Vaginal delivery in women with perianal Crohn's disease: why not?

BACKGROUND: Pregnant women with active perianal Crohn's disease indicate a cesarean delivery according to the current European Crohn's and Colitis Organisation guidelines. This advice is based on the assumption that vaginal delivery leads to exacerbation of perianal disease and worsening of fecal continence. However, there is no strong evidence to support this. OBJECTIVE: This study aims to examine the effects of the delivery method on perianal disease progression and fecal incontinence in women with perianal Crohn's disease. STUDY DESIGN: In this retrospective cohort study, 102 women were selected from the 1000 inflammatory bowel disease cohort of a tertiary hospital in the Netherlands. All women are aged >18 years, have perianal Crohn's disease, and have given birth. In addition, all women completed a questionnaire. Fecal continence was scored using the Vaizey score. Using SPSS, descriptive analysis and linear regression analysis were performed, and P values <.05 were considered statistically significant. RESULTS: The cesarean delivery rate within our cohort was 19.5%. Within the group of women who delivered at least one child vaginally (n=84), 25.5% reported alteration of fecal continence, compared with 13.1% in women who only had cesarean delivery (n=18). After a mean follow-up of 15 years, the median Vaizey score within the cesarean delivery group was 5, compared with 7 in the vaginal delivery group. Within the vaginal delivery group, 18.8% reported perianal disease progression, compared with 22.2% in the cesarean delivery group. No significant relation between mode of delivery and fecal continence or perianal disease progression was found (B, 0,97 [-1,19 to 3,14], P=.38). CONCLUSION: Fecal incontinence and perianal disease progression after vaginal delivery in Crohn's disease women with active perianal fistula is not significantly increased in this retrospective cohort. This study opens the discussion for more tailored obstetric advice in women with perianal Crohn's disease.

Interobserver agreement of current and new proposed endoscopic scores for postoperative recurrence in Crohn's disease.

BACKGROUND AND AIMS: The modified Rutgeerts' score (mRS) is widely used for the assessment of endoscopic postoperative recurrence (ePOR) in Crohn's disease (CD) after ileocolic resection to guide therapeutic decisions. To improve the validity and prognostic value of this endoscopic assessment, two new scores have been proposed. This study assessed the interobserver agreement of the current (mRS) and new endoscopic scores for ePOR in CD. METHODS: Sixteen Dutch academic and non-academic IBD specialists assessed endoscopic videos (n=71) of postoperative CD patients (n=66) retrieved from nine Dutch centers. Each video was assessed for the degree of inflammation by four gastroenterologists using the mRS and the new proposed endoscopic score: REMIND score (separate score of anastomosis and neoterminal ileum) and updated Rutgeerts score (assessment of lesions at the anastomotic line, ileal inlet, ileal body and neoterminal ileum). In addition, lesions at the ileal body, ileal inlet, neoterminal ileum, colonic and/or ileal blind loop were separately assessed. Interobserver agreement was assessed using Fleiss' weighted kappa. RESULTS: Fleiss' weighted kappa for the mRS was 0.67 (95% confidence interval [CI] 0.59-0.74). The weighted kappa for the REMIND score was 0.73 (95% CI 0.65-0.80) for lesions in the neoterminal ileum and 0.46 (95% CI 0.35-0.58) for anastomotic lesions. The weighted kappa for the updated Rutgeerts' score was 0.69 (95% CI 0.62-0.77). The weighted kappa for lesions in the ileal body, ileal inlet, neoterminal ileum, colonic and ileal blind loop was 0.61 (95% CI 0.49-0.73), 0.63 (95% CI 0.54-0.72), 0.61 (95% CI 0.49-0.74), 0.83 (95% CI 0.62-1.00) and 0.68 (95% CI 0.46-0.89). CONCLUSION: The interobserver agreement of the mRS is substantial. Similarly, the interobserver agreement is substantial for the updated Rutgeerts' score. According to the REMIND score, the interobserver agreement was substantial for lesions in the neoterminal ileum, whereas only moderate for anastomotic lesions. Since therapeutic decisions in clinical practice are based on these assessments and these scores are used as outcome measure in clinical studies, further improvement of the interobserver agreement is essential.

Mucosal host-microbe interactions associate with clinical phenotypes in inflammatory bowel disease.

