The Sofia Lyme FIA employs immunofluorescence for the rapid differential detection of human IgM and IgG antibodies to Borrelia burgdorferi from serum and plasma specimens from patients suspected of B. burgdorferi infection. This qualitative test is intended for use as an aid in the diagnosis of Lyme disease. A negative result does not preclude infection with B. burgdorferi. All positive results for IgM and/or IgG should be further tested by a corresponding second-tier western blot assay. Test results are to be used in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures.

The Sofia Lyme FIA may be used with Sofia or Sofia 2.

Device Description

The Sofia Lyme FIA is an immunofluorescence-based, lateral flow assay for detection of IgM and/or IgG antibodies to Borrelia burgdorferi in patient specimens. Reagents for the assay are ready-to-use and provided in the kit.

The assay uses a bidirectional test strip format to detect both IgM and IgG antibodies to B. burgdorferi. One side of the test strip detects IgM antibodies to B. burgdorferi and the other side of the test strip detects IgG antibodies to B. burgdorferi.

To perform the test, a patient serum or plasma specimen is obtained and added to a pre-filled vial containing the lyme running buffer. The diluted sample is then pipetted into the round sample port in the center of the Test Cassette.

The Test Cassette is loaded into Sofia 2 in either the READ NOW Mode or WALK AWAY Mode. In READ NOW Mode, the user allows the cassette to develop on the countertop for 10 minutes. In WALK AWAY Mode, the user immediately after adding the specimen to the cassette is inserted into Sofia 2. Sofia 2 will analyze the test strip at 3, 5, 8, and 10 minutes until both IgM and IgG positive results are received. This feature allows for earlier read times.

Each Sofia Lyme FIA kit will contain one Positive and one Negative Control-each provided in separate dropper bottles. The Positive QC control is formulated with patient Lyme IgM and IgG positive plasma diluted into 1X PBS, and 0.3% Microcide is added to the solution as an antimicrobial. The Negative QC control is formulated with patient negative serum diluted into 1X PBS and 0.3% Microcide is added to the solution as an antimicrobial. External Controls will be tested by adding 2 drops to the test cassette.

AI/ML Overview

Here's an analysis of the provided text to extract the acceptance criteria and study details for the Sofia Lyme FIA device.

Note: The provided document is a 510(k) summary for a medical device. It focuses on demonstrating substantial equivalence to a predicate device, rather than proving that the device meets specific acceptance criteria in the way one might see for a novel AI device with clearly defined performance targets post-development. The performance data section describes the types of studies performed and their general positive outcomes ("good performance," "very good," "comparable performance"), but it does not specify quantitative acceptance criteria or report specific numbers for sensitivity, specificity, or predictive values from a test set against a pre-defined ground truth. The acceptance criteria referred to here are implicitly those required to demonstrate substantial equivalence for regulatory approval, which are less stringent than the "acceptance criteria" usually found in the context of AI/ML model validation against specific quantitative metrics.

Therefore, the answers below are based on the available information, highlighting what is present and noting what is not explicitly stated in this type of regulatory document.

Acceptance Criteria and Device Performance

Based on the nature of a 510(k) submission, the "acceptance criteria" are broad and relate to demonstrating substantial equivalence to a legally marketed predicate device. The performance data presented focuses on analytical and clinical performance attributes that support this claim. Specific quantitative acceptance values are not explicitly listed in the summary, but rather implied by the successful completion of the studies and the conclusion of substantial equivalence.

