The Gold Standard Diagnostics Borrelia burgdorferi B31 IgM Line Blot Test Kit is intended for the qualitative detection of IgM antibodies to B. burgdorferi sensu stricto (B31) in human serum. This test is intended for use in testing human serum samples which have been found positive or equivocal using an ELISA or IFA test procedure to provide supportive evidence of infection with B. burgdorferi.

Device Description

The assay requires a total of 70 minutes incubation time. The test uses purified antigens coated on nitrocellulose strips. Serum sample is added to each strip and incubated for 30 minutes. If Borrelia burgdorferi antibodies are present they will bind to the antigens on the strips. Unbound serum is removed by washing the wells three times. An enzyme-conjugated anti-human IgM is then added to each strip and incubated for 30 minutes. It will bind to the any antibody that was attached to the antigen on the strip. The wells are again washed three times followed by a DI water wash to remove any unbound conjugate. After unbound conjugate has been removed by a further washing step, a visualization of the antigenantibody-antibody complex is accomplished by the addition of a substrate which forms blue-violet precipitates at each site (antigen bands). The reaction is stopped by washing the nitrocellulose strip with distilled or deionized water. Depending on the observed band pattern one can interpret the presence or absence of specific IgM antibodies to B. burgdorferi infection.

AI/ML Overview

Here's an analysis of the provided text, outlining the acceptance criteria and study details for the Borrelia burgdorferi IgM B31 Line Blot Test Kit:

Acceptance Criteria and Device Performance

The acceptance criteria are implied by the performance of the predicate device and the comparison studies. For some metrics, the specific numerical targets for acceptance are stated (e.g., 95% positivity for low positive samples in reproducibility).

Acceptance Criteria Category	Specific Metric (If available)	Reported Device Performance (GSD B31 IgM Line Blot)
Reproducibility (Band)	Negative Sample: 0 significant bands	0 significant bands (100% agreement)
	High Negative Sample: <=1 significant band	79 for 23kDa band (≤1 significant band, 87.8%)
	Low Positive Sample: 2 significant bands	86 for 41kDa, 90 for 23kDa (176/180 total; 97.8% agreement)
	Moderate Positive Sample: 3 significant bands	90 for 41kDa, 90 for 39kDa, 90 for 23kDa (100% agreement)
Reproducibility (Sample Interpretation)	Negative samples: 100% negative	100% (90/90) Negative
	High Negative samples: 100% negative	100% (90/90) Negative
	Low Positive samples: 95% positive	95.6% (86/90) Positive
	Moderate Positive samples: 100% positive	100% (90/90) Positive
Cross-Reactivity	Minimal or no cross-reactivity with specified conditions	Low rates (e.g., 4% Tick-borne relapsing fever, 5% Ehrlichiosis, 10% Babesiosis). Discrepancies often matched in predicate device.
Interfering Substances	No change in final interpretation	None detected at tested concentrations
Specimen Stability (2-8°C)	Consistent results for up to 168 hours	Consistent results
Specimen Stability (Room Temp)	Consistent results for up to 8 hours	Consistent results
Specimen Stability (Freeze/Thaw)	Consistent results for up to 10 cycles	Consistent results
Clinical Sensitivity (Early Lyme)	Comparable to predicate device	87.5% (35/40) [73.2%-95.8%] (Predicate: 77.5%)
Clinical Sensitivity (Disseminated Lyme)	Comparable to predicate device	95.0% (19/20) [75.1%-99.9%] (Predicate: 85%)
Clinical Sensitivity (Late Lyme)	Comparable to predicate device	27.5% (11/40) [14.6%-43.9%] (Predicate: 22.5%)
Analytical Specificity (Endemic)	High specificity (e.g., 100%)	100% (0/115 positive)
Analytical Specificity (Non-endemic)	High specificity (e.g., 100%)	100% (0/119 positive)
CDC Reference Panel (Healthy)	100% agreement	100% (5/5)
CDC Reference Panel (Early, 0-2 months)	Comparable to predicate device	86.7% (13/15) (Predicate: 73.3%)
CDC Reference Panel (Intermediate, 3-12 months)	Comparable to predicate device	92.3% (12/13) (Predicate: 84.6%)
CDC Reference Panel (Late, >1 year)	Comparable to predicate device	57.1% (4/7) (Predicate: 57.1%)
Method Comparison (Positive Percent Agreement)	High agreement with predicate device (e.g., >95%)	99.4% (154/155) [95% CI: 96.5-100%]
Method Comparison (Negative Percent Agreement)	High agreement with predicate device (e.g., >95%)	99.4% (154/155) [95% CI: 96.5-100%]

