← Product Code [LSR](/submissions/MI/subpart-d%E2%80%94serological-reagents/LSR) · K180264

# Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit (K180264)

_Gold Standard Diagnostics · LSR · May 2, 2018 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/LSR/K180264

## Device Facts

- **Applicant:** Gold Standard Diagnostics
- **Product Code:** [LSR](/submissions/MI/subpart-d%E2%80%94serological-reagents/LSR.md)
- **Decision Date:** May 2, 2018
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.3830
- **Device Class:** Class 2
- **Review Panel:** Microbiology

## Indications for Use

The Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test kit is intended as a qualitative presumptive (first step) test for the detection of IgG and IgM antibodies to B. burgdorferi sensu stricto in human serum from symptomatic patient or people suspected of infection. Positive and equivocal results must be supplemented by testing with a second-step Western blot assay.

## Device Story

The Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit is an in vitro diagnostic assay used in clinical laboratories. It detects IgG and IgM antibodies to B. burgdorferi sensu stricto in human serum samples. The device utilizes an antigen-coated microtiter plate (B. burgdorferi B31 lysate, 2591 lysate, and recombinant VlsE) to capture specific antibodies. Following sample incubation and washing, a horseradish peroxidase-conjugated goat anti-human IgG/IgM antibody is added, followed by a TMB chromogenic substrate. The enzymatic reaction produces a color change (blue to yellow upon adding stop solution), which is measured photometrically at 450nm. Results are interpreted as positive, equivocal, or negative based on unit conversion. The test serves as a first-step presumptive screen; positive or equivocal results require confirmation via a second-step Western blot assay. The output assists clinicians in the diagnostic workup of patients suspected of having Lyme disease.

## Clinical Evidence

Clinical sensitivity evaluated on 89 characterized Lyme disease samples (early, disseminated, late stages) and a CDC-provided panel. Sensitivity: 76.3% (early), 100% (disseminated), 97.2% (late). CDC panel agreement: 86.7% (early), 53.8% (convalescent), 100% (late). Method comparison with predicate (n=520) showed 96.0% positive percent agreement and 97.5% negative percent agreement. Analytical specificity (n=210) was 97.3% (endemic) and 98.0% (non-endemic).

## Technological Characteristics

ELISA-based immunoassay. Components: polystyrene 96-well microtiter plates, B. burgdorferi antigens (B31, 2591, recombinant VlsE), goat anti-human IgG/IgM-HRP conjugate, TMB substrate, stop solution. Detection via photometric microplate reader at 450nm. Manual or automated processing. No specific software algorithm class stated; relies on standard photometric absorbance measurement.

## Regulatory 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), the Treponema pallidum immobilization test (T.P.I.), and other treponemal tests used to identify antibodies to Treponema pallidum directly from infecting treponemal organisms in serum. The identification aids in the diagnosis of syphilis caused by bacteria belonging to the genus Treponema and provides epidemiological information on syphilis.

## Predicate Devices

- Trinity Biotech Captia™ Borrelia burgdorferi IgG/IgM ELISA Test Kit ([K033070](/device/K033070.md))

## Submission Summary (Full Text)

> This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com.
>
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number: K180264
B. Purpose for Submission: To obtain a substantial equivalence determination and FDA clearance for a new device.
C. Measurand: Anti-Borrelia burgdorferi (IgM and IgG) antibodies
D. Type of Test: Enzyme Immunoassay
E. Applicant: Gold Standard Diagnostics
F. Proprietary and Established Names: Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit

G. Regulatory Information:

1. Regulation section: 21 CFR 866.3830; Treponema pallidum treponemal test reagents.
2. Classification: Class II
3. Product code: LSR; Reagent, Borrelia Serological Reagent
4. Panel: Microbiology

H. Intended Use:

1. Intended use(s): The Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit is intended as a qualitative presumptive (first-step) test for the detection of IgG and IgM antibodies to B. burgdorferi sensu stricto in human serum from symptomatic patients or people suspected of infection. Positive and equivocal results must be supplemented by testing with a second-step Western blot assay.
2. Indication(s) for use: Same as Intended Use
3. Special conditions for use statement(s): For prescription use only.
4. Special instrument requirements: N/A

I. Device Description: The Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM test consists of antigenic proteins specific for B. burgdorferi (sensu stricto) which are either purified or cloned and expressed in the surrogate host E.coli. The individual antigens are transferred to polystyrene 96 well microtiter plates.

