Vstrip H. pylori Antigen Rapid Test

K183573 · Panion & BF Biotech, Inc. · LYR · Mar 14, 2019 · Microbiology

Device Facts

• Record ID: K183573
• Device Name: Vstrip H. pylori Antigen Rapid Test
• Applicant: Panion & BF Biotech, Inc.
• Product Code: LYR · Microbiology
• Decision Date: Mar 14, 2019
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3110
• Device Class: Class 1
• Attributes: Pediatric

Indications for Use

Vstrip® H.pylori Antigen Rapid Test is a single use immunochromatographic assay for the qualitative detection of H. pylori antigen in unpreserved human stool specimens. Test results are intended to aid in the initial diagnosis and treatment of H. pylori infection. Test results should be taken into consideration by the physician in conjunction with the patient history and symptoms.

Device Story

Vstrip H. pylori Antigen Rapid Test is a qualitative immunochromatographic assay for detecting H. pylori antigens in human stool. Input: unpreserved stool specimen mixed with diluent buffer in a sample preparation tube. Operation: diluted sample flows through a pad containing red-colored antibody-coated latex particles; if antigen is present, antigen-antibody-latex complexes form and migrate via capillary action to a nitrocellulose membrane. Output: visual pink-red test line (positive) and blue control line (validity check) in a result window. Used in clinical settings by healthcare professionals. Results aid physicians in initial diagnosis of H. pylori infection when combined with patient history and symptoms. Benefits include rapid, point-of-care detection of infection.

Clinical Evidence

Prospective multi-site clinical study (n=333) compared Vstrip H. pylori Antigen Rapid Test to an FDA-cleared ELISA. Study population: 70% female, 30% male, ages 4-86. Results: Positive Percent Agreement (PPA) 96.7% (95% CI: 88.6%-99.1%); Negative Percent Agreement (NPA) 98.2% (95% CI: 95.8%-99.2%). No invalid results observed. Analytical performance included reproducibility (97.8%-100% agreement), LoD determination, and cross-reactivity/interference testing with various microorganisms and substances. No high-dose hook effect observed.

Technological Characteristics

Lateral flow immunochromatographic assay. Components: monoclonal anti-H. pylori antibody-coated latex beads, test cassette with nitrocellulose strip, sample diluent buffer. Qualitative visual readout. Storage: 15-30°C. No electronic components or software.

Indications for Use

Indicated for qualitative detection of H. pylori antigen in unpreserved human stool specimens to aid in initial diagnosis and treatment of H. pylori infection in patients suspected of infection.

Regulatory Classification

Identification

Campylobacter fetus serological reagents are devices that consist of antisera conjugated with a fluorescent dye used to identify Campylobacter fetus from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by this bacterium and provides epidemiological information on these diseases. Campylobacter fetus is a frequent cause of abortion in sheep and cattle and is sometimes responsible for endocarditis (inflammation of certain membranes of the heart) and enteritis (inflammation of the intestines) in humans.

Predicate Devices

• ImmunoCard STAT!® HpSA® (K032222)

Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE

A. 510(k) Number:
K183573

B. Purpose for Submission:
To obtain a substantial equivalence determination for the detection of *Helicobacter pylori* antigens in human stool

C. Measurand:
*H. pylori* antigen

D. Type of Test:
Qualitative immunochromatographic assay

E. Applicant:
Panion & BF Biotech Inc.

F. Proprietary and Established Names:
Vstrip H. pylori Antigen Rapid Test

G. Regulatory Information:
1. Regulation section:
21 CFR 866.3110 *Campylobacter fetus* serological reagents
2. Classification:
Class I
3. Product code:
LYR

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4. Panel:

83-Microbiology

H. Intended Use:

1. Intended use(s):

Vstrip H. pylori Antigen Rapid Test is a single use immunochromatographic assay for the qualitative detection of *H. pylori* antigen in unpreserved human stool specimens. Test results are intended to aid in the initial diagnosis and treatment of *H. pylori* infection. Test results should be taken into consideration by the physician in conjunction with the patient history and symptoms.

