Chiara Montesani

Lamina propria T cells in Crohn's disease and other gastrointestinal inflammation show defective CD2 pathway-induced apoptosis

BACKGROUND & AIMS Normal human lamina propria lymphocytes manifest increased unstimulated apoptosis compared with peripheral lymphocytes, which are enhanced after stimulation via the CD2 activation pathway. This activation-induced apoptosis down-regulates cell expansion and cytokine production. In previous studies, it was shown that lamina propria T cells from patients with Crohns disease and ulcerative colitis manifest abnormal proliferation and cytokine production. It was therefore of interest to determine if such cells also showed abnormal patterns of apoptosis. METHODS Apoptosis was evaluated by propidium iodide staining of cells followed by flow cytometric analysis. Fas expression and Bcl-2 levels in cells were evaluated by immunofluorescence. RESULTS Lamina propria lymphocytes from patients with Crohns disease and ulcerative colitis as well as from 2 patients with diverticulitis showed defective CD2 pathway-induced apoptosis. Studies of the mechanisms of this defect focusing on cells from patients with Crohns disease showed that Crohns disease lamina propria lymphocytes from inflamed tissues express the same amount of cell surface Fas but are less sensitive to Fas-mediated apoptosis than control cells. In addition, lamina propria lymphocytes from inflamed Crohns disease tissues manifest increased expression of Bcl-2 after CD2 pathway stimulation and elevated Bcl-2 levels in cultures of unstimulated T cells. CONCLUSIONS T cells isolated from areas of inflammation in Crohns disease, ulcerative colitis, and other inflammatory states manifest decreased CD2 pathway-induced apoptosis. Studies of cells from inflamed Crohns disease tissue indicate that this defect is accompanied by elevated Bcl-2 levels. These changes are probably caused by the chronic inflammation and may aggravate the underlying disease processes that are present.

Probiotic administration in patients with ileal pouch–anal anastomosis for ulcerative colitis is associated with expansion of mucosal regulatory cells

Background: Probiotics have anti‐inflammatory effects in patients with inflammatory bowel disease and appear to regulate mucosal immune response through reductions in proinflammatory cytokines. The probiotic VSL#3 prevents pouchitis if started within a week of ileostomy closure and maintains remission following antibacterial treatment in patients with refractory or recurrent pouchitis. However, the efficacy of probiotics and their effects on regulatory cells if started at a greater time after surgery in patients undergoing ileal pouch anal anastomosis (IPAA) for ulcerative colitis are unknown. Methods: We conducted an open‐label study in which 31 patients at different periods from surgery without signs and symptoms of pouchitis were randomized to 2 sachets of VSL#3 once daily or no treatment for 12 months. Pouchitis disease activity index (PDAI) was evaluated at baseline and after 3, 6, and 12 months. The percentage of CD4+ T lymphocytes expressing CD25 and the inactive form of transforming growth factor‐&bgr; [latency‐associated peptide (LAP)] were evaluated at baseline and after 3 and 6 months in peripheral‐blood mononuclear cells and mucosal biopsies. Variation in tissue interleukin‐1&bgr; and Foxp3 mRNA expression was also evaluated. Results: During the study period, VSL#3‐treated patients showed a significant reduction in PDAI score and a significant increase in the percentage of mucosal CD4+CD25high and CD4+ LAP‐positive cells compared with baseline values. Tissue samples at different points showed a significant reduction in IL‐1&bgr; mRNA expression, and a significant increase in Foxp3 mRNA expression. Conclusions: We conclude that VSL#3 administration in patients with IPAA modulates the PDAI and expands the number of mucosal regulatory T cells.

Small intestine contrast ultrasonography (SICUS) for the detection of small bowel complications in crohn's disease: A prospective comparative study versus intraoperative findings

Background: In Crohns disease (CD) patients, small intestine contrast ultrasonography (SICUS) accurately assesses small bowel lesions. Its diagnostic role is not known in the assessment of intraabdominal CD complications. The aim was to assess the value of SICUS to detect intestinal complications in patients with CD. Methods: Forty‐nine CD patients (21 female, mean age 37.7 years; range 12–78 years) underwent resective bowel surgery and were included in this study. The accuracy of SICUS to preoperatively detect number, site, and length of strictures, fistulas, and abscesses was compared with surgical and pathological findings by kappa statistics. Results: SICUS identified at least one stricture in 39/40 and excluded it in 9/9 (97.5% sensitivity, 100% specificity, k = 0.93); two or more strictures in 9/12 (75% sensitivity, 100% specificity, k = 0.78). The agreement by k‐statistics between SICUS and surgery in identifying proximal and distal small intestine site of stricture was 1 and 0.92, respectively. The extension of strictures was 6.8 ± 5.4 cm at surgery, 6.6 ± 5.4 cm at SICUS (NS). Fistulas were correctly identified in 27/28 patients and excluded in 19/21 patients (96% sensitivity, 90.5% specificity, k = 0.88). Intraabdominal abscesses were correctly detected in 10/10 patients and excluded in 37/39 patients (100% sensitivity, 95% specificity, k = 0.89). Conclusions: SICUS is an accurate method for the detection of small intestinal complications in CD. Noninvasive SICUS is valuable as a primary investigative method for evaluating and planning proper treatment in patients with severe CD of the small bowel. (Inflamm Bowel Dis 2011;)

HIV-1 gp120 Accelerates Fas-Mediated Activation-Induced Human Lamina Propria T Cell Apoptosis