1. A table of acceptance criteria and the reported device performance

Acceptance Criteria (Implied for 510(k) Equivalence)	Reported Device Performance (General Statements)
Analytical Studies: Limit of Detection, Sofia and Sofia 2 Comparison, Matrix Comparison, Early Read, System Temperature (Read Now vs. Walk Away) acceptable.	"All studies demonstrated good performance."
Precision/Repeatability: Within-run, within-day, between-day precision acceptable.	"The total precision results for IgM and IgG were not significantly different within-run, within-day, between day and total when tested with the negative (C0), high negative (C5), low positive (C95) and moderate positive (2-3X LOD) samples."
Analytical Specificity: Acceptable specificity in healthy populations from endemic and non-endemic regions.	"The overall specificity of the Sofia Lyme FIA was very good."
Method Comparison (Clinical Performance): Comparable performance to predicate devices (Vidas Lyme IgG and IgM tests) for prospectively collected specimens.	"This study demonstrated that Sofia Lyme FIA with Sofia 2 has comparable performance to the Vidas Lyme IgG and Vidas Lyme IgM tests when testing prospectively collected specimens from subjects suspected of having Lyme disease."
Reproducibility: Acceptable intra- and inter-laboratory reproducibility.	"The operators and laboratories obtained accurate results with the Sofia Lyme FIA on Sofia 2."

2. Sample size used for the test set and the data provenance (e.g., country of origin of the data, retrospective or prospective)

Test Set Sample Size: Not explicitly stated in the summary. The "Method Comparison" mentions "prospectively collected specimens from subjects suspected of having Lyme disease," but does not provide a number. "Specificity Study" used "samples obtained from asymptomatic (healthy, normal) populations," also without a specified sample size.
Data Provenance:
- Country of Origin: Not specified.
- Retrospective or Prospective: The "Method Comparison" study explicitly states "prospectively collected specimens." The "Specificity Study" refers to "samples obtained from asymptomatic (healthy, normal) populations," likely indicating prospective collection for that purpose.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

This device is an in vitro diagnostic (IVD) test, which directly measures biomarkers (antibodies) in patient samples. The concept of "experts" establishing ground truth for individual cases, as in interpreting medical images, does not directly apply here. The performance is evaluated against established methods (the predicate device) or by spiking samples with known concentrations.
The "ground truth" for evaluating an IVD is typically the true antibody status (positive/negative) determined by reference methods (like Western Blot as mentioned for confirmatory testing) or by known sample characteristics (e.g., healthy controls, defined positive controls). The summary alludes to results being used "in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures," implying clinical diagnosis and confirmatory tests serve as the ultimate clinical ground truth, but this wasn't directly adjudicated by "experts" for the test set in the same way a radiologist would read an X-ray.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

Not applicable in the context of this IVD device. Adjudication methods like 2+1 or 3+1 are typically used for subjective assessments (e.g., image interpretation) where human readers establish ground truth. For an IVD, the "ground truth" is derived from a reference laboratory test or clinical definition, not subjective expert consensus on the diagnostic output itself.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

No, an MRMC study was not done. This device is not an AI-assisted diagnostic tool that supports human readers in interpretation. It's an automated immunoassay.

6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done

This device is inherently "standalone" in its measurement. It's an automated fluorescent immunoassay (FIA) system where the Sofia 2 analyzer performs the reading and provides a result. There isn't a separate "algorithm" being validated outside of the full Sofia Lyme FIA-Sofia 2 system. The performance studies described (analytical, precision, specificity, method comparison, reproducibility) are all evaluating the performance of this system as a whole.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

For the Method Comparison study, the ground truth was likely established by the comparative performance against the predicate devices (Vidas Lyme IgG and Vidas Lyme IgM tests), which are themselves established diagnostic tests.
For the Specificity Study, the ground truth for these samples was "asymptomatic (healthy, normal) populations," implying that the absence of the disease (and thus, antibodies) served as the ground truth.
For the overall clinical utility, the "Indications for Use" states that the test results are to be used "in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures," and "All positive results for IgM and/or IgG should be further tested by a corresponding second-tier western blot assay." This implies that confirmatory testing (like Western Blot), along with clinical evaluation, contribute to the definitive diagnosis or "ground truth" in clinical practice. The studies themselves don't explicitly detail how definitive ground truth for each case was established beyond comparison with predicate or known healthy status.

8. The sample size for the training set

This information is not provided because the Sofia Lyme FIA is not an AI/ML device that requires a separate "training set" for model development. It's a chemical immunoassay, and its "development" involves assay optimization and validation rather than model training.

