ASCA-CHEK

K071711 · Techlab Inc., Corporate Research Center · NBT · Nov 7, 2007 · Immunology

Device Facts

• Record ID: K071711
• Device Name: ASCA-CHEK
• Applicant: Techlab Inc., Corporate Research Center
• Product Code: NBT · Immunology
• Decision Date: Nov 7, 2007
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.5785
• Device Class: Class 2
• Attributes: Pediatric

Indications for Use

The ASCA-CHEK test is an enzyme-linked immunosorbent assay (ELISA) for the qualitative detection of human anti-S. cerevisiae antibodies (ASCA) in feces and serum. The test result is used as an aid in the diagnosis of Crohn’s disease in combination with clinical and other laboratory findings. FOR IN VITRO DIAGNOSTIC USE.

Device Story

ASCA-CHEK is an ELISA-based in vitro diagnostic test for qualitative detection of human anti-Saccharomyces cerevisiae antibodies (ASCA) in serum and feces. Device utilizes microplate strips coated with S. cerevisiae antigens. Patient samples are emulsified in diluent, transferred to wells, and incubated; ASCA present in sample binds to immobilized antigens. After washing, HRP-conjugated goat anti-human polyclonal immunoglobulin is added, followed by TMB substrate. Color development is measured spectrophotometrically at 450 nm or 450/620 nm. Performed in clinical laboratories by trained technicians. Results are interpreted against a defined OD cut-off (≥0.110 at 450 nm or ≥0.080 at 450/620 nm). Output assists clinicians in diagnosing Crohn’s disease when combined with other clinical and laboratory findings.

Clinical Evidence

Clinical performance evaluated in 351 subjects (pediatric and adult patients plus healthy controls). ASCA-CHEK vs. disease status showed 62% sensitivity and 93% specificity. Comparison against predicate (QUANTA Lite™ ASCA) showed 80% positive percent agreement and 88% negative percent agreement. Study confirms diagnostic utility as an aid in identifying Crohn's disease.

Technological Characteristics

ELISA; 96-well microtiter plate format; S. cerevisiae antigen coating; HRP-conjugated goat anti-human polyclonal immunoglobulin; TMB substrate; 0.6N sulfuric acid stop solution. Requires microplate reader (450 nm or 450/620 nm). Manual wash procedure. Qualitative output based on OD threshold.

Indications for Use

Indicated for use as an aid in the diagnosis of Crohn’s disease in patients (pediatric and adult) presenting with symptoms of inflammatory bowel disease. Prescription use only.

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.”

Predicate Devices

• Quanta Lite™ ASCA (S. Cerevisiae) IgG ELISA (k000732)

Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number:
k071711

B. Purpose for Submission:
Addition of sample matrix (serum) to a cleared device

C. Measurand:
Anti-Saccharomyces Cerevisiae Antibody (ASCA)

D. Type of Test:
Qualitative ELISA

E. Applicant:
TECHLAB®

F. Proprietary and Established Names:
ASCA-CHEK

G. Regulatory Information:
1. Regulation section:
21 CFR 866.5785, Anti-Saccharomyces Cerevisiae (ASCA) test system
2. Classification:
II
3. Product code:
NBT, Antibodies, Saccharomyces Cerevisiae (S. Cerevisiae)
4. Panel:
Immunology 82

H. Intended Use:
1. Intended use(s):
The ASCA-CHEK test is an enzyme-linked immunosorbent assay (ELISA) for the qualitative detection of human anti-S. cerevisiae antibodies (ASCA) in feces and serum. The test result is used as an aid in the diagnosis of Crohn’s disease in combination with clinical and other laboratory findings.
FOR IN VITRO DIAGNOSTIC USE.
2. Indication(s) for use:
Same as intended use.
3. Special conditions for use statement(s):
The devices are for prescription use only.
4. Special instrument requirements:
Microplate reader capable of measuring optical density (OD) at 450 nm or 450/620 nm.