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During the test procedure, antibodies to *B. burgdorferi* (sensu stricto) if present in the human serum sample will bind to the antigens coated onto the wells forming antigen-antibody complexes. Excess antibodies are removed by washing. A conjugate of goat anti-human IgG/IgM antibodies conjugated with horseradish peroxidase are then added, which binds to the antigen-antibody complexes. Excess conjugate is removed by washing. This is followed by the addition of a chromogenic substrate, tetramethylbenzidine (TMB). If specific antibodies to the antigen are present in the patients’ serum, a blue color will develop. The enzymatic reaction is then stopped with a stopping solution causing the contents of the well to turn yellow. The wells are read photometrically with a microplate reader at 450nm.

## J. Substantial Equivalence Information:

1. Predicate device name(s): Trinity Biotech Captia *Borrelia burgdorferi* IgG/IgM ELISA Test Kit.
2. Predicate 510(k) number(s): K033070
3. Comparison with predicate:

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate (K033070)  |
|  Intended Use | The Gold Standard Diagnostics *Borrelia burgdorferi* IgG/IgM ELISA Test Kit is intended as a qualitative presumptive (first-step) test for the detection of IgG and IgM antibodies to *B. burgdorferi* sensu stricto in human serum from symptomatic patients or people suspected of infection. Positive and equivocal results must be supplemented by testing with a second-step Western blot assay. | Trinity Biotech Captia *Borrelia burgdorferi* IgG/IgM ELISA Test Kit is intended for the qualitative presumptive (first-step) detection of total (IgG/IgM) antibodies to *B. burgdorferi* in human serum. This ELISA should only be used for patients with signs and symptoms that are consistent with Lyme disease. Equivocal or positive results must be supplemented by testing with a standardized Western blot (second step) procedure. Positive supplemental (second-step) results are supportive evidence of exposure to *B. burgdorferi* and can be used to support a clinical diagnosis of Lyme disease. The diagnosis of Lyme  |

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|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate (K033070)  |
|   |  | disease must be made based on history, signs (such as erythema migrans), symptoms, and other laboratory data, in addition to the presence of antibodies to B. burgdorferi. Negative results (either first or second step) should not be used to exclude Lyme disease.  |
|  Assay Format | Antigen coated microtiter plate – 96 wells. | Same  |
|  Technology | ELISA | Same  |
|  Sample Matrix | Human serum | Same  |
|  Controls Provided | Positive, Cut-off, Negative | Same  |
|  Reagents Provided | Diluent, Wash, Conjugate, Substrate, Stop Solution | Same  |
|  Reported Results | Positive, Equivocal, Negative | Same  |
|  Interpretation | Optical density readings from Spectrophotometer | Same  |
|  Differences  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Sample Processing | Dilute Samples 1:100 in Diluent | Dilute Samples 1:20 in Diluent  |
|  Volumes | 100ul sample, 50ul substrate, 50ul stop solution | 100ul sample, 100ul substrate, 100ul stop solution  |
|  Incubation | 15/15/15 minutes at room temperature | 25/25/10-15 minutes at room temperature  |
|  Antigens | B. burgdorferi B31 strain, B. burgdorferi 2591 strain, B. burgdorferi recombinant VlsE, B31 strain | B. burgdorferi B31 strain  |
|  Results Interpretation | Convert to units. Negative: <9 Equivocal: 9.0-11.0 Positive: >11.0 | Convert to units. Negative: ≤0.90 Equivocal: 0.91-1.09 Positive: ≥1.10  |

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K. Standard/Guidance Document Referenced (if applicable): N/A
L. Test Principle: Enzyme Immunoassay

M. Performance Characteristics (if/when applicable):

1. Analytical performance:
a. Precision/Reproducibility:

Precision: To determine the precision of the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test, a within-lab precision study was conducted. A precision panel consisting of a negative sample, a high negative sample, a low positive sample, and a moderate positive sample, along with the kit controls, was tested in-house. The sample panel was masked and randomized. Each of the panel members was tested in duplicate, twice per day, for 12 days. The results are summarized in the following table.

