Ulcerative Colitis: Marth T

Schmidt C, Marth T, Wittig BM, Hombach A, Abken H, Stallmach A. · Abteilung für Innere Medizin II, Universität des Saarlandes, Homburg/Saar, Deutschland. · Pathobiology. · Pubmed #12571423 No free full text.

Abstract: Inflammatory bowel diseases (IBDs; Crohn's disease (CD) and ulcerative colitis) are chronic inflammatory diseases leading to destruction of gastrointestinal tissue. They are characterized by an exaggerated immune response. In CD, an increased expression of T-helper-1 (Th1) cytokines was observed in which interleukin-12 (IL-12) seems to play a pivotal role. Different immunosuppressive agents have been used to treat patients suffering from IBD, nevertheless remarkable side effects or treatment failure are limiting factors in this regard. Therefore, studies on more specific treatment of CD have recently been published, using recombinant anti-inflammatory cytokines or inhibitors of proinflammatory cytokines and their receptors. Beyond these principles anti-IL-12 strategies seem to play a promising role because of the central position of this Th1-inducing cytokine in the inflammatory cascade. Up to now anti-IL-12 antibodies, complement receptor-3 antibodies and IL-12p40 homodimers have been evaluated in their potential to suppress the mucosal inflammation. Based on our understanding of the pathogenesis of CD, the available data and experiences concerning these principles are presented in this review.

Schmidt C, Giese T, Goebel R, Schilling M, Marth T, Ruether A, Schreiber S, Zeuzem S, Meuer SC, Stallmach A. · Department of Internal Medicine II, Saarland University, Homburg, Germany. · Int J Colorectal Dis. · Pubmed #17318554 No free full text.

Abstract: BACKGROUND AND AIMS: It has been suggested that Crohn's Disease (CD) is associated with an elevated T helper 1 response as manifested by increased production of interleukin-18 (IL-18). Local concentrations of neutralizing IL-18 binding proteins (IL-18 bp) may counteract biological functions of mature IL-18 in mucosal inflammation. Therefore, we investigated the IL-18/IL-18 bp system in a large group of patients with active inflammatory bowel disease (IBD) to identify patients that could respond theoretically to IL-18 neutralizing treatment strategies. PATIENT/METHODS: IL-18 and IL-18 bp messenger RNA (mRNA) expression in colonic mucosa from patients with active CD (n = 72), active ulcerative colitis (UC; n = 32), and non-IBD controls (infectious colitis or diverticulitis; n = 19) and normal, non-diseased controls (n = 20) were measured by reverse-transcribed real-time polymerase chain reaction. Mature IL-18 protein and IL-18 bp expression in inflamed mucosa were assessed by Western blotting. RESULTS/FINDINGS: Although IL-18 mRNA was increased in some patients with CD, the increase was not statistically significant. Densitometric evaluation of IL-18/alpha-actin ratio in patients with active CD (n = 20) and patients with UC (n = 10) demonstrated an increased ratio of IL-18 protein in CD when compared to UC (1.04 vs 0.72 [median]). On closer inspections, only 7/20 CD patients had an increased IL-18 protein expression in inflamed areas compared to noninflamed mucosa. INTERPRETATION/CONCLUSION: IL-18 expression in active CD is heterogeneous, only a minority of patients expresses elevated levels. Further treatment strategies targeting IL-18 expression in active CD should be concentrated on this subgroup of patients.

Schmidt C, Giese T, Ludwig B, Mueller-Molaian I, Marth T, Zeuzem S, Meuer SC, Stallmach A. · Department of Internal Medicine II , Saarland University, Homburg, Germany. · Inflamm Bowel Dis. · Pubmed #15674109 No free full text.

Abstract: BACKGROUND: It has been suggested that Crohn's disease (CD) is associated with an exaggerated T-helper 1 cytokine response manifested by increased production of interleukin (IL)-12. IL-12 is a heterodimeric protein comprising 2 disulfide-linked subunits designated p35 and p40. Recently, IL-12-related cytokines, IL-23 and IL-27, were described. Biologically active IL-23 is a heterodimer whose p40 subunit is identical to IL-12p40 whereas its p19 subunit is distantly related to IL-12p35. IL-27 consists of EBI3, an IL-12p40-related protein, and p28, a newly discovered IL-12p35-related polypeptide. AIM: We sought to determine whether mucosal expression of IL-23p19 and IL-27p28 transcripts correlate with the inflammatory activity in inflammatory bowel disease (IBD). PATIENTS/METHODS: Messenger RNA expression in colonic mucosa from patients with Crohn's disease (CD; n = 37) and ulcerative colitis (UC; n = 19), and in non-IBD control subjects (specific colitis [SC]; n = 16) and normal, nondiseased control patients (n = 12) was measured by reverse-transcribed real-time polymerase chain reaction. RESULTS: IL-23p19 was significantly increased in inflamed mucosa in CD (P = 0.0377) and to a lesser extent also in UC patients but not in SC patients. Elevation of IL-23p19 transcript levels in CD correlated with the severity of endoscopic lesions. IL-27p28 transcripts and EBI3 transcripts were significantly elevated only in active CD. DISCUSSION: IL-23p19, IL-27p28, and EBI3 transcripts are strongly up-regulated in CD. The stimulatory effects of these cytokines on naive T cells in addition to a strongly synergistic action with IL-12 to trigger interferon-gamma production may contribute to the perpetuation of the inflammatory process in patients with CD. Notably, increased expression of IL-23 and IL-27 transcripts in CD suggests a T helper 1-dominated immunologic function in this disease.

Stallmach A, Marth T, Adrian N, Wittig BM, Ecker KW, Schilling M, Zeitz M. · Department of Internal Medicine II, Saarland University, 66421 Homburg, Germany. · Int J Colorectal Dis. · Pubmed #12172923 No free full text.

Abstract: BACKGROUND AND AIMS: Since interleukin-12 is pathogenetically involved in Crohn's disease (CD) but not in ulcerative colitis (UC), expression and mechanisms of induction of interleukin-12 receptor (IL-12R) subunits beta(1) and beta(2) were analyzed in lamina propria mononuclear cells (LPMNC) of patients with CD and UC. PATIENTS AND METHODS: LPMNC from patients with CD ( n=17), UC ( n=14), and controls ( n=19) were isolated by standard techniques. IL-12R beta(1) and IL-12R beta(2) transcripts were semiquantified by RT-PCR, and expression of IL-12R beta(2) chain was characterized by flow cytometry. LPMNC were activated by cross-linking with anti-CD3 antibodies and B7-1 costimulation. RESULTS: IL-12R beta(1) and IL-12R beta(2) transcript concentrations were higher in inflamed specimens than in noninflamed segments of patients with CD but not in UC. Increased percentage of mucosal CD4(+)/IL-12R beta(2)(+) cells was observed in active CD, but not UC. In vitro stimulation of LPMNC with anti-CD3 antibodies resulted in an increase in IL-12R beta(1) transcripts irrespective of B7-1 mediated costimulation (84% and 95%, respectively). However, increased expression of IL-12R beta(2) mRNA (110%) was detected only after B7-1 costimulation. CONCLUSION: Our data indicate that increased mucosal expression of IL-12R beta(2) on LPMNC in CD but not in UC may be the result of B7-1 costimulation. Modulation or inhibition of IL-12R beta(2) expression on LPMNC could provide a selective therapeutic approach in CD.