Serum matrix metalloproteinase-7: a potential biomarker in patients with Lynch Syndrome.

BACKGROUND AND AIMS: The expression of tissue and serum matrix metalloproteinase-7 (MMP-7) was shown to be elevated both in colon cancer and dysplastic lesions. We aimed to evaluate, for the first time, its role as a diagnostic marker in Lynch syndrome (LS) carriers, a hereditary syndrome with predisposition to colon cancer. METHODS: This was a case control study. Baseline serum MMP-7 levels were determined by ELISA in 40 colon cancer patients, 62 LS-carriers and 60 healthy controls. Retrieved data from medical files included demographics, background diseases, clinical data regarding tumor characteristics and genetic data. We assessed the association of serum MMP-7 levels with different variables in the study cohort using linear regression model adjusted for potential confounders. RESULTS: In crude analysis, serum MMP-7 levels were significantly higher in colon cancer group compared to LS-carriers and controls [median (IQR) 4.1 ng/ml (2.7-6.0), 2.3 ng/ml (1.7-3.1), 2.5 ng/ml (1.5-3.7), respectively; p value - p < 0.001) while there was no difference between the two last groups (p value = 0.583). However, after adjusting for age and gender, LS-carriers' patients had 18% higher concentrations of serum MMP-7 compared to healthy controls (p value = 0.037), while colon cancer patients had 50% higher serum MMP-7 level in comparison to healthy controls (p value < 0.001). Additionally, age was positively associated with higher serum MMP-7 levels across all study groups (r = 0.67, p value < 0.001). In contrast, no correlation was observed between serum MMP-7 and either tumor staging and gene mutation. CONCLUSIONS: Age-adjusted serum MMP-7 levels in asymptomatic LS carriers are higher than its levels in healthy population. While in colon cancer, MMP-7 higher level probably reflects the tumor burden and may have a prognostic effect, its significance and clinical applicability as a biomarker for tumorigenesis in LS is less clear and should be elucidated.

Host transcriptome signatures in human faecal-washes predict histological remission in patients with IBD.

BACKGROUND: Colonoscopy is the gold standard for evaluation of inflammation in inflammatory bowel diseases (IBDs), yet entails cumbersome preparations and risks of injury. Existing non-invasive prognostic tools are limited in their diagnostic power. Moreover, transcriptomics of colonic biopsies have been inconclusive in their association with clinical features. AIMS: To assess the utility of host transcriptomics of faecal wash samples of patients with IBD compared with controls. METHODS: In this prospective cohort study, we obtained biopsies and faecal-wash samples from patients with IBD and controls undergoing lower endoscopy. We performed RNAseq of biopsies and matching faecal-washes, and associated them with endoscopic and histological inflammation status. We also performed faecal mass-spectrometry proteomics on a subset of samples. We inferred cell compositions using computational deconvolution and used classification algorithms to identify informative genes. RESULTS: We analysed biopsies and faecal washes from 39 patients (20 IBD, 19 controls). Host faecal-transcriptome carried information that was distinct from biopsy RNAseq and faecal proteomics. Transcriptomics of faecal washes, yet not of biopsies, from patients with histological inflammation were significantly correlated to one another (p=5.3×10-12). Faecal-transcriptome had significantly higher statistical power in identifying histological inflammation compared with transctiptome of intestinal biopsies (150 genes with area under the curve >0.9 in faecal samples vs 10 genes in biopsy RNAseq). These results were replicated in a validation cohort of 22 patients (10 IBD, 12 controls). Faecal samples were enriched in inflammatory monocytes, regulatory T cells, natural killer-cells and innate lymphoid cells. CONCLUSIONS: Faecal wash host transcriptome is a statistically powerful biomarker reflecting histological inflammation. Furthermore, it opens the way to identifying important correlates and therapeutic targets that may be obscured using biopsy transcriptomics.

Infliximab levels and antibodies in IBD-related peripheral arthralgia.