2. Indication(s) for use:

Same as Intended use

3. Special conditions for use statement(s):

For prescription use only

4. Special instrument requirements:

None

I. Device Description:

The Vstrip H. pylori Antigen Rapid Test is a qualitative immunochromatographic assay which employs antibody-coated latex beads to detect *Helicobacter pylori* (*H. pylori*) antigens in stool specimens from patients suspected of *H. pylori* infection. Each assay kit contains the materials needed for 20 tests, and includes the test cassettes, sample preparation tubes, positive control reagent, and the package insert and instructions. The test cassette houses the diagnostic strip which incorporates a pair of *H. pylori*-specific monoclonal antibodies for detecting *H. pylori* antigens in stool. Results are visualized in the test cassette “Result Window”. The sample preparation tube contains sample diluent buffer, and it incorporates a sampler tool attached to the underside of the tube cap and a dispenser tool attached to the top of the tube. The positive control reagent contains inactivated *H. pylori*.

J. Substantial Equivalence Information:

1. Predicate device name(s):

ImmunoCard STAT! HpSA

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2. Predicate 510(k) number(s):

K032222

3. Comparison with predicate:

| Similarities | | |
| --- | --- | --- |
| Item | Device: Vstrip H. pylori Antigen Rapid Test (K183573) | Predicate: ImmunoCard STAT! HpSA (K032222) |
| Intended use | Vstrip H. pylori Antigen Rapid Test is a single use immunochromatographic assay for the qualitative detection of H. pylori antigen in unpreserved human stool specimens. Test results are intended to aid in the initial diagnosis and treatment of H. pylori infection. Test results should be taken into consideration by the physician in conjunction with the patient history and symptoms. | ImmunoCard STAT! HpSA is a rapid in vitro qualitative assay for the detection of Helicobacter pylori antigen (HpSA) in human stool. The stool antigen detection is intended to aid in the diagnosis of H. pylori infection and to demonstrate loss of H. pylori stool antigen following treatment. Conventional medical practice recommends that testing by any method to confirm the loss of antigen be done at least four weeks following completion of therapy. |
| Technology | Immunochromatographic | Same |
| Type of test | Qualitative | Same |
| Result interpretation | Manual end point visualization of colored bands. | Same |
| Measurand | H. pylori antigen | Same |
| Controls | Internal Control Line Positive and negative controls included in kit | Same |
| Test line capture antibody | Monoclonal anti-H. pylori | Same |
| Conjugate | Red latex particle conjugated anti-H. pylori | Same |

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| Differences | | |
| --- | --- | --- |
| Item | Device: Vstrip H. pylori Antigen Rapid Test (K183573) | Predicate: ImmunoCard STAT! HpSA (K032222) |
| Time to read | 10 minutes | 5 minutes |
| Kit storage temperature | 15 – 30 °C | 2 - 8 °C |
| Specimen type | Formed stool, semi-solid stool only | Formed stool, semi-solid stool, and liquid stool |
| Use | Aid in initial diagnosis | Aid in initial diagnosis and monitor antigen loss after treatment |

## K. Standard/Guidance Document Referenced (if applicable):

Not applicable

## L. Test Principle:

To perform the test, a small portion of stool sample is diluted and mixed in the sample preparation tube, and the diluted sample is added to the test cassette. The sample flows through a labeled pad containing red-colored antibody-coated latex particles. If the sample contains *H. pylori* antigen, the antigen will bind to the antibody to form antigen-antibody-latex complexes which flow through the nitrocellulose membrane by capillary action. The complexes bind *H. pylori* specific antibodies at the test line position to form a pink-red line. A blue line at the control line position serves as an internal control to show that adequate flow of the sample has occurred, and that active components have been employed during a test run. For a positive result, a pink-red test line (next to the letter T) along with a blue control line (next to the letter C) must be visible in the “Result Window”. If *H. pylori* antigen is not present or is present at very low levels in the stool sample, only a blue control line will be visible, and the test result is negative. If the blue control line does not develop within 10 minutes, the test result is invalid.

