Search

Background: To date, responsiveness to tumor necrosis factor alpha inhibitors in ulcerative colitis (UC) patients is not predictable. This is partially due to a lack of understanding of the underlying inflammatory processes. The aim of this study was to identify immunological subgroups of patients with UC and to test responsiveness to adalimumab in these subgroups in the mouse model of ulcerative colitis (UC), which is based on NOD/scid IL-2Rγ null (NSG) mice reconstituted with peripheral blood mononuclear cells (PBMCs; NSG-UC)., Methods: The immunological profiles of 40 UC patients and 16 non-UC donors were determined by flow cytometric analysis of PBMCs in a snapshot and longitudinal study and analyzed by principal component, orthogonal partial least square discrimination (oPLS-DA), and hierarchical clustering analysis. NSG mice were reconstituted 5 times at consecutive time points with PBMCs from a single donor and were analyzed for frequencies of human leukocytes and histological phenotype. The response to adalimumab of 2 identified subgroups was tested in the NSG-UC model. We used the clinical, colon, and histological score, serum levels of glutamic and aspartic acid, and IL-6 and IL-1ß. Response was analyzed by oPLS-DA., Results: Analysis revealed a distinction between UC and non-UC donors. Hierarchical clustering identified 2 major subgroups in UC patients. Group I was characterized by TH17 and M1 monocytes, group II by TH2/TH1, and switched B cells. These subgroups reflect the dynamics of inflammation as patients. NSG-UC mice achieved an immunological phenotype reflecting the patient's immunological phenotype. oPLS-DA revealed that NSG-UC mice reconstituted with PBMCs from group II responded better to adalimumab., Conclusions: The combination of profiling and testing of therapeutics in the NSG-UC model may lead to individualized and phase-dependent therapies., (© 2019 Crohn’s & Colitis Foundation. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation.)

Background: CD1a-expressing CD14+ monocytes have been identified as inducers of autoreactive T cells. In this study, the link between inflammatory and metabolic signals and CD1a-expressing monocytes in vitro and in vivo was examined, and CD1a was evaluated as a potential therapeutic target for treatment of ulcerative colitis (UC)., Methods: Peripheral blood mononuclear cells (PBMCs) from UC patients and non-UC donors were incubated with phosphatidylcholine (PC) for 2 and 7 days and subjected to flow cytometric analysis. Triacylglycerol (TAG) and cholesterol levels and frequencies of CD14+ CD1a+ monocytes were determined in a mouse model of UC that is based on NOD/scid IL2Rγnull mice reconstituted with PBMCs from UC patients (NSG-UC). NSG-UC mice were treated with anti-CD1a antibodies. Response to treatment was determined by clinical and histological scores, flow cytometric analysis of human leucocytes from the spleen and colon, and expression levels of TGFß1, HGF, IFNγ, and TARC., Results: Incubation of PBMCs with PC resulted in an increase of the frequency of CD1a+ CD14+ monocytes at the expense of CCR2-, CD86-, and TSLPR-expressing CD14+ monocytes. CD1a+ CD14+ monocytes induced the activation of CD4+ T cells and differentiation of Th cells. In vivo, TAG and cholesterol levels increased upon inflammation and correlated positively with CD14+ CD1a+ monocytes. NSG-UC mice benefitted from treatment with anti-CD1a antibodies, as indicated by a reduced histological score and reduced frequencies of CD1a+ CD14+ monocytes in the colon and spleen of mice., Conclusion: CD1a-expressing monocytes might act as sensors and mediators of inflammation in UC. Mice benefitted from treatment with anti-CD1a antibodies., (© 2018 Crohn’s & Colitis Foundation. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation.)

Background: Lipocalin-2 (LCN2) is a potent bacteriostatic protein. We aimed to investigate its role as a disease activity marker in patients with inflammatory bowel disease (IBD) and its induction by the Th17 cytokines IL-17A, IL-22, and TNF-α in colonic epithelial cells. Moreover, we analyzed the influence of IBD-associated IL23R alleles on LCN2 serum levels in IBD patients., Methods: LCN2 serum levels were determined in 131 IBD patients (71 with Crohn's disease [CD], 60 with ulcerative colitis [UC]) and 63 healthy controls. IBD patients were genotyped for 10 IBD-associated IL23R polymorphisms. LCN2 expression after stimulation with IL-17A, IL-22, and TNF-α was measured in human colonic epithelial cell lines., Results: A significant upregulation of serum LCN2 in active IBD (median [IQR], 36.84 [21.17-73.74] ng/mL; P = 0.01) compared with healthy controls (24.22 [17.76-35.25] ng/mL) was confined to active UC (42.21 [28.97-73.74] ng/mL; P = 0.0006). LCN2 proved to be a marker of UC disease activity (area under the curve 0.75, sensitivity 0.83, specificity 0.63; P = 0.0002). IL-17A showed a synergistic effect with IL-22 and TNF-α in inducing colonic epithelial expression of LCN2 and its essential transcription factor IKBZ. In CD, LCN2 concentrations were significantly modulated by IL23R genotype status with homozygous carriers of IBD risk-increasing alleles showing particularly low LCN2 levels., Conclusions: Serum LCN2 proves to be a biomarker of active UC. Lower LCN2 levels in CD patients carrying IBD risk-increasing IL23R variants may result from a restricted upregulation of LCN2 due to an impaired Th17 immune response.