Disrupted host-microbe interactions at the mucosal level are key to the pathophysiology of IBD. This study aimed to comprehensively examine crosstalk between mucosal gene expression and microbiota in patients with IBD. To study tissue-specific interactions, we perform transcriptomic (RNA-seq) and microbial (16S-rRNA-seq) profiling of 697 intestinal biopsies (645 derived from 335 patients with IBD and 52 from 16 non-IBD controls). Mucosal gene expression patterns in IBD are mainly determined by tissue location and inflammation, whereas the mucosal microbiota composition shows a high degree of individual specificity. Analysis of transcript-bacteria interactions identifies six distinct groups of inflammation-related pathways that are associated with intestinal microbiota (adjusted P < 0.05). An increased abundance of Bifidobacterium is associated with higher expression of genes involved in fatty acid metabolism, while Bacteroides correlates with increased metallothionein signaling. In patients with fibrostenosis, a transcriptional network dominated by immunoregulatory genes is associated with Lachnoclostridium bacteria in non-stenotic tissue (adjusted P < 0.05), while being absent in CD without fibrostenosis. In patients using TNF-α-antagonists, a transcriptional network dominated by fatty acid metabolism genes is linked to Ruminococcaceae (adjusted P < 0.05). Mucosal microbiota composition correlates with enrichment of intestinal epithelial cells, macrophages, and NK-cells. Overall, these data demonstrate the presence of context-specific mucosal host-microbe interactions in IBD, revealing significantly altered inflammation-associated gene-taxa modules, particularly in patients with fibrostenotic CD and patients using TNF-α-antagonists. This study provides compelling insights into host-microbe interactions that may guide microbiota-directed precision medicine and fuels the rationale for microbiota-targeted therapeutics as a strategy to alter disease course in IBD.

Clinical Validation of a Capillary Blood Home-Based Self-Sampling Technique for Monitoring of Infliximab, Vedolizumab, and C-Reactive Protein Concentrations in Patients With Inflammatory Bowel Disease.

BACKGROUND: Therapeutic drug monitoring provides important guidance for treatment of patients with inflammatory bowel disease (IBD) and could help to early identify treatment failure. This study aimed to validate a finger prick-based capillary blood sampling technique to measure biological trough levels and C-reactive protein (CRP) and evaluate patient performance and -support. METHODS: In this prospective cohort study, patients with IBD receiving infliximab (IFX) or vedolizumab (VEDO) therapy performed finger prick-based capillary blood sampling at home. Additionally, blood was collected through routinely performed in-hospital venepuncture prior to biological infusion. IFX, VEDO, and CRP concentrations were measured by enzyme-linked immunosorbent assay. The concordance between methods was statistically evaluated and a survey was conducted to assess practicality and patient support. RESULTS: In total, 81 patients (46 IFX, 35 VEDO) were enrolled. Mean differences between both methods were 0.42 (95% confidence interval, -1.74 to 2.58) µg/mL for IFX and 0.72 (95% confidence interval, -5.50 to 6.94) µg/mL for VEDO. Passing-Bablok regressions demonstrated no evidence for systematic or proportional biases. Venous and capillary IFX (ρ = 0.96, P < .001) and VEDO (ρ = 0.97, P < .001) levels strongly correlated and showed high intermethod agreement (Cohen's kappa: IFX = 0.82; VEDO = 0.94). Similarly, venous and capillary CRP levels were strongly correlated (ρ = 0.99, P < .001). Most patients (>95%) were able to successfully perform the self-sampling at home without prior instructions. CONCLUSIONS: This study clinically validated a finger prick-based capillary blood self-sampling technique allowing concomitant home monitoring of biological levels and CRP for patients with IBD, who reported substantial support, tolerability, and practicality.

Phage-display immunoprecipitation sequencing of the antibody epitope repertoire in inflammatory bowel disease reveals distinct antibody signatures.

