated. The unbound Anti-IgG/A/M is washed away and the substrate PNPP (p-nitrophenyl phosphate) is added. After a 30-minute incubation period, the reaction is stopped by addition of a sodium hydroxide solution. The optical density of the color that develops is measured in a spectrophotometer.

#### V. Intended Use

PF4 ENHANCED® is a qualitative solid phase enzyme linked immunosorbent assay (ELISA) designed to detect antibodies reactive with platelet factor 4 (PF4)

Suite 200 20925 Crossroads Circle Waukesha, WI 53186-4054 [phone] [phone] Fax [phone] Ernail [e-mail]

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when it is complexed to polyanionic compounds such as Polyvinyl Sulfonate (PVS). These antibodies are found in some patients undergoing heparin therapy.

### VI. Support of substantial equivalence based on comparison of features, characteristics and components to the predicate device:

The characteristics of the two devices can be summarized as follows:

| Features/Characteristics | PF4 ELISA Assay | PF4 ENHANCED® |
|-----------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Type of Test | Qualitative | Qualitative |
| Intended Use | PF4® ELISA Assay is a<br>qualitative solid phase<br>enzyme linked<br>immunosorbent assay<br>(ELISA) designed to<br>detect antibodies reactive<br>with platelet factor 4<br>(PF4) when it is<br>complexed to<br>polyanionic compounds<br>such as Polyvinyl<br>Sulfonate (PVS). These<br>antibodies are found in<br>some patients<br>undergoing heparin<br>therapy. | PF4 ENHANCED® is a<br>qualitative solid phase<br>enzyme linked<br>immunosorbent assay<br>(ELISA) designed to<br>detect antibodies reactive<br>with platelet factor 4<br>(PF4) when it is<br>complexed to<br>polyanionic compounds<br>such as Polyvinyl<br>Sulfonate (PVS). These<br>antibodies are found in<br>some patients<br>undergoing heparin<br>therapy. |
| Technology Used in<br>Assay | ELISA | ELISA |
| Detection Method | Optical Density | Optical Density |

In addition, these products have the same:

- . indications for use
- performance characteristics .
- assay protocol .
- labeling (except for name) .
- scientific technology .

The differences between the two products are related to changes of materials within existing reagents:

- 1. A different wash buffer is used in PF4 Enhanced
- 2. A stabilizer was added to the storage buffer used in the alkaline phosphatase conjugated anti-IgG/A/M of PF4 Enhanced.

Suite 200 20925 Crossroads Circle Waukesha, WI 53186-4054 [phone] [phone] Fax [phone] Email [e-mail]

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Image /page/2/Picture/0 description: The image shows the letters "GTI" in a bold, sans-serif font. The letters are large and take up most of the image. The letters are black, and the background is white. The letters appear to have a slightly rough or textured appearance.

Risk analysis did not identify any new issues of safety or effectiveness.

#### VII. Support of substantial equivalence with performance data:

The performance data used to validate the of the wash buffer change includes:

- a) Data showing the effect of the material change on assay results using known patient samples.
- b) Data showing the effect of the material change on kit stability (real time stability).

The performance data used to validate the stabilizer added to the storage buffer used in the alkaline phosphatase conjugated anti-IgG/A/M includes:

- Data showing the effect of the material change on component stability a) (accelerated and real time stability studies on the alkaline phosphatase conjugated anti-IgG/A/M.)
- b) Data showing the effect of the material change on kit stability (real time).
- Data showing the effect of the material change on assay results using c) known patient samples.
- Data showing the effect of the material change on assay reproducibility d) (within run precision, lot to lot reproducibility, and total reproducibility).
- Data showing the effect of the material change on assay specificity e) (cross reactivity of other antibodies).

The details of each of these studies along with results and analysis can be found in Section 8: Performance Data Section.

Summary:

The data show that PF4 Enhanced is equivalent to PF4 ELISA.

#### VIII. Conclusion:

Based on comparison with the legally marketed PF4 ELISA, the data demonstrate that PF4 Enhanced ELISA performs as well as the predicate device and does not present new issues of safety and effectiveness.

Suite 200 20925 Crossroads Circle Waukesha, WI 53186-4054 [phone] [phone] Fax [phone] Email [e-mail]

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DEPARTMENT OF HEALTH & HUMAN SERVICES

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Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Ms. Leigh Ann Tidey, MS, MT(ASCP)SBB Quality Assurance Manager Genetic Testing Institute, Inc. 20925 Crossroads Circle Waukesha, WI 53186

JAN 2 0 2006

k053559 Re: Trade/Device Name: PF4 ENHANCED® Regulation Number: 21 CFR § 864.7695 Regulation Name: Platelet factor 4 radioimmunoassay Regulatory Class: II Product Code: LCO Dated: December 19, 2005 Received: December 21, 2005

Dear Ms. Tidey:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). 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 registration, 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 (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). This letter will allow you to begin marketing your device as described in your Section 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.

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If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html

Sincerely yours,

lobatz Beckerh

Robert L. Becker, Jr., MD, PA Director Division of Immunology and Hematology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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# Indications for Use

510(k) Number (if known):

K053559

Device Name:_PF4 ENHANCED®

Indications For Use:

GTI PF4 ENHANCED® is designed as a solid phase enzyme-linked immunosorbent assay (ELISA). The product is intended to be used as an in vitro diagnostics kit by hematology, (ELIG/Y). The produce is the pathology laboratories to assist in screening patient samples for the presence of heparin-associated antibodies commonly found in patients with heparin induced thrombocytopenia or thrombosis.

Prescription Use
(Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Counter Use (21 CFR 801 Subpart C)

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

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

Josephine Bautista

Division Sign/Off

Office of In Vitro Diagnostic Device Evaluation and Safety

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