← Product Code [OKM](/submissions/IM/subpart-f%E2%80%94immunological-test-systems/OKM) · K081248

# QUANTA LITE OMP PLUS ELISA (K081248)

_Inova Diagnostics, Inc. · OKM · Oct 27, 2008 · Immunology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/IM/subpart-f%E2%80%94immunological-test-systems/OKM/K081248

## Device Facts

- **Applicant:** Inova Diagnostics, Inc.
- **Product Code:** [OKM](/submissions/IM/subpart-f%E2%80%94immunological-test-systems/OKM.md)
- **Decision Date:** Oct 27, 2008
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.5785
- **Device Class:** Class 2
- **Review Panel:** Immunology

## Indications for Use

The QUANTA Lite™ OMP Plus kit is an enzyme-linked immunosorbent assay (ELISA) for the semi-quantitative detection of anti-OMP antibodies of the IgA class in human serum. It is intended to be used in conjunction with anti-Saccharomyces cerevisiae (S. cerevisiae) antibody (ASCA) IgG and/or IgA test systems. The presence of OMP (outer membrane proteins) IgA antibodies, used in conjunction with clinical findings and other laboratory tests, may aid in the diagnosis of patients with Crohn's disease.

## Device Story

QUANTA Lite™ OMP Plus is an ELISA-based in vitro diagnostic test. It detects anti-outer membrane protein (OMP) IgA antibodies in human serum samples. The assay is performed in a clinical laboratory setting by trained personnel. The device transforms the presence of specific antibodies into a semi-quantitative optical density measurement via an enzyme-linked reaction. Results are interpreted by clinicians alongside ASCA IgG/IgA test results and clinical findings to support the diagnosis of Crohn's disease. The test provides diagnostic information to assist in patient management.

## Clinical Evidence

No clinical data provided in the document.

## Technological Characteristics

Enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA antibodies. Utilizes outer membrane protein (OMP) antigens. Standard laboratory plate-based format.

## Regulatory Identification

The Anti-Saccharomyces cerevisiae (S. cerevisiae ) antibody (ASCA) test system is an in vitro diagnostic device that consists of the reagents used to measure, by immunochemical techniques, antibodies to S. cerevisiae (baker's or brewer's yeast) in human serum or plasma. Detection of S. cerevisiae antibodies may aid in the diagnosis of Crohn's disease.

## Special Controls

*Classification.* Class II (special controls). The special control is FDA's “Guidance for Industry and FDA Reviewers: Class II Special Control Guidance Document for Anti-*Saccharomyces cerevisiae* (*S. cerevisiae* ) Antibody (ASCA) Premarket Notifications.”

## 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:
k081248

B. Purpose for Submission:
New Device

C. Measurand:
Anti-OMP IgA Antibodies

D. Type of Test:
Semi-quantitative ELISA

E. Applicant:
INOVA Diagnostics, Inc.

F. Proprietary and Established Names:
QUANTA Lite™ OMP Plus IgA ELISA

G. Regulatory Information:
1. Regulation section:
21 CFR 866.5785 - Anti-Saccharomyces cerevisiae (S. Cerevisiae) Antibody (ASCA) Test Systems.
2. Classification:
Class II
3. Product code:
OKM, Antibodies, outer-membrane proteins
4. Panel:
Immunology 82

H. Intended Use:
1. Intended use(s):
The QUANTA LiteTM OMP Plus kit is an enzyme-linked immunosorbent assay (ELISA) for the semi-quantitative detection of anti-OMP antibodies of the IgA class in human serum. It is intended to be used in conjunction with anti-Saccharomyces cerevisiae (S. cerevisiae) antibody (ASCA) IgG and/or IgA test systems. The presence of OMP (outer membrane proteins) IgA antibodies, used in conjunction with clinical findings and other laboratory tests, may aid in the diagnosis of patients with Crohn's disease.
2. Indication(s) for use:
Same as Intended Use.
3. Special conditions for use statement(s):
Prescription use only.
4. Special instrument requirements:
Microplate reader capable of measuring OD at 450 nm (or 620 for dual wavelength readings)

I. Device Description:
QUANTA Lite™ OMP Plus ELISA consists of a polystyrene microwell ELISA plate coated with a proprietary lysate of outer membrane and associated proteins derived from 2 strains of anaerobic bacteria; high positive, low positive, and negative controls; sample diluent; wash concentrate; goat anti-human IgG horseradish peroxidase

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conjugate; TMB chromogen; and stop solution.