I. Device Description:
Each device contains the following: microplate strips with breakaway microwells (12 strips x 8 wells/strip) coated with antigens of Saccharomyces cerevisiae; goat anti-human polyclonal immunoglobulin-horse radish peroxidase conjugate; positive control; wash buffer 20X concentrate; diluent 10X concentrate; tetramethylbenzidine and peroxide substrate; 0.6N Sulfuric acid stop solution.

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J. Substantial Equivalence Information:

1. Predicate device name(s):
Quanta Lite™ ASCA (S. Cerevisiae) IgG ELISA

2. Predicate K number(s):
k000732

3. Comparison with predicate:

| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| | ASCA-CHEK | Quanta Lite™ ASCA IgG ELISA |
| Intended use | To aid in the diagnosis of Crohn's disease | Same |
| Technology | ELISA | Same |
| Substrate | TMB | Same |
| OD reading | 450 nm or 450/620nm | Same |
| Platform | 96 well microtiter plates | Same |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Assay Format | Qualitative | Semi-quantitative |
| Antigen | Purified antigen from Saccharomyces cerevisiae | Partially purified and disrupted S. cerevisiae antigen |
| Enzyme-Conjugate | HRP goat anti-human polyclonal immunoglobulin conjugate | HRP goat anti-human IgG conjugate |
| Incubation times | 30-30-15 | 30-30-30 |
| Positive control | Ready to use Positive Sera | Prediluted: ASCA IgG Low and High Positive Sera |
| Negative control | 1X Diluent | Prediluted Negative Serum |
| Sample type | Feces and Serum | Serum |
| Sample dilution and sample volume required | 1:1000 dilution with sample diluent | 1:101 dilution of 5 μL serum with 500 μL HRP Sample Diluent |
| Sample diluent | 10X Phosphate Buffered Protein solution with 0.2% thimerosal | Tris-buffered saline, Tween-20, protein stabilizer and preservative |
| Wash buffer concentrate | 20X Phosphate-buffered saline, detergent, and 0.2% thimerosal | 40X Tris-buffered saline and Tween 20 |
| Stop solution | 0.6N sulphuric acid | 0.344M sulphuric acid |
| Washing procedure and number of washes | Manual wash using a Squirt bottle with fine-tipped nozzle with ~400 μL of 1X Wash Solution; total of four washes | Microplate washing device (200-300 μL of diluted HRP wash buffer using a repeating, or multichannel pipette, or automated system); total of three washes |
| OD measurement | Within 2-10 minutes | Within one hour |
| ASCA Results | (1) 450 nm wavelength: (single | Results in Units: |

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| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Interpretation | wavelength spectrophotometer) Negative: OD450<0.110 Positive: OD450≥0.110 | Negative: 0.0-20.0 Equivocal: 20.1-24.9 Positive: ≥25.0 |
| | (2) 450/620 nm wavelength: (dual wavelength spectrophotometer) Negative: OD450/620<0.080 Positive: OD450/620≥0.080 | |

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

CLSI EP7-A Interference Testing in Clinical Chemistry

# L. Test Principle:

The microwells are pre-coated with immobilized antigens of Saccharomyces cerevisiae. An aliquot of either serum or fecal specimen is emulsified in the diluent. The diluted specimen, the ready to use positive control, and the 1X diluent negative control are transferred to the microwell. If ASCA are present in the specimen, they will bind to the immobilized antigens. After incubation, the wells are washed and the conjugate added. The conjugate binds to the ASCA captured by the immobilized antigens. A second series of wash steps remove any unbound material. Following the addition of the substrate, a color is detected spectrophotometrically due to the enzyme-antibody-antigen complexes that form the presence of ASCA.