Study Details

Sample size used for the test set and the data provenance:
- Reproducibility: 4 samples (negative, high negative, low positive, moderate positive), each tested in triplicate for 5 days, twice a day (90 data points per sample).
- Cross-Reactivity: 215 specimens from patients known to have potentially cross-reactive antibodies or diagnoses mistaken for Lyme disease.
- Interfering Substances: 6 sera (2 positive, 1 low positive, 1 high negative, 2 negative).
- Specimen Collection and Handling: 3 samples tested in triplicate.
- Clinical Sensitivity: 100 clinically characterized samples (40 early, 20 disseminated, 40 late stage Lyme disease).
- Analytical Specificity: 234 asymptomatic samples (115 endemic, 119 non-endemic regions).
- CDC Reference Panel: 40 samples (5 healthy, 15 early, 13 intermediate, 7 late).
- Method Comparison (Prospective Clinical Study): 310 samples after initial ELISA/IFA screening.
- Data Provenance:
  - Clinical Sensitivity samples: Obtained from Allen C. Steere, MD at the Massachusetts General Hospital (USA).
  - Analytical Specificity samples: From endemic and non-endemic regions (specific countries not mentioned, but implies US and potentially other regions).
  - CDC Reference Panel: Provided by the Center of Disease Control (USA).
  - Method Comparison samples: Collected from three different geographic sites in the U.S. (Pennsylvania, North Carolina, and California).
  - Overall, the data is retrospective and prospective, primarily from the United States.
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not explicitly state the number or qualifications of experts used to establish ground truth for the test set.
- For Clinical Sensitivity, samples were "clinically characterized" from a physician (Allen C. Steere, MD), suggesting medical diagnosis and potentially expert consensus, but the process is not detailed.
- For the CDC Reference Panel, the CDC itself established the categorization, implying a high level of expert consensus and standardized classification.
- For the Method Comparison, initial positive/equivocal ELISA/IFA results were used as a pre-screen, and then tests against a predicate device and a second commercially available assay were used to resolve discrepancies and establish comparative "ground truth" relative to existing methods.
Adjudication method for the test set:
- The document specifies an adjudication step for the Method Comparison study: "The discrepant samples were tested on a second commercially available assay." This suggests a mechanism to resolve differences between the new device and the predicate by consulting a third, independent test, which acts as a form of adjudication. The specific rules (e.g., 2+1) are not explicitly stated, but the process of using a second assay for discrepancies implies a form of resolution.
- For other studies, explicit adjudication methods are not detailed.
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:
- This device is an in vitro diagnostic (IVD) kit for detecting antibodies, not an AI-powered diagnostic imaging or interpretation tool. Therefore, a multi-reader multi-case (MRMC) comparative effectiveness study focusing on human reader performance with or without AI assistance is not applicable to this device.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- This is an antibody detection kit. The "performance" is the detection of specific antibody bands on a nitrocellulose strip, which is then interpreted. The kit itself operates as a "standalone" chemical assay. While human eyes read the bands, the core performance measures (sensitivity, specificity, agreement) directly reflect the kit's analytical capabilities without an "algorithm only" vs. "human-in-the-loop" distinction in the context of AI. The interpretation is visual, and the consistency of that visual interpretation is assessed through reproducibility studies involving multiple technicians.
The type of ground truth used:
- Clinical Sensitivity: "Clinically characterized samples" from a medical expert (Allen C. Steere, MD at Massachusetts General Hospital) implies a clinical diagnosis/outcome as ground truth, likely based on patient history, symptoms, and other diagnostic tests.
- CDC Reference Panel: Categorization by the Center for Disease Control (CDC), which likely relies on a combination of clinical criteria, confirmed infections, and perhaps other established laboratory methods, representing a highly authoritative expert consensus.
- Method Comparison: Ground truth for comparison was established by agreement with a predicate legally marketed device (Trinity Biotech B. burgdorferi (IgM) Marblot Strip Test System) and further adjudicated by a second commercially available assay for discrepant results. This is a form of comparison to an established method/reference standard.
The sample size for the training set:
- Not applicable / Not explicitly stated. This is a chemical assay kit, not a machine learning or AI model that requires a "training set" in the traditional computational sense. The "development" and "optimization" of such a kit would involve testing various antigen preparations, conjugate concentrations, and protocols, but this isn't typically referred to as a "training set" for an algorithm.
How the ground truth for the training set was established:
- Not applicable. As the device is not an AI/ML model, there is no "training set" or corresponding ground truth establishment in that context.

