BACKGROUND Loss of response to anti-TNFα treatment occurs frequently in IBD- patients. We evaluatedthe predictive value of serum albumin and γ-globulin concentrations for treatment failure. METHODS Prospectively, all patients treated for the first time with either infliximab or adalimumab for IBD between 2007 and 2018 were included. All patients were tested for serum albumin and γ-globulin concentrations and were followed up until June 2018. RESULTS 128 patients (95 Crohn's disease, 67 females, age 40.1 ± 13.7 years) were included in the study. 81patients (63.3%) received infliximab and 47 (36.7%) adalimumab first line. Eight patients (6.3%) were primary non-responders, 50 patients (39.0%) showed a sustained clinical remission and 70 patients (54.7%) developed a secondary loss of response. Meantime to develop secondary loss of response was 24.5 ± 20.5 months. Albumin serum concentrations in the clinical response group were significantly higher than in the secondary loss of response group (39.8 ± 5.7 g/L vs. 35.0 ± 5.4 g/L). γ-globulin serum concentrations in the sustained response group were significantly lower than in the secondary loss of response group (11.8 ± 2.8 g/L vs. 14.7 ± 4.5 g/L). Hypoalbuminemia and hypergammaglobulinemia were associated with the loss of response. Immunosuppressant co-medication in patients with high γ-globulin serum concentrations reduced the risk of secondary loss of response. CONCLUSION Low albumin and increased γ-globulin serum concentrations are strongly associated with a higher risk for loss of response to an anti-TNFα treatment. Increased serum γ-globulin concentrations may have a higher risk to produce anti-drug antibodies or a different phenotype of disease less responsive to anti-TNFα treatment.

Introduction: Interferon gamma (IFN gamma) has been originally identified by its anti-viral activity and has been demonstrated to act as potent modulator of the immune system with a range of target cells limited largely to immune cell populations. Although IFN gamma has been shown to directly affect the barrier function of intestinal epithelial cells, only limited information is available about other functional effects of IFN gamma on intestinal epithelial cells.Methods: The effects on intestinal epithelial cell migration were studied using a previously described in-vitro model of epithelial restitution in confluent IEC-6 cell monolayers. Intestinal epithelial cell proliferation rates were assessed in various human and rat intestinal and colon epithelial cell lines using colorimetric MTT assays. Apoptosis of IEC-6 cells exposed to IFN gamma was assessed by flow cytometry. In addition, transforming growth factor beta mRNA expression after IFN gamma treatment of IEC-6 cells was assessed by Northern blot analysis.Results: IFN gamma significantly stimulated intestinal epithelial cell migration in an in-vitro wounding model. Furthermore, IFN gamma caused a significant dose-dependent inhibition of epithelial cell proliferation in non-transformed small intestinal IEC-6 cells and human colon cancer-derived HT-29 cells and no significant rates of apoptosis were detected in the exposed epithelial cells. The effect of IFN gamma on epithelial cell migration and proliferation could be completely blocked by neutralizing antibodies against TGF beta indicating that these effects are mediated through a TGF beta dependent pathway. In addition, increased expression of TGF beta 1 mRNA by IEC-6 cells after treatment with IFN gamma supports the hypothesis that IFN gamma modulates intestinal epithelial cell function through a TGF beta-dependent pathway.Conclusion: These studies suggest that IFN gamma produced by constituents of the mucosal immune system modulates epithelial cell functions with relevance for intestinal wound healing and may play a role in preserving the integrity of the intestinal epithelium following various forms of injuries. (C) 2011 Elsevier B.V. All rights reserved.

Objective/background: Signals for the expression of EGF, TGF alpha and related proteins are largely unknown. Having shown earlier, that activation of the afferent sensory nervous system by capsaicin induced epithelial cell proliferation and TGF alpha expression in vivo the aim of this study was to demonstrate, that neurotransmitters of the afferent sensory nervous system induce TGF alpha expression via mast cells and fibroblasts.Results: A significant increase in TGF alpha-mRNA and protein expression was detected in epithelial cells exposed to supernatants of CGRP-stimulated mast cells and SP-stimulated fibroblasts. Epithelial cell proliferation was only detected in epithelial cells exposed to supernatants of CGRP-stimulated mast cells but not in epithelial cells exposed to supernatants of SP-stimulated fibroblasts. TGF beta mRNA expression was increased in epithelial cells exposed to fibroblasts but not to mast cells. No increase in EGF-receptor expression was detected in epithelial cells exposed to either fibroblast or mast cell supernatants.Conclusion: Neurotransmitters of the afferent sensory nervous system induce TGF alpha expression in epithelial cells mediated by mast cells and fibroblasts. Release of CGRP and SP from neuroeffector junctions is an important signal for the TGF alpha expression after mucosal injury. Mucosal expression of TGF alpha may contribute to the protective effects of the sensory nervous system after mucosal injury. (C) 2010 Elsevier B.V. All rights reserved.