BACKGROUND: Extra-intestinal manifestations (EIM) are common in inflammatory bowel diseases (IBD) and may affect up to 40% of the patients during the course of the disease. Peripheral arthralgia (PA) is by far the most common EIM. To date, TNFα inhibitors are the most established treatment for EIMs in IBD. Infliximab (IFX) trough levels (TL) and anti-IFX antibodies (ATI) are correlated with multiple outcomes in IBD such as clinical response and remission, mucosal healing, fistular healing, and more. So far, a correlation between PA and IFX TL\ATI has not been evaluated. METHODS: This retrospective study included IBD patients followed by the gastroenterology department of Sheba Medical Center. Patients with active PA at onset of IFX treatment were included. IFX TL and ATI were evaluated at week 6, 14, and 26 and correlated with PA persistence. RESULTS: Forty patients (37 Crohn's and 3 ulcerative colitis) with IBD-related PA were included. The overall prevalence of PA was 55% (22/40), 42.5% (17/40), and 55% (22/40) after 6, 14, and 26 weeks, respectively. IFX trough drug levels were not associated with reported PA at week 6 [median, 11.8 µg/ml (IQR 6.6-15.5) vs 10.05 µg/ml (IQR 7.35-12.87), p = 0.56], week 14 [median, 4.7 µg/ml (IQR 2.3-7) vs 3.1 µg/ml (IQR 1.35-7.35), p = 0.55], and week 26 [median, 3 µg/ml (IQR 1.15-5.17) vs 3.4 µg/ml (IQR 0.13-6.75), p = 0.94]. Detectable ATI were significantly more prevalent in patients with PA than in patients without PA at week 26 [11/22 (50%) vs 3/18 (16.7%), p = 0.028]. CONCLUSIONS: In patients with IBD-related PA, ATI are associated with an increased risk of persistence of PA. No direct correlation was demonstrated between IFX TL and persistence of PA.

Prolonged Recurrent Abdominal Pain is Associated With Ongoing Underlying Mucosal Inflammation in Patients who had an Episode of Acute Complicated Diverticulitis.

BACKGROUND: Recent data suggest continuous chronic inflammation in patients after an acute diverticulitis (AD) episode. GOALS: The aim of this article was to compare clinical parameters, inflammatory cytokine expression, and immune-cell infiltrates between patients after severe versus nonsevere AD, as defined by radiology examination during the acute episode. STUDY: Sixteen patients, after suffering an episode of AD, were included, and, of them, 8 had severe disease. Demographic data, disease characteristics, and inflammatory markers were collected. Tissue samples from diverticular and unaffected tissue were obtained during colonoscopy. Mucosal inflammation was assessed histologically and by measuring inflammatory cytokine mRNA expression. RESULTS: Clinically, continued nonspecific abdominal symptoms were significantly more prevalent among patients after severe AD compared with patients after nonsevere AD (P=0.0002). Patients after severe AD also had significantly higher C reactive protein levels (9.85±7.5 vs. 3±2.1 mg/dL; P=0.027) and tendency for higher calprotectin levels (115.7±85 vs. 35±8.7 mg/g; P=0.08). Reverse transcription polymerase chain reaction-determined cytokines levels were 5.4±4.4, 5.14±10, and 0.8±0.82 for tumor necrosis factor alpha, interleukin-6, and interleukin-1ß, respectively, in affected mucosa compared with 1.06±1.57, 1.56±2.1, and 0.35±0.5, respectively, in nonaffected mucosa (P=0.01, 0.05, 0.14, respectively). Cytokine expression in patients after nonsevere AD did not differ significantly between affected and nonaffected mucosa. Histologic scores for crypt distortion, lymphoid aggregates, and lymphocyte infiltration were all significantly higher in patients after severe AD compared with patients after nonsevere AD (P<0.05 for all comparisons). CONCLUSIONS: Patients after severe AD have more prolonged chronic symptoms, higher inflammatory markers, higher tissue inflammatory cytokine levels, and more inflammatory infiltrates in diverticular colonic tissue than patients after nonsevere AD. These results may contribute to patients' risk stratification and guide therapeutic decisions.

Association of Vedolizumab Level, Anti-Drug Antibodies, and α4ß7 Occupancy With Response in Patients With Inflammatory Bowel Diseases.