Summary

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2012

510(k) Summary

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

1) Submitter's Name:	Gold Standard Diagnostics
Address:	2851 Spafford St. Davis, CA. 95618
Phone Number:	530-759-8000
Contact Person:	Napoleon Monce
Date:	May 27, 2012

1. Product and Trade Name: Borrelia burgdorferi IgM B31 Line Blot Test Kit Common Name or Classification Name: Borrelia burgdorferi IgM Western blot
  Product Code: LSR

3) Legally marketed device to which the submitter claims equivalence B. burgdorferi (IgM) Marblot Strip Test System (Distributed by Trinity Biotech) (K951709).

4) Description of the device:

5) Intended use of the device

6) Comparison with the predicate device

The Gold Standard Diagnostics Borrelia Burgdorferi B31 IgM Line Blot Test Kit was compared to a commercially marketed kit by Trinity Biotech the B. burgdorferi (IgM) Marblot Strip Test System

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(K951709). Both kits have the same intended use and use the same methodology. Below are tables comparing the reagents and the procedures of the two devices.

Gold Standard Diagnostics B. burgdorferiB31 IgM Line Blot Test Kit	Trinity Biotech B. burgdorferi (IgM)Marblot Strip Test
Antigen coated nitrocellulose strips	Antigen coated nitrocellulose strips
IgM Conjugate - 100x	IgM Conjugate - 10x
Substrate – BCIP/NBT	Substrate
IgM Positive Control	IgM Band Locator Control
IgM Cutoff Control	IgM Weak Reactive Control
IgM Negative Control	IgM Negative Control .
Diluent/Wash Concentrate - 10x	Diluent/Wash Concentrate - 10x

Table 1: Reagent Comparison

Table 2: Procedure Comparison

Gold Standard Diagnostics B. burgdorferiB31 IgM Line Blot Test Kit	Trinity Biotech B. burgdorferi (IgM)Marblot Strip Test
Dilute Samples 1:101 in Diluent/Wash	Dilute Samples 1:101 in Diluent/Wash
Add 15ul of Samples	Add 20ul of Samples
Incubate for 30 minutes while rocking	Incubate for 30 minutes while rocking
Wash three times with reconstituted	Wash three times with reconstituted
Diluent/Wash Solution	Diluent/Wash Solution
Add 1.5ml of reconstituted Conjugate	Add 2ml of reconstituted Conjugate
Incubate for 30 minutes while rocking	Incubate for 15 minutes while rocking
Wash three times with reconstituted	Wash three times with reconstituted
Diluent/Wash Solution	Diluent/Wash Solution
Wash one time with DI water	Wash one time with DI water
Add 1.5ml of Substrate	Add 2ml of Substrate
Incubate for 10 minutes ± 3 minutes while rocking	Incubate for 4-12 minutes while rocking
Wash three times with 1.5ml DI water	Wash three times with 2.0ml DI water