Signals for the expression of the peptide growth factors epidermal growth factor and transforming growth factor-α (TGFα) in the gastrointestinal mucosa are largely unknown. We have shown earlier that extrinsic afferents in the gastrointestinal tract induce TGFα expression in colonic mucosa via the deliberation of neurotransmitters substance P and calcitonin gene-related peptide. The aim of our present study was to determine the effects of carbachol on mucosal TGFα expression and epithelial cell proliferation in vivo.

Objective/background Epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) protect gastrointestinal mucosa against injury. Having shown earlier, that TGFa but not EGF is locally increasingly expressed after mucosal injury in the colon, we now wanted to explore the pattern of expression of EGF and TGFa in the remaining gastrointestinal tract and to infer from the pattern of expression, to possible signals for the induction of the growth factor expression and further mechanisms for mucosal protection.Design/methods The trinitrobenzene sulfonic acid/ethanol-induced model of colitis in rats was used. TGF alpha-mRNA and EGF-mRNA expression was evaluated in inflamed and noninflamed colon, in the ileum, jejunum, duodenum, stomach, and in the submandibulary glands.Results A significant increase of TGF alpha-mRNA and EGF-mRNA expressions was detected in the duodenal mucosa and a significant increase in TGF alpha-mRNA expression was observed in the inflamed colonic mucosa after mucosal injury in the colon within the first hours of colitis.Conclusion The increased expression of EGF and TGF alpha in the duodenum may lead to neutralization of gastric acid and proteolytic enzymes in the upper gastrointestinal tract during the course of colitis. Possible signals for the increased expression of EGF and TGFa presumably are fasting, parasympathetic, or adrenergic parts of the enteric nervous system or yet unknown mechanisms.

BACKGROUND:Calcitonin-gene-related peptide (CGRP) and substance P (SP) are neurotransmitters of extrinsic primary afferent neurons located within the dorsal root ganglia. In experimental models of colitis in rats and rabbits, a protective role of SP and CGRP on intestinal mucosa was presumed. The mucosal protection partly depends on a CGRP-mediated modulation of mucosal blood flow. Limited data are available regarding CGRP- or SP-mediated effects on epithelial cell restitution. Having shown earlier that SP-stimulated fibroblasts but not CGRP-stimulated fibroblasts induce epithelial cell migration in vitro, the aim of this study was to explore whether mast cells mediate effects of SP and CGRP on epithelial cell restitution in vitro.METHODS:Mast cells (C57) were exposed to SP [10(-12)-10(-6 M)] and CGRP [10(-12)-10(-7 M)]. After a 24-h incubation period, the cell supernatants (conditioned media, CDM) were taken from mast cell cultures and directly applied to rat intestinal epithelial cell lines-18 or Caco-2 monolayers, which had been wounded with a razor blade 24 h prior to the experiments. Epithelial cell migration was assessed by counting cells across the wound edge and epithelial cell proliferation was measured using 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide test.RESULTS:CGRP significantly induced epithelial cell migration and proliferation via mast cells when supernatants were directly applied to epithelial cells in vitro. The effects on epithelial cell migration were abolished after neutralizing anti-transforming growth factor-beta (TGF-beta) had been added to the cell cultures. SP had no effects on epithelial cells following stimulation of mast cells.CONCLUSION:CGRP modulates epithelial cell restitution in vitro mediated by mast cells. The CGRP- and mast-cell-induced epithelial cell migration is TGF-beta dependent. This observation underlines an important role for extrinsic primary afferent neurons in mucosal defence and repair and in keeping the mucosal homeostasis. This knowledge leads to a better understanding of the interaction of the enteric nervous system and wound healing and may, in the future, lead to new therapeutic approaches to inflammatory diseases of the intestine.

Glucagon like peptide-2 (GLP-2) exerts intestinotrophic actions, but the underlying mechanisms are still a matter of debate. Recent studies demonstrated the expression of the GLP-2 receptor on fibroblasts located in the subepithelial tissue, where it might induce the release of growth factors such as keratinocyte growth factor (KGF) or vascular endothelial growth factor (VEGF). Therefore, in the present studies we sought to elucidate the downstream mechanisms involved in improved intestinal adaptation by GLP-2. Human colonic fibroblasts (CCD-18Co), human colonic cancer cells (Caco-2 cells) and rat ileum IEC-18 cells were used. GLP-2 receptor mRNA expression was determined using real time RTPCR. Conditioned media from CCD-18Co cells were obtained following incubation with GLP-2 (50-250 nM) for 24 h. Cell viability was assessed by a 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide (MTT)-assay, and wound healing was determined with an established migration-assay. Transforming Growth Factor beta (TGF-beta), VEGF and KGF mRNA levels were determined by RT-PCR. Protein levels of VEGF and TGF-beta in CCD-18Co cells following GLP-2 stimulation were determined using ELISA. Neutralizing TGF-beta and VEGF-A antibodies were utilized to assess the role of TGF-beta and VEGF-A in the process of wound healing. GLP-2 receptor expression was detected in CCD-18Co cells. Conditioned media from CCD-18Co cells dose-dependently induced proliferation in Caco-2 cells, but not in IEC-18 cells. Conditioned media also enhanced cell migration in IEC-18 cells (P<0.01), while migration was even inhibited in Caco-2 cells (P<0.0012). GLP-2 significantly stimulated mRNA expression of VEGF and TGF-beta, but not of KGF in CCD-18Co. The migratory effects of GLP-2 were completely abolished in the presence of TGF-beta and VEGF-A antibodies. GLP-2 exerts differential effects on the epithelium of the small intestine and the colon. Thus, in small intestinal cells GLP-2 stimulates wound repair, whereas no such effects were observed in colonic cells. The mechanisms underlying GLP-2 induced intestinal wound repair seem to involve the secretion of VEGF and, subsequently, TGF-beta from subepithelial fibroblasts, whereas KGF appeared to be less important. (C) 2007 Elsevier B.V All rights reserved.