## M. Performance Characteristics (if/when applicable):

### 1. Analytical performance:

#### a. Precision/Reproducibility:

A reproducibility study was conducted at three laboratory sites in the US. Three lots of the Vstrip H. pylori Antigen Rapid Test were used. Two trained operators per site tested a coded and randomized sample panel once per day over five days. The panels consisted of 12 frozen samples contrived from pooled negative stool matrix spiked with known amounts of cultured *H. pylori*, and a true negative sample. Positive samples at different levels included three replicates each of medium positive (4X

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LoD), low positive (1-2X LoD, near $C_{95}$ concentration expected to be positive approximately $95\%$ of the time), high negative (near $C_5$ concentration expected to be negative approximately $95\%$ of the time). In total 90 data points were collected for each panel member. Across all sites and operators, agreement with the expected result was $97.8\%$ (88/90) for the moderate positive panel member, $97.8\%$ (88/90) for the low positive panel member, $98.9\%$ (89/90) for the high negative panel member, and $100\%$ (90/90) for the true negative panel member. The reproducibility study results were acceptable.

b. Linearity/assay reportable range:

Not applicable

c. Traceability, Stability, Expected values (controls, calibrators, or methods):

Controls:

Internal controls. Each test strip contains a blue internal control line to confirm correct sample flow and active reagents for the test run. If the blue control line is not visible, the result is invalid and the test should be repeated. The background color of the strip should be white and should not interfere with the reading of the test result. If the background strip color interferes with line reading, it is recommended to repeat the test.

External controls. The kit instructions recommend that external positive and negative controls should be tested with each new kit shipment. One vial of positive control reagent is provided with each test kit, and the kit sample diluent buffer serves as the negative control. The positive and negative controls are intended to ensure that the kit is functional to produce the expected results. The kit should not be used if either external control fails to deliver the correct test results.

External positive and negative controls were run during clinical and reproducibility studies, and all controls passed.

Sample stability:

Studies were conducted to examine the stability of stool samples when stored refrigerated at $2 - 8^{\circ}\mathrm{C}$ or frozen at $-20^{\circ}\mathrm{C}$. Negative stool samples and contrived positive samples were stored either refrigerated or frozen/thawed and tested over time with the Vstrip H. pylori Antigen Rapid Test. The positive samples consisted of $H.$ pylori organisms spiked into negative stool matrix at moderate positive (5X LoD), low positive (1-2X LoD), and high negative (below 1X LoD) concentrations. The study results supported the recommendations that stool samples can be stored for up to seven days refrigerated at $2 - 8^{\circ}\mathrm{C}$, up to 20 days frozen at $-20^{\circ}\mathrm{C}$, and can undergo up to three freeze/thaw cycles.

d. Detection limit:

The limit of detection (LoD) was determined using negative stool matrix spiked with

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serial dilutions of two strains of cultured $H.$ pylori (ATCC 43504 and ATCC 51653). The initial LoD was established by two operators testing at least ten replicates of each dilution. The initial LoD concentrations were confirmed by testing an additional 20 replicates at the target concentration by two additional operators. The LoD was defined as the lowest concentration at which $95\%$ or more of the replicates were positive. An assay cutoff value was defined as the concentration that produced a $50\%$ positive rate. The LoD was determined to be $8 \times 10^{5}$ CFU/mL for $H.$ pylori strain ATCC 43504 and $4.5 \times 10^{4}$ CFU/mL for $H.$ pylori strain ATCC 51653.

# Analytical inclusivity (reactivity):

In addition to the $H.$ pylori strains assessed in the LoD study, analytical inclusivity of the Vstrip H. pylori Antigen Rapid Test was also demonstrated with three additional strains. All strains were detected $100\%$ of the time at the concentrations listed (Table 1).