Background: In contrast to anti-TNF-α antibodies, anti-IL-17A antibodies lacked clinical efficacy in a trial with patients suffering from Crohn's disease. We therefore analyzed how IL-17A modulates the inflammatory response elicited by TNF-α in intestinal epithelial cells (IEC)., Methods: Target mRNA levels in IEC and colonic biopsies were assessed by RNA microarray and quantitative real-time PCR. Signaling pathways were analyzed using receptor neutralization and pharmacological inhibitors. Target protein levels were determined by immunoblotting., Results: Microarray analysis demonstrated that IL-17A alone is a weak inducer of gene expression in IEC (29 regulated transcripts), but significantly affected the TNF-α-induced expression of 547 genes, with strong amplification of proinflammatory chemokines and cytokines (>200-fold increase of CCL20, CXCL1, and CXCL8). Interestingly, IL-17A differentially modulated the TNF-α-induced expression of several inflammatory bowel disease susceptibility genes in IEC (increase of JAK2 mRNA, decrease of FUT2, ICAM1, and LTB mRNA). Negative regulation of ICAM-1 by IL-17A was verified on protein level. The significance of these findings is emphasized by inflamed lesions of patients with inflammatory bowel disease demonstrating significant correlations (P < 0.01, Rho, 0.57-0.85) for JAK2, ICAM1, and LTB mRNA with IL17A and TNF mRNA., Conclusions: Our study demonstrates the modulation of inflammatory bowel disease susceptibility gene mRNA in IEC as a novel important property of IL-17A. Given the weak impact of sole IL-17A stimulation on IEC target gene expression, our study provides an important explanation for the lack of clinical efficacy of sole IL-17A neutralization, but suggests a beneficial effect of combined IL-17A/TNF-α that is currently in clinical development.

Background: In patients with Crohn's disease (CD), the effect of anti-tumor necrosis factor alpha (TNF-α) antibody therapy on postoperative complications remains unclear. We aimed to determine the effects of infliximab on postoperative complication rates in patients undergoing abdominal surgery for CD., Methods: Infliximab-treated CD patients undergoing abdominal surgery were identified in a prospective database. Gender- and age-matched CD patients without infliximab treatment served as controls. General and complication-related information was retrieved from patient records., Results: Forty-eight patients underwent abdominal surgery within 3 months (median 60 days, range 1-90 days) after infliximab administration (56% female, median age 35 years, range 17-66 years). Forty-eight patients without infliximab served as controls (50% female, 39 [17-68] years). Patient characteristics and number of minor complications were comparable between groups: wound infection (infliximab: 19% vs. controls: 15%), prolonged postoperative ileus (15% vs. 4%), and urinary tract infection (2% vs. 0%; all P > 0.05). No differences were found in major complications: anastomotic leakage (infliximab: 4% vs. controls: 13%), abscess formation (6% vs. 10%), bowel perforation (2% vs. 4%), stoma complication (6% vs. 2%), postoperative hemorrhage (8% vs. 2%), and enterocutaneous fistula (4% vs. 0%; all P > 0.05). One malnourished infliximab-treated patient with a complicated course of disease died postoperatively after anastomotic leakage, sepsis, and cardiac arrhythmia. Eleven infliximab and 10 control patients required reoperation (P > 0.05). Hospital stay was comparable between groups (infliximab: 13 [5-41] vs. controls: 12 [5-54] days; P > 0.05)., Conclusions: Infliximab does not affect postoperative complication rates, suggesting no need to alter surgical management in these patients., (Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.)