# J. Substantial Equivalence Information:

1. Predicate device name(s): QUANTA Lite™ ASCA IgG ELISA
2. Predicate K number(s): k000732
3. Comparison with predicate:

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Indication for Use | To aid in the diagnosis of patients with Crohn's disease. | Same  |
|  Technology | ELISA | Same  |
|  Assay Format | Semi-quantitative | Same  |
|  Platform | 96 well microtiter plates | Same  |
|  ELISA Negative control | Pre-diluted human serum, Ready to use | Same  |
|  Sample type and dilution | Serum, 1:101 | Same  |
|  Sample volume | 5 uL | Same  |
|  Enzyme conjugate | Horseradish peroxidase, goat anti-human IgG | Same  |
|  Substrate | TMB Chromogen | Same  |
|  Incubation times | 30-30-30 minutes | Same  |
|  O.D. Reading | 450 nm (or 620 for dual wavelength readings) | Same  |
|  Result Interpretation | <20 units = negative 20-24.9 units = equivocal ≥ 25 units = positive | Same  |
|  Cut-off | 25 | Same  |
|  Differences  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Intended Use | Semi-quantitative detection of anti-OMP (outer membrane proteins) antibodies of the IgA class in human serum. To be used in conjunction with ASCA (IgG and IgA). | Semi-quantitative detection of anti-Saccharomyces cerevisiae antibodies (ASCA) of the IgG class in human serum.  |
|  Antigen | Partially purified lysate of outer membrane and associated proteins from two different species of intestinal bacteria | Partially purified and disrupted S.cerevisiae antigen  |
|  High Positive and Low Positive Controls | OMP Plus IgA ELISA High and Low positive controls. Pre-diluted. Ready to use | ASCA IgG ELISA High and Low positive controls. Pre-diluted. Ready to use  |

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

Not referenced.

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L. Test Principle:

A proprietary lysate of partially purified outer membrane and associated proteins derived from 2 species of anaerobic bacteria are bound to the wells of a polystyrene microwell plate under conditions that will preserve the antigen in its native state. Pre-diluted controls and diluted patient sera are added to separate wells, allowing any OMP antibodies present to bind to the immobilized antigen. Unbound sample is washed away and an enzyme labeled anti-human IgA conjugate is added to each well. A second incubation allows the enzyme labeled anti-human IgA to bind to any patient antibodies, which have become attached to the microwells. After washing away any unbound enzyme labeled anti-human IgA, the remaining enzyme activity is measured by adding a chromogenic substrate and measuring the intensity of the color that develops. The assay can be evaluated spectrophotometrically by measuring and comparing the color intensity that develops in the patient wells with the color in the control wells.

M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

Intra-assay studies: Eight samples (3 specimens with moderate OMP antibody levels (46.2, 45.5, 41.8 units, respectively), 2 specimens just over the cut-off (26.9, 26.3 units, respectively), and 3 equivocal samples (21.8, 23.9, 24.5 units, respectively)) were assayed in 10 replicates each. Results showed acceptable %CV ranging from 2.1 to 6.4.

Intra-assay Performance of QUANTA Lite™ OMP Plus ELISA

|   | Specimen  |   |   |   |   |   |   |   |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   |  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8  |
|  Mean units | 46.2 | 26.9 | 45.5 | 26.3 | 41.8 | 24.5 | 23.9 | 21.8  |
|  SD | 1.17 | 0.78 | 2.91 | 0.72 | 0.93 | 0.86 | 0.83 | 0.46  |
|  CV % | 2.5 | 2.9 | 6.4 | 2.8 | 2.2 | 3.5 | 3.5 | 2.1  |

Inter-assay: Nine specimens (2 equivocal, 3 low positive, and 3 moderate positive) plus the high positive control were tested in duplicate twice daily for 3 days. The results showed acceptable %CV ranging from 1.1 to 4.3.

Inter-assay Performance for QUANTA Lite™ OMP Plus ELISA

|   | Specimen  |   |   |   |   |   |   |   |   |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   |  HPC | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8  |
|  Mean units | 69.8 | 50.0 | 26.6 | 54.1 | 29.2 | 46.2 | 27.3 | 24.7 | 23.5  |
|  SD | 2.35 | 0.74 | 0.89 | 2.23 | 1.07 | 1.63 | 1.14 | 1.07 | 0.89  |
|  CV % | 3.4 | 1.1 | 3.4 | 4.1 | 3.7 | 3.5 | 4.2 | 4.3 | 3.8  |

b. Linearity/assay reportable range:

No claims were made regarding linearity for the assay. Reactivity is related to the quantity of antibody present in a non-linear fashion.