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

# 1. Analytical performance:

# a. Precision/Reproducibility:

Precision testing was done on a single wavelength spectrophotometer $(\mathrm{OD}_{450})$ . The intra-assay reproducibility was determined by testing 8 human serum specimens (4 ASCA positive and 4 ASCA negative) 8 times in the same run. The positive samples comprised of samples with varying concentrations of ASCA. For the analysis, each serum was diluted 1:1000 with the kit diluent. The OD data were reformatted to reflect the reportable result of the assay, which would either be positive or negative. The table below summarizes the OD output as well as the final call for each of the replicates.

| # | Test 1 OD450 | Test 2 OD450 | Test 3 OD450 | Test 4 OD450 | Test 5 OD450 | Test 6 OD450 | Test 7 OD450 | Test 8 OD450 | Final Call for each replicate |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 13 | 0.281 | 0.253 | 0.280 | 0.283 | 0.306 | 0.318 | 0.273 | 0.274 | Positive |
| 34 | 0.287 | 0.277 | 0.230 | 0.295 | 0.232 | 0.230 | 0.264 | 0.242 | Positive |
| 40 | 0.136 | 0.129 | 0.117 | 0.125 | 0.127 | 0.118 | 0.114 | 0.112 | Positive |
| 46 | 0.155 | 0.150 | 0.127 | 0.121 | 0.125 | 0.127 | 0.115 | 0.124 | Positive |
| | | | | | | | | | |
| 26 | 0.045 | 0.045 | 0.047 | 0.046 | 0.039 | 0.041 | 0.042 | 0.039 | Negative |
| 29 | 0.044 | 0.048 | 0.042 | 0.048 | 0.040 | 0.041 | 0.043 | 0.041 | Negative |
| 32 | 0.064 | 0.074 | 0.065 | 0.065 | 0.063 | 0.062 | 0.072 | 0.061 | Negative |
| 44 | 0.047 | 0.044 | 0.053 | 0.044 | 0.043 | 0.058 | 0.060 | 0.051 | Negative |

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The inter-assay precision was determined by testing 4 ASCA Ig- positive and 4 ASCA Ig-negative serum specimens eight times over a two-day period using a single lot of the ASCA-CHEK test. Results are summarized below.

| # | Test 1 OD450 | Test 2 OD450 | Test 3 OD450 | Test 4 OD450 | Test 5 OD450 | Test 6 OD450 | Test 7 OD450 | Test 8 OD450 | Final call for each replicate |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 33 | 0.293 | 0.277 | 0.178 | 0.240 | 0.256 | 0.365 | 0.316 | 0.282 | Positive |
| 34 | 0.268 | 0.253 | 0.198 | 0.269 | 0.253 | 0.366 | 0.260 | 0.299 | Positive |
| 40 | 0.134 | 0.164 | 0.163 | 0.126 | 0.124 | 0.124 | 0.144 | 0.143 | Positive |
| 46 | 0.159 | 0.189 | 0.138 | 0.186 | 0.132 | 0.135 | 0.142 | 0.168 | Positive |
| | | | | | | | | | |
| 24 | 0.051 | 0.039 | 0.042 | 0.041 | 0.037 | 0.053 | 0.045 | 0.045 | Negative |
| 29 | 0.052 | 0.042 | 0.045 | 0.040 | 0.040 | 0.063 | 0.048 | 0.052 | Negative |
| 29 | 0.052 | 0.044 | 0.039 | 0.040 | 0.047 | 0.062 | 0.050 | 0.054 | Negative |
| 31 | 0.070 | 0.056 | 0.041 | 0.070 | 0.084 | 0.103 | 0.060 | 0.088 | Negative |

b. Linearity/assay reportable range: Not applicable.