BACKGROUND & AIMS: There are few data available on the real-life pharmacokinetic and pharmacodynamics features of vedolizumab, a monoclonal antibody against integrin α4ß7. We performed a prospective study of patients with inflammatory bowel diseases (IBDs) treated with vedolizumab to determine serum drug concentrations, formation of antivedolizumab antibodies (AVAs), and integrin α4ß7 saturation. METHODS: We performed a prospective study of 106 patients with IBD (67 with Crohn's disease and 39 with ulcerative colitis) treated with vedolizumab from September 2014 through March 2017 at 2 tertiary medical centers in Israel. Clinical data and serum samples were collected before and during induction and maintenance therapy. Clinical remission was defined as Harvey-Bradshaw index scores below 5 or as Simple Clinical Colitis Activity Index scores of 3 or less. We measured serum levels of vedolizumab, AVAs, and markers of inflammation. Peripheral blood mononuclear cells were obtained from some patients at designated trough time points and CD3+ CD45RO+ T cells were isolated from 36 samples. Cells were incubated with fluorescent-conjugated vedolizumab and flow cytometry was used to quantify α4ß7 integrin saturation. We also performed flow cytometry analyses of CD3+ CD45RO+ lamina propria T cells isolated from intestinal mucosa of patients without IBD (non-IBD controls, n = 6), patients with IBD not treated with vedolizumab (untreated IBD controls, n = 8), and patients with IBD treated with vedolizumab (n = 15). RESULTS: Clinical remission was achieved by 48 of 106 patients (45%) by week 6 and 50 of 106 patients (48%) by week 14 of treatment. The median level of vedolizumab at week 6 was higher in patients in clinical remission (40.2 µg/mL) than in patients with active disease (29.7 µg/mL; P = .05). The median serum level of vedolizumab was significantly higher in patients with a normal level of C-reactive protein (21.8 µg/mL vedolizumab) vs the level in those with a high level of C-reactive protein (11.9 µg/mL vedolizumab) during maintenance treatment (P = .0006). The other clinical outcomes measured were not associated with median serum level of vedolizumab at any time point examined. AVAs were detected in 17% of patients during induction therapy and 3% of patients during maintenance therapy, but did not correlate with clinical outcomes. Flow-cytometry analysis of peripheral blood memory T cells (n = 36) showed near-complete occupancy of α4ß7 integrin at weeks 2 and 14 and during the maintenance phase, regardless of response status or drug levels. Most intestinal CD3+CD45RO+ memory T cells of healthy and IBD controls expressed α4ß7 (72%; interquartile range, 56%-81%). In contrast, free α4ß7 was detectable on only 5.6% of intestinal memory cells (interquartile range, 4.4%-11.2%) (P < .0001) from vedolizumab-treated patients, regardless of response. CONCLUSIONS: In a prospective study of real-life patients with IBD, we associated vedolizumab drug levels with remission and inflammatory marker level. Integrin α4ß7 was blocked in almost all T cells from patients treated with vedolizumab, regardless of serum level of the drug or response to treatment. These findings indicate a need to explore alternative mechanisms that prevent response to vedolizumab.

Prospective Observational Evaluation of Time-Dependency of Adalimumab Immunogenicity and Drug Concentrations: The POETIC Study.

OBJECTIVES: Adalimumab is usually self-injected at home, making prospective serial-sampling studies challenging and scarce. This has led to a gap in knowledge about evolution of anti-adalimumab antibodies (AAAs) over time and its correlation with clinical and inflammatory outcomes. METHODS: A program for home visits by physicians at induction, every 3 months and at event of relapse, was established prospectively for Crohn's disease (CD) patients. At each visit, patients' clinical scores were determined and sera were obtained for C-reactive protein, drug, and AAA levels. This cohort was compared to a parallel prospective cohort of infliximab-treated CD patients. In a subgroup of 29 patients, trough and in-between-trough levels were compared, to elucidate the importance of timing of sampling during the injection cycle. RESULTS: Ninety-eight CD patients starting adalimumab were prospectively followed (median follow-up 44 weeks) and 621 serum samples were analyzed. Thirty-three patients (32%) developed AAA; 18/33 (55%) of them as early as week 2, and 26/33 (79%) by week 14. Induction period AAAs were strongly associated with primary non-response (odds ratio (OR) = 5.4, 95% confidence interval (CI): 1.6-17.8, p = 0.005). As compared to antibodies-to-infliximab (ATI), AAA formation rate over time was significantly lower (p = 0.01) and AAA were much more specific-85% of AAA events were associated with loss-of-response compared with 58% rate for ATI (p = 0.01). In 29 patients sampled serially during an injection cycle, levels of drug and AAA seemed comparable between four time-points during a single cycle both in patients with or without AAA (n = 8, n = 21, respectively). CONCLUSIONS: When followed prospectively and serially, AAAs are found to arise earlier than previously appreciated and their impact may be more pronounced for primary rather than secondary, non-response. Drug and AAA levels were similar both at trough and in-between injections, enabling to simplify therapeutic drug monitoring of adalimumab.

Association Between Infliximab Drug and Antibody Levels and Therapy Outcome in Pediatric Inflammatory Bowel Diseases.