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

There is no reference standard for OMP Antibodies. The results are reported in arbitrary units

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d. Detection limit:

Not applicable.

e. Analytical specificity:

Interference:

Interference by endogenous substances: No data provided. The package insert states that grossly hemolyzed, icteric, microbially contaminated, or heat-treated samples should be avoided in this assay.

Cross-reactivity with other autoantibodies:

Sera from 36 patients with various autoimmune or infectious disease and positive for associated antibodies including 8 rheumatoid arthritis, 2 soluble liver antigen (SLA), 2 liver kidney microsome (LKM), 2 chromatin, 2 Jo-1, 2 centromere, 1 SS-A, 2 SS-B, 2 anti-mitochondrial antibody (AMA), 2 tissue transglutaminase (tTG), 1 Scl-10, 1 RNP, 3 glomerular basement membrane (GBM), 2 cytomegalovirus (CMV), 2 rubella virus, 2 herpes simplex virus (HSV), were tested with the QUANTA Lite™ OMP Plus ELISA to assess the assay's specificity. No specimens were interpreted as positive and only one sample (an autoimmune hepatitis patient positive for SLA) was interpreted as equivocal at 22.2 units on the OMP Plus ELISA. Additional testing showed the specimen was moderately positive for ASCA IgG (76.1 units) and had an equivocal level of ASCA IgA antibodies. Sera from 226 patients with celiac disease were tested with the OMP Plus IgA ELISA and  $27\%$  were found positive. On the same cohort,  $27\%$  were positive for ASCA IgA and  $31\%$  for ASCA IgG antibodies. 14  $(6.2\%)$  of the celiac patients were triple positive (OMP Plus IgA, ASCA IgG, and ASCA IgA).

f. Assay cut-off:

To validate the cut-off, a panel of 500 apparently healthy individuals from the US (250 male and 250 female) with a median age of 41 years (range 18-80 years old) were tested. The median value obtained was 12.5 units. The cutoff was set at 25 units. This resulted in a specificity of  $92\%$  (468/500).

2. Comparison studies:

a. Method comparison with predicate device:

A panel of 1186 sera consisting of 365 specimens from patients with Crohn's disease (CD) and 821 patients from patients without Crohn's disease including specimens from 234 patients with ulcerative colitis (UC) and 587 healthy controls were tested with both the QUANTA Lite™ OMP Plus ELISA and the predicate QUANTA Lite™ ASCA IgG ELISA. Demographic information for the patient population was not available. The CD, UC and normal samples for the clinical method comparison were of European and Canadian origin.

|   | QUANTA Lite™ ASCA IgG ELISA  |   |   |   |   |
| --- | --- | --- | --- | --- | --- |
|   |   |  Pos | Eq* | Neg | Total  |
|  QUANTA Lite™ OMP Plus ELISA | Pos | 117 | 13 | 70 | 200  |
|   |  Eq* | 34 | 14 | 52 | 100  |
|   |  Neg | 167 | 45 | 674 | 886  |
|   |  Total | 318 | 72 | 796 | 1186  |

*Equivocal results counted as negative (not-positive).

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Positive percent agreement: 36.8% (117/318)

Negative percent agreement: 90.4% (674+14+45+52/868 = 785/868)

Overall Agreement 76.1% (117+785/1186)

b. Matrix comparison:

Both assays use serum as the matrix.

3. Clinical studies:

a. Clinical Sensitivity and Specificity:

The study consisted of the following: CD (365), UC (234), and Healthy Normal (587) for a total of 1186 samples.

