5,25–29 Neutrophils are not normally present in normal colonic mucosa. The presence and infiltration of neutrophils into the lamina propria, crypt epithelium (cryptitis) and crypt lumen (crypt abscesses) is a sign of active disease, with the degree of neutrophilic inflammation an indication of disease activity. It is, however, also present in infectious

colitis and other colitides and is not pathognomonic of UC. A minority of UC patients may have cecal patch inflammation, rectal sparing (pediatric patients) or backwash ileitis. Level of agreement: a-82%, b-18%, c-0%, d-0%, e-0% Quality of evidence: II-2 Classification of recommendation: B Non-classical UC features which include cecal patch inflammation, rectal sparing and backwash ileitis have been observed Buparlisib manufacturer in a small proportion of patients. These features should not be PI3K Inhibitor Library confused with CD.30–42 Inflammation of the peri-appendiceal cecal mucosa (‘cecal patch’) is well described in western series, particularly those with left-sided

colitis.30–32 The clinical features and natural history of those with cecal patch inflammation appear to be similar to those with isolated left-sided disease.31 Similarly, cecal patch inflammation has also been described in Asian UC patients, being seen more frequently in those with less extensive disease.33–36 In one study from Japan, it has been shown to better respond to medical therapy but this observation will require confirmation in large controlled MCE公司 studies.35 Endoscopic and histologic rectal sparing has been observed in a small proportion of pediatric UC patients at the time of initial presentation37–39 while in adults, it may be seen after topical or systemic therapy for UC.20–23 On the other hand, ‘relative’ rectal sparing has been reported in adult UC patients at presentation.43,44 Inflammation of the distal terminal ileum, termed ‘backwash ileitis’ is seen in up to 20%

of UC patients, typically in those with pancolitis although rarely ileal erosions may occur in those without cecal involvement.40–42 Serological tests (ASCA, pANCA) are not required for the diagnosis of UC but may occasionally be helpful in differentiation of UC from CD. Level of agreement: a-65%, b-23%, c-12%, d-0%, e-0% Quality of evidence: II-1 Classification of recommendation: B Serological markers perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) have been extensively studied in the Caucasian IBD population45 but less data exists for Asian IBD patients.46–55 Although pANCA and ASCA are more specific for UC and CD, respectively, their usefulness is limited by their low sensitivity and not required for the diagnosis of UC in clinical practice. In a meta-analysis, pANCA positivity alone has a 55.3% sensitivity and 88.5% specificity for UC.