Saccharomyces cerevisiae Antibody, IgA, Serum
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Helping clinicians distinguish between ulcerative colitis and Crohnâ€™s disease in patients suspected of having inflammatory bowel disease
Enzyme-Linked Immunosorbent Assay (ELISA)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Saccharomyces cerevisiae Ab, IgA, S
ASCA (Saccharomyces cerevisiae Antibody)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.5 mL
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Mild OK; Gross reject
Mild OK; Gross OK
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Serum||Refrigerated (preferred)||21 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Inflammatory bowel disease (IBD) refers to 2 diseases, ulcerative colitis (UC) and Crohn's disease (CD), that produce inflammation of the large or small intestines.(1) The diagnoses of both diseases are based on clinical features, the results of barium X-rays, colonoscopy, mucosal biopsy histology, and in some cases operative findings and resected bowel pathology and histology.
Recently, patients with IBD have been shown to have antibodies in serum that help distinguish between CD and UC.(2) Patients with UC often have measurable neutrophil-specific antibodies, which react with as yet uncharacterized target antigens in human neutrophils; whereas, patients with CD often have measurable antibodies of the IgA and/or IgG isotypes, which react with cell wall mannan of Saccharomyces cerevisiae strain Su 1.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative: 0.0-20.0 U
Equivocal: 20.1-24.9 U
Weakly positive: 25.0-34.9 U
Positive: > or =35.0 U
In IBDP/81443 Inflammatory Bowel Disease Serology Panel, Serum, anti-Saccharomyces cerevisiae antibodies (ASCA) and neutrophil-specific antibodies (NSA) are measured. The finding of NSA with normal levels of IgA and IgG ASCA is consistent with the diagnosis of ulcerative colitis (UC); the finding of negative NSA with elevated IgA and IgG ASCA is consistent with Crohn's disease (CD).
NSA are detectable in approximately 50% of patients with UC.
Elevated levels of either IgA or IgG ASCA occur in approximately 55% of patients with CD.
Approximately 40% of patients with CD have elevated levels of both IgA and IgG ASCA.
Employed together, the tests for NSA and ASCA have the following positive predictive values (PPV) for UC and CD, respectively:(2)
-NSA-positive with normal levels of IgA and IgG ASCA, PPV of 91%
-NSA-negative with elevated levels of IgA and IgG ASCA, PPV of 90%
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
IBDP/81443 Inflammatory Bowel Disease Serology Panel, Serum is useful as an adjunct in the diagnosis of ulcerative colitis (UC) and Crohnâ€™s disease (CD), but should not be relied upon exclusively to establish the diagnosis of UC or CD, or to distinguish between these 2 diseases. Some patients with CD have detectable neutrophile-specific antibodies (NSA), and some patients with UC have elevated levels of IgA and/or IgG anti-Saccharomyces cerevisiae antibodies (ASCA).
Measurement of ASCA and NSA are not useful to determine the extent of disease in patients with inflammatory bowel disease or to determine the response to disease-specific therapy including surgical resection of diseased intestine.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. The Autoimmune Diseases: Inflammatory Bowel Diseases. Edited by NR Rose, IR Mackay. New York, NY, Elsevier Academic Press, 2008
2. Sandborn WJ, Loftus EV Jr, Homburger HA, et al: Evaluation of serological disease markers in a population-based cohort of patients with ulcerative colitis and Crohn's disease. Inflamm Bowel Dis 2001 Aug;7(3):192-201
Method Description Describes how the test is performed and provides a method-specific reference
IgA anti Saccharomyces cerevisiae antibodies (ASCA) are measured by commercial, microtiter enzyme immunoassays (INOVA Diagnostics, San Diego, CA). This assay uses polystyrene microtiter plates coated with partially purified Saccharomyces cerevisiae antigens to capture antibodies from patient's sera and horseradish peroxidase-conjugated anti-IgA antibodies to detect IgA ASCA. Results of the test for IgA ASCA are reported in arbitrary units (U).(Package insert: QUANTA LITE ASCA [Saccharomyces cerevisiae] IgA ELISA 708870)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 5 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Same day/1 day
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|AASCA||Saccharomyces cerevisiae Ab, IgA, S||47320-7|