Differentiation of Crohn's Disease from non-Crohn's Disease (ulcerative colitis and normal controls) Specimens

|  N=1186 |   | Crohn's Disease | Non-Crohn's Disease | Total  |
| --- | --- | --- | --- | --- |
|  Quanta Lite OMP Plus ELISA | Pos | 137 | 63 | 200  |
|   |  Neg | 228 | 758 | 986  |
|   |  Total | 365 | 821 | 1186  |

Equivocal results counted as negative (i.e. not positive)

Clinical Sensitivity: 37.5% (137/365) (95% CI, 0.325 to 0.427)

Clinical Specificity: 92.3% (758/821) (95% CI, 0.903 to 0.941)

Differentiation of Crohn's Disease from Ulcerative Colitis Specimens

|  N =599 |  | Crohn's Disease | Ulcerative Colitis | Total  |
| --- | --- | --- | --- | --- |
|  Quanta Lite OMP Plus ELISA | Pos | 137 | 26 | 163  |
|   |  Neg | 228 | 208 | 436  |
|   |  Total | 365 | 234 | 599  |

Equivocal results counted as negative (i.e. not positive)

Clinical Sensitivity: 37.5% (137/365) (95% CI, 0.325 to 0.427)

Clinical Specificity: 88.9% (208/234) (95% CI, 0.841 to 0.926)

The OMP Plus assay is intended as a supplemental assay to ASCA IgG and ASCA IgA. The clinical sensitivities of the new device and the predicate device were tested with both the Quanta Lite™ OMP Plus ELISA and both the Quanta Lite™ ASCA IgG and ASCA IgA ELISA kits.

The simultaneous presence of ASCA IgG, ASCA IgA, and OMP Plus antibodies (triple positive) may prove to be of value for clinical assessment. As shown in the table below, when the whole 510(k) cohort was examined, the presence of at least one of the three markers (ASCA IgG, ASCA IgA, or OMP Plus) resulted in a specificity of 79.4% (652/821), the presence of at least 2 markers resulted in a specificity of 96.3% (791/821), and the presence of all three markers had a

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specificity of  $99.5\%$  (817/821). The increasing specificity of the marker combination assessment results in decreasing sensitivity. It may however, aid in ruling-in or ruling-out some specimens. For example of the total of 97 triple positive specimens, 93/97  $(95.9\%)$  were CD patients. The other 4 consisted of 3 UC and 1 "normal" healthy donor.

|  At least 1 marker Positive |   | At least 2 markers positive |   | 3 markers positive  |   |
| --- | --- | --- | --- | --- | --- |
|  Sensitivity | Specificity | Sensitivity | Specificity | Sensitivity | Specificity  |
|  72.1% (263/365) | 79.2% (652/821) | 46% (168/365) | 96.3% (791/365) | 25.5% (93/365) | 99.5% (817/821)  |

A comparison between the OMP Plus, ASCA IgG, and ASCA IgA demonstrated the added value of the OMP assay results to the results obtained from CD and the ASCA IgG and ASCA IgA is shown in the venn diagrams below.

Fig. 1: Sensitivity of ASCA IgG, ASCA IgA, and OMP for CD, non-CD (and healthy normal), and UC patients.
Crohn's Patients - Whole Cohort
![img-0.jpeg](img-0.jpeg)
Note: Equivocal results counted as neg (i.e not positive)

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# Non-Crohn's Patients

![img-1.jpeg](img-1.jpeg)
Non-Crohn's Patients

- ASCA G and/or ASCA IgA pos= 123; Specificity =85%
- Omp Plus additional 46+ pos (5.6%)
- 1 or more ASCA G,ASCA A, Omp Plus = 20.5% (169/821) Specificity = 79.4% (652/821)
- 2 or more pos Specificity = 96.3% (30/821)
- Triple Pos = 4/821 Specificity = 99.5% (4/821)

Note: Equivocal results counted as neg (i.e not positive)

# Ulcerative Colitis Patients (510K)

![img-2.jpeg](img-2.jpeg)
UC Patients

- ASCA G and/or ASCA IgA pos= 40; specificity = 82.9%
- Omp Plus additional 26+ pos (11.1%)
- 1 or more ASCA G,ASCA A, Omp Plus = 57 (20.5%) Specificity = 75.6% (177/234)
- 2 or more pos =11 Specificity = 95.3% (223/234)
- Triple Pos = 3 Specificity = 98.7% (231/234)

Note: Equivocal results counted as neg (i.e not positive)

4. Clinical cut-off:
See assay cut-off

5. Expected values/Reference range:
The expected value in the normal population is negative, however the performance of the assay has not been assessed in patients with Irritable Bowel Syndrome (IBS). The median value obtained from the 500 healthy normal individuals (see assay cutoff) was 12.5 units.

N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

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/IM/subpart-f%E2%80%94immunological-test-systems/OKM/K081248](https://fda.innolitics.com/submissions/IM/subpart-f%E2%80%94immunological-test-systems/OKM/K081248)

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