AESKULISA ASCA A
Device Facts
| Record ID | K051492 |
|---|---|
| Device Name | AESKULISA ASCA A |
| Applicant | Aesku, Inc. |
| Product Code | NBT · Immunology |
| Decision Date | Nov 14, 2005 |
| Decision | SESE |
| Submission Type | Traditional |
| Regulation | 21 CFR 866.5785 |
| Device Class | Class 2 |
Indications for Use
The AESKULISA® ASCA-A is a solid phase enzyme immunoassay (ELISA) employing purified mannan for the semi-quantitative and qualitative detection of IgA anti-Saccharomyces cerevisiae antibodies (ASCA) in human serum. ASCA recognize specifically mannan, a component of the outer cell wall of yeast. The assay is an aid in the diagnosis of Crohn's disease and should be used in conjunction with other serological tests and clinical findings. The AESKULISA® ASCA-A kit should not be used as a screening test for ASCA, since some Crohn's disease patients do not have ASCA IgA antibodies. The AESKULISA® ASCA-A kit should be used to compliment, but not to replace or to substitute for ASCA IgG antibody testing. The AESKULISA® ASCA-G is a solid phase enzyme immunoassay (ELISA) employing purified mannan for the semi-quantitative and qualitative detection of IgA anti-Saccharomyces cerevisiae antibodies (ASCA) in human serum. ASCA recognize specifically mannan, a component of the outer cell wall of yeast. The assay is an aid in the diagnosis of Crohn's disease and should be used in conjunction with other serological tests and clinical findings.
Device Story
AESKULISA ASCA-A and ASCA-G are solid-phase enzyme immunoassays (ELISA) for detecting IgA and IgG antibodies against Saccharomyces cerevisiae mannan in human serum. The device utilizes purified mannan antigen to capture specific antibodies from patient serum samples. Following incubation and washing, bound antibodies are detected via an enzymatic reaction, producing a colorimetric signal proportional to the antibody concentration. The assay is intended for professional use in clinical laboratory settings. Results are interpreted by healthcare providers alongside clinical symptoms and other diagnostic tests to aid in the diagnosis of Crohn's disease. The device provides semi-quantitative and qualitative results to assist in clinical decision-making.
Clinical Evidence
No clinical data provided in the document.
Technological Characteristics
Solid-phase enzyme immunoassay (ELISA) utilizing purified mannan antigen. Detects IgA and IgG antibodies in human serum. Semi-quantitative and qualitative output. In vitro diagnostic device.
Indications for Use
Indicated for the semi-quantitative and qualitative detection of IgA and IgG anti-Saccharomyces cerevisiae antibodies (ASCA) in human serum as an aid in the diagnosis of Crohn's disease. Used in conjunction with other serological tests and clinical findings.
Regulatory Classification
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)
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
A. 510(k) Number:
k051492
B. Purpose for Submission:
New Device
C. Measurand:
Anti-Saccharomyces cerevisiae antibodies (ASCA), IgA and IgG
D. Type of Test:
Solid phase ELISA
E. Applicant:
AESKU Diagnostics
F. Proprietary and Established Names:
AESKULISA® ASCA-A, REF 7507, REF 30-7507
AESKULISA® ASCA-G REF 7508, REF 30-7508
G. Regulatory Information:
1. Regulation section:
21 CFR 866.5785
2. Classification:
Class II
3. Product code:
NBT, Anti-Saccharomyces cerevisiae (S. cerevisiae) antibody (ASCA) test systems.
4. Panel:
Immunology 82
H. Intended Use:
1. Intended use(s):
The AESKULISA® ASCA-A is a solid phase enzyme immunoassay (ELISA) employing purified mannan for the semi-quantitative and qualitative detection of IgA anti-Saccharomyces cerevisiae antibodies (ASCA) in human serum. ASCA recognize specifically mannan, a component of the outer cell wall of yeast. The assay is an aid in the diagnosis of Crohn's disease and should be used in conjunction with other serological tests and clinical findings. The AESKULISA® ASCA-A kit should not be used as a screening test for ASCA, since some Crohn's disease patients do not have ASCA IgA antibodies. The AESKULISA® ASCA-A kit should be used to compliment, but not to replace or to substitute for ASCA IgG antibody testing.
The AESKULISA® ASCA-G is a solid phase enzyme immunoassay (ELISA) employing purified mannan for the semi-quantitative and qualitative detection of IgA anti-Saccharomyces cerevisiae antibodies (ASCA) in human serum. ASCA recognize specifically mannan, a component of the outer cell wall of yeast. The assay is an aid in the diagnosis of Crohn's disease and should be used in conjunction with other serological tests and clinical findings.
