Development and Clinical Validation of a Blood Test Based on 29-Gene Expression for Early Detection of Colorectal Cancer.

PURPOSE: A blood test for early detection of colorectal cancer is a valuable tool for testing asymptomatic individuals and reducing colorectal cancer-related mortality. The objective of this study was to develop and validate a novel blood test able to differentiate patients with colorectal cancer and adenomatous polyps (AP) from individuals with a negative colonoscopy. EXPERIMENTAL DESIGN: A case-control, multicenter clinical study was designed to collect blood samples from patients referred for colonoscopy or surgery. Predictive algorithms were developed on 75 controls, 61 large AP (LAP) ≥1 cm, and 45 colorectal cancer cases and independently validated on 74 controls, 42 LAP, and 52 colorectal cancer cases (23 stages I-II) as well as on 245 cases including other colorectal findings and diseases other than colorectal cancer. The test is based on a 29-gene panel expressed in peripheral blood mononuclear cells alone or in combination with established plasma tumor markers. RESULTS: The 29-gene algorithm detected colorectal cancer and LAP with a sensitivity of 79.5% and 55.4%, respectively, with 90.0% specificity. Combination with the protein tumor markers carcinoembryonic antigen (CEA) and CYFRA21-2 resulted in a specificity increase (92.2%) with a sensitivity for colorectal cancer and LAP detection of 78.1% and 52.3%, respectively. CONCLUSIONS: We report the validation of a novel blood test, Colox®, for the detection of colorectal cancer and LAP based on a 29-gene panel and the CEA and CYFRA21-1 plasma biomarkers. The performance and convenience of this routine blood test provide physicians a useful tool to test average-risk individuals unwilling to undergo upfront colonoscopy. Clin Cancer Res; 22(18); 4604-11. ©2016 AACR.

Effects of T cell-induced colonic inflammation on epithelial barrier function.

BACKGROUND: Epithelial barrier disturbance is thought to contribute to the pathogenesis of inflammatory bowel diseases; however, it remains unclear whether it is a primary defect participating to the onset of inflammation or only a consequence of sustained inflammation. METHODS: A time course study of epithelial barrier functions and immune mediators was performed in the CD4(+)CD45RB(hi) T cell transfer model of colitis using Ussing chambers. RESULTS: In nonreconstituted severe combined immunodeficiency (SCID) mice, no epithelial dysfunction was observed. However, after transfer of CD4(+)CD45RB(hi) T cells or total CD4(+) T cells, colon of SCID mice displayed a decreased epithelial resistance, even before overt microscopic inflammation had occurred. Sustained colitis of CD4(+)CD45RB(hi) T cell reconstituted mice was also associated with enhanced subepithelial resistance, enhanced paracellular permeability, and decreased net ion transport. All these reflect a disturbance of barrier function and may contribute to diarrhea. Epithelial resistance was positively correlated with interleukin 10 (IL-10) and transforming growth factor beta (TGF-beta) levels and net ion transport inversely correlated with tumor necrosis factor alpha (TNF-alpha) levels, pointing to the protective effect of IL-10 and TGF-beta and to a damaging effect of TNF-alpha. Indomethacin, a nonselective COX inhibitor, decreased epithelial resistance independent of T cells and inflammation, but its effect was more pronounced in inflamed colon. CONCLUSIONS: Induction of colitis by transfer of CD4(+)CD45RB(hi) T cells in SCID mice leads to changes in the colonic epithelium before colitis develops. Decreased epithelium resistance might contribute to the development of colitis; however, it is not sufficient to lead to chronic inflammation.

[Chronic pancreatitis]. / Pancréatite chronique.

New insights in the pathogenesis, classification and the identification of novel risk factors and novel mutations involved in pancreas divisum and in idiopathic pancreatitis have been introduced. Despite novel diagnosis methods, the identification of early pancreatitis, of pancreatitis with minimal morphological changes and the differential diagnosis between chronic pancreatitis and pancreatic carcinoma remain challenges. Treatment of pain associated with pancreatitis remains also difficult; evidence for endoscopic and surgical approaches is still missing. These new discoveries in pathogenesis, etiology and diagnosis methods did not yet lead to improved diagnosis and treatment of chronic pancreatitis.