Sample dilution

The specimen dilution of 1:1000 was optimized using titrations (1:100 to 1:1000) of known ASCA-positive and ASCA-negative serum specimens. The 1:1000 dilution was then challenged using healthy control serum panel and clinical specimens using 3 different $\mathrm{OD}_{450\mathrm{nm}}$ cut-offs (0.110, 0.120 and 0.150). The dilution and $\mathrm{OD}_{450\mathrm{nm}}$ cut-off (1:1000 and $\geq 0.110$ ) that provided the highest range of correlations to Crohn's disease was considered optimal. This was further challenged in the clinical evaluations.

c. Traceability, Stability, Expected values (controls, calibrators, or methods): There is no recognized standard or reference material for ASCA. The calibrator and positive control (confirmed ASCA positive) were prepared in-house and the designated O.D. was assigned during development process.

d. Detection limit: Not applicable.

e. Analytical specificity:

Interference: Interference studies were performed as follows: Control samples shown below were divided into two aliquots. One aliquot was mixed with equal volumes of high ASCA-Ig-positive serum samples. The other aliquot was mixed with equal volumes of ASCA Ig-negative samples. All samples were tested seven times using ASCA CHEK. All ASCA-Ig-positive samples remained positive and all ASCA Ig-negative samples remained negative. No interference was observed.

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| Test Substance | Method of Analysis | Concentration |
| --- | --- | --- |
| Lipase | Hitachi 917 | >20 U/L |
| Cholesterol | Olympus AU 5000 | 504 mg/dL |
| RF | Nephelometry | 27.9 IU/mL |
| ANA | Nephelometry | 0.263 ratio |
| Bilirubin (free) | Beckman LX20 | 19 mg/dL |
| Bilirubin (conjugated) | Beckman LX20 | 18 mg/dL |
| Hemolyzed blood | Visual red color | Hemolyzed |

## Cross-reactivity:

Sera from non-Crohn's disease were tested in the ASCA-CHEK test and showed a positivity range of 4% to 13%.

| Non-Crohn's disease group | Number tested | Number positive | %Positive |
| --- | --- | --- | --- |
| Ulcerative colitis | 46 | 6 | 13% |
| Irritable bowel syndrome | 30 | 3 | 10% |
| Constipation | 1 | 0 | 0% |
| Esophagitis | 1 | 0 | 0% |
| H.pylori | 1 | 0 | 0% |
| Alcoholic cirrhosis | 20 | 1 | 5% |
| ANA-positive | 3 | 0 | 0% |
| Healthy | 91 | 4 | 4% |

Distribution of ASCA reactivity in patients with autoimmune liver disease and inflammatory bowel disorders shown in the table below is from a publication by Muratori P, Muratori L, et.al.(Clin Exp Immunol 2003;132:473-476).

| | No. of patients | ASCA | ASCA IgA | ASCA IgG | ASCA IgA + IgG |
| --- | --- | --- | --- | --- | --- |
| AMA-pos. PBC | 106 | 19 (18) | 17 (16) | 7 (7) | 4 (4) |
| AMA-neg. PBC | 17 | 9 (53) | 6 (35) | 6 (35) | 3 (18) |
| Type 1 AIH | 30 | 8 (27) | 6 (20) | 7 (23) | 5 (17) |
| Type 2 AIH | 37 | 4 (11) | 2 (5) | 4 (11) | 2 (5) |
| PSC | 25 | 11 (44) | 8 (32) | 7 (28) | 4 (16) |
| Crohn's disease | 23 | 16 (70) | 12 (52) | 16 (70) | 12 (52) |
| Ulcerative colitis | 25 | 9 (36) | 5 (20) | 7 (28) | 5 (20) |
| Blood donors | 19 | 1 (5) | 1 (5) | 0 | 0 |
| AMAMA, antimitochondrial antibody; PBC, primary biliary cirrhosis; AIH, autoimmune hepatitis; PS PSC, primary sclerosing cholangitis. | | | | | |

## f. Assay cut-off:

Two hundred and fifty-seven (257) serum specimens (172 Crohn's disease and 85 non-Crohn's disease) were used to determine the optimal OD cut-off

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for a positive result. $\mathrm{OD}_{450}$ (single wavelength spectrophotometer) cut-offs at $\geq 0.110$ , 0.120 and 0.150 and $\mathrm{OD}_{450/620}$ (dual wavelength spectrophotometer) at $\geq 0.080$ and 0.110 were evaluated.