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2. Indication(s) for use:
Same as Intended Use.
3. Special conditions for use statement(s):
For prescription use only.
4. Special instrument requirements:
Microplate reader capable of measuring OD 450 nm.
I. Device Description:
The AESKULISA® ASCA-A and AESKULISA® ASCA-G assays each consist of a microplate coated with S. cerevisiae purified mannan antigen, positive, negative and cut-off control materials, 6 calibrators, peroxidase-conjugated goat anti-human immunoglobulins (IgA or IgG, respectively), enzyme (TMB) substrate, stop solution, wash and sample buffers, frame and instructions for use.
J. Substantial Equivalence Information:
1. Predicate device name(s):
INOVA QUANTA Lite ASCA (S. cerevisiae) IgA and
INOVA QUANTA Lite ASCA (S. cerevisiae) IgG
2. Predicate 510(k) number(s):
k000733 and k000732
3. Comparison with predicate:
| Similarities | | |
| --- | --- | --- |
| Item | New Device | Predicate Device |
| Intended use & Indications for Use | Aid in the diagnosis of Crohn’s disease | same |
| Technology | Indirect, non-competitive ELISA | same |
| Antigen | purified mannan | same |
| Controls | Positive, negative and cut-off controls, calibrators | High and Low Positive, negative and cut-off controls |
| Differences | | |
| --- | --- | --- |
| Item | New Device | Predicate Device |
| Calibrators | 6 levels (0, 3, 10, 30, 100, and 300 U/mL) | 2 levels (High positive and Low positive) |
| Incubation times | 30-15-15-5; 30-30-30-5 (min) | 30-30-30 (min) |
| Read time | within 30 min of stopping reaction | within 1 hr of stopping reaction |
| Cut-off | 15 U/mL | 20 U/mL |
| Equivocal range | none | 20.1-24.9 U/mL |
| Assay Format | Semi-quantitative and Qualitative | Semi-quantitative only |
K. Standard/Guidance Document Referenced (if applicable):
Class II Special Control Guidance Document for Anti-Saccharomyces cerevisiae antibody (ASCA) Premarket Notifications.
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L. Test Principle:
The AESKULISA® ASCA-A and G kits are both solid phase enzyme immunoassays for the semi-quantitative and qualitative detection of IgA and IgG antibodies, respectively, against anti-S. cerevisiae antibodies (ASCA) in human serum. The wells of the microplate are coated with purified mannan, a component of the outer cell wall of yeast, which ASCA recognizes. Antibodies specific to ASCA present in the patient sera bind to the antigen. In a second step, the enzyme-labeled secondary antibody (conjugate) of specific isotype (IgA or IgG, respectively), bind to the antigen-antibody-antigen complex. The enzyme-labeled antigen-antibody complex converts the added substrate to form a colored solution. The rate of color formation from the chromogen is a function of the amount of conjugate complexed with the bound antibody and is proportional to the initial concentration fo the respective antibodies in the patient serum. The results are read spectrophotometrically and are interpreted by comparison to a cut-off calibrator (qualitative) or a standard curve (semi-quantitative).
M. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility:
For each kit (ASCA-A and ASCA-G), three samples (high, medium, and "near the cut-off"/low) were assayed 18 times on three different microplates on different days for the inter-assay study. The same samples were assayed 24 times on a microplate for the intra-assay variation study. Both studies were performed using the 30-15-15 kits. The acceptance %CV criteria for both the inter- and intra-assay studies were set at ≤ 10%.
| | Inter-assay Precision | | |
| --- | --- | --- | --- |
| ASCA-A | Sample 1 | Sample 2 | Sample 3 |
| CV (%) | 5.56 | 5.05 | 2.88 |
| Mean (U/mL) | 18.18 | 52.45 | 112.56 |
| ASCA-G | | | |
| CV (%) | 7.94 | 5.97 | 2.89 |
| Mean (U/mL) | 15.5 | 36.1 | 69.82 |
| | Intra-assay Precision | | |
| --- | --- | --- | --- |
| ASCA-A | Sample 1 | Sample 2 | Sample 3 |
| CV (%) | 4.44 | 4.35 | 3.42 |
| Mean (U/mL) | 19.03 | 48.45 | 115.47 |
| ASCA-G | | | |
| CV (%) | 3.94 | 9.15 | 3.12 |
| Mean (U/mL) | 16.41 | 33.5 | 74.12 |
b. Linearity/assay reportable range:
i. Study design: Two samples known to contain different levels of Anti-ASCA IgA and another two samples known to contain different levels of Anti-ASCA IgG were chosen and serially diluted to determine the linearity of the assay. From an initial dilution of 1/100, further dilutions
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of 1:200, 1:400 and 1:800 were made, providing a (calculated) range of 15.6-125 U/mL and 36.9-295 U/mL for ASCA-A and 38.2-305.4 U/mL and 13.3-106 U/mL for ASCA-G.
