Inflammatory Bowel Disease (IBD) Expanded Profile

Serum

1 mL

0.5 mL

Red-top tube or gel-barrier tube

Aids in the diagnosis of inflammatory bowel disease (IBD) and the differential diagnosis of Crohn's disease (CD) and ulcerative colitis (UC); prognostic aid for clinical management of patients with CD.

Results of this panel should be used in conjunction with clinical findings and other laboratory tests.

Enzyme immunoassay (EIA) for ACCA, ALCA, AMCA, gASCA; indirect fluorescent antibody (IFA) for atypical pANCA

When the only positive marker is pANCA, the interpretive comment on the report will read: "Suggestive of ulcerative colitis."

When only one of ACCA, ALCA, AMCA, or gASCA is positive and pANCA is negative, the interpretive comment will read: "Suggestive of Crohn's disease. Pattern is not conclusive for disease behavior risk stratification."

When only one of ACCA, ALCA, AMCA, or gASCA is positive and pANCA is positive, the interpretive comment will read: "Suggestive of inflammatory bowel disease. Pattern is not conclusive for any specific disease form."

When any two of ACCA, ALCA, AMCA, or gASCA are positive and pANCA is positive or negative, the interpretive comment will read: "Suggestive of Crohn's disease with high risk of aggressive disease behavior (development of strictures or fistulae)."

When any three or more of ACCA, ALCA, AMCA, or gASCA are positive and pANCA is positive or negative, the interpretive comment will read: "Suggestive of Crohn's disease with the very high risk of aggressive disease behavior (development of strictures or fistulae)."

When all markers are negative, the interpretive comment on the report will read: "Pattern is not suggestive of inflammatory bowel disease."

Inflammatory bowel disease is a chronic disorder of the lower gastrointestinal tract that may occur in three forms: Crohn's disease (CD), ulcerative colitis (UC), and indeterminate colitis (IC). Its prevalence in the adult population approaches 0.3%.¹ The differential diagnosis of the different forms of IBD is often difficult, time-consuming, and invasive.² The gold standard for diagnosis is endoscopy with biopsies for histologic examination.³ In recent years, however, a number of serological markers have been introduced. The most commonly employed serological markers of IBD are anti-Saccharomyces cerevisiae antibody (ASCA) and atypical perinuclear antineutrophil cytoplasmic antibody (pANCA). ASCA positivity is found predominantly in patients with CD, while pANCA positivity is found predominantly in patients with UC.² A combination of ASCA and pANCA has a specificity of as high as 99% for differentiation of CD from UC.³ Nevertheless, there are a substantial number of patients with IBD who are negative for both. The addition of novel serological markers improves the sensitivity of the conventional ASCA/pANCA combination.³

About two-thirds of patients with CD develop either a stricturing or penetrating disease course within 10 years after diagnosis. As many as 80% of all CD patients undergo surgery at least once during the course of their disease. Consequently, the identification of individuals susceptible to the development of more complicated disease behavior would allow for earlier and more aggressive treatment.⁴

This profile offers three novel markers: antichitobioside IgA (ACCA), antilaminaribioside IgG (ALCA), antimannobioside IgG (AMCA), together with anti-Saccharomyces cerevisiae IgG (gASCA) and pANCA. These markers provide additional diagnostic and prognostic information depending on the combination of results.^3-6

The antibodies included in the panel are ASCA (anti-Saccharomyces cerevisiae antibodies), ALCA (antilaminaribioside carbohydrate antibodies), ACCA (antichitobioside carbohydrate antibodies), and AMCA (antimannobioside carbohydrate antibodies).^3,5,6 Numerous studies of CD have demonstrated an association between ileal disease and the presence of ACCA,³ ALCA,^3,6 AMCA,⁶ and ASCA.^3,5-10 Among these antibodies, the association with localization to the small intestine increased with the number of positive antibodies and with the concentration of individual antibodies.^3,5,6,9,11 A more aggressive or complicated disease course in CD (as indicated by stricturing or perforation of the intestine or need for surgery), has also been associated with the presence of ACCA,^3,5 ALCA,^3,5,6 AMCA,^3,5 and ASCA.^3,5,6,8-10 Among these antibodies, the association with complicated disease behavior or surgery increased with the number and concentration of antibodies.^3,5,9,11