Specimens were diluted at 1:1000 and tested by the ASCA-CHEK test for ASCA Ig. The optimal cut-off that provided the best correlation to clinically confirmed Crohn's disease was determined. The OD cut-off of $\geq 0.110$ at $\mathrm{OD}_{450}$ and $\geq 0.080$ at $\mathrm{OD}_{450/620}$ provided the largest number of samples that correlated to Crohn's disease. The following table shows the results for the ASCA-CHEK test. The number of Crohn's and non-Crohn's samples above and below each OD cutoff was determined.

| OD450 | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| Site | OD | N | Crohn's samples | | Non-Crohn's samples | |
| | | | above cut-off | below cut-off | above cut-off | below cut-off |
| Children's Hospital of Harvard | 0.110 | 94 | 49 | 23 | 17 | 5 |
| | 0.120 | 94 | 41 | 31 | 17 | 5 |
| | 0.150 | 94 | 35 | 37 | 19 | 3 |
| Riley Hospital | 0.110 | 23 | 12 | 8 | 3 | 0 |
| | 0.120 | 23 | 11 | 9 | 3 | 0 |
| | 0.150 | 23 | 8 | 12 | 3 | 0 |
| Mayo clinic | 0.110 | 63 | 34 | 14 | 15 | 0 |
| | 0.120 | 63 | 32 | 16 | 15 | 0 |
| | 0.150 | 63 | 30 | 18 | 15 | 0 |
| OD450/620 | | | | | | |
| Kliniken Essen-Mitte | 0.080 | 77 | 18 | 14 | 42 | 3 |
| | 0.110 | 77 | 13 | 19 | 42 | 3 |

# 2. Comparison studies:

a. Method comparison with predicate device:

A total of 180 (163 Inflammatory Bowel Disease, 17 Irritable Bowel Syndrome/non-IBD) patients were enrolled at 3 clinical sites. Each patient was assessed for active inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). In addition, each patient was diagnosed using in-house procedures and a single serum specimen was collected for analysis with the ASCA-CHEK test. For clinical sites #1 - 3, serum specimens were frozen and sent to TECHLAB®, Inc. for analysis for ASCA Ig. Site 1 and site 2 tested only pediatric samples. The following results were obtained:

# Pediatric samples:

Site #1 (Children's Hospital of Harvard Medical School) (frozen sera)

| N = 94 | QuantaLite ASCA IgG | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| ASCA Check | Positive | 35 | 13 | 48 |
| | Negative | 9 | 37 | 46 |
| | Total | 44 | 50 | 94 |

Positive percent agreement $= 80\%$ (95%CI 64-90%)

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Negative percent agreement = 74% (95%CI 59-85%)
Overall percent agreement = 77% (95%CI 68-86%)

Site #2 Riley’s Children’s Hospital (frozen sera)

| N = 23 | QuantaLite ASCA IgG | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| ASCA Check | Positive | 9 | 3 | 12 |
| | Negative | 1 | 10 | 11 |
| | Total | 10 | 13 | 23 |

Positive percent agreement = 90% (95%CI 54-100%)
Negative percent agreement = 77% (95%CI 46-94%)
Overall percent agreement = 83% (95%CI 64-93%)

## Adult samples:

Site #3 Mayo Clinic (frozen sera)

| N = 63 | QuantaLite ASCA IgG | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| ASCA Check | Positive | 30 | 4 | 34 |
| | Negative | 8 | 21 | 29 |
| | Total | 38 | 25 | 63 |

Positive percent agreement = 79% (95%CI 62-90%)
Negative percent agreement = 84% (95%CI 63-95%)
Overall percent agreement = 81% (95%CI 70-88%)

Since frozen samples were used in the comparison studies, the sponsor evaluated the effect of a single freeze-thaw cycle on test results in the serum ASCA-CHEK test. For the analysis, 9 ASCA Ig-positive serum samples and 5 ASCA Ig-negative serum samples were tested. An aliquot from each sample was removed and frozen at -20°C followed by a single thaw at room temperature on the day of analysis. The test results for the frozen and unfrozen specimens showed all negative samples remained negative and all positive samples remained positive at all time periods.

