Alinity i Toxo IgM

K233932 · Abbott Laboratories · LGD · Aug 30, 2024 · Microbiology

Device Facts

• Record ID: K233932
• Device Name: Alinity i Toxo IgM
• Applicant: Abbott Laboratories
• Product Code: LGD · Microbiology
• Decision Date: Aug 30, 2024
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3780
• Device Class: Class 2

Intended Use

The Alinity i Toxo IgM assay is a chemiluminescent microparticle immunoassay (CMIA) used for the qualitative detection of IgM antibodies to Toxoplasma gondii in human serum, serum separator, and plasma tubes (lithium heparin, lithium heparin separator, and tripotassium EDTA) on the Alinity i system. The Alinity i Toxo IgM assay is to be used as an aid in the diagnosis of acute or recent Toxoplasma gondii infection in suspected individuals including women of child-bearing age. It is recommended that the assay be performed in conjunction with a Toxoplasma gondii IgG assay. The Alinity i Toxo IgM assay has not been cleared for use in screening blood, plasma, or tissue donors.

Device Story

Automated two-step chemiluminescent microparticle immunoassay (CMIA) for qualitative detection of anti-Toxoplasma gondii IgM antibodies. Input: human serum or plasma samples. Process: sample incubated with anti-human IgM coated paramagnetic microparticles; anti-Toxo IgM binds to microparticles; conjugate complex (acridinium-labeled anti-Toxo p30 antibody and native T. gondii lysate) added; chemiluminescent reaction measured as relative light units (RLU). Output: RLU compared to cutoff to determine reactive/nonreactive status. Used in clinical laboratories; operated by trained personnel. Results aid clinicians in diagnosing acute/recent Toxoplasma infection when used with IgG testing.

Clinical Evidence

Clinical performance evaluated in two populations (n=897 and n=234) and a CDC serum panel (n=97). Population 1 PPA 94.94% (95% CI: 90.33-97.41%), NPA 94.44% (95% CI: 92.55-95.88%). Population 2 PPA 94.74% (95% CI: 75.36-99.06%), NPA 100% (95% CI: 98.24-100%). CDC panel showed 100% PPA and 100% NPA. Matrix equivalency confirmed for serum and various plasma tubes.

Technological Characteristics

CMIA technology; uses anti-human IgM (murine monoclonal) coated paramagnetic microparticles and acridinium-labeled anti-Toxo p30 antigen (murine monoclonal) conjugate. Reagents include TRIS/phosphate buffers, bovine/goat protein stabilizers, and detergents. Automated system; connectivity via Alinity i platform. Calibration storage up to 30 days.

Indications for Use

Indicated for qualitative detection of IgM antibodies to Toxoplasma gondii in human serum and plasma to aid in diagnosis of acute or recent infection in suspected individuals, including women of child-bearing age. Not for blood, plasma, or tissue donor screening.

Regulatory Classification

Identification

Toxoplasma gondii serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to Toxoplasma gondii in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identify Toxoplasma gondii from clinical specimens. The identification aids in the diagnosis of toxoplasmosis caused by the parasitic protozoan Toxoplasma gondii and provides epidemiological information on this disease. Congenital toxoplasmosis is characterized by lesions of the central nervous system, which if undetected and untreated may lead to brain defects, blindness, and death of an unborn fetus. The disease is characterized in children by inflammation of the brain and spinal cord.

Predicate Devices

• bioMérieux VIDAS TOXO IgM assay (k923166)

Submission Summary (Full Text)

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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

August 30, 2024

Abbott Laboratories Laura Fraczek Regulatory Affairs Senior Specialist 100 Abbott Park Rd. Abbott Park, Illinois 60064

Re: K233932

Trade/Device Name: Alinity i Toxo IgM Regulation Number: 21 CFR 866.3780 Regulation Name: Toxoplasma Gondii Serological Reagents Regulatory Class: Class II Product Code: LGD Dated: December 13, 2023 Received: December 14, 2023

Dear Laura Fraczek:

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 (the 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

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Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30. Design controls; 21 CFR 820.90. Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatory

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assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

Image /page/2/Picture/3 description: The image shows a digital signature. The signature indicates that the document was digitally signed by JORGE L. MUNOZ -S. The date of the signature is August 30, 2024. The timestamp of the signature is 10:42:40 -04'00'.