6(b1) Nonclinical Tests:

. Reproducibility

The reproducibility of the assay was done by testing a negative sample, a high negative sample, a low positive sample, and a moderate positive sample in triplicate for five days, twice a day, at three sites with two technicians per site giving a total of 90 data points per sample. Results of band reproducibility and sample reproducibility are shown below:

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Band Reproducibility

Sample/kDa	41	39	23	Numberof Bands
Negative	0	0	0	0significantbands
HighNegative	0	0	79	≤1significantbands
LowPositive	86	0	90	2significantbands
ModeratePositive	90	90	90	3significantbands

Sample Reproducibility

		Final Interpretation
	Band Reproducibility	Positive	Negative
Sample
Negative	100% (0/0)		100% (90/90)
High Negative	87.8% (79/90)		100% (90/90)
Low Positive*	97.8% (176/180)	95.6% (86/90)
Moderate Positive	100% (270/270)	100% (90/90)

A low positive sample is expected to yield a positivity of 95%.

Cross Reactivity

A cross reactivity study was performed on 215 specimens known to contain potentially cross reactive antibodies to B. burgdorferi. Sera from patients with infections and sera from patients with diagnoses that can be confused with the late manifestations of Lyme disease were tested. The results are summarized in the following table:

Infection / Diagnosis	Number of sera tested	# Positive / (%)
Tick-borne relapsing fever /Rickettsial Diseases	23	1 / (4%)
Treponemal Infections	12	0 / (0%)
Ehrlichiosis	20	1 / (5%)
Babesiosis	20	2 / (10%)
Leptospirosis	1	0 / (0%)

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Parvovirus B19	9	0 / (0%)
Epstein-Barr Virus	11	0 / (0%)
Cytomegalovirus	32	0 / (0%)
H. pylori	12	0 / (0%)
Fibromyalgia	10	0 / (0%)
Rheumatoid Arthritis	12	0 / (0%)
Herpes Simplex Virus	16	0 / (0%)
Varicella Zoster Virus	12	0 / (0%)
Autoimmune Disease	25	0 / (0%)

Two of the 20 Babesiosis samples and one each of the 23 Tick-borne relapsing fever / Rickettsial Disease and 20 Ehrlichiosis specimens were positive on the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot Test. These samples were also tested on the predicate device which also gave positive results.

Interfering Substances

The effect of potential interfering substances on samples using the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot Test was evaluated. High levels of hemoglobin, bilirubin, cholesterol and intralipids in serum samples were tested on six sera (two positive, one low positive, one high negative, and two negatives). The recommended concentrations from the guideline "Interference Testing in Clinical Chemistry" from the Clinical and Laboratory Standards Institute were used. The interferents at the concentrations tested did not have any influence on the band pattern. A small variability in band intensity was seen that is in the normal range of deviation and did not change the final interpretation. The results are summarized in the following table:

Substance	Concentration	Interference
Hemoglobin	2 g/l	None detected
Bilirubin	342 µmol/l	None detected
Cholesterol	13 mmol/l	None detected
Intralipids	37 mmol/l	None detected

Specimen Collection and Handling Conditions

A study was performed to substantiate the specimen storage and handling conditions for the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot Test. Three samples were tested in triplicate after the following storage conditions:

A) 2-8ºC for 24, 48, 72, 96, 120, 144 and 168 hours.
B) Room temperature for 2, 6 and 8 hours.
C) After 1, 5 and 10 freeze and thaw cycles.

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The samples gave consistent results for all testing parameters above, therefore the specimens can be held at 2-8°C for at least 168 hours or at room temperature for up to 8 hours and withstand up to 10 freeze and thaw cycles.

