Measuring IgG anti-Saccharomyces cerevisiae antibodies as a part of a profile to aid in distinguishing between ulcerative colitis and Crohn disease in patients for whom the specific diagnosis is unclear based on endoscopic, pathologic, and imaging evaluations
This test is not useful for determining the extent of disease in patients with inflammatory bowel disease or determining the response to disease-specific therapy including surgical resection of diseased intestine
Enzyme-Linked Immunosorbent Assay (ELISA)
ASCA (Saccharomyces cerevisiae Antibody)
Saccharomyces cerevisiae
Serum
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
0.4 mL
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | OK |
Heat-treated specimen | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 21 days | |
Frozen | 21 days |
Measuring IgG anti-Saccharomyces cerevisiae antibodies as a part of a profile to aid in distinguishing between ulcerative colitis and Crohn disease in patients for whom the specific diagnosis is unclear based on endoscopic, pathologic, and imaging evaluations
This test is not useful for determining the extent of disease in patients with inflammatory bowel disease or determining the response to disease-specific therapy including surgical resection of diseased intestine
Inflammatory bowel disease (IBD) refers to 2 diseases, ulcerative colitis (UC) and Crohn disease (CD, regional enteritis), both of which result from chronic inflammation in the gastrointestinal (GI) tract.(1) CD is characterized by chronic diarrhea, abdominal pain, and fatigue.(2) In comparison, UC frequently presents with bloody diarrhea that is of an urgent nature.(3) Inflammation in UC most frequently affects the rectum and proximal colon, and presents with continue mucosal involvement. In CD, inflammation can affect almost any area of the GI tract, and is usually evidenced as patchy, transmural lesions.
Diagnosis of IBD is primarily based on clinical evaluation, endoscopy with biopsy, and imaging studies.(4) Because CD and UC are characterized by GI inflammation, fecal calprotectin can be used to differentiate IBD from non-inflammatory conditions such as irritable bowel syndrome (IBS). Fecal calprotectin is useful in excluding IBD as a diagnosis and avoiding unnecessary endoscopic or imaging procedures.
CD and UC are associated with the presence of various anti-microbial and autoantibodies.(5) Patients with UC often have measurable antineutrophil cytoplasmic antibodies (ANCA), which react with as yet uncharacterized target antigens in human neutrophils; in contrast, patients with CD often have measurable IgA and/or IgG antibodies which react with cell wall mannan of Saccharomyces cerevisiae. Despite these associations, current guidelines indicate that testing for these antibodies is not sufficiently sensitive for use in the diagnosis of IBD.(2,3) Rather, these antibodies should be limited to distinguishing between CD and UC in cases where the specific diagnosis is unclear based on pathologic and imaging studies.
Negative: <20.0 RU/mL
Positive: > or =20.0 RU/mL
Reference values apply to all ages.
The presence of antineutrophil cytoplasmic antibodies (ANCA) in the absence of IgA and IgG anti-Saccharomyces cerevisiae antibodies (ASCA) is consistent with the diagnosis of ulcerative colitis; the presence of IgA and IgG ASCA in the absence of ANCA is consistent with Crohn disease.
Results from this test should not be exclusively relied upon to establish the diagnosis of ulcerative colitis (UC) or Crohn disease (CD) or to distinguish between these 2 diseases. Saccharomyces cerevisiae IgA and IgG antibodies (ASCA) are most useful for distinguishing between UC and CD when assessed in conjunction with antineutrophil cytoplasmic antibodies (ANCA).
Some patients with CD have detectable ANCA, and some patients with UC have detectable IgA and/or IgG ASCA. Some patients with UC or CD do not have detectable ANCA, IgA ASCA, or IgG ASCA.
1. Rose NR, Mackay IR, eds: Inflammatory bowel diseases. In: The Autoimmune Diseases: Elsevier; 2008
2. Lichtenstein GR, Loftus EV, Isaacs KL, Regueiro MD, Gerson LB, Sands BE: ACG Clinical Guideline: Management of Crohn's disease in adults. Am J Gastroenterol. 2018 Apr;113(4):481-517
3. Rubin DT, Ananthakrishnan AN, Siegel CA, Sauer BG, Long MD: ACG Clinical Guideline: Ulcerative colitis in adults. Am J Gastroenterol. 2019 Mar;114(3):384-413
4. Clark C, Turner J: Diagnostic modalities for inflammatory bowel disease: Serologic markers and endoscopy. Surg Clin North Am. 2015 Dec;95(6):1123-1141
5. Zhou G, Song Y, Yang W, et al: ASCA, ANCA, ALCA and many more: Are they useful in the diagnosis of inflammatory bowel disease? Dig Dis. 2016;34(1-2):90-97. doi: 10.1159/000442934
Immunoglobulin G (IgG) anti-Saccharomyces cerevisiae antibodies (ASCA) are measured by commercial, microtiter enzyme immunoassay. This assay uses polystyrene microtiter plates coated with purified mannan from the cell wall of S cerevisiae to capture antibodies from patient sera and horseradish peroxidase-conjugated anti-IgG antibodies to detect IgG ASCA. Results of the test for IgG ASCA are reported in relative units per milliliter (RU/mL).(Package insert: Anti-Saccharomyces cerevisiae ELISA (IgG). EUROIMMUN Medizinische Labordiagnostika AG; 5/2011)
Tuesday, Thursday
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
86671
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
SCERG | Saccharomyces cerevisiae Ab, IgG, S | 47321-5 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
SCERG | Saccharomyces cerevisiae Ab, IgG, S | 47321-5 |