IL-33 is a novel member of the IL-1 family and ligand for the IL-1 receptor-related protein, ST2. Recent evidence suggests that the IL-33/ST2 axis plays a critical role in several autoimmune and inflammatory disorders; however, its role in inflammatory bowel disease (IBD) has not been clearly defined. We characterized IL-33 and ST2 expression and modulation after conventional anti-TNF therapy in Crohn's disease and ulcerative colitis (UC) patients and investigated the role of IL-33 in SAMP1/YitFc (SAMP) mice, a mixed Th1/Th2 model of IBD. Our results showed a specific increase of mucosal IL-33 in active UC, localized primarily to intestinal epithelial cells (IEC) and colonic inflammatory infiltrates. Importantly, increased expression of full-length IL-33, representing the most bioactive form, was detected in UC epithelium, whereas elevated levels of cleaved IL-33 were present in IBD serum. ST2 isoforms were differentially modulated in UC epithelium, and sST2, a soluble decoy receptor with anti-inflammatory properties, was also elevated in IBD serum. Infliximab (anti-TNF) treatment of UC decreased circulating IL-33 and increased sST2, whereas stimulation of HT-29 IEC confirmed IL-33 and sST2 regulation by TNF. Similarly, IL-33 significantly increased and correlated with disease severity, and potently induced IL-5, IL-6, and IL-17 from mucosal immune cells in SAMP mice. Taken together, the IL-33/ST2 system plays an important role in IBD and experimental colitis, is modulated by anti-TNF therapy, and may represent a specific biomarker for active UC.inflammatory bowel disease | anti-TNF therapy | SAMP1/YitFc mouse model

Low vitamin B(6) plasma levels, an independent risk factor for thrombosis, are frequent in patients with IBD, especially those with active disease.

The major inherited risk factors for thrombosis are significantly less frequent in thrombotic IBD patients than in thrombotic non-IBD subjects, suggesting that acquired risk factors play the most relevant role in determining thromboembolic events observed in IBD patients, particularly during active phases of the disease.

Background In a 6-year, multicenter, prospective nested case–control study, we aimed to evaluate risk factors for incident cancer in inflammatory bowel disease (IBD), when considering clinical characteristics of IBD and immunomodulator use. The secondary end point was to provide characterization of incident cancer types. Methods All incident cases of cancer occurring in IBD patients from December 2011–2017 were prospectively recorded in 16 Italian Group for the Study of Inflammatory Bowel Disease units. Each of the IBD patients with a new diagnosis of cancer was matched with 2 IBD patients without cancer, according to IBD phenotype (ulcerative colitis [UC] vs Crohn’s disease [CD]), age (±5 years), sex. Risk factors were assessed by multivariate logistic regression analysis. Results Cancer occurred in 403 IBD patients: 204 CD (CD cases), 199 UC (UC cases). The study population included 1209 patients (403 IBD cases, 806 IBD controls). Cancer (n = 403) more frequently involved the digestive system (DS; 32%), followed by skin (14.9%), urinary tract (9.7%), lung (6.9%), genital tract (6.5%), breast (5.5%), thyroid (1.9%), lymphoma (2.7%, only in CD), adenocarcinoma of the small bowel (SBA; 3.9%, 15 CD, 1 pouch in UC), other cancers (15.9%). Among cancers of the DS, colorectal cancer (CRC) more frequently occurred in UC (29% vs 17%; P < 0.005), whereas SBA more frequently occurred in CD (13% vs 6.3% P = 0.039). In CD, perforating (B3) vs non-stricturing non-perforating (B1) behavior represented the only risk factor for any cancer (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.33–4.11). In CD, risk factors for extracolonic cancer (ECC) were a B3 vs B1 and a stricturing (B2) vs B1 behavior (OR, 2.95; 95% CI, 1.62–5.43; OR, 1.79; 95% CI, 1.09–2.98). In UC, risk factors for ECC and for overall cancer were abdominal surgery for UC (OR, 4.63; 95% CI, 2.62–8.42; OR, 3.34; 95% CI, 1.88–5.92) and extensive vs distal UC (OR, 1.73; 95% CI, 1.10–2.75; OR, 1.99; 95% CI, 1.16–3.47). Another risk factor for ECC was left-sided vs distal UC (OR, 1.68; 95% CI, 1.00–2.86). Inflammatory bowel disease duration was a risk factor for skin and urinary tract cancers. Conclusions Perforating CD, extensive UC, and abdominal surgery for UC were identified as risk factors for overall incident cancer and for ECC. The clinical characteristics associated with severe IBD may increase cancer risk.