Inflammatory bowel diseases (IBDs), e.g., Crohn's disease (CD) and ulcerative colitis (UC), are chronic immune-mediated inflammatory diseases. A comprehensive overview of an IBD-specific antibody epitope repertoire is, however, lacking. Using high-throughput phage-display immunoprecipitation sequencing (PhIP-Seq), we identified antibodies against 344,000 antimicrobial, immune, and food antigens in 497 individuals with IBD compared with 1,326 controls. IBD was characterized by 373 differentially abundant antibody responses (202 overrepresented and 171 underrepresented), with 17% shared by both IBDs, 55% unique to CD, and 28% unique to UC. Antibody reactivities against bacterial flagellins dominated in CD and were associated with ileal involvement, fibrostenotic disease, and anti-Saccharomyces cerevisiae antibody positivity, but not with fecal microbiome composition. Antibody epitope repertoires accurately discriminated CD from controls (area under the curve [AUC] = 0.89), and similar discrimination was achieved when using only ten antibodies (AUC = 0.87). Individuals with IBD thus show a distinct antibody repertoire against selected peptides, allowing clinical stratification and discovery of immunological targets.

Immune Checkpoint Inhibitor-related Pancreatitis: A Case Series, Review of the Literature and an Expert Opinion.

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of various malignancies, but are associated with serious adverse events like pancreatitis. Current guidelines are limited to the first step in treating acute ICI-related pancreatitis with steroids but lack treatment advices for steroid dependent pancreatitis. We describe a case series of 3 patients who developed ICI-related pancreatitis with chronic features such as exocrine insufficiency and pancreatic atrophy at imaging. Our first case developed after treatment with pembrolizumab. The pancreatitis responded well after discontinuation of immunotherapy but imaging showed pancreatic atrophy and exocrine pancreatic insufficiency persisted. Cases 2 and 3 developed after treatment with nivolumab. In both, pancreatitis responded well to steroids. However during steroid tapering, pancreatitis recurred and the latter developed exocrine pancreatic insufficiency and pancreatic atrophy at imaging. Our cases demonstrate resemblances with autoimmune pancreatitis based on clinical and imaging findings. In line, both diseases are T-cell mediated and for autoimmune pancreatitis azathioprine is considered as maintenance therapy. Guidelines of other T-cell mediated diseases like ICI-related hepatitis suggest tacrolimus. After adding tacrolimus in case 2 and azathioprine in case 3, steroids could be completely tapered and no new episodes of pancreatitis have occurred. These findings support the idea that the treatment modalities for other T-cell mediated diseases are worthwhile options for steroid dependent ICI-related pancreatitis.

Hepcidin and Iron Status in Patients With Inflammatory Bowel Disease Undergoing Induction Therapy With Vedolizumab or Infliximab.

BACKGROUND: Hepcidin, the systemic iron regulator, could be critical in differentiating iron deficiency (ID) from functional iron restriction in inflammatory bowel disease (IBD). We assessed hepcidin as a diagnostic ID marker and explored the relationship between hepcidin and its regulators in patients with IBD undergoing induction therapy with infliximab (IFX) or vedolizumab (VEDO). METHODS: Patients with active IBD receiving induction therapy with IFX or VEDO were included. Serum samples at baseline and after 6 weeks of induction therapy were analyzed for hepcidin, inflammation- and hypoxia-associated cytokines, and oxidative stress. Data were analyzed by stratifying based on the response at week 14. Results were compared with samples from age- and sex-matched healthy control subjects. RESULTS: Patients receiving induction therapy with IFX (n = 71) or VEDO (n = 51) and healthy control subjects (n = 50) were included. At baseline, hepcidin correlated positively with ferritin and negatively with soluble transferrin receptor/log ferritin index (P < .001). ID was prevalent in 96.7% of patients who had hepcidin levels below the median. Hepcidin accurately identified ID: the area under the curve (hepcidin) was 0.89 (95% confidence interval, 0.82-0.95; P < .001). In total, 75.4% of patients responded to induction therapy; inflammation, hepcidin, and ferritin decreased significantly, while transferrin increased during induction therapy. These changes were observed only in patients who responded to the therapy. CONCLUSIONS: Hepcidin levels in IBD are primarily determined by ID, even in an inflammatory state. In addition, induction therapy can decrease hepcidin levels, which might lead to better bioavailability of iron supplements. Therefore, hepcidin is a potential diagnostic ID biomarker that could assist therapeutic decision making.

Absolute iron deficiency is the primary determinant of hepcidin levels, even in an inflammatory state. Induction therapy can decrease hepcidin levels, which might improve iron bioavailability. Hence, hepcidin is a potential diagnostic iron deficiency biomarker that could assist therapeutic decision making.