Jorge Munoz, Ph.D. Branch Chief Division of Microbiology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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# Indications for Use

510(k) Number (if known) K233932

Device Name Alinity i Toxo IgM

#### Indications for Use (Describe)

The Alinity i Toxo IgM assay is a chemiluminescent microparticle immunoassay (CMIA) used for the qualitative detection of IgM antibodies to Toxoplasma gondii in human serum separator, and plasma tubes (Ithium heparin, lithium heparin separator, and tripotassium EDTA) on the Alinity i system.

The Alinity i Toxo IgM assay is to be used as an aid in the diagnosis of acute or recent Toxoplasma gondii infection in suspected individuals including women of child-bearing age. It is recommended that the assay be performed in conjunction with a Toxoplasma gondii IgG assay.

The Alinity i Toxo IgM assay has not been cleared for use in screening blood, plasma, or tissue donors.

| Type of Use (Select one or both, as applicable) |
|-------------------------------------------------|
|-------------------------------------------------|

X Prescription Use (Part 21 CFR 801 Subpart D)

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

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### 510(k) Summary

This summary of the 510(k) safety and effectiveness information is submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

### I. 510(k) Number

K233932

# II. Applicant Name

Abbott Laboratories Department 09AA 100 Abbott Park Road Abbott Park, IL 60064

Primary contact person for all communications:

Laura Fraczek, Senior Specialist Regulatory Affairs Abbott Diagnostics Division Telephone Number: [phone] Fax Number: [phone]

Secondary contact person for all communications:

Jacob Richards, Associate Director, Regulatory Affairs Abbott Diagnostic Division Telephone Number: [phone] Fax Number: [phone]

Date summary prepared: August 28, 2024

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### III. Device Name

Alinity i Toxo IgM

### Reagents

Trade Name: Alinity i Toxo IgM Reagent Kit Device Classification: Class II Classification Name: Toxoplasma gondii serological reagents Governing Regulation: 21 CFR 866.3780 Code: LGD

### Calibrator

Trade Name: Alinity i Toxo IgM Calibrator Device Classification: Class II Classification Name: Toxoplasma gondii serological reagents Governing Regulation: 21 CFR 866.3780 Code: LGD

### Controls

Trade Name: Alinity i Toxo IgM Controls Device Classification: Class II Classification Name: Toxoplasma gondii serological reagents Governing Regulation: 21 CFR 866. 3780 Code: LGD

### IV. Predicate Device

bioMérieux VIDAS TOXO IgM assay (k923166)

### V. Description of Device

### Reagents

The kit configurations of the Alinity i Toxo IgM Reagent Kit are described below.

| List Number (LN) | 07P4740 | 07P4745 |
|------------------------------|---------|---------|
| Tests per cartridge | 100 | 500 |
| Number of cartridges per kit | 2 | 2 |
| Tests per kit | 200 | 1000 |
| Microparticles | 6.6 mL | 27.0 mL |
| Conjugate | 6.1 mL | 26.5 mL |

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- Microparticles: Anti-human IgM (murine, monoclonal) antibody coated microparticles in TRIS buffer with protein (bovine and goat) stabilizers, and detergent. Minimum concentration: 0.08 % solids. Preservatives: antimicrobial agents.
- Conjugate: Conjugate complex consisting of acridinium-labeled anti-Toxoplasma ● p30 antigen antibody (murine, monoclonal) and native Toxoplasma gondii lysate in phosphate buffer with protein (bovine) stabilizer, and detergent. Minimum concentration: 25 µg/mL. Preservative: sodium azide.

# Calibrator

The Alinity i Toxo IgM Calibrator is described below.

- Calibrator 1: Contains anti-Toxoplasma p30 antigen IgM antibody (human, • monoclonal) prepared in recalcified human plasma. The calibrator is reactive for IgM antibodies to Toxoplasma gondii (anti-Toxo IgM). Preservatives: ProClin 950 and sodium azide.

| Calibrator | Quantity |
|--------------|------------|
| Calibrator 1 | 1 x 3.0 mL |

The Alinity i Toxo IgM Calibrator is manufactured and referenced to an internal reference standard.

### Controls

The Alinity i Toxo IgM Controls are described below.

- Negative Control: Contains recalcified human plasma. •
- Positive Control: Contains anti-Toxoplasma p30 antigen IgM antibody (human, . monoclonal) prepared in recalcified human plasma. The positive control is reactive for IgM antibodies to Toxoplasma gondii (anti-Toxo IgM).
- Preservatives: ProClin 950 and sodium azide. •

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| | | Anti-Toxo IgM | |
|------------------|------------|------------------|-----------------|
| Control | Quantity | Target<br>(S/CO) | Range<br>(S/CO) |
| Negative Control | 1 x 4.0 mL | - | < 0.67 |
| Positive Control | 1 x 4.0 mL | 2.50 | 1.25 - 3.75 |

The targets and ranges for the controls are provided in the table below.