8) Clinical Testing

Sensitivity Testing

A sensitivity study was performed on 100 clinically characterized samples obtained from Allen C. Steere, MD at the Massachusetts General Hospital. The samples encompassed early, disseminated, and late stages of Lyme disease. The results are summarized in the following table:

	Number ofSamples	Line Blot Sensitivitywith 95% CI	Commercially AvailableDevice Sensitivity with95% CI
Early	40	87.5% (35/40)[73.2%-95.8%]	77.5% (31/40)[61.6%-89.2%]
Disseminated	20	95.0% (19/20)[75.1%-99.9%]	85% (17/20)[62.1%-96.8%]
Late	40	27.5% (11/40)[14.6%-43.9%]	22.5% (9/40)[10.8%-38.5%]

Analytical Specificity (endemic & non-endemic)

For the determination of analytical specificity, testing of 234 asymptomatic samples from both endemic and non-endemic regions was performed. The results are summarized in the following table:

Region	Number of Samples	Number Positive	Analytical Specificity
Endemic	115	0	100%
Non-endemic	119	0	100%

CDC Reference Panel

A standard panel of positive and negative specimens provided by the Center of Disease Control (CDC) for Lyme disease detection was tested both on the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot Test and on the predicate device. The results are summarized in the following table:

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Stage	Total	GSD Line Blot% Agreement	CommerciallyAvailable Device% Agreement
Healthy	5	100% (5/5)	100% (5/5)
Early(0-2 months)	15	86.7% (13/15)	73.3% (11/15)
Intermediate(3-12 months)	13	92.3% (12/13)	84.6% (11/13)
Late(>1year)	7	57.1% (4/7)	57.1% (4/7)

Method Comparison

The performance of the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot test was determined by conducting a prospective clinical study at three different geographic sites (Pennsylvania, North Carolina, and California) in the U.S. The patient samples were tested by an anti-B. burgdorferi total antibody ELISA test first and the resulting equivocal and positive specimens were tested on the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot test and a commercially available B. burgdorferi IgM Blot test. The results are summarized in the following table:

		Trinity Biotech IgM Blot
		Positive	Negative
Gold Standard Diagnostics	Positive
IgM Line Blot	Negative

Positive Percent Agreement = 99.4% (154/155) [95% CI: 96.5-100%] Negative Percent Agreement = 99.4% (154/155) [95% CI: 96.5-100%]

The discrepant samples were tested on a second commercially available assay. On the one Line Blot negative sample that was positive by the predicate, the second assay gave a positive result. Of the one Line Blot positive and predicate negative samples, the second assay called the sample positive.

The 310 samples were also tested by the Gold Standard B. burgdorferi IgG Line Blot test and 36.8% ( 14/310) were found to be positive and 63.2% (196/310) were found to be negative.

9) Conclusion

From the performance data and kit comparison above, it is our conclusion that the Gold Standard Diagnostics B. burgdorferi B31 IgM Line Blot Test Kit is substantially equivalent to the B. burgdorferi (IgM) Marblot Strip Test System (K951709) commercially marketed by Trinity Biotech.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/6/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" around the perimeter. Inside the circle is a stylized image of a human figure embracing a bird, which is a symbol representing the department's mission to protect and promote the health and well-being of Americans.

Food and Drug Administration

10903 New Hampshire Avenue Silver Spring, MD 20993

Gold Standard Diagnostics C/O Napoleon Monce Director, Product Development 2851 Spafford St. Davis, CA. 95618

JUN - 1 2012

Re: K113846

Trade/Device Name: Borrelia burgdorferi B31 IgM Line Blot Test Kit Regulation Number: 21 CFR 866.3830 Regulation Name: Treponema pallidum treponemal test reagents Regulatory Class: Class II Product Code: LSR Dated: December 28, 2011 Received: March 8, 2012

Dear Mr. Monce:

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 class II (Special Controls), 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); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). This letter

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Page 2 - Napoleon Monce

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.

If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 796-5450. 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.

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 (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

Uwe Schref for

Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices 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): K113846

Device Name: Borrelia burgdorferi B31 IgM Line Blot Test Kit

Indications For Use:

Prescription Use × (Part 21 CFR 801 Subpart D) AND/OR

Over-The-Counter Use (21 CFR 807 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)

Tuare Felmberg

Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

510(K) 1/2 11 38 4 6

Page 1 of

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).