Intestinal mucosa represents an important portal of entry of HIV and a site of virus reservoir and active replication. Recently, in HIV patients, an early depletion of intestinal lamina propria T lymphocytes (LPT) has been described. HIV-1 gp120 has been demonstrated to promote apoptosis in noninfected isolated peripheral blood T cells, therefore we investigated whether gp120 modulates apoptosis of normal human intestinal lamina propria T cells. Purified T cells were obtained by immunomagnetic negative selection from human lamina propria mononuclear cells isolated from surgical specimens by enzymatic procedure. Cells were incubated with or without recombinant gp120 (10 μg/ml) and cultured either in the absence of any stimulus or in the presence of plate-bound anti-CD3 Ab (OKT3) or soluble anti-CD2 Ab (T112 + T113). Apoptosis was assessed by flow cytometric analysis after propidium iodide staining. We demonstrated that preincubation of normal LPT cells with HIV-1 gp120 accelerates the apoptosis observed during CD2-pathway stimulation of LPT cells. This process is mediated by Fas/Fas ligand interaction and related to an increased induction of Fas ligand mRNA by gp120. Therefore HIV-1 gp120 could contribute to the depletion of noninfected LPT cells inducing a premature cell death.

Lamina Propria CD4+LAP+ Regulatory T Cells Are Increased in Active Ulcerative Colitis but Show Increased IL-17 Expression and Reduced Suppressor Activity

BACKGROUND A CD4+CD25- regulatory T cell population expressing the surface TGF-β in its latent form LAP+ [latency associated peptide] cells was proved to be protective in experimental colitis and to be suppressive of human peripheral blood [PB] T proliferation. We investigated the frequency and function of lamina propria [LP] CD4+LAP+ T cells in inflammatory bowel disease [IBD] patients. METHODS Specimens from patients undergoing colonoscopy or bowel resection for IBD and colonic cancer were used as source of lamina propria mononuclear cells [LPMC]. The ulcerative colitis [UC] group was divided according to endoscopic activity evaluated with modified Baron Score. IL-17, IFN-γ, IL-10, LAP, and Foxp3 expression in CD3+CD8- [CD4] or CD3+/CD4+ gated cell population was assessed by immunofluorescence. The ability of FACS-sorted LP CD3+CD8-[CD4] LAP+CD25- to inhibit stimulated autologous PB CD3+CD8-[CD4] LAP- CD25- cells proliferation was assessed. RESULTS LP CD4LAP+ cells were significantly increased, when compared with controls, in active UC patients and not in Crohns disease patients. The majority of LP CD4+LAP+ cells were Foxp3-. The percentage of IL-17+ cells in LP CD3+CD8-[CD4] LAP+ cells was significantly higher in active UC patients when compared with controls. LP CD3+CD8-[CD4]LAP+CD25- isolated from UC patients showed reduced or no ability to inhibit autologous PB CD3+CD8-[CD4]LAP-CD25- cell proliferation when compared with controls. Removal of IL-17+ cells from LP CD3+CD8-[CD4] LAP+ cells increases their suppressive ability. CONCLUSIONS The percentage of LP CD4LAP+ cells is increased in active UC, showing reduced suppressor activity due to their increased proportion of intracellular IL-17 expression.

Bombesin as a Stimulator of the Exocrine Pancreas in Healthy Subjects and Patients with Chronic Pancreatitis

The aims of the present study were (1) to compare the effect of bombesin (BBS) on exocrine pancreatic secretion in healthy subjects and in patients with chronic pancreatitis (CP), (2) to assess in the same subject possible differences between secretincaerulein(S-C-) and BBS-stimulated secretion, and (3) to establish whether BBS can play a role in the differential diagnosis between healthy subjects and patients with CP.

Adenocarcinoma of the ileal pouch mucosa: a new diagnostic challenge

Dear editor, We read with interest the manuscript recently published by O’Mahoney et al. entitled “Adenocarcinoma of the ileal pouch mucosa: case report and literature review” [1]. The authors well presented a case of adenocarcinoma of ileal pouch mucosa diagnosed after 13 years of pouch creation. They reviewed literature for true pouch adenocarcinoma, and a total of 27 patients have been described around the world. Of these, 63 % (17/27) had neoplasia in their original proctocolectomy specimen. Mean time of adenocarcinoma development was 8.9 years. Five-year survival after excision of the pouch was 70 %. In our experience of 112 ileal pouch anastomosis, we had one case of true pouch adenocarcinoma. A 71-year-old man was diagnosed of ulcerative colitis for 30 years; he underwent a total colectomy 26 years ago (on 1985). Patient course was complicated by chronic pouchitis medically treated. After 11 years of follow-up, primary sclerosing cholangitis diagnosis was done. During annual endoscopic control, a polypectomy was performed. At pathology, a wide area of high-grade dysplasia with a minute focus of adenocarcinoma polyp was observed. A magnetic resonance imaging was performed, and a mucosal thickening was observed. Considering oncological indication to remove the pouch, patient age, and technical difficulty to restore intestinal continuity, the patient underwent ileal pouch excision with end ileostomy. After 34 months of follow-up, the patient is alive with no local or systemic recurrence. In our experience, mean age at surgery was 37 years old with a mean follow-up of 123 months. For a 6-month endoscopical follow-up for the first 4 years after surgery and if no complication is observed, a 12-month control is performed. We agree with O’Mahoney et al. highlighting the need for long-term follow-up and attention to these patients. Through the absence of consensus in the surveillance of pouch, many authors may suggest there own clinical practice [2–4]. However, we suggest to perform a closed follow-up with random biopsy in all patients, with or without previous neoplasia. In patients with ileal pouch anastomosis, no limits of time should be considered to be out of risk.