OBJECTIVES: While infliximab pharmacokinetics are associated with therapy outcome in adult inflammatory bowel disease (IBD) population, limited data are available in pediatric patients. We aimed to define the relationship between infliximab trough and antibodies' levels (IFX-TL, ATI) and clinical, biomarker remission. METHODS: IFX-TL and ATI were routinely obtained between 2011 and 2017. Associations with clinical and inflammatory (C-reactive protein, CRP) end-points were studied throughout the first year of infliximab therapy. RESULTS: A total of 63 patients (50 Crohn disease, 13 ulcerative colitis, median follow-up 16 months, median 8 samples/patient) were included, and 773 sera-samples were analyzed. Sera of patients in clinical remission had higher median IFX-TLs than sera of those with active disease (4 vs 2.25 µg/mL, P < 0.0001). In addition, patients with normal CRP had a higher median IFX-TL than those with elevated CRP (P = 0.02). Moreover, IFX-TL > 9.2 µg/mL at week 2 predicted clinical remission by week 14 (sensitivity 71.4%, specificity 81.2%, area under curve (AUC) = 0.73, P = 0.02) and IFX-TL > 2.2 µg/mL at week 6 predicted infliximab retention beyond 1 year of treatment (sensitivity 88.9%, specificity 100.0%, AUC = 0.974, P < 0.0001). CONCLUSIONS: A significant association between IFX-TL and ATI and clinical and biomarker remission status in pediatric IBD patients was demonstrated, including a temporal association between week 2, 6 levels and outcome of induction and between week 6 and 14 levels and remission at 1 year of therapy. These findings suggest that therapeutic drug monitoring may be considered for management guidance among pediatric IBD patients.

Cross-immunogenicity: antibodies to infliximab in Remicade-treated patients with IBD similarly recognise the biosimilar Remsima.

OBJECTIVE: The cross-immunogenicity of the recently approved infliximab-biosimilar Remsima (CT-P13) with the originator drug Remicade is still unknown. DESIGN: Sera of patients with IBD with or without measurable anti-Remicade antibodies to infliximab (ATI) were tested for their cross-reactivity to two batches of Remsima. Experiments were repeated after deglycosylation of Remicade/Remsima, IgG purification, excipients' dialysis and monomer purification by size exclusion chromatography. Anti-Remicade antibodies were tested for their functional inhibition of TNF-α binding by Remsima/Remicade by competition assay. Cross-reactivity of anti-adalimumab antibodies with Remicade/Remsima was also investigated. RESULTS: 125 patients' and controls' sera were tested (median age 31 years, IQR 24.5-39.5). All 56 anti-Remicade ATI-negative controls (14 healthy individuals, 42 patients with IBD) were also negative for anti-Remsima ATI. All 69 positive anti-Remicade IBD sera were cross-reactive with Remsima. ATI titres against Remicade or Remsima were strongly correlated (r values between 0.92 and 0.99, p<0.001 for all experiments, Spearman's correlation test). The background ELISA signal for Remsima was slightly higher compared with Remicade in negative controls (1.25±0.6 µg/mL vs 0.76±0.5 µg/mL, respectively, p<0.001), and persisted after deglycosylation, dialysis or protein size filtration, but abolished by IgG purification and significantly diminished by monomer purification. Anti-Remicade ATIs of patients with IBD (n=10) exerted similar functional inhibition on Remsima or Remicade TNF-α binding capacity (p=NS for all inhibition curve points). Antibodies-to-adalimumab in adalimumab-treated patients with IBD (n=7) did not cross-react with either Remicade or Remsima. CONCLUSIONS: Anti-Remicade antibodies in patients with IBD recognise and functionally inhibit Remsima to a similar degree, suggesting similar immunogenicity and shared immunodominant epitopes on these two infliximab agents. In contrast, anti-adalimumab antibodies do not cross-react with Remsima or Remicade.

Optimizing Anti-TNF-α Therapy: Serum Levels of Infliximab and Adalimumab Are Associated With Mucosal Healing in Patients With Inflammatory Bowel Diseases.

BACKGROUND & AIMS: It is not clear what serum levels of anti-tumor necrosis factor are associated with reduced intestinal inflammation in patients with inflammatory bowel disease (IBD). We aimed to identify serum levels of infliximab and adalimumab associated with mucosal healing in patients with IBD and to evaluate the putative gain in control of inflammation by incremental increases in drug levels. METHODS: We performed a retrospective cross-sectional study of 145 patients with IBD treated with infliximab (n = 78) or adalimumab (n = 67) at a medical center in Israel from 2009 through 2014. We collected data from colonoscopy examinations; mucosal healing was defined as simple endoscopic score of <3 or a Mayo score ≤1. These data were compared with serum levels of anti-tumor necrosis factor agents, clinical scores, and levels of C-reactive protein. RESULTS: Median serum levels of infliximab and adalimumab were significantly higher in patients with mucosal healing than patients with active disease (based on endoscopy) (for infliximab, 4.3 vs 1.7 µg/mL, P = .0002; for adalimumab, 6.2 vs 3.1 µg/mL, P = .01). Levels of infliximab above 5 µg/mL (area under the curve = 0.75; P < .0001) and levels of adalimumab above 7.1 µg/mL (area under the curve = 0.7; P = .004) identified patients with mucosal healing with 85% specificity. Increasing levels of infliximab beyond 8 µg/mL produced only minimal increases in the rate of mucosal healing, whereas the association between higher level of adalimumab and increased rate of mucosal healing reached a plateau at 12 µg/mL. In patients with measurable levels of infliximab >3 µg/mL, the presence of antibodies to infliximab was associated with a lower rate of mucosal healing compared with patients with similar drug level without antibodies (16% vs 50%, respectively; P = .003). CONCLUSIONS: In a retrospective study, we found significant association between serum levels of anti-tumor necrosis factor agents and level of mucosal healing. We propose that serum levels of 6-10 µg/mL for infliximab and 8-12 µg/mL for adalimumab are required to achieve mucosal healing in 80%-90% of patients with IBD, and that this could be considered as a "therapeutic window." Exceeding these levels produces only a negligible gain in proportion of patients with mucosal healing.