The Alinity i Toxo IgM Positive Control is referenced to an internal reference standard.

# Biological Principles of the Procedure

The Alinity i Toxo IgM assay is an automated, two-step immunoassay for the qualitative detection of IgM antibodies to Toxoplasma gondii in human serum and plasma using chemiluminescent microparticle immunoassay (CMIA) technology.

Pre-diluted sample and anti-human IgM murine monoclonal antibody coated paramagnetic microparticles are combined and incubated. Together with IgM antibodies of other specificities, anti-Toxo specific IgM present in the sample binds to the anti-human IgM murine monoclonal antibody coated microparticles, forming an antibody-antibody complex. The mixture is washed. A conjugate complex consisting of an acridinium-labeled anti-Toxo p30 antigen murine monoclonal F(ab')2 fragment and native Toxoplasma gondii lysate, containing the p30 antigen, is added to create a reaction mixture and incubated. This conjugate complex is bound by anti-Toxo specific IgM that has been captured by the anti-human IgM murine monoclonal antibody coated microparticles, forming an antibody-antibody-conjugate complex. Following a wash cycle, Pre-Trigger and Trigger Solutions are added.

The resulting chemiluminescent reaction is measured as a relative light unit (RLU). There is a direct relationship between the amount of anti-Toxo IgM in the sample and the RLU detected by the system optics.

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The presence or absence of anti-Toxo IgM in the sample is determined by comparing the chemiluminescent RLU in the reaction to the cutoff RLU determined from an active calibration.

# VI. Intended Use of the Device

The Alinity i Toxo IgM assay is a chemiluminescent microparticle immunoassay (CMIA) used for the qualitative detection of IgM antibodies to Toxoplasma gondii in human serum, serum separator, and plasma tubes (lithium heparin, lithium heparin separator, and tripotassium EDTA) on the Alinity i system.

The Alinity i Toxo IgM assay is to be used as an aid in the diagnosis of acute or recent Toxoplasma gondii infection in suspected individuals including women of child-bearing age. It is recommended that the assay be performed in conjunction with a Toxoplasma gondii IgG assay.

The Alinity i Toxo IgM assay has not been cleared for use in screening blood, plasma, or tissue donors.

# VII. Comparison of Technological Characteristics

The Alinity i Toxo IgM assay (subject device) utilizes a CMIA methodology for the qualitative in vitro detection of IgM antibodies to Toxoplasma gondii and is intended for use on the Alinity i system.

The similarities and differences between the subject device and the predicate device are presented in the following tables.