Wireless capsule pH monitoring: does it fulfil all expectations?

pH monitoring has been used as a diagnostic tool in gastro-oesophageal reflux disease (GERD) for many years. Recent studies have shown that wireless capsule pH monitoring is better tolerated and interferes less with daily activities as compared to traditional catheter-based pH monitoring. Moreover, prolonged recording time (48 h instead of 24 h) is possible with wireless pH monitoring. The main secondary effect of wireless capsule pH monitoring is induction of thoracic discomfort in 10-65% of the patients, which can vary from mild foreign body sensation to severe chest pain. Sensitivity and specificity of wireless capsule monitoring is comparable to that of traditional pH monitoring. It has not been proven yet that better tolerability and a longer recording time increases the diagnostic yield of wireless capsule monitoring in GERD.

Effects of interleukin 4 on CD25+CD4+ regulatory T cell function.

CD25+CD4+ regulatory T cells (Tregs) contribute to the maintenance of peripheral tolerance against self and non-self. The modulatory effects of cytokines, such as interleukin 4 (IL-4) on the function of Tregs have not been explored in detail. We here report that IL-4 prevents spontaneous apoptosis and the decline of foxp3 mRNA which were found to occur during culture of isolated Tregs. Tregs exposed to IL-4 were more potent in suppressing the proliferation of naïve CD4+ T cells and they better inhibited IFN-gamma production by CD4+ T cells as compared to Tregs cultured in medium. IL-4 also enhanced membrane IL-2Ralpha (CD25) expression on Tregs above the levels observed on freshly isolated cells. IL-4-mediated effects on Treg function persisted in Tregs from Stat6-/- mice, pointing to a Stat6-independent intracellular transduction pathway. In conclusion, our data suggest that the anti-inflammatory function of IL-4 could partly be mediated by effects on Tregs function.

Infliximab induces apoptosis of monocytes and T lymphocytes in a human-mouse chimeric model.

Tumor necrosis factor (TNF) antagonism with monoclonal antibodies is an effective therapy for severe Crohn's disease and rheumatoid arthritis. Recent studies have suggested that induction of apoptosis of inflammatory cells contributes to this therapeutic effect. We investigated whether infliximab (a mouse-human IgG1 chimeric anti-TNF monoclonal antibody) could induce apoptosis in vivo in human-mouse chimeras, created by reconstitution of severe combined immunodeficiency/beige mice with THP-1 (human monocytic cell line) or Jurkat cells (human T cell line). Infliximab treatment of chimeric mice depleted spleen and peritoneum from THP-1 cells and Jurkat cells and decreased production of the human cytokines IL-10 and IL-12 in vivo. Cell death was shown to occur already within 1 h of treatment. Infliximab effects were independent of FcgammaR binding or complement activation. Cell death resulted from apoptosis induction in a caspase-dependent pathway, as evidenced by the in vitro protective effect of the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethyketone (Z-VAD-FMK). These data provide support for caspase-dependent apoptosis induction being the mechanism of action of infliximab in vivo.

Functional expression of 4-1BB (CD137) in the inflammatory tissue in Crohn's disease.

4-1BB ligand (L) expressed on antigen presenting cells (APC) interacts with 4-1BB, expressed on activated T cells and this interaction costimulates T cells to secrete cytokines and to proliferate. We investigated whether 4-1BB/4-1BBL interactions might be involved in the pathogenesis of Crohn's disease (CD). In immunohistochemistry, we found 4-1BB expression on lamina propria (LP) cells in inflamed and to a lesser extend in non-inflamed gut tissue from CD patients. mRNA levels for 4-1BB were also elevated in intestinal CD tissue. In contrast, only few 4-1BB-expressing cells were found in inflamed tissue from ulcerative colitis (UC) patients and almost no positive cells were found in control intestinal tissue. 4-1BB expression was better sustained on in vitro activated lamina propria T cells from CD patients compared to controls. Finally, agonistic anti-4-1BB antibody enhanced interferon-gamma (IFN-gamma) production and proliferation of lamina propria T cells from CD patients. Taken together, our data suggest that 4-1BB/4-1BBL interactions contribute to the persistence of gut inflammation in CD.

Inhibition of glycolipid biosynthesis by N-(5-adamantane-1-yl-methoxy-pentyl)-deoxynojirimycin protects against the inflammatory response in hapten-induced colitis.