Table 1. Inclusivity

| Strain | Origin | CFU/mL |
| --- | --- | --- |
| ATCC 700392 (BCRC 17219) | UK | 3.8 X 105 |
| ATCC 51110 (BCRC 17025) | N/A | 1.9 X 105 |
| Taiwan (BCRC 17132) | Taiwan | 3.8 X 106 |

# e. Analytical specificity:

# Cross reactivity:

The potential cross reactivity and microbial interference of the Vstrip H. pylori Antigen Rapid Test was assessed by testing high concentrations of non-target microorganisms in triplicate in the presence or absence of $H.$ pylori (2-3X LoD) in negative stool matrix (Table 2). The non-target microorganisms were spiked into the samples at $\geq 10^{6}$ CFU/mL for bacteria and at $\geq 10^{5}$ TCID $_{50}$ /mL for viruses. No false positive or false negative Vstrip H. pylori Antigen Rapid Test results were observed in the presence of the non-target microorganisms.

Table 2. Cross Reactivity Panel

| Microorganism | Source | Microorganism | Source |
| --- | --- | --- | --- |
| Aeromonas hydrophila | ATCC 43414 | Streptococcus Group A | ATCC 19615 |
| Bacillus sp. | ATCC 31006 | Streptococcus Group B | ATCC 12386 |
| Borrelia burgdorferi | ATCC 35210 | Streptococcus Group C | ATCC 12388 |
| Campylobacter jejuni | ATCC 33292 | Streptococcus Group F | ATCC 12392 |
| Candida albicans | ATCC 18804 | Streptococcus Group G | ATCC 43492 |
| Citrobacter freundii | ATCC 8090 | Streptococcus mutans | ATCC 25175 |
| Clostridium difficile | ATCC 43596 | Streptococcus pneumoniae | ATCC 6301 |
| Clostridium perfringens | ATCC 13124 | Streptococcus sanguis | ATCC 49295 |
| Enterobacter cloacae | ATCC 13047 | Vibrio cholerae | NCTC 8021 |
| Escherichia coli | ATCC 23815 | Yersinia enterocolitica | ATCC 23715 |
| Haemophilus influenzae | ATCC 9007 | Listeria innocua | ATCC 33091 |
| Klebsiella pneumoniae | ATCC 13883 | Salmonella hilversum | ATCC 15784 |
| Proteus vulgaris | ATCC 8427 | Salmonella paratyphi | ATCC 9281 |
| Pseudomonas aeruginosa | ATCC 31156 | Salmonella typhimurium | ATCC 13311 |
| Salmonella enteriditis 16 | ATCC 13076 | Adeno virus type 7 | Chang Gung University |

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| Microorganism | Source | Microorganism | Source |
| --- | --- | --- | --- |
| Salmonella typhi 17 | ATCC 6539 | Adeno virus type 41* | Chang Gung University |
| Serratia marcescens18 | ATCC 21074 | Coxsackie type B2 | Chang Gung University |
| Shigella boydii | ATCC 35966 | Coxsackie type B6 | Chang Gung University |
| Shigella dysenteriae | ATCC 13313 | Echovirus Type 11 | Chang Gung University |
| Shigella flexneri | ATCC 12022 | Rotavirus (VR-2104) | ATCCVR-2104 |
| Shigella sonnei | ATCC 25931 | Rotavirus (VR-2272) | ATCCVR-2272 |
| Staphylococcus aureus | ATCC 12715 | | |
| Staphylococcus epidermidis | ATCC 12228 | | |

* Tested at 1.0 x 10³ TCID₅₀/mL

## Interfering substances

An interfering substances study was conducted to assess the potential interference of exogenous and exogenous substances on the performance of the Vstrip H. pylori Antigen Rapid Test (Table 3). High concentrations of the substances were tested in negative stool matrix in the presence or absence of H. pylori spiked at two to three times the LoD. The samples were tested in triplicate. No false positive or false negative Vstrip H. pylori Antigen Rapid Test results were observed for the substances at the concentrations tested.