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| | Subject Device | Predicate Device | |
|-----------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Characteristics | Alinity i Toxo IgM<br>K233932 | VIDAS TOXO IgM Assay<br>k923166 | |
| Intended Use and<br>Indications for Use | The Alinity i Toxo IgM assay is a<br>chemiluminescent microparticle immunoassay<br>(CMIA) used for the qualitative detection of<br>IgM antibodies to Toxoplasma gondii in human<br>serum, serum separator, and plasma tubes<br>(lithium heparin, lithium heparin separator, and<br>tripotassium EDTA) on the Alinity i system.<br>The Alinity i Toxo IgM assay is to be used as<br>an aid in the diagnosis of acute or recent<br>Toxoplasma gondii infection in suspected<br>individuals including women of child-bearing<br>age. It is recommended that the assay be<br>performed in conjunction with a Toxoplasma<br>gondii IgG assay.<br>The Alinity i Toxo IgM assay has not been<br>cleared for use in screening blood, plasma, or<br>tissue donors. | The VIDAS® TOXO IgM (TXM) assay is intended<br>for use on the instruments of the VIDAS® family<br>(VITEK® ImmunoDiagnostic Assay System) as an<br>automated enzyme-linked fluorescent immunoassay<br>(ELFA) for the presumptive qualitative detection of<br>anti-Toxoplasma gondii IgM antibodies in human<br>serum, as an aid in the diagnosis of acute, recent, or<br>reactivated Toxoplasma gondii infection. This assay<br>must be performed in conjunction with an anti-<br>Toxoplasma gondii lgG antibody assay. VIDAS®<br>TOXO IgM (TXM) assay performance has not been<br>established for prenatal screening or newborn<br>testing. This assay has not been cleared by the FDA<br>for blood/plasma donor screening. | |
| | Calibrator(s) | 1 Calibrator | 1 Calibrator |
| | Control(s) | 2 (Negative and Positive) | 2 (Negative and Positive) |
| | | Subject Device<br>Alinity i Toxo IgM | Predicate Device<br>VIDAS TOXO IgM Assay |
| | Characteristics | K233932 | k923166 |
| | Antigen and<br>Antibody Used | • Anti-Toxoplasma p30 antigen antibody<br>(murine, monoclonal) and native<br><i>Toxoplasma gondii</i> lysate<br>• Anti-human IgM murine monoclonal<br>antibody | • Immunocomplex of <i>T. gondii</i> antigen (RH Sabin<br>strain)<br>• Mouse monoclonal anti-P30 antibodies |
| | Type of Specimen | Serum and Plasma | Serum |
| | Methodology | Chemiluminescent microparticle immunoassay | Enzyme-linked fluorescent immunoassay |
| | Interpretation of<br>Results | Nonreactive: < 0.83 S/CO<br>Grayzone/Equivocal: 0.83 to < 1.00 S/CO<br>Reactive: ≥ 1.00 S/CO | Negative: < 0.55 Test Value<br>Equivocal: ≥ 0.55 to < 0.65 Test Value<br>Positive: ≥ 0.65 Test Value |
| | Components | Microparticles – Anti-human IgM (murine,<br>monoclonal) antibody coated microparticles in<br>TRIS buffer with protein (bovine and goat)<br>stabilizers, and detergent. Minimum<br>concentration: 0.08 % solids. Preservatives:<br>antimicrobial agents.<br>Conjugate - Conjugate complex consisting of<br>acridinium-labeled anti-Toxoplasma p30<br>antigen antibody (murine, monoclonal) and<br>native <i>Toxoplasma gondii</i> lysate in phosphate<br>buffer with protein (bovine) stabilizer, and<br>detergent. Minimum concentration: 25 µg/mL.<br>Preservative: sodium azide. | Solid Phase Receptacle (SPR) – SPR coated goat<br>anti-μ chain antibodies<br>Reagent Strip – Strip consists of 10 wells covered<br>with labeled, foil seal. The wells contain the various<br>reagents required for the assay including:<br>• Sample diluent: 300 µL of TRIS buffered saline<br>(0.05 mol/L, pH 7.4) with protein and chemical<br>stabilizers and 1 g/L sodium azide.<br>• Pre-wash: 600 µL of TRIS buffered saline<br>(0.05 mol/L, pH 7.4) with protein and chemical<br>stabilizers and 1 g/L sodium azide.<br>• Wash buffer: 600 µL of TRIS buffered saline<br>(0.05 mol/L, pH 7.4) with protein and chemical<br>stabilizers and 1 g/L sodium azide.<br>• Conjugate: 400 µL of immunocomplex of<br><i>T. gondii</i> antigen (RH Sabin strain) grown in mice<br>(9) and mouse monoclonal anti-P30 antibodies |
| | Subject Device<br>Alinity i Toxo IgM<br>K233932 | Predicate Device<br>VIDAS TOXO IgM Assay<br>k923166 | |
| Characteristics | | conjugated to alkaline phosphatase with<br>gentamycin 0.02% and 0.9 g/L sodium azide.<br>• Reading cuvette with substrate: 4-Methyl-<br>umbelliferyl phosphate (0.6 mmol/L) +<br>diethanolamine (DEA) (0.62 mol/L or 6.6%,<br>pH 9.2) + 1 g/L sodium azide (300 µL). | |
| Calibration Storage | Maximum of 30 days | 14 days | |

# Assay Similarities

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# Assay Differences

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### VIII. Summary of Nonclinical Performance

### A. Assav Cutoff

The cutoff for the Alinity i Toxo IgM assay was established using samples characterized with a commercially available anti-Toxo IgM assay. A total of 1219 samples (1053 anti-Toxo IgM nonreactive samples and 166 anti-Toxo IgM reactive samples) were included. A receiver-operating characteristic analysis showed a clear separation of the nonreactive and reactive results using a cutoff of 1.00 S/CO (with a grayzone from 0.83 to < 1.00 S/CO).