Aims: Substance P (SP) and calcitonin gene related peptide (CGRP) are neurotransmitters of the extrinsic afferent sensory nervous system. In experimental animal models of colitis, a protective role of SP and CGRP on intestinal mucosa was presumed. The mucosal protection in part depends on a SP and CGRP mediated modulation of mucosal blood flow after injury, but other mechanism seem to add to that protective effect. We demonstrate a mast cell and fibroblast mediated effect of SP and CGRP on epithelial cell restitution in vitro and identified potential contributing cytokines.

Substance P (SP) and calcitonin gene-related peptide (CGRP) are neurotransmitters of the afferent sensory nervous system. In experimental models of colitis in rats and rabbits, a protective role of SP and CGRP on the intestinal mucosa was presumed. In part, mucosal protection depends on a SP-mediated and CGRP-mediated modulation of mucosal blood flow after injury. We thought to explore whether there is a fibroblast-mediated effect of SP and CGRP on epithelial cell restitution in vitro.

BACKGROUND:Animal experiments on hernia repair demonstrated better biocompatibility of light-weight polypropylene meshes. However, implanted medical devices trigger a variety of adverse tissue responses, such as inflammation, fibrosis, infection and thrombosis, but the mechanisms involved in such responses remain largely unknown. This study aimed to determine the effect of transforming growth factor beta1 (TGF-beta1) on host tolerance by quantification of foreign body reaction in cultured fibroblasts depending on the amount and composition of implanted material used for hernia repair.MATERIALS AND METHODS:An NRK-49F fibroblast culture was incubated in the presence of 4 commercially available meshes approved for hernia repair. A mesh-free cell suspension served as a control group, in which the influence of TGF-beta1 on fibroblasts was evaluated. Levels of TGF-beta1 in the supernatant were dynamically measured in a time interval of 6 to 96 h and cell proliferation rates were assessed colorimetrically using MTT test.RESULTS:A dose-dependent suppression of fibroblasts proliferation by TGF-beta1 was observed. All meshes suppressed the secretion of TGF-beta1 and conversely increased significantly cell proliferation in comparison to the control group (p<0.01) in the first 24 to 48 h of incubation. That effect was more pronounced in meshes partially containing absorbable material when compared to samples of pure polypropylene meshes (p<0.05) and to the control group (p<0.001).CONCLUSION:Our experiment revealed that early biological reaction of connective tissue cells towards polypropylene meshes and their variants depended much more on the composition and type of the material than on its absolute amount. The assumption that material weight reduction alone might affect the foreign body reaction of mesh implants could not be confirmed by our in vitro study.

Background: The role of mutations in the serine protease inhibitor Kazal type 1 (SPINK1) gene in chronic pancreatitis is still a matter of debate. Active SPINK1 is thought to antagonize activated trypsin. Cases of SPINK1 mutations, especially N34S, have been reported in a subset of patients with idiopathic chronic pancreatitis. However, the inheritance pattern is still unknown. Some cases with N34S heterozygosity have been reported with and without evidence for CP indicating neither an autosomal recessive nor dominant trait. Therefore SPINK1 mutations have been postulated to act as a disease modifier requiring additional mutations in a more complex genetic model. Familial hypocalciuric hypercalcemia (FHH) caused by heterozygous inactivating mutations in the calcium sensing receptor ( CASR) gene is considered a benign disorder with elevated plasma calcium levels. Although hypercalcemia represents a risk factor for pancreatitis, increased rates of pancreatitis in patients with FHH have not been reported thus far.Methods: We studied a family with a FHH-related hypercalcemia and chronic pancreatitis. DNA samples were analysed for mutations within the cationic trypsinogen (N29I, R122H) and SPINK1 ( N34S) gene using melting curve analysis. Mutations within CASR gene were identified by DNA sequencing.Results: A N34S SPINK1 mutation was found in all screened family members. However, only two family members developed chronic pancreatitis. These patients also had FHH caused by a novel, sporadic mutation in the CASR gene (518T> C) leading to an amino acid exchange ( leucine-> proline) in the extracellular domain of the CASR protein.Conclusion: Mutations in the calcium sensing receptor gene might represent a novel as yet unidentified predisposing factor which may lead to an increased susceptibility for chronic pancreatitis. Moreover, this family analysis supports the hypothesis that SPINK1 mutations act as disease modifier and suggests an even more complex genetic model in SPINK1 related chronic pancreatitis.