The incidence of Crohn's disease (CD) and ulcerative colitis (UC) is increasing, but differentiating between them is often extremely difficult. Pancreatic (PAB) and goblet cell autoantibodies (GAB) are specific for CD and UC, respectively, but with low sensitivity. In combination with anti-Saccharomyces cerevisiae (ASCA) and anti-neutrophil cytoplasmic antibodies (pANCA) testing, these antibodies may improve differentiation between the diseases. This study determined the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of PAB and GAB ± ASCA and pANCA testing in Chinese and Caucasian IBD populations.
Patients were recruited from Caucasian and Chinese populations (CD, n = 100; UC, n = 99; controls, n = 100). PAB was highly specific for CD, and detection was greater in patients less than 35 years old and in Chinese compared with Caucasian patients with CD (CD, 46% versus 22%, P = 0.018; UC, 2% versus 6%; controls, 0% versus 2%). GAB detection was poor in all groups (<2%). PAB showed a PPV of 93% to differentiate all patients with CD from patients with UC, but only 62% for those with isolated colonic disease. The PPV of PAB increased to 100%, specificity was 100%, and sensitivity was 21% for isolated colonic disease when combined with pANCA and ASCA. PAB expression was not associated with stricturing or perforating CD.
This study identified that GAB was not useful in our patients with IBD. PAB expression was highly specific for CD and more sensitive in Chinese than Caucasian patients with CD. The combination of PAB, pANCA, and ASCA testing improved the differentiation between UC and CD, particularly in isolated colonic disease, compared with pANCA and ASCA testing alone.