### B. Within- Laboratory Precision (20-Day)

A 20-day within-laboratory precision study was performed based on guidance from CLSI EP05-A3. * Testing was conducted using 3 lots of the Alinity i Toxo IgM reagents, 3 lots of the Alinity i Toxo IgM Calibrator, 3 lots of the Alinity i Toxo IgM Controls, and 1 instrument. Two controls and 4 recalcified human plasma panels (representing serum matrix) were tested in 3 replicates at 2 separate times per day on 20 days using 3 reagent lot/calibrator lot combinations, where a unique reagent lot and a unique calibrator lot are paired. The performance is shown in the following table.

| | | Mean | Repeatability<br>(Within-Run) | | Between-Run | | Between-Day | | Between-Lot a | | Overall Within<br>Laboratory b | |
|---------------------------|------|--------|-------------------------------|-----|-------------|-----|-------------|-----|---------------|-----|--------------------------------|-----|
| Sample ID | N | (S/CO) | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV |
| Negative Control | 360 | 0.14 | 0.012 | NAc | 0.000 | NAc | 0.004 | NAc | 0.008 | NAc | 0.014 | NAc |
| Positive Control | 360 | 2.72 | 0.077 | 2.8 | 0.034 | 1.3 | 0.031 | 1.2 | 0.051 | 1.9 | 0.104 | 3.8 |
| True Nonreactive<br>Panel | 358d | 0.14 | 0.013 | NAc | 0.000 | NAc | 0.005 | NAc | 0.006 | NAc | 0.015 | NAc |
| High Nonreactive<br>Panel | 360 | 0.81 | 0.028 | NAc | 0.006 | NAc | 0.009 | NAc | 0.027 | NAc | 0.040 | NAc |
| Low Reactive Panel | 359d | 1.34 | 0.047 | 3.5 | 0.000 | 0.0 | 0.007 | 0.5 | 0.042 | 3.2 | 0.064 | 4.7 |
| Reactive Panel | 359d | 2.54 | 0.078 | 3.1 | 0.000 | 0.0 | 0.023 | 0.9 | 0.073 | 2.9 | 0.109 | 4.3 |

Almity i Toxo IgM reagent lot and Alinity i Toxo IgM callbrator lot are confounding effect is represented by betweenlot.

b Overall within-laboratory variability contains repeatability (within-run), between-day, and between-lot variance components.

ు Not applicable

d In cases where n < 360, replicate(s) were excluded due to an instrument error and no results were reported.

^* Clinical and Laboratory Standards Institute (CLSI). Evaluation of Quantitative Measurement Procedures: Approved Guideline-Third Edition. CLSI Document EP05-A3. Wayne, PA: CLSI; 2014.

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# C. Analytical Specificity

# Potentially Interfering Endogenous Substances

The Alinity i Toxo IgM assay was evaluated for potential interference caused by endogenous substances based on guidance from CLSI EP07, 3rd ed. * and CLSI EP37, 1st ed. * Each substance was evaluated using samples containing anti-Toxo IgM at the target ranges of 0.60 to 0.99 S/CO and 1.00 to 2.00 S/CO.

No significant interference (interference ≤ +0.10 S/CO for samples < 1.00 S/CO and ≥ -10% for samples ≥ 1.00 S/CO) was observed at the following concentrations.

| No Significant Interference | |
|-----------------------------------|-------------------|
| Potentially Interfering Substance | Interferent Level |
| Unconjugated Bilirubin | 40 mg/dL |
| Conjugated Bilirubin | 40 mg/dL |
| Hemoglobin | 1000 mg/dL |
| Total Protein | 15 g/dL |
| Triglycerides | 3000 mg/dL |

### Potentially Interfering Other Conditions

The Alinity i Toxo IgM assay was evaluated for potential interference caused by HAMA and RF based on guidance from CLSI EP07, 3rd ed.16. Each condition was evaluated using samples containing anti-Toxo IgM at the following target range: 1.00 to 1.40 S/CO.

No significant interference (interference ≤± 10%) was observed at the following concentrations.

Clinical and Laboratory Standards Institute (CLSI). Interference Testing in Clinical Chemistry. 3rd ed. CLSI Guideline EP07. Wayne, PA: CLSI; 2018.

^* Clinical and Laboratory Standards Institute (CLSI). Supplemental Tables for Interference Testing in Clinical Chemistry. 1st ed. CLSI supplement EP37. Wayne, PA: CLSI; 2018.