Since glycolipid biosynthesis is potentially involved in immunological and inflammatory responses, we tested the effect of a novel inhibitor of intracellular glycolipid biosynthesis N-(5-adamantane-1-yl-methoxy-pentyl)-deoxynojirimycin (AMP-DNM) in two hapten-induced colitis models: trinitrobenzene sulphonic acid (TNBS)- and oxazolone (4-ethoxymethylene-2phenyl-2oxazoline-5-one; Oxa)-induced colitis. AMP-DNM was given either by intraperitoneal injection or orally via the diet. Mice treated with AMP-DNM had less severe colitis and a more rapid weight recovery, less edema and less wall thickness. Cellular infiltration, goblet cell loss and myeloperoxidase (MPO) activity were reduced in colons of AMP-DNM-treated animals. Intralesional IFN-gamma and IL-18 production were lower in mice of the AMP-DNM-treated groups. Furthermore, AMP-DNM treatment reduced the serum anti-TNBS and anti-Oxa antibody levels. Our findings show that the glycolipid biosynthesis inhibitor AMP-DNM has a strong anti-inflammatory and immune suppressive activity on both TNBS- and Oxa-induced colitis. The data also provide evidence that glycolipid biosynthesis is involved in the inflammatory cascade in these inflammatory bowel disease (IBD) models.

Targeting of costimulatory molecules as a therapeutic approach in inflammatory bowel disease.

Crohn's disease and ulcerative colitis are inflammatory bowel diseases (IBD) of unknown pathogenesis, for which no curative treatment is currently available. Although the recent introduction of agents designed to neutralise tumour necrosis factor has been an important achievement towards the control of Crohn's disease, further development of more fundamental and non-toxic therapies is still required. One potential approach is the targeting of costimulatory membrane interactions between cells of the immune system. Costimulatory transmembrane ligands interact with receptors on target cells to enhance activation of the latter. Costimulatory interactions between antigen-presenting cells and T lymphocytes and between T lymphocytes and effector macrophages are of utmost importance for the activation of these cell types, which are all thought to be pivotal players in the immunopathology of IBD. Targeting these interactions with humanised monoclonal antibodies or soluble receptor fusion proteins is proposed as a potential new treatment modality of these often devastating pathologies. On the basis of experimental data, and in view of their essential role in the activation of antigen-presenting cells and T lymphocytes, the CD40/CD40 ligand and CD28/B7 interactions are likely to be the best targets for successful therapy.

In vitro analysis of interferon gamma (IFN-gamma) and interleukin-12 (IL-12) production and their effects in ileal Crohn's disease.

Crohn's disease is an inflammatory disease of the gut in which tumour necrosis factor (TNF) and T helper 1 (Th1) cytokines (interleukin (IL)-12, interferon (IFN)-gamma) are thought to play a major role. After the successes obtained with neutralisation of TNF, interest is now growing for therapy aiming at neutralisation of Th1-associated cytokines. Since cytokines are linked in a delicate network, in vitro cultures of ileal lamina propria mononuclear cells (LPMC) were set up for evaluation of a) IFN-gamma and IL-12 production, b) effects of rhIFN-gamma and rhIL-12 and c) effects of anti-IFN-gamma and anti-IL-12 on pro-inflammatory cytokines and IL-10 production. LPMC were isolated from surgical specimens of a total of 27 Crohn's disease and 17 caecum carcinoma (control) patients. Cells were stimulated with CD40L (which triggers myeloid CD40-expressing cells) or anti-CD3 +CD80 (which triggers T cells). LPMC from involved ileal, Crohn's disease produced, in both non-stimulated and stimulated conditions, more IFN-gamma and IL-12p70 than LPMC from non-involved tissue or from control patients. rhIFN-gamma significantly enhanced TNF production in both controls and in ileal Crohn's disease patients, while rhIL-12 enhanced IFN-gamma but not TNF production. LPMC from involved tissue were more sensitive to IL-12 than control LPMC. LP-T cell-dependent activation of monocytes was then studied by co-culture of anti-CD3/CD80-stimulated LPMC with fresh monocytes, which resulted in high IL-12, IFN-gamma, TNF and IL-10 production. The data show that neutralisation of either IL-12 or IFN-gamma with mAb in these cultures also affects secretion of the reciprocal cytokine and (in the case of anti-IL-12) also that of the anti-inflammatory cytokine IL-10. However, no effect of anti-IL-12 or anti-IFN-gamma on production of TNF, a cytokine with an important pathogenic role in Crohn's disease, could be found. Therapies aiming at neutralisation of IFN-gamma or IL-12 are therefore unlikely to replace anti-TNF, but they might provide an additive or synergistic effect.