Table 1: Precision Study

|  Sample | N | Mean Units |  | Within-Run | Between-Run | Between-Day | Total  |
| --- | --- | --- | --- | --- | --- | --- | --- |
|  Moderate Positive | 48 | 196 | SD | 0.815 | 1.534 | 1.472 | 1.737  |
|   |   |   |  CV | 4.2% | 7.8% | 7.5% | 8.9%  |
|  Low Positive | 48 | 12.1 | SD | 0.267 | 1.417 | 1.248 | 1.442  |
|   |   |   |  CV | 2.2% | 11.7% | 10.3% | 11.9%  |
|  High Negative | 48 | 6.1 | SD | 0.211 | 0.662 | 0.642 | 0.695  |
|   |   |   |  CV | 3.4% | 10.8% | 10.5% | 11.4%  |
|  Negative | 48 | 1.7 | SD | 0.113 | 0.164 | 0.151 | 0.199  |
|   |   |   |  CV | 6.6% | 9.6% | 8.8% | 11.6%  |

Reproducibility: A reproducibility panel consisting of a negative sample, a high negative sample, a low positive sample, and a moderate positive sample, along with the kit controls, was tested at three different sites. The sample panel was masked and randomized. Each of the panel members was tested in triplicate, twice per day, for five days. The Within-Run, Between-Run, Between-Days, and Between-Sites Standard Deviation and Coefficients of Variation (CV) were calculated. The results are summarized in the following table.

Table 2: Reproducibility Study

|  Sample | N | Mean Units |  | Within-Run | Between-Run | Between-Day | Between-Sites | Total  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  Moderate Positive | 90 | 21.1 | SD | 1.117 | 1.543 | 1.434 | 0.386 | 1.905  |
|   |   |   |  CV | 5.3% | 7.3% | 6.8% | 1.8% | 9.0%  |
|  Low Positive | 90 | 13.8 | SD | 0.591 | 1.155 | 1.026 | 0.404 | 1.297  |
|   |   |   |  CV | 4.3% | 8.4% | 7.5% | 2.9% | 9.4%  |

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b. Linearity/assay reportable range: N/A
c. Traceability, Stability, Expected values (controls, calibrators, or methods): N/A
d. Detection limit: N/A
e. Analytical specificity:

Analytical Specificity: The analytical specificity was determined by testing 210 asymptomatic individuals' samples from endemic (Pennsylvania) and non-endemic (Arizona) regions. The Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test results are summarized in the following table.

Table 3: Analytical Specificity Study

|   | Number of Samples | Number Positive/Equivocal | Analytical Specificity  |
| --- | --- | --- | --- |
|  Endemic Region | 110 | 3 | 97.3%  |
|  Non-endemic Region | 100 | 2 | 98.0%  |

Cross Reactivity: A study using 221 samples was conducted to evaluate potential cross reactivity from different disease conditions. The samples were obtained from serum vendors who confirmed their positivity for each respective marker. The samples were tested on the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test. The results are summarized in the following table.

Table 4: Cross-Reactivity Study

|  Infection / Diagnosis | Number of Sera Tested | # Positive / (%)  |
| --- | --- | --- |
|  Tick-borne Relapsing Fever | 26 | 2 / (7.7%)  |
|  Treponemal Infections | 23 | 2* / (8.7%)  |
|  Rickettsia | 10 | 0 / (0%)  |
|  Ehrlichiosis | 10 | 0 / (0%)  |
|  Babesiosis | 11 | 0 / (0%)  |
|  Leptospirosis | 11 | 0 / (0%)  |
|  Parvovirus B19 | 12 | 0 / (0%)  |
|  Influenza A&B | 10 | 0 / (0%)  |
|  Epstein-Barr Virus | 10 | 0 / (0%)  |
|  Cytomegalovirus | 19 | 0 / (0%)  |
|  H. pylori | 11 | 0 / (0%)  |

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|  Fibromyalgia | 10 | 1/ (10%)  |
| --- | --- | --- |
|  Rheumatoid Arthritis | 11 | 0 / (0%)  |
|  Herpes Simplex Virus | 13 | 0 / (0%)  |
|  Varicella Zoster Virus | 12 | 0 / (0%)  |
|  Autoimmune Disease | 22 | 0 / (0%)  |

*Also positive on the predicate device

Interfering Substances: The effect of potential interfering substances on samples using the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test was evaluated. Three samples, a negative, a low positive, and a moderate positive were spiked with high levels of interferants and were tested along with serum without spiked interferants. The recommended concentrations from the guideline "Interference Testing in Clinical Chemistry EP7-A2" from the Clinical and Laboratory Standards Institute were used. The tested substances did not affect the performance of the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test.

Table 5: Interfering Substances Study

|  Substance | Concentration | Interference  |
| --- | --- | --- |
|  Albumin | 120 g/L | None detected  |
|  Bilirubin | 342 μmol/L | None detected  |
|  Cholesterol | 13 mmol/L | None detected  |
|  Hemoglobin | 2 g/L | None detected  |
|  Triglycerides | 37 mmol/L | None detected  |

f. Assay cut-off:

Determination of the Assay Cut-off: The cut-off was determined by testing a total of 200 normal sera which consisted of 100 sera from an endemic region of Lyme disease and 100 sera from a non-endemic region. The mean plus two standard deviations was used to determine the assay cut-off. After the cut-off was determined 125 characterized Lyme disease samples were tested. An ROC analysis was then generated with the 325 samples (200 normal and 125 characterized samples) to verify the chosen cut-off. The analysis confirmed that the assay cut-off provided an optimal level of sensitivity and specificity.