## b. Matrix comparison:

Serum is the only matrix tested in this submission.

## 3. Clinical studies:

### a. Clinical Sensitivity/Clinical specificity:

The same samples used in method comparison were used to assess sensitivity and specificity. In addition, 77 samples from adult patients were tested on Site 4 (Kliniken Essen-Mitte) for clinical assessment. The following results were obtained:

Site #1 (Children’s Hospital of Harvard Medical School)
False positive samples were from patients with ulcerative colitis. Sera from non-Crohn’s disease tested in the ASCA-CHEK test showed a positivity range

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of 4% to 13%. This accounts for a lower specificity for this site.

| N = 94 Pediatric samples | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn’s disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 43 | 5 | 48 |
| | Negative | 29 | 17 | 46 |
| | Total | 72 | 22 | 94 |

Sensitivity = 60% (95%CI 48-71%)
Specificity = 77% (95%CI 54-91%)

Site #2 (Riley’s Children’s Hospital)

| N = 23 Pediatric samples | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn’s disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 12 | 0 | 12 |
| | Negative | 8 | 3 | 11 |
| | Total | 20 | 3 | 23 |

Sensitivity = 60% (95%CI 36-80%)
Specificity = 100%

Site #3 (Mayo Clinic)

| N = 63 Adult samples | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn’s disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 34 | 0 | 34 |
| | Negative | 14 | 15 | 29 |
| | Total | 48 | 15 | 63 |

Sensitivity = 71% (95%CI 56-83%)
Specificity = 100%

Site #4 (Kliniken Essen-Mitte)

| N = 77 Adult samples | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn’s disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 18 | 4 | 22 |
| | Negative | 14 | 41 | 55 |
| | Total | 32 | 45 | 77 |

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Sensitivity = 56% (95%CI 38-73%)

Specificity = 91% (95%CI 78-97%)

The combined test results for both pediatric study sites to clinical assessments for disease diagnosis including non-IBD healthy controls is shown below.

| N = 136 | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn's disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 55 | 6 | 61 |
| | Negative | 37 | 38 | 75 |
| | Total | 92 | 44 | 136 |

Sensitivity = 60% (95%CI 49-70%)

Specificity = 86% (95%CI 58-76%)

The combined test results for both adult study sites to clinical assessments for disease diagnosis including non-IBD healthy controls is shown below.

| N = 215 | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn's disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 52 | 7 | 59 |
| | Negative | 28 | 128 | 156 |
| | Total | 80 | 135 | 215 |

Sensitivity = 65% (95%CI 53-75%)

Specificity = 95% (95%CI 89-98%)

The combined test results for all 4 study sites including samples from 94 healthy persons showed the following:

| N = 351 | Diagnosis | | | |
| --- | --- | --- | --- | --- |
| | | Crohn's disease | Ulcerative colitis and non-IBD | Total |
| ASCA Check | Positive | 107 | 13 | 120 |
| | Negative | 65 | 166 | 231 |
| | Total | 172 | 179 | 351 |

Sensitivity = 62% (95%CI 55-69%)

Specificity = 93% (95%CI 88-96%)

c. Other clinical supportive data (when a. and b. are not applicable): Not applicable

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4. Clinical cut-off:
Same as assay cut-off

5. Expected values/Reference range:
Expected value in normal population is negative. Of the 94 healthy persons tested, 4% tested 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 a substantial equivalence decision.

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