ii. Results/Acceptance criteria: The Anti-ASCA A assay had a recovery range of 91.3% to 106.9%. The Anti-ASCA G had a recovery range of 90.1% to 108.1%. Based on this study, the dynamic range of the assay is 1 to 300 U/mL.
c. Traceability, Stability, Expected values (controls, calibrators, or methods): There is no reference standard available. The standards are prepared in-house and values are assigned during the development process. Positive and negative controls are prepared in-house.
d. Detection limit:
The sample diluent was diluted according to the directions for use and measured 40 times for each assay. The value for the analytical sensitivity (detection limit) was calculated as the mean of the optical densities of the sample diluent. The analytical sensitivity was 1.0 U/mL.
e. Analytical specificity:
i. Interference by endogenous substances: No data provided. The package inserts states not to use icteric, lipemic, hemolysed or bacterially contaminated samples in the assays and sera with particles should be cleared first by low speed centrifugation.
ii. Cross-reactivity to other autoantibodies: The ASCA-A and ASCA-G assays were tested with sera from patients with other autoimmune diseases.
1. ASCA-A: Two hundred sixty-four samples were tested with the 30-15-15 ASCA-A kit for the presence of ASCA. Sixteen subjects, with diseases other than Crohn's Disease, demonstrated the presence of ASCA.
| Diseases | # subjects | # Pos | # Neg |
| --- | --- | --- | --- |
| Crohn’s Disease | 100 | 59 | 41 |
| Ulcerative colitis | 55 | 9 | 46 |
| Healthy | 50 | 0 | 50 |
| Celiac Disease | 30 | 2 | 28 |
| Systemic Lupus erythematosus | 10 | 2 | 8 |
| Wegener’s granulomatosis | 2 | 0 | 2 |
| Sjogren’s Syndrome | 4 | 2 | 2 |
| Reactive arthritis | 11 | 1 | 10 |
| Mixed connective tissue disease | 1 | 0 | 1 |
| Chronic arthritis | 1 | 0 | 1 |
| Total # tested | 264 | 75 | 189 |
2. ASCA-G: Two hundred seventy-one samples were tested with the 30-15-15 ASCA-G kit for the presence of ASCA. Twenty-one subjects, with diseases other than Crohn’s Disease, demonstrated the presence of ASCA, including three healthy
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donors.
| Diseases | # subjects | # Pos | # Neg |
| --- | --- | --- | --- |
| Crohn’s Disease | 103 | 81 | 22 |
| Ulcerative colitis | 59 | 9 | 50 |
| Healthy | 50 | 3 | 47 |
| Celiac Disease | 30 | 5 | 25 |
| Systemic Lupus erythematosus | 10 | 1 | 9 |
| Wegener’s granulomatosis | 2 | 0 | 2 |
| Sjögren’s Syndrome | 4 | 2 | 2 |
| Reactive arthritis | 11 | 1 | 10 |
| Mixed connective tissue disease | 1 | 0 | 1 |
| Chronic arthritis | 1 | 0 | 1 |
| Total # tested | 271 | 102 | 169 |
f. Assay cut-off:
The cut-off value of 15 U/mL for the ASCA-A and ASCA-G devices was based on the testing of 77 healthy donor samples. Of the 77 donor subjects, 98.7% and 97.4% were negative for the ASCA-A and ASCA-G assays respectively. The results are depicted in the two graphs below. The ASCA-A graph, shows 76 of 77 subjects had results equal to or below 9 U/mL, where the ASCA-G graph shows 75 of 77 subjects had results equal to or below 12 U/mL. The three subjects above the cut-off demonstrated results of 39 (ASCA-A), and 17 and 22 U/mL (ASCA-G).