Exposure to Thioguanine During 117 Pregnancies in Women With Inflammatory Bowel Disease.

BACKGROUND: Safety of thioguanine in pregnant patients with inflammatory bowel disease [IBD] is sparsely recorded. This study was aimed to document the safety of thioguanine during pregnancy and birth. METHODS: In this multicentre case series, IBD patients treated with thioguanine during pregnancy were included. Data regarding disease and medication history, pregnancy course, obstetric complications, and neonatal outcomes were collected. RESULTS: Data on 117 thioguanine-exposed pregnancies in 99 women were collected. Most [78%] had Crohn's disease and the mean age at delivery was 31 years. In 18 pregnancies [15%], IBD flared. Obstetric and infectious complications were seen in 15% [n = 17] and 7% [n = 8] of pregnancies, respectively. Ten pregnancies [8.5%] resulted in a first trimester miscarriage, one in a stillbirth at 22 weeks of gestational age and one in an induced abortion due to trisomy 21. In total, 109 neonates were born from 101 singleton pregnancies and four twin pregnancies. One child was born with a congenital abnormality [cleft palate]. In the singleton pregnancies, 10 children were born prematurely and 10 were born small for gestational age. Screening for myelosuppresion was performed in 16 neonates [14.7%]; two had anaemia in umbilical cord blood. All outcomes were comparable to either the general Dutch population or to data from three Dutch cohort studies on the use of conventional thiopurines in pregnant IBD patients. CONCLUSION: In this large case series, the use of thioguanine during pregnancy is not associated in excess with adverse maternal or neonatal outcomes.

Prophylactic Medication for the Prevention of Endoscopic Recurrence in Crohn's Disease: a Prospective Study Based on Clinical Risk Stratification.

BACKGROUND: To prevent recurrence after ileocolonic resection [ICR] in Crohn's disease [CD], postoperative prophylaxis based on risk stratification is recommended in international guidelines. This study aimed to evaluate postoperative CD recurrence after implementation of a clinical management algorithm and to determine the predictive value of clinical and histological risk factors [RFs]. METHODS: In this multicentre, prospective cohort study, CD patients [≥16 years] scheduled for ICR were included. The algorithm advised no postoperative medication for low-risk patients, and treatment with prophylaxis [immunosuppressant/biological] for high-risk patients [≥1 RF: active smoking, penetrating disease, prior ICR]. Clinical and histological RFs [active inflammation, granulomas, plexitis in resection margins] for endoscopic recurrence [Rutgeerts' score ≥i2b at 6 months] were assessed using logistic regression and ROC curves based on predicted probabilities. RESULTS: In total, 213 CD patients after ICR were included [age 34.5 years; 65% women] (93 [44%] low-risk; 120 [56%] high-risk: 45 [38%] smoking; 51 [43%] penetrating disease; 51 [43%] prior ICR). Adherence to the algorithm was 82% in low-risk [no prophylaxis] and 51% in high-risk patients [prophylaxis]. Endoscopic recurrence was higher in patients treated without prophylaxis than with prophylaxis in both low [45% vs 16%, p = 0.012] and high-risk patients [49% vs 26%, p = 0.019]. Clinical risk stratification including the prescription of prophylaxis corresponded to an area under the curve [AUC] of 0.70 (95% confidence interval [CI] 0.61-0.79). Clinical RFs combined with histological RFs increased the AUC to 0.73 [95% CI 0.64-0.81]. CONCLUSION: Adherence to this management algorithm is 65%. Prophylactic medication after ICR prevents endoscopic recurrence in low- and high-risk patients. Clinical risk stratification has an acceptable predictive value, but further refinement is needed.

Effectiveness and safety of tofacitinib for ulcerative colitis: two-year results of the ICC Registry.