The temporal evolution of antidrug antibodies in patients with inflammatory bowel disease treated with infliximab.

OBJECTIVE: To characterise the temporal evolution of antibodies to infliximab (ATI). DESIGN: Prospective observational study of infliximab-treated patients with inflammatory bowel disease between 2009 and 2012. INTERVENTIONS: Trough levels of infliximab and ATI were measured before each infusion by anti-λ ELISA. Patients were monitored for disease activity by clinical activity indexes and for dose-intensification or infliximab cessation. The occurrence of transient ATI disappearing spontaneously without intervention was recorded separately. RESULTS: 125 patients were included (98 Crohn's disease, 27 ulcerative colitis, median follow-up 11.5±22 months) and 1119 sera were analysed for infliximab and ATI levels. Kaplan-Meier analysis showed that 42% of patients remained ATI-free by 4 years of treatment. Most (90%) of the patients who developed ATI did so within the first 12 months of therapy, whereas transient ATI were detected throughout the duration of infliximab therapy (p<0.001). ATI incidence was similar between patients who received infliximab previously (episodic/interrupted therapy patients, n=14) and scheduled-therapy patients (n=111). In the scheduled group, combination immunomodulator+infliximab resulted in longer ATI-free survival compared with monotherapy (p=0.003, logrank test). Survival free of clinical loss of response was enjoyed by 51% of patients, and serial measurements showed that ATI development often preceded the onset of clinical flare. CONCLUSIONS: When followed prospectively, most patients who develop ATI do so within the first 12 months of therapy. This incidence is reduced by concomitant immunomodulator even in scheduled-therapy patients. In contrast, transient ATI, which are of little clinical significance, can appear haphazardly at any time during treatment. The onset of clinical loss of response may lag behind the appearance of anti-infliximab antibodies.

Prospective Observational Evaluation of the Time-Dependency of Adalimumab Immunogenicity and Drug Concentration in Ulcerative Colitis Patients: the POETIC II Study.

BACKGROUND AND AIMS: Home self-injection of the human anti-tumour necrosis alpha [anti-TNFα] monoclonal adalimumab complicates prospective serial-sampling studies. Although a recent study examined adalimumab levels and immunogenicity in Crohn's disease [CD] patients, prospective real-world data from ulcerative colitis [UC] patients are lacking. METHODS: A three-monthly home-visit programme from induction was established prospectively for UC patients. Clinical scores were determined at each visit, and sera were obtained for assessment of drug and anti-adalimumab antibody levels. Calprotectin was measured using a smartphone-based app. This cohort was compared to a parallel prospective cohort of adalimumab-treated CD patients [POETIC1]. RESULTS: Fifty UC patients starting adalimumab [median follow-up 28 weeks] were compared to 98 adalimumab-treated CD patients [median follow-up 44 weeks]. Only 11/50 UC patients [22%] continued treatment to the end of the follow-up compared with 50/98 [51%] CD patients (odds ratio [OR] = 0.27, p = 0.001). Loss of response was significantly more common in UC patients [OR = 3.2, p = 0.001]. Seventeen patients [34%] in the UC cohort developed anti-adalimumab antibodies, 9/17 [52.9%] as early as week 2. There was no difference between patient cohorts in the overall development of anti-adalimumab antibodies [34% vs 30.6%, respectively, OR = 1.67, p = 0.67], nor was there a difference in early immunogenicity [OR = 1.39, p = 0.35]. There was no difference in low drug levels [<3 µg/mL] between the two cohorts [OR = 0.87, p = 0.83]. CONCLUSIONS: Loss of response to adalimumab therapy was significantly more common in the UC compared to the CD cohort and was driven by a higher rate of non-immunogenic, pharmacodynamic parameters.