2. Comparison studies:

a. Method comparison with predicate device:

Comparison with Predicate Device: Comparison studies were conducted at three sites (one internal and two external reference laboratories) using prospective samples submitted for Lyme serology testing. Five hundred and twenty (520) serum samples were tested on both the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test and on the predicate B. burgdorferi IgG/IgM ELISA Test. The results are summarized in the following table.

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Table 6: Percent Agreement with Predicate Device

|   | Predicate IgG/IgM ELISA |   |   |   |   |
| --- | --- | --- | --- | --- | --- |
|   |   |  Positive | Equivocal* | Negative | Total  |
|  Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit | Positive | 55 | 7 | 2 | 64  |
|   |  Equivocal | 8 | 2 | 9 | 19  |
|   |  Negative | 2 | 1 | 434 | 437  |
|   | Total | 65 | 10 | 445 | 520  |

*Equivocal samples counted as positive

Positive percent agreement  $= 96.0\%$  (72/75)  $95\%$  CI  $(88.8\% - 99.2\%)$

Negative percent agreement  $= 97.5\%$  (434/445)  $95\%$  CI  $(95.6\% - 98.8\%)$

b. Matrix comparison: N/A

# 3. Clinical studies:

# a. Clinical Sensitivity:

Sensitivity Study: A sensitivity study was performed on 89 clinically characterized samples. The samples encompass early, disseminated, and late stages of Lyme disease. The samples were tested on both the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test and on the predicate B. burgdorferi IgG/IgM ELISA Test. The results are summarized in the following table.

Table 7: Case Confirmed Lyme Disease Samples

|  Disease Stage | n | Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit | Predicate IgG/IgM ELISA  |
| --- | --- | --- | --- |
|  Early | 38 | 76.3% (29/38) | 78.9% (30/38)  |
|  Disseminated | 15 | 100.0% (15/15) | 100.0% (15/15)  |
|  Late | 36 | 97.2% (35/36) | 94.4% (34/36)  |

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

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Table 8: Testing of CDC Lyme Disease Panel

|  Disease Stage | n | Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test Kit |   | Predicate IgG/IgM ELISA  |   |
| --- | --- | --- | --- | --- | --- |
|   |   |  Positive or Equivocal | % Agreement with Clinical Diagnosis | Positive or Equivocal | % Agreement with Clinical Diagnosis  |
|  Healthy | 5 | 0 | 100% | 0 | 100%  |
|  Early (0-2 months) | 15 | 13 | 86.7% | 12 | 80.0%  |
|  Convalescent (3-12 months) | 13 | 7 | 53.8% | 7 | 53.8%  |
|  Late (>1 year) | 7 | 7 | 100% | 7 | 100%  |

b. Clinical specificity: N/A
c. Other clinical supportive data (when a. and b. are not applicable): N/A

4. Clinical cut-off: N/A
5. Expected values/Reference range:

The range of values and positivity rate among different studies and populations for the Gold Standard Diagnostics Borrelia burgdorferi IgG/IgM ELISA Test are as follows.

Table 9: Expected Values

|  Population | #Samples | Unit Results |   |   | Qualitative Results  |   |
| --- | --- | --- | --- | --- | --- | --- |
|   |   |  Mean | Range | Std. Dev. | #Positive/ Equivocal | %Positive/ Equivocal  |
|  Normal Endemic | 110 | 5.8 | 06.- 11.3 | 2.075 | 3 | 2.7%  |
|  Normal Non-Endemic | 100 | 4.2 | 0.9- 12.3 | 2.077 | 2 | 2.0%  |
|  Prospective Study | 520 | 6.3 | 0.70-32.3 | 5.407 | 83 | 16.0%  |
|  Sensitivity Study | 89 | 25.0 | 3.6-34.9 | 8.449 | 79 | 88.8%  |

Note: It is recommended that each laboratory determine its own normal range based on the population.

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N. Proposed Labeling:

The labeling is sufficient and it satisfies the requirements of 21 CFR Parts 801 and 809, as applicable.

O. Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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**Source:** [https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/LSR/K180264](https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/LSR/K180264)

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