BACKGROUND: Tofacitinib is an oral Janus kinase (JAK) inhibitor and is registered for the treatment of ulcerative colitis (UC). The effectiveness of tofacitinib has been evaluated up to 12 months of treatment. AIM: The aim of this study was to assess the effectiveness and safety of 24 months of tofacitinib use in UC patients in the Netherlands. METHODS: Patients initiating tofacitinib treatment were included in the ICC Registry, a nationwide, observational registry. Patients were prospectively evaluated for up to 24 months. The primary outcome was corticosteroid-free clinical remission (CSFR, Simple Clinical Colitis Activity Index [SCCAI] ≤2) at week 104. Secondary outcomes included biochemical remission (C-reactive protein (CRP) ≤5 mg/L and faecal calprotectin (FC) ≤250 µg/g), safety, and discontinuation rate. RESULTS: We included 110 patients of whom 104 (94.5%) were anti-TNF experienced. After 104 weeks of tofacitinib, 31.8% (34/107) were in CSFR, 23.4% (25/107) in biochemical remission and 18.7% (20/107) in combined clinical and biochemical remission. Of the patients in CSFR at week 52, 76.5% (26/34) remained so after 104 weeks of treatment. Sixty-one patients (55.5%) discontinued tofacitinib after a median duration of 13 weeks (IQR 7-34). The main reasons for discontinuation were non-response (59%), loss of response (14.8%), and adverse events (18%). There were 33.9 possible tofacitinib-related adverse events per 100 patient-years during follow-up. Adverse events most probably related to tofacitinib were skin reactions and headaches. There were 6.4 herpes zoster infections per 100 patient-years. CONCLUSION: Tofacitinib was effective in 31.8% of patients after 24 months of treatment.

Superior Effectiveness of Tofacitinib Compared to Vedolizumab in Anti-TNF-experienced Ulcerative Colitis Patients: A Nationwide Dutch Registry Study.

BACKGROUND & AIMS: Clinicians face difficulty in when and in what order to position biologics and Janus kinase inhibitors in patients with anti-tumor necrosis factor-alpha (TNF) refractory ulcerative colitis (UC). We aimed to compare the effectiveness and safety of vedolizumab and tofacitinib in anti-TNF-exposed patients with UC in our prospective nationwide Initiative on Crohn and Colitis Registry. METHODS: Patients with UC who failed anti-TNF treatment and initiated vedolizumab or tofacitinib treatment were identified in the Initiative on Crohn and Colitis Registry in the Netherlands. We selected patients with both clinical as well as biochemical or endoscopic disease activity at initiation of therapy. Patients previously treated with vedolizumab or tofacitinib were excluded. Corticosteroid-free clinical remission (Simple Clinical Colitis Activity Index ≤2), biochemical remission (C-reactive protein ≤5 mg/L or fecal calprotectin ≤250 µg/g), and safety outcomes were compared after 52 weeks of treatment. Inverse propensity score-weighted comparison was used to adjust for confounding and selection bias. RESULTS: Overall, 83 vedolizumab- and 65 tofacitinib-treated patients were included. Propensity score-weighted analysis showed that tofacitinib-treated patients were more likely to achieve corticosteroid-free clinical remission and biochemical remission at weeks 12, 24, and 52 compared with vedolizumab-treated patients (odds ratio [OR], 6.33; 95% confidence interval [CI], 3.81-10.50; P < .01; OR, 3.02; 95% CI, 1.89-4.84; P < .01; and OR, 1.86; 95% CI, 1.15-2.99; P = .01; and OR, 3.27; 95% CI, 1.96-5.45; P < .01; OR, 1.87; 95% CI, 1.14-3.07; P = .01; and OR, 1.81; 95% CI, 1.06-3.09; P = .03, respectively). There was no difference in infection rate or severe adverse events. CONCLUSIONS: Tofacitinib was associated with superior effectiveness outcomes compared with vedolizumab in anti-TNF-experienced patients with UC along with comparable safety outcomes.

Proteomic analyses do not reveal subclinical inflammation in fatigued patients with clinically quiescent inflammatory bowel disease.