Diet-omics in the Study of Urban and Rural Crohn disease Evolution (SOURCE) cohort.

Crohn disease (CD) burden has increased with globalization/urbanization, and the rapid rise is attributed to environmental changes rather than genetic drift. The Study Of Urban and Rural CD Evolution (SOURCE, n = 380) has considered diet-omics domains simultaneously to detect complex interactions and identify potential beneficial and pathogenic factors linked with rural-urban transition and CD. We characterize exposures, diet, ileal transcriptomics, metabolomics, and microbiome in newly diagnosed CD patients and controls in rural and urban China and Israel. We show that time spent by rural residents in urban environments is linked with changes in gut microbial composition and metabolomics, which mirror those seen in CD. Ileal transcriptomics highlights personal metabolic and immune gene expression modules, that are directly linked to potential protective dietary exposures (coffee, manganese, vitamin D), fecal metabolites, and the microbiome. Bacteria-associated metabolites are primarily linked with host immune modules, whereas diet-linked metabolites are associated with host epithelial metabolic functions.

Celiac disease resolution after allogeneic bone marrow transplantation is associated with absence of gliadin-specific memory response by donor-derived intestinal T-cells.

PURPOSE: To elucidate the relative role of the immune system and intestinal epithelium in the ethiopatogenesis of Celiac disease (CD). METHODS: A patient with childhood CD who underwent allogeneic bone marrow transplantation (BMT) for chronic myelogenous leukemia was followed for 5 years after resumption of gluten containing diet. Immunological memory to gliadin epitopes was assessed in the index patient and in 5 newly diagnosed CD patients by standard serology testing and by CFSE-based proliferation assays of peripheral blood CD4+ cells and of intestinal LPL towards gliadin-TTG antigens. Intestinal lymphocytes' origin was determined by combined immuno-histochemistry and fluorescent in-situ hybridiazation (FISH). RESULTS: Over 5 years of follow-up after receiving BMT from a HLA-matched woman and cessation of gluten-free diet, the patient has remained well, with negative periodic antibodies assays and unremarkable serial duodenal biopsies. In vitro proliferation assays showed lack of a memory response of the patient's peripheral blood and lamina propria CD4+ T-cells towards TTG, gliadin or TTG-treated gliadin, whereas memory responses were evident in the newly diagnosed CD patients. Immuno-FISH of post-BMT duodenal mucosa showed that the chromosomal phenotype of all the epithelial cells was XY. In contrast, CD45+ lymphocytic lineage cells were all donor-derived XX cells, presumably originating in the transplanted bone marrow and re-populating the intestinal wall. CONCLUSIONS: CD resolution following allogeneic BMT is associated with absent gliadin-specific memory response, and with a dichotomous lymphocyte-epithelial chimeric intestine. These observations suggest that the pathogenesis of CD is critically dependent upon the immune system rather than the epithelial compartment.

Addition of an immunomodulator to infliximab therapy eliminates antidrug antibodies in serum and restores clinical response of patients with inflammatory bowel disease.

There are few therapeutic options for patients with inflammatory bowel disease who lose response to infliximab because they produced antibodies against the drug. We performed a retrospective analysis to investigate whether administration of immune modulators to 5 patients who developed antibodies to infliximab (ATI) restored response to this drug; 3 patients were given azathioprine/6-mercaptopurine and 2 patients were given methotrexate. Concentrations of infliximab and ATIs, and antitumor necrosis factor (TNF) activity, were analyzed using enzyme-linked immunosorbent assay-based competition assays of serum samples collected before and after patients were given the immunomodulator. In all patients, levels of ATIs gradually decreased and trough levels of infliximab increased; clinical responses were restored to all patients. In competition assays, immunomodulator-induced elimination of ATIs was associated with increased anti-TNF activity in serum. The addition of immunomodulators to therapy might be helpful to patients who have lost response to anti-TNF agents owing to formation of antidrug antibodies.

Baseline Peripheral Blood Mononuclear Cell Transcriptomics Before Ustekinumab Treatment Is Linked With Crohn's Disease Clinical Response at 1 Year.