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| No Significant Interference | |
|-----------------------------------------|-------------------|
| Potentially Interfering Other Condition | Interferent Level |
| HAMA | 800 ng/mL |
| RF | 200 IU/mL |

Potentially Interfering Drugs and Other Substances

The Alinity i Toxo IgM assay was evaluated for potential interference caused by exogenous substances based on guidance from CLSI EP07, 3rd ed. and CLSI EP37, 1 st ed. Each substance was evaluated using samples containing anti-Toxo IgM at the target ranges of 0.60 to 0.99 S/CO and 1.00 to 2.00 S/CO.

No significant interference (interference ≤ +0.10 S/CO for samples < 1.00 S/CO and ≥ -10% for samples ≥ 1.00 S/CO) was observed at the following concentrations.

| No Significant Interference | |
|-----------------------------------|-------------------|
| Potentially Interfering Substance | Interferent Level |
| Ascorbic Acid | 300 mg/L |
| Atovaquone | 120 mg/L |
| Beta Carotene | 6 mg/L |
| Biotin | 4250 ng/mL |
| Clindamycin | 5.1 mg/dL |
| Folic Acid | 100 nmol/L |
| Pyrimethamine | 15 mg/L |
| Spiramycine | 4.2 mg/L |
| Sulfadiazine | 25.5 mg/dL |
| Sulfamethoxazole | 210 mg/dL |
| Trimethoprim | 4.2 mg/dL |

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### Potential Cross-Reactivity

Potential cross-reactivity for the Alinity i Toxo IgM assay was determined by testing a total of 177 serum specimens from individuals with other medical conditions unrelated to Toxoplasmosis infection, in addition to individuals with high titer Toxoplasmosis IgG. Out of 10 RF specimens, one resulted in a false reactive result with the Alinity i Toxo IgM assay.

| Category | n | Number of Alinity i Toxo IgM<br>False Reactive Results |
|------------------------------------------|-----|--------------------------------------------------------|
| Anti-dsDNA Antibodies | 10 | 0 |
| Anti-nuclear Antibody (ANA) | 10 | 0 |
| Cytomegalovirus (IgM) | 10 | 0 |
| Epstein-Barr Virus (EBV) IgM | 9 | 0 |
| Herpes Simplex Virus Types 1/2 (IgG/IgM) | 18 | 0 |
| Human anti-mouse antibody | 10 | 0 |
| Hyper IgG | 10 | 0 |
| Hyper IgM | 10 | 0 |
| Influenza vaccine recipients | 10 | 0 |
| Measles (IgM) | 10 | 0 |
| Parvovirus B19 (IgG) | 6 | 0 |
| Parvovirus B19 (IgM) | 4 | 0 |
| Rheumatoid Factor | 10 | 1a |
| Rubella (IgM) | 10 | 0 |
| Samples from immunocompromised patients | 10 | 0 |
| Syphilis | 10 | 0 |
| Toxoplasmosis High Titer (IgG) | 10 | 0 |
| Varicella Zoster Virus | 10 | 0 |
| Total | 177 | 1 |

a One out of 10 RF specimens was falsely reactive with the Alinity i Toxo IgM assay.

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### D. Matrix Equivalency

A study was performed to evaluate whether specific blood collection tube types are suitable for use with the Alinity i Toxo IgM assay. The matrix collection tube type equivalency study was conducted including 43 donors of reactive (20 donors) and nonreactive (23 donors) samples in 5 types of blood collection tubes (serum, serum separator, lithium heparin plasma, lithium heparin plasma separator, and tripotassium EDTA plasma) for use with the Alinity i Toxo IgM assay. Data was analyzed using regression analysis comparing numerical S/CO results of all matrices to serum to evaluate any potential bias. All of the blood collection tube types tested are acceptable for use with the Alinity i Toxo IgM assay.

### E. Class Specificity

Class specificity testing of the Alinity i Toxo IgM assay demonstrated reactivity only to human anti-Toxoplamsa IgM. No reactivity to human anti-Toxoplasma IgG was observed.

### F. CDC Panel Agreement

The Centers for Disease Control and Prevention (CDC) Toxoplasma 1998 Human Serum Panel was tested using the Alinity i Toxo IgM assay. The Alinity i Toxo IgM assay results were submitted to the CDC for data analysis and for the result interpretation for each sample. The panel consisted of 32 true positive Toxoplasma specimens and 65 true negative Toxoplasma specimens. The Alinity i Toxo IgM assay detected the 32 positive specimens as reactive and the 65 negative specimens as nonreactive. The CDC performed kit sensitivity (positive percent agreement [PPA]) and kit specificity (negative percent agreement [NPA]) analyses and sent the results to Abbott.

The percent agreement of the Alinity i Toxo IgM assay relative to the CDC results was calculated. The PPA was 100% with a 95% confidence interval (CI) of 89.28% to 100.00%. The NPA was 100% with a 95% CI of 94.42% to 100.00%.

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The results are presented as a means to convey further information on the performance of this assay with a masked, characterized serum panel. This does not imply endorsement of the assay by the CDC.

| Alinity i Toxo IgM Interpretation | CDC Interpretation | | Positive % Agreement (95% CI)ª | Negative % Agreement (95% CI)ª |
|-----------------------------------|--------------------|----------|--------------------------------|--------------------------------|
| | Positive | Negative | | |
| Reactive | 32 | 0 | 100.00<br>(32/32) | 100.00<br>(65/65) |
| Grayzone/Equivocal | 0 | 0 | | |
| Nonreactive | 0 | 65 | | |

a The 95% CI for negative percent and positive percent agreement were estimated using the Wilson score method.

# IX. Summary of Clinical Performance

# A. Expected Values

Representative performance data are provided in this section. Results obtained in individual laboratories may vary.

The Alinity i Toxo IgM results from the clinical method comparison study for each category in the US intended use population are summarized in the following table.

| Category | Number of<br>Reactive (%) | Number of<br>Grayzone/<br>Equivocal (%) | Number of<br>Nonreactive (%) | Total |
|--------------|---------------------------|-----------------------------------------|------------------------------|-------|
| Population 1 | 1 (0.6) | 0 (0.0) | 168 (99.4) | 169 |
| Population 2 | 1 (0.5) | 0 (0.0) | 206 (99.5) | 207 |
| Total | 2 (0.5) | 0 (0.0) | 374 (99.5) | 376 |

Note: Population 1 are consecutively collected remnant specimens sent to a laboratory for anti-Toxo IgM testing. Population 2 are consecutively collected remnant specimens from pregnant women sent to a laboratory for anti-Toxo IgM testing.

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The Alinity i Toxo IgM assay was reactive in 2 (0.5%) of the collected specimens in the US intended use population (n = 376).

# B. Reproducibility Study (5-Day)

A 5-day reproducibility study was conducted at 3 US sites, using the same sample panels used in the within-laboratory precision study, in addition to one positive and one negative control based on the guidance from CLSI EP05-A3. Four replicates per sample were evaluated in 2 runs per day over 5 days. Testing was conducted using 3 lots of the Alinity i Toxo IgM reagents, 2 lots of the Alinity i Toxo IgM Calibrator, and 1 lot of the Alinity i Toxo IgM Controls at each of the 3 testing sites.

| | | Mean | | Repeatability | | Between-<br>Run | | Between-Day | | Between-Site | | Between-Lota | | Reproducibilityb | |
|------------------------------|-----|------|-------|---------------|-------|-----------------|-------|-------------|-------|--------------|-------|--------------|-------|------------------|--|
| Sample | N | S/CO | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |
| Negative<br>Control | 360 | 0.13 | 0.013 | NAc | 0.002 | NAc | 0.001 | NAc | 0.009 | NAc | 0.008 | NAc | 0.018 | NAc | |
| Positive<br>Control | 360 | 2.62 | 0.074 | 2.8 | 0.031 | 1.2 | 0.022 | 0.8 | 0.056 | 2.1 | 0.075 | 2.9 | 0.132 | 5.1 | |
| True<br>Nonreactive<br>Panel | 360 | 0.11 | 0.013 | NAc | 0.000 | NAc | 0.004 | NAc | 0.006 | NAc | 0.008 | NAc | 0.017 | NAc | |
| High<br>Nonreactive<br>Panel | 360 | 0.76 | 0.030 | NAc | 0.009 | NAc | 0.006 | NAc | 0.000 | NAc | 0.023 | NAc | 0.041 | NAc | |
| Low<br>Reactive<br>Panel | 360 | 1.3 | 0.042 | 3.2 | 0.017 | 1.3 | 0.000 | 0.0 | 0.016 | 1.3 | 0.040 | 3.1 | 0.067 | 5.1 | |
| Reactive<br>Panel | 360 | 2.49 | 0.077 | 3.1 | 0.032 | 1.3 | 0.019 | 0.8 | 0.059 | 2.4 | 0.080 | 3.2 | 0.136 | 5.5 | |

Alinity i Toxo IgM reagent lot and Alinity i Toxo IgM calibrator lot are confounding effect is represented by betweena lot.

b Reproducibility contains repeatability, between-day, between-lot, between-site, and site-lot interaction variance components.

c Not applicable

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### C. Clinical Agreement

A clinical method comparison study was conducted to evaluate the clinical performance of the Alinity i Toxo IgM assay based on guidance from CLSI EP12-A2, 2nd ed. * , to evaluate the percent agreement between the Alinity i Toxo IgM investigational assay and a current FDA-cleared, commercially available anti-Toxo IgM assay with specimens collected from 2 populations. Population 1 was comprised of 897 consecutively collected remnant specimens sent to a laboratory for anti-Toxo IgM testing including specimens collected in the US (n = 169) and outside of the US (n = 710), and Population 2 was comprised of 207 consecutively collected remnant specimens from pregnant women sent to a laboratory for anti-Toxo IgM testing in the US.

Demographic information for specimens collected in the US from Population 1 and 2 is shown in the table below (n=376).

| Specimen | Age | Female (n) | Male (n) | Unknown (n) | Total (n) |
|-------------------------|----------------|------------|----------|-------------|-----------|
| Population 1<br>(n=169) | ≤ 5 years | 2 | 2 | 0 | 4 |
| | 6 to 21 years | 5 | 7 | 0 | 12 |
| | 22 to 59 years | 75 | 36 | 1 | 112 |
| | ≥ 60 years | 20 | 19 | 0 | 39 |
| | Unknown | 0 | 2 | 0 | 2 |
| | Total | 102 | 66 | 1 | 169 |
| Population 2<br>(n=207) | ≤ 5 years | 0 | 0 | 0 | 0 |
| | 6 to 21 years | 8 | 0 | 0 | 8 |
| | 22 to 59 years | 196 | 0 | 0 | 196 |
| | ≥ 60 years | 0 | 0 | 0 | 0 |
| | Unknown | 3 | 0 | 0 | 3 |
| | Total | 207 | 0 | 0 | 207 |
| Total | ≤ 5 years | 2 | 2 | 0 | 4 |
| | 6 to 21 years | 13 | 7 | 0 | 20 |
| | 22 to 59 years | 271 | 36 | 1 | 308 |
| | ≥ 60 years | 20 | 19 | 0 | 39 |
| | Unknown | 3 | 2 | 0 | 5 |
| | Total | 309 | 66 | 1 | 376 |

^* Clinical and Laboratory Standards Institute (CLSI). User Protocol for Evaluation of Qualitative Test Performance; Approved Guideline-Second Edition. CLSI Document EP12-A2. Wayne, PA: CLSI; 2008.

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| Specimen<br>Category | Alinity i Toxo IgM<br>Result | Comparator Result | | | Positive %<br>Agreement<br>(95% CI)a | Negative %<br>Agreement<br>(95% CI)a |
|--------------------------|------------------------------|-------------------|----|-----|--------------------------------------|----------------------------------------|
| Population 1<br>(n=897) | Reactive | 150 | 16 | 11 | 94.94<br>(150/158)<br>(90.33, 97.41) | 94.44<br>(697/738)<br>(92.55, 95.88) |
| | Grayzone/Equivocal | 1 | 1 | 14 | | |
| | Nonreactive | 6 | 1 | 697 | | |
| | Total | 157 | 18 | 722 | | |
| Specimen<br>Category | Alinity i Toxo IgM<br>Result | Comparator Result | | | Positive %<br>Agreement<br>(95% CI)a | Negative %<br>Agreement<br>(95% CI)a |
| Population 2b<br>(n=234) | Reactive | 18 | 0 | 0 | 94.74<br>(18/19)<br>(75.36, 99.06) | 100.00<br>(215/215)<br>(98.24, 100.00) |
| | Grayzone/Equivocal | 0 | 0 | 0 | | |
| | Nonreactive | 1 | 0 | 215 | | |
| | Total | 19 | 0 | 215 | | |

PPA and NPA between the Alinity i Toxo IgM assay and an FDA-cleared assay was calculated for each population separately and are shown in the tables below.

a The 95% CI for PPA and NPA were estimated using the Wilson score method.

b Twenty-seven specimens from Population 1 were from pregnant females and therefore, were also included in Population 2.

## X. Conclusion Drawn from Nonclinical and Clinical Laboratory Studies

The results presented in this 510(k) premarket notification demonstrate that the subject device (Alinity i Toxo IgM) performance is substantially equivalent to the predicate assay (bioMérieux VIDAS TOXO IgM assay, k923166).