Fatigue is a common and clinically challenging symptom in patients with inflammatory bowel diseases (IBD), occurring in ~ 50% of patients with quiescent disease. In this study, we aimed to investigate whether fatigue in patients with clinically quiescent IBD is reflected by circulating inflammatory proteins, which might reflect ongoing subclinical inflammation. Ninety-two (92) different inflammation-related proteins were measured in plasma of 350 patients with clinically quiescent IBD. Quiescent IBD was defined as clinical (Harvey-Bradshaw Index < 5 or Simple Clinical Colitis Activity Index < 2.5) and biochemical remission (C-reactive protein < 5 mg/L and absence of anemia) at time of fatigue assessment. Leukemia inhibitory factor receptor (LIF-R) concentrations were inversely associated with severe fatigue, also after adjustment for confounding factors (nominal P < 0.05). Although solely LIF-R showed weak ability to discriminate between mild and severe fatigue (area under the curve [AUC] = 0.61, 95%CI: 0.53-0.69, P < 0.05), a combined set of the top seven (7) fatigue-associated proteins (all P < 0.10) was observed to have reasonable discriminative performance (AUC = 0.82 [95%CI: 0.74-0.91], P < 0.01). Fatigue in patients with IBD is not clearly reflected by distinct protein signatures, suggesting there is no subclinical inflammation defined by the studied inflammatory proteins. Future studies are warranted to investigate other proteomic markers that may reflect fatigue in clinically quiescent IBD.

Serological Biomarkers of Extracellular Matrix Turnover and Neutrophil Activity Are Associated with Long-Term Use of Vedolizumab in Patients with Crohn's Disease.

Crohn's disease (CD) is a relapsing-remitting inflammatory disease of the gastrointestinal (GI) tract characterized by increased extracellular matrix (ECM) remodeling. The introduction of the α4ß7-integrin inhibitor vedolizumab (VEDO) has improved disease management, although there is a high rate of primary non-response in patients with CD. We studied whether ECM biomarkers of neutrophil activity and mucosal damage could predict long-term response to VEDO in patients with CD. Serum levels of human neutrophil elastase (HNE)-derived fragments of calprotectin (CPa9-HNE), and matrix metalloproteinase (MMP)-derived fragments of type I (C1M), III (C3M), IV (C4M), and VI (C6Ma3) collagen, type III collagen formation (PRO-C3), basement membrane turnover (PRO-C4) and T-cell activity (C4G), were measured using protein fingerprint assays in patients with CD (n = 32) before VEDO therapy. Long-term response was defined as VEDO treatment of at least 12 months. CPa9-HNE was significantly increased at baseline in non-responders compared with responders (p < 0.05). C1M, C3M, C4M, C6Ma3, and PRO-C4 were also significantly increased at baseline in non-responders compared with responders (all p < 0.05). All biomarkers were associated with response to VEDO (all p < 0.05). To conclude, baseline levels of serum biomarkers for neutrophil activity and mucosal damage are linked to the pathology of CD, and are associated with long-term use of VEDO in patients with CD. Therefore, these biomarkers warrant further validation and could aid in therapeutic decision-making concerning vedolizumab therapy.

Serological Biomarkers of Intestinal Collagen Turnover Identify Early Response to Infliximab Therapy in Patients With Crohn's Disease.

Background: Crohn's disease (CD) is characterized by excessive protease activity and extracellular matrix (ECM) remodeling. To date, 30-50% of patients experience non-response to anti-TNF-α treatment. This study aimed to assess whether serological biomarkers of ECM turnover could monitor or predict response to infliximab (IFX) induction therapy in patients with and without a surgical history. Methods: Serum biomarkers of type I (C1M), III (C3M), IV (C4M), and VI (C6Ma3) collagen degradation, type III (PRO-C3) and VI (PRO-C6) collagen formation, basement membrane turnover (PRO-C4), and T-cell activity (C4G), were measured at baseline and week 14, in 63 patients with CD undergoing IFX induction therapy. Patients were stratified according to surgical history. Results: C4M was elevated at baseline in responders with a surgical history (n = 10) and associated with response at baseline (P < 0.05). Additionally, C6Ma3, PRO-C3, and PRO-C6 were elevated at week 14 in responders compared with non-responders (n = 8) and could differentiate between the two groups (P < 0.05). Two biomarker ratios (C4M/C4G and PRO-C4/C4G) were elevated at week 14 in non-responders (n = 5) without a surgical history compared with responders (n = 40) and could differentiate between the response groups (P < 0.05). Conclusion: Baseline levels of a serological biomarker for type IV collagen degradation associated with response to IFX induction therapy, and biomarkers of type III and VI collagen formation may be used to monitor response at the end of induction therapy in patients with a surgical history. Biomarker ratios of type IV collagen turnover demonstrated promising results in monitoring treatment response in patients without a surgical history.

Use of Tumor Necrosis Factor-α Antagonists Is Associated With Attenuated IgG Antibody Response Against SARS-CoV-2 in Vaccinