Determination of anti-neutrophil cytoplasmic antibody (ANCA) and anti- Saccharomyces cerevisiae antibody (ASCA) is considered investigational/experimental in the workup and monitoring of patients with inflammatory bowel disease.  There is a lack of scientific evidence that the use of these tests is likely to alter the diagnostic workup, the final diagnosis made, or the treatment provided for patients with suspected IBD.  A participating, preferred, or network provider may bill the member for the denied tests.

Description

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. Ulcerative colitis (UC) and Crohn's disease (CD) are two types of IBD, both of which present with symptoms of diarrhea and abdominal pain. The large intestine (colon) can be inflamed in ulcerative colitis, involving the inner lining of the colon, or by Crohn's disease, which extends the inflammation deeper into the intestine wall. Crohn's disease can also involve the small intestine, or can involve both the small and large intestine.

In approximately 90% of cases, a definitive diagnosis of inflammatory bowel disease can be made by a combination of standard diagnostic modalities (e.g., clinical course, radiographic studies, endoscopy, and interpretation of biopsy material). The histologic description of the biopsied tissue is a crucial factor in establishing the diagnosis. After IBD is diagnosed, it is sometimes difficult to distinguish between UC and CD. This occurs in approximately 10-15% of patients diagnosed with IBD.

Two serum antibody markers, anti-neutrophil cytoplasmic antibody (ANCA) for UC and anti-Saccharomyces cerevisiae antibody (ASCA) for CD have the potential to improve the efficiency and accuracy of diagnosing IBD and to potentially decrease the extent of the diagnostic work-up or to avoid invasive diagnostic imaging. Most clinical laboratories can perform testing for the ANCA marker. However, testing is not as widely available for the ASCA marker. There are no specific CPT codes for the detection of ANCA or ASCA markers.

Prometheus, Inc. has developed a proprietary testing system that uses combinations of tests for ANCA and/or ASCA to aid in the diagnosis of IBD and to differentiate between Crohn's disease and ulcerative colitis. The Prometheus system first screens for ANCA or ASCA using an ELISA (enzyme linked immunoabsorbent assay) test. If the screening test is positive for ANCA, further analysis is performed by indirect immunofluorescence (IIF) to determine the specific staining pattern. Specific enzyme reagents proprietary to the company are used to distinguish between true positives and artifacts of fixation when a perinuclear pattern is obtained by the staining. The specificity of the test is increased compared to other laboratories, according to Prometheus. If the screening for ASCA is positive, further analysis is performed by an ELISA microplate assay. When the antibody level exceeds a predetermined cut-off point, positive specimens are identified. Other laboratories can perform a similar method of detecting ANCA and ASCA compared to Prometheus. However, the methods by other laboratories are not an exact duplication of the Prometheus methods.

NOTE:

This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.

This medical policy may not apply to FEP.  Medical policy is not an authorization, certification, explanation of benefits or a contract.  Benefits are determined by the Federal Employee Program.

National Blue Cross Blue Shield Association TEC Assessment, Vol. 14, No. 16, 07/1999

National Blue Cross Blue Shield Association Medical Policy 2.04.17, Serum Antibodies for the Diagnosis of Inflammatory Bowel Disease, 02:2008

Ferrante M, et al. New serological markers in inflammatory bowel disease are associated with complicated disease behavior. Gut. 2007 Oct; 56(10): 1394-403

Papp M, Nirman GL, Altorjay I, Lakatos PL. Utility of Serological Markers in Inflammatory Bowel Disease: Gadget or Magic? World J Gasdtroenterol. 2007 Apr; 13(14): 2028-2036

Mainardi E, Villanacci V, Bassotti G, Liserre B, Rossi E, Incardona P, Falchetti D, Tonegatti L, Montanelli A, Barabine A, Coccia C, Gambine C. Diagnostic Value of Serological Assays in Pediatric Inflammatory Bowel Disorders. Digestion. 2007 Jan; 45: 210-214

Mokrowiecka A, Gasiorowska A, Malecka-Panus E. pANCA and ASCA in the Diagnosis of Different Subtypes of Inflammatory Bowel Disease. Hepato-Gastroenterology. 2007 Jul; 54(77): 1443-1448