Background: The pregnane X receptor (PXR/NR1I2) is an important regulator of xenobiotic metabolism and intestinal integrity. However, there are controversial studies on the role of PXR/NR1I2 in inflammatory bowel disease (IBD). We therefore initiated the largest analysis to date on PXR/NR1I2 gene variants in IBD patients., Methods: Genomic DNA from 2823 individuals of Caucasian origin including 859 patients with Crohn's disease (CD), 464 patients with ulcerative colitis (UC), and 1500 healthy, unrelated controls was analyzed for eight PXR/NR1I2 single nucleotide polymorphisms (SNPs) (rs12721602 (-25564), rs3814055 (-25385), rs1523128 (-24756), rs1523127 (-24381), rs45610735 = p.Gly36Arg (+106), rs6785049 (+7635), rs2276707 (+8055), and rs3814057 (+11156)). In addition, detailed haplotype and genotype-phenotype analyses were performed., Results: The PXR/NR1I2 SNP rs2276707 was weakly associated with UC susceptibility (P = 0.01; odds ratio [OR] 1.27 [1.06-1.52]). None of the other PXR/NR1I2 SNPs were associated with UC or CD susceptibility. However, several rare PXR/NR1I2 haplotypes were highly associated with CD susceptibility. In CD, the strongest disease association was found for a haplotype consisting of the SNPs rs12721602-rs3814055-rs1523128-rs1523127-rs12721607-rs6785049-rs2276707-rs3814057 (omnibus P-value: 6.50 × 10(-15)) which was found in two separate cohorts (cohort I = discovery cohort: CD: n = 492, controls: n = 793; P = 4.51 × 10(-17); Bonferroni corrected: P = 1.27 × 10(-15); cohort II = replication cohort: CD: n = 367, controls: n = 707; P = 7.12 × 10(-4); P(corr) = 1.99 × 10(-2))., Conclusions: Several PXR/NR1I2 haplotypes contribute to CD susceptibility, suggesting a role for PXR in the IBD pathogenesis of a certain patient subcohort. Given the accumulating evidence for an important role of PXR in intestinal inflammation, further analyses are required to investigate the functional and pharmacogenetic implications of these PXR/NR1I2 gene variants in IBD., (Copyright © 2010 Crohn's & Colitis Foundation of America, Inc.)

Background: Anti-tumor necrosis factor (TNF) therapy used in patients with inflammatory bowel disease (IBD) has been associated with induction of autoantibodies including antinuclear antibodies (ANA), double-strand (ds) DNA antibodies, and the occurrence of lupus-like syndrome (LLS). However, the clinical relevance of autoantibody formation and predictive factors are unclear., Methods: 180 IBD patients treated with anti-TNF antibodies (infliximab or adalimumab, or infliximab and adalimumab consecutively) were analyzed regarding ANA and dsDNA antibody values and the development of LLS, including factors predicting the development of LLS., Results: In all, 44.4% of anti-TNF-treated patients had ANA titers ≥1:240, while 15.6% had dsDNA serum levels ≥9 U/mL. However, only a minority of these patients experienced clinical symptoms of LLS; 8.9% presented with mild lupus-like symptoms with no need for intervention; 1.1% had severe symptoms consistent with LLS requiring immediate stop of anti-TNF therapy. Multivariate logistic regression analyses identified age as an independent risk factor for developing ANA ≥1:240 (P < 0.001) and LLS (P = 0.002), while concomitant immunosuppressive therapy was protective against autoantibody formation (ANA: P = 0.05) and LLS development (P = 0.04). There was a significant association between dsDNA antibody values ≥9 U/mL and LLS (P = 0.02) but not between ANA titers and LLS., Conclusions: dsDNA antibody levels ≥9 U/mL, but not ANA titers ≥1:240, are associated with clinical symptoms of LLS. IBD patients of higher age treated with anti-TNF-α antibodies are at increased risk for development of ANA and LLS, while concomitant immunosuppressive therapy may have a protective effect., (Copyright © 2010 Crohn's & Colitis Foundation of America, Inc.)

Background: Immunosuppressive therapy with anti-TNF-alpha antibodies is effective in patients with inflammatory bowel disease (IBD). However, there is an increased risk for infections associated with this therapy., Methods: Here, we report the case of a 58-year-old patient with Crohn's disease (CD) treated with steroids and azathioprine who developed severe Legionella pneumophila pneumonia after 3 infusions of infliximab. The patient presented at our IBD department with severe active CD complicated by inflammatory small bowel stenoses and entero-enteral fistulas despite long-term high-dose steroid therapy. To achieve steroid tapering and control of disease activity, immunosuppressive therapy with azathioprine was initiated. Due to persistent symptoms, infusion therapy with the anti-TNF-alpha antibody infliximab was started, subsequently leading to significant clinical improvement. However, after the third infliximab infusion the patient was hospitalized with fever, severe fatigue, and syncope., Results: Laboratory findings and chest X-ray revealed left-sided pneumonia; cultural analysis showed L. pneumophila serogroup 1 leading to respiratory insufficiency, which required mechanical ventilation for 2 weeks in the intensive care unit. After discontinuation of all immunosuppressive agents and immediate antibiotic therapy the patient recovered completely., Conclusions: To our knowledge, this is the third case of L. pneumophila pneumonia in an IBD patient treated with infliximab. Similar to other published cases, concomitant treatment of immunosuppressives and anti-TNF agents is a major risk factor for the development of L. pneumophila infection, which should be ruled out in all cases of pneumonia in patients with such a therapeutic regimen. Appropriate prevention strategies should be provided in these patients.