Healthy donors ASCA-A
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# Healthy donors ASCA-G
## 2. Comparison studies:
a. Method comparison with predicate device: The AESKULISA® ASCA-A and ASCA-G kits were compared with their respective predicate devices using sera obtained from patients having various autoimmune diseases. The percentage of cases from male donors was 43.2% and from female donors, 56.8%. In addition, 18.5% of the sera were from donors younger than 26 years, 55.7% were between 26-44 years, and 25.8% were older than 45 years of age. The samples were tested using the 30-15-15 assay protocols and analysis was performed according to the instructions for use.
i. ASCA-A assay – Testing was performed on 264 samples including 100 confirmed Crohn’s Disease (CD); 55 Ulcerative colitis (UC); 50 Healthy; 30 Celiac Disease; 10 Systemic Lupus Erythematosus (SLE); 2 Wegener’s granulomatosis (WG); 4 Sjögren’s syndrome (SS); 11 reactive arthritis, 1 mixed connective tissue disease (MCTD) and 1 chronic arthritis. Seven cases (3 CD and 4 UC) cases were assayed on the QUANTA Lite IgA predicate but not on the AESKULISA ASCA-A device; therefore they were not included in the comparison.
ASCA-A Comparison data:
| | Quanta Lite IgA predicate | | Total | |
| --- | --- | --- | --- | --- |
| | | (+) | | (-) |
| AESKULISA | (+) | 74 | 1 | 75 |
| ASCA-A | (-) | 0 | 189 | 189 |
| Total | | 74 | 190 | 264 |
Positive percent agreement: 100% (74/74)
Negative percent agreement: 99.5% (189/190)
Overall agreement: 99.6% (263/264)
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ii. ASCA-G assay – Testing was performed on 271 samples including 103 confirmed CD; 59 UC; 50 Healthy; 30 Celiac Disease; 10 SLE; 2 WG; 4 SS; 11 reactive arthritis, 1 MCTD and 1 chronic arthritis.
ASCA-G Comparison data:
| | Quanta Lite IgG predicate | | Total | |
| --- | --- | --- | --- | --- |
| | | (+) | | (-) |
| AESKULISA | (+) | 84 | 18 | 102 |
| ASCA-G | (-) | 0 | 169 | 169 |
| Total | | 84 | 187 | 271 |
| Positive percent agreement: | | | 100% (84/84) | |
| Negative percent agreement | | | 90.4% (169/187) | |
| Overall agreement: | | | 93.3% (253/271) | |
iii. Protocol comparison studies: The comparability of the two ASCA-A assays were assessed with 78 sera tested on both REF 7507 (30-15-15 minute protocol) and REF 30-7507 (30-30-30 minute protocol). The linear regression analysis is depicted in the large figure below with $r^2 = 0.99$ . The upper left small figure shows selected results close to the 15 U/ml cut-off ( $r^2 = 0.92$ ).
The comparability of the two ASCA-G assays were assessed with 85 sera tested on both REF 7508 (30-15-15 minute protocol) and REF 30-7508 (30-30-30 minute protocol). The linear regression analysis is depicted in the large figure below with $r^2 = 0.99$ . The upper left small figure shows selected results close to the $15\mathrm{U / mL}$ cut-off ( $r^2 = 0.95$ ).
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b. Matrix comparison:
Both assays use serum as the matrix.
# 3. Clinical studies:
a. Clinical Sensitivity and specificity:
The tables below show the same samples mentioned in the above comparison data, but the results are according to the diagnosis.
Sera with Diagnosis with the AESKULISA® ASCA-A kit
| | Diagnosis | | Total | |
| --- | --- | --- | --- | --- |
| | | (+) | | (-) |
| AESKULISA | (+) | 59 | 16 | 75 |
| ASCA-A | (-) | 41 | 148 | 189 |
| Total | | 100 | 164 | 264 |
Clinical sensitivity: $59\%$ (59/100)
Clinical specificity: $90.2\%$ (148/164)
Sera with Diagnosis with the AESKULISA® ASCA-G kit
| | Diagnosis | | Total | |
| --- | --- | --- | --- | --- |
| | | (+) | | (-) |
| AESKULISA | (+) | 81 | 21 | 102 |
| ASCA-G | (-) | 22 | 147 | 169 |
| Total | | 103 | 168 | 271 |
Clinical sensitivity: $78.6\%$ (81/103)
Clinical specificity: $87.5\%$ (147/168)
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4. Clinical cut-off:
See assay cut-off.
5. Expected values/Reference range:
Expected value in the normal population is negative. However, the sponsor cited literature where 7% of the normal population tested was positive for ASCA.
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 the substantial equivalence decision.
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