Table 3. Interfering Substances Panel

| Interfering substance | Concentration |
| --- | --- |
| Aspirin | 3 mg/mL |
| Barium Sulfate | 2 % (w/v) |
| Bilirubin | 0.25 mg/mL |
| Cimetidine | 5 mg/mL |
| Hemoglobin | 12.5 % (w/v) |
| Leukocytes | 50 % (v/v) |
| Metronidazole | 0.25 mg/mL |
| Mylanta | 5% (w/v) |
| Omeprazole | 5 mg/mL |
| Palmitic acid | 4 % (w/v) |
| Pepto-Bismol | 5% (v/v) |
| Stearic acid | 4 % (w/v) |
| Tums Antacid | 5mg/mL |
| Whole blood | 40 % (v/v) |
| Mucin | 3.4 % (w/v) |

## High-dose hook effect/prozone:

A high-dose hook effect (prozone) study was conducted to evaluate potential interference from high concentrations of H. pylori antigen on test performance. Cultures of five H. pylori strains were tested in triplicate at concentrations ranging from 10⁶ – 10⁷ CFU/mL (10 – 100X LoD). No false negative results suggestive of a high-dose hook effect were observed.

## f. Assay cut-off:

Not applicable

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# 2. Comparison studies:

# a. Method comparison with predicate device:

The performance of the Vstrip H. pylori Antigen Rapid Test was evaluated in a multi-site prospective clinical study. Three sites (one site in the US and two sites in Taiwan) used freshly collected, leftover stool samples from patients suspected of $H$ . pylori infection and tested the samples with the Vstrip H. pylori Antigen Rapid Test.

The Vstrip H. pylori Antigen Rapid Test results were compared to results from an FDA cleared $H.$ pylori stool antigen ELISA. Performance of the FDA cleared comparator ELISA was previously established in comparison to an endoscopy biopsy composite reference method (i.e., culture, histology, and RUT) for initial $H.$ pylori diagnosis with demonstrated sensitivity and specificity point estimates greater than or equal to $95\%$ , and a lower bound of the two-sided $95\%$ confidence intervals (CI) greater than $89\%$ for each. The performance of the Vstrip H. pylori Antigen Rapid Test was reported as positive percent agreement (PPA) and negative percent agreement (NPA) with the FDA cleared comparator ELISA results.

A total of 333 fresh stool samples were tested in the study (150 collected in the US and 183 collected in Taiwan). The study population was $70\%$ (232) female, $30\%$ (101) male, and the ages ranged from four to 86 years old (Table 4).

Table 4. Study Population Demographics

| Age | Sex | | |
| --- | --- | --- | --- |
| | F | M | Total |
| 4-18 | 13 | 6 | 19 |
| 19-60 | 153 | 60 | 213 |
| >60 | 63 | 34 | 97 |
| Unknown | 3 | 1 | 4 |
| Grand Total | 232 | 101 | 333 |

No invalid results were observed for the Vstrip H. pylori Antigen Rapid Test or the comparator ELISA.

The Vstrip H. pylori Antigen Rapid Test demonstrated a positive percent agreement of $96.7\%$ [58/60; $95\%$ CI $88.6\% - 99.1\%$ ] and a negative percent agreement of $98.2\%$ [268/273; $95\%$ CI $95.8\% - 99.2\%$ ] with the comparator ELISA (Table 5).

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Table 5. Clinical Study Performance

| | FDA-Cleared
H. pylori Antigen
ELISA | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| Vstrip H. pylori
Antigen Rapid
Test Result | Positive | 58 | 5 | 63 |
| | Negative | 2 | 268 | 270 |
| | Total | 60 | 273 | 333 |
| | | | 95% CI |
| --- | --- | --- | --- |
| PPA | 96.7% | (58/60) | 88.6% to 99.1% |
| NPA | 98.2% | (268/273) | 95.8% to 99.2% |

b. Matrix comparison:
Not applicable

3. Clinical studies:
a. Clinical Sensitivity:
Not applicable
b. Clinical specificity:
Not applicable
c. Other clinical supportive data (when a. and b. are not applicable):
Not applicable

4. Clinical cut-off:
Not applicable

5. Expected values/Reference range:
Not applicable

N. Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.

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O. Conclusion:

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

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