9. How the ground truth for the training set was established

Not applicable, as there is no "training set" in the AI/ML sense for this device.

Summary

{0}------------------------------------------------

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 FDA logo is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

February 28, 2018

Quidel Corporation Jennifer Rial Director, Regulatory Affairs 12544 High Bluff Drive, Suite 200 San Diego, California 92130

Re: K173691

Trade/Device Name: Sofia Lyme FIA, Sofia 2 analyzer, Sofia 2 Installation Pack Regulation Number: 21 CFR 866.3830 Regulation Name: Treponema pallidum treponemal test reagents Regulatory Class: Class II Product Code: LSR Dated: November 29, 2017 Received: December 1, 2017

Dear Jennifer Rial:

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. 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.

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 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR

{1}------------------------------------------------

Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Kristian M. Roth-S For:

Uwe Scherf, M.S., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

{2}------------------------------------------------

Indications for Use

510(k) Number (if known) K173691

Device Name Sofia Lyme FIA

Indications for Use (Describe)

The Sofia Lyme FIA employs immunofluorescence for the rapid differential detection of human IgM and IgG antibodies to Borrelia burgdorferi from serum and plasma specimens from patients suspected of B. burgdorferi infection. This qualitative test is intended for use as an aid in the disease. A negative result does not preclude infection with B. burgdorferi. All positive results for IgG should be further tested by a corresponding second-tier western blot assay. Test results are to be used in conjunction with information obtained from the patient's clinical evaluation and other diagnostic procedures.

The Sofia Lyme FIA may be used with Sofia or Sofia 2.

X Prescription Use (Part 21 CFR 801 Subpart D)

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

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

{3}------------------------------------------------

Image /page/3/Picture/0 description: The image features the logo of QuidelOrtho Corporation. The logo consists of a square shape with rounded corners, divided into two sections. The larger section is filled with a mosaic of colors, creating a rainbow-like effect. The smaller section is a solid blue color. Below the square is the word "QUIDEL" in a sans-serif font, with the trademark symbol next to it.

510(K) SUMMARY ട.

5.1. Submitter

Quidel Corporation 12544 High Bluff Drive, Suite 200 San Diego, California 92130 Telephone: 858-552-7910 Fax: 858-646-8045

Submission Contact 5.2.

Jennifer S. Rial

5.3. Date Prepared

November 29, 2017

5.4. Proprietary and Established Names

Sofia Lyme FIA

5.5. Common Name

Lyme IgG and Lyme IgM test

5.6. Regulatory Information

Product Code	Classification	Regulatory Section	Panel
LSR	II	21 CFR 866.3830	Immunology andMicrobiology Devices

5.7. Predicate Device

Vidas Lyme IgG and Vidas Lyme IgM

{4}------------------------------------------------

Image /page/4/Picture/0 description: The image features the logo of QuidelOrtho Corporation. The logo consists of a stylized square divided into two sections. The top section is a gradient of colors, including red, orange, yellow, green, and blue. The bottom section is a geometric pattern of blue and purple triangles. Below the square is the word "QUIDEL" in a simple, sans-serif font.

5.8. Device Description

5.9. Intended Use

The Sofia Lyme FIA may be used with Sofia or Sofia 2.

5.10. Substantial Equivalence Information:

1. Predicate Device Name: Vidas Lyme IgM and Vidas Lyme IgG
1. Predicate 510(k) Numbers: K122979 and K122986

{5}------------------------------------------------

Image /page/5/Picture/0 description: The image features the logo for Quidel. The logo consists of a square shape with a smaller square in the bottom right corner. The larger square is filled with a gradient of colors, including yellow, green, blue, and red. The word "QUIDEL" is written in black font below the square.

Item	Proposed Device	Predicate IgM Device	Predicate IgG Device
Features	Sofia Lyme FIA withSofia	Biomerieux Vidas LymeIgM	Biomerieux Vidas LymeIgG
Intended Use	The Sofia Lyme FIAemploysimmunofluorescencefor the rapiddifferential detectionof human IgM andIgG antibodies toBorrelia burgdorferifrom serum andplasma specimensfrom patientssuspected of B.burgdorferi infection.This qualitative test isintended for use as anaid in the diagnosis ofLyme disease. Anegative result doesnot preclude infectionwith B. burgdorferi .All positive results forIgM and/or IgGshould be furthertested by acorresponding second-tier western blotassay. Test results areto be used inconjunction withinformation obtainedfrom the patient'sclinical evaluation andother diagnosticprocedures.The Sofia Lyme FIAmay be used with Sofiaor Sofia 2.	The VIDAS Lyme IgMassay is an automatedqualitative enzymeimmunoassay intended foruse on the instruments of theVIDAS family in thepresumptive detection ofhuman IgG antibodies toBorrelia burdorferi inhuman serum or plasma. Itshould be used to testpatients with a historyand/or symptoms ofinfection with B.burgdorferi . All VIDASLyme IgG positivespecimens should be furthertested with a Western BlotIgG assay to obtainsupportive evidence ofinfection with B.burgdorferi .	The VIDAS Lyme IgGassay is an automatedqualitative enzymeimmunoassay intended foruse on the instruments of theVIDAS family in thepresumptive detection ofhuman IgG antibodies toBorrelia burdorferi inhuman serum or plasma. Itshould be used to testpatients with a historyand/or symptoms ofinfection with B.burgdorferi . All VIDASLyme IgG positivespecimens should be furthertested with a Western BlotIgG assay to obtainsupportive evidence ofinfection with B.burgdorferi .
Instrument	Sofia 2 (and Sofia)	VIDAS and miniVIDAS	VIDAS and miniVIDAS
Item	Proposed Device	Predicate IgM Device	Predicate IgG Device
Features	Sofia Lyme FIA withSofia	Biomerieux Vidas LymeIgM	Biomerieux Vidas LymeIgG
Analyte	Human IgM and IgGantibodies against B.burgdorferi proteins	Human IgM antibodiesagainst B. burgdorferiproteins	Human IgG antibodiesagainst B. burgdorferiproteins
AutomatedAnalysis	Yes	Yes	Yes
Read Results	Read results on instrumentscreen or print withoptional printer	Result report is printed	Result report is printed
Read ResultTime	Sofia 2 - Potential for earlyread in Walk-Away Modewith Sofia 2. Sofia 2 willimage cassette at 3, 5, 8,and 10 minutes until bothIgM and IgG positiveresults are received.Sofia – 10 minutes	27 minutes	27 minutes
SpecimenTypes	Serum and plasma	Serum and plasma	Serum and plasma
Qualitative	Yes	Yes	Yes
Test Principle	ImmunofluorescenceDevice	Immunofluorescence Device	Immunofluorescence Device
Format	Lateral-flow Bi-directionalTest Cassette	Enzyme-linked fluorescentassay (ELFA)	Enzyme-linked fluorescentassay (ELFA)
AntibodiesUsed	Monoclonal anti-humanIgG and polyclonal anti-human IgM	Anti-human IgM antibodies	Anti-human IgG antibodies
Antigens Used	Recombinant Proteins andsynthetic peptides of B.burgdorferi	Recombinant proteins of B.burgdorferi	Recombinant proteins of B.burgdorferi
DetectionMethod	Polystyrene microparticlesdyed with Europiumchelate	Alkaline phosphatase/4-MUP	Alkaline phosphatase/4-MUP
Storage	Room Temperature (15-30°C)	2-8°C	2-8°C
RunningBufferSolution	One pre-filled vialcontaining PBS	Sample diluent and washbuffer	Sample diluent and washbuffer
Item	Proposed Device	Predicate IgM Device	Predicate IgG Device
Features	Sofia Lyme FIA with Sofia	Biomerieux Vidas Lyme IgM	Biomerieux Vidas Lyme IgG
QualityControlFeatures	Built-in features include:Built-in procedural control zone scanned by the analyzer to determine whether adequate flow occurred on the IgG side of the assay. Built-in reference control line scanned by the analyzer to determine whether adequate flow occurred on the IgM side of the assay. Analyzer prevents used or expired cartridge from being read by the reader Cassette must be properly inserted	One positive and one negative control are included and must be tested after opening a new kit to monitor reagent failure.	One positive and one negative control are included and must be tested after opening a new kit to monitor reagent failure.

Comparison with Predicate

{6}------------------------------------------------

Image /page/6/Picture/0 description: The image shows the logo for QuidelOrtho Corporation. The logo features a square shape with a smaller square cut out of the bottom right corner. The larger square is filled with a gradient of colors, transitioning from red and orange at the top to blue and purple at the bottom. Below the square is the word "QUIDEL" in a sans-serif font.

{7}------------------------------------------------

Image /page/7/Picture/0 description: The image shows the logo for QuidelOrtho Corporation. The logo features a square shape with a smaller square cut out of the bottom right corner. The larger square is filled with a gradient of colors, transitioning from red and orange at the top to blue and purple at the bottom. Below the square is the word "QUIDEL" in a sans-serif font.

5.11. Performance Data

Additional studies were performed to document the performance characteristics of Sofia Lyme FIA with the Sofia 2 analyzer. The studies included the following:

Various Analytical Studies a.
Analytical studies included Limit of Detection, Sofia and Sofia 2 Comparison, Matrix Comparison, Early Read, System Temperature (Read Now vs. Walk Away). All studies demonstrated good performance.
b. Precision
This study evaluated the within laboratory precision / repeatability of the Sofia Lyme FIA and the Sofia 2 analyzer. The total precision results for IgM and IgG were not significantly different within-run, within-day, between day and total when tested with the negative (C0), high negative (C5), low positive (C95) and moderate positive (2-3X LOD) samples.

{8}------------------------------------------------

Image /page/8/Picture/0 description: The image shows the logo for QuidelOrtho Corporation. The logo features a square shape with a smaller square cut out of the bottom right corner. The larger square is filled with a gradient of colors, ranging from red and orange to yellow, green, blue, and purple. Below the square is the word "QUIDEL" in a sans-serif font.

Specificity Study C.
This study evaluated the analytical specificity of the Sofia Lyme FIA on Sofia 2 using samples obtained from asymptomatic (healthy, normal) populations in both endemic and non-endemic regions. The overall specificity of the Sofia Lyme FIA was very good.
d. Method Comparison
This study demonstrated that Sofia Lyme FIA with Sofia 2 has comparable performance to the Vidas Lyme IgG and Vidas Lyme IgM tests when testing prospectively collected specimens from subjects suspected of having Lyme disease.
Reproducibility e.
This study demonstrated intra- and inter-laboratory reproducibility with a panel of test samples at various concentrations of IgM and IgG antibodies to B. burgdorferi. The operators and laboratories obtained accurate results with the Sofia Lyme FIA on Sofia 2.

5.12. Conclusion

These studies demonstrated the substantial equivalence of the Sofia Lyme FIA with Sofia 2 to the Vidas Lyme IgG and Vidas Lyme IgM tests. Such studies are a critical element in establishing the fundamental safety and effectiveness of the product and its appropriateness for commercial distribution.

Regulation Number and Section

§ 866.3830

Treponema pallidum treponemal test reagents.(a)
Identification. Treponema pallidum treponemal test reagents are devices that consist of the antigens, antisera and all control reagents (standardized reagents with which test results are compared) which are derived from treponemal sources and that are used in the fluorescent treponemal antibody absorption test (FTA-ABS), theTreponema pallidum immobilization test (T.P.I.), and other treponemal tests used to identify antibodies toTreponema pallidum directly from infecting treponemal organisms in serum. The identification aids in the diagnosis of syphilis caused by bacteria belonging to the genusTreponema and provides epidemiological information on syphilis.(b)
Classification. Class II (performance standards).