INTRODUCTION: Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin (IL)-12 and IL-23, is used for Crohn's disease (CD), and the documented clinical remission rate after 1 year was observed in approximately 50% of patients. We aimed to identify predictors for a clinical response using peripheral blood obtained from patients with CD just before ustekinumab treatment initiation. METHODS: RNA extraction from peripheral blood mononuclear cells was followed by mRNA paired-end sequencing. Differential gene expression was performed using DESeq2. RESULTS: We processed samples from 36 adults with CD (13 men, 36%) obtained at baseline before starting ustekinumab treatment. Twenty-two of 36 (61%) were defined as responders and 14/36 (39%) as nonresponders after 1 year based on Physician Global Assessment. Differential gene expression between responders (n = 22) and nonresponders (n = 14) did not show a gene expression signature that passed false discovery rate (FDR) correction. However, the analyses identified 68 genes, including CXCL1/2/3, which were induced in nonresponders vs responders with P < 0.05 and fold change above 1.5. Functional annotation enrichments of these 68 genes using ToppGene indicated enrichment for cytokine activity (FDR = 1.98E-05), CXCR chemokine receptor binding (FDR = 2.11E-05), IL-10 signaling (FDR = 5.03E-07), genes encoding secreted soluble factors (FDR = 1.73E-05), and myeloid dendritic cells (FDR = 1.80E-08). DISCUSSION: No substantial differences were found in peripheral blood mononuclear cell transcriptomics between responders and nonresponders. However, among the nonresponders, we noted an increased inflammatory response enriched for pathways linked with cytokine activity and chemokine receptor binding and innate myeloid signature. A larger cohort is required to validate and further explore these findings.

Do Vedolizumab trough Levels Predict the Outcome of Subsequent Therapy in Inflammatory Bowel Disease?

Background: Vedolizumab trough serum levels have been associated with clinical and endoscopic response in patients with inflammatory bowel disease (IBD). A recent study demonstrated that higher trough levels before dose escalation are associated with favorable outcomes. Objectives: We aimed to identify whether vedolizumab trough levels predict outcome of subsequent therapy. Methods: This retrospective study included IBD patients consecutively receiving vedolizumab therapy between November 2014 and June 2021. Only patients with a loss of response (LOR) to vedolizumab and available trough drug levels prior to therapy cessation were included. Clinical and endoscopic scores were recorded at 6 and 12 months post switching therapy. Results: Overall, 86 IBD patients (51 Crohn's disease, 35 ulcerative colitis) who discontinued vedolizumab were included; of those, 72 (83.7%) were due to LOR. Upon vedolizumab discontinuation, 66.3% of patients were switched to another biologic therapy. Trough vedolizumab levels at discontinuation due to LOR did not differ between patients with clinical response and LOR regarding subsequent therapy at 6 months [median 33.8 µg/mL (IQR 13.2-51.6) versus 31.7 µg/mL (IQR 9.1-64.8), p = 0.9] and at 12 months [median 29.6 µg/mL (IQR 14.3-51.6) versus 34.1 µg/mL (IQR 12.2-64.7), p = 0.6]. Patients progressing to subsequent surgery had numerically lower vedolizumab trough levels at LOR compared with patients who were treated with an additional medical therapy (median 14.3, IQR 4-28.2 µg/mL versus 33.5, IQR 13-51.6 µg/mL, p = 0.08). Conclusions: Vedolizumab trough levels upon LOR do not predict response to subsequent medical therapy; however, lower drug levels may suggest a more aggressive disease pattern and future need for surgery.

Distal Fecal Wash Host Transcriptomics Identifies Inflammation Throughout the Colon and Terminal Ileum.

BACKGROUND & AIMS: Noninvasive modalities for assessing active endoscopic and histologic inflammation in Crohn's disease and ulcerative colitis patients are critically needed. Fecal wash host shed-cell transcriptomics has been shown to be a robust classifier of endoscopic and histologic inflammation in inflammatory bowel disease patients with distal colitis. Whether such fecal washes can inform on inflammatory processes occurring in more proximal intestinal segments is currently unknown. METHODS: Fifty-nine inflammatory bowel disease patients and 50 controls were prospectively enrolled. Biopsy specimens and fecal washes from the distal colon, proximal colon, and terminal ileum were compared. Host transcriptomics were performed on the biopsy specimens and fecal washes obtained during colonoscopy at predefined locations throughout the colon and terminal ileum and results were associated with concurrent clinical, endoscopic, and histologic parameters. RESULTS: We found that host transcriptomics of distal fecal washes robustly classify histologic inflammation in ileal and proximal colonic Crohn's disease, even without distal colonic involvement (area under the receiver operating characteristic curve, 0.94 ± 0.09). We further found that fecal washes consist of modules of co-expressed genes of immune, stromal, and epithelial origin that are indicative of endoscopic disease severity. Fecal wash host transcriptomics also captures expression of gene modules previously associated with a lack of response to biological therapies. CONCLUSIONS: Our study establishes the accuracy of distal colonic fecal washes for identifying and scoring inflammatory processes throughout the entire ileal-colonic axis.

The immunogenic part of infliximab is the F(ab')2, but measuring antibodies to the intact infliximab molecule is more clinically useful.

OBJECTIVES: To localise the immunogenic part of infliximab and evaluate the clinical usefulness of measuring antibodies against infliximab fragments. DESIGN: Observational study. SETTINGS: A specialised inflammatory bowel disease (IBD) centre in a tertiary hospital. INTERVENTIONS: Serum was collected from patients with IBD and controls. Antibodies against whole infliximab (ATI) and against the digested Fc, F(ab')(2) and F(ab') fragments were measured by a specifically developed ELISA and by western blotting. A separate ELISA was used to determine infliximab levels in serum. RESULTS: 109 serum samples from 62 infliximab-treated patients were tested along with 64 control samples. Anti-F(ab')(2) antibodies were found in 28/42 (67%) samples with positive ATI, all from infliximab-exposed patients. Anti-F(ab')(2) antibodies were also present in 26 of the remaining 67 (39%) samples from exposed patients despite absent ATI. No specific anti-Fc antibodies were detected. Low trough infliximab level and high ATI level was found in 10/12 patients (83%) with complete loss of response to infliximab, but in only 5/14 patients (36%, p=0.02) who regained response to intensified infliximab regimen and in 2/24 patients (8%, p<0.001) in maintained remission while on 5 mg/kg/8 week infliximab treatment. Although Anti-F(ab')(2) antibodies showed similar test characteristics to ATI in patients losing response to infliximab, they were also detected in 61% of patients in maintained remission, thereby limiting their clinical usefulness. No cross reactivity to adalimumab was noted. CONCLUSIONS: F(ab')(2) is the immunogenic fragment of infliximab. However, ATI level in serum--combined with measurement of trough infliximab level--is better correlated with the clinical response to infliximab or with its loss.

Acute Chest Pain as an Infusion Reaction to Vedolizumab.

Vedolizumab-associated adverse effects, including infusion reactions, are generally uncommon. Less than 5% of patients experience an infusion-related reaction. We report a 67-year-old male with ulcerative colitis under prolonged maintenance therapy who presented with recurring chest pain occurring immediately after consecutive vedolizumab infusions. Medical workup of possible etiologies for chest pain were investigated and excluded. Vedolizumab drug trough levels were negative, accompanied by high detectable levels of anti-vedolizumab antibodies. These findings demonstrate an uncommon case of an infusion reaction to vedolizumab infusion.

Delaying an infliximab infusion by more than 3 days is associated with a significant reduction in trough levels but not with clinical worsening.

Background: Higher infliximab trough levels (TLs) correlate with better clinical, inflammatory, and endoscopic outcomes among inflammatory bowel disease (IBD) patients. Although standard scheduled infliximab therapy regimen consists of infusions at pre-defined time-points (weeks 0, 2, 6, and every 8 weeks), short-period deviations from therapeutic schedule are common in 'real life', but the pharmacokinetic impact of these deviations has not been explored. In this study, we aim to determine whether short-period deviations from infusion schedule affect infliximab-TL. Methods: A retrospective analysis of all IBD patients receiving infliximab maintenance therapy every 8 weeks was conducted in a tertiary medical center. Patients with anti-drug antibodies, deliberate interval shortening and <3 sequential maintenance sera available were excluded. Associations between time since last infusion and TL were studied. Statistical analysis was performed using generalized estimating equations. Results: Out of over 10,000 sera, 2088 sera of 302 maintenance period stable infliximab-therapy-patients met inclusion criteria (median TL 4.1 µg/mL, interquartile range (IQR) 2.3-6.5 µg/mL). A delay beyond 3 days in infusion schedule (n > 59 days since last infusion) was found to significantly affect TL (mean difference in TL 0.9 µg/mL, 95% confidence interval (CI): 0.03-1.9 µg/mL, p < 0.04). Furthermore, among patients with delayed infusions, 80% had TL below 5 µg/mL, in comparison to 55% of patients who were not late (odds ratio (OR): 2.81, CI: 2.02-3.92, p < 0.0001). Conclusion: Real-life delays of ⩽3 days from infusion protocol can probably be allowed. Delays >3 days culminate in measurable decrease of TL, although effect on clinical outcome is unclear. This needs to be taken into account when interpreting drug-level test results. Summary: A total of 2088 sera of 302 maintenance period inflammatory bowel disease (IBD) patients treated with infliximab were analyzed, to assess effect of small deviations from infusion schedule on TLs. A significant decline in patients' trough level (TL) was noted as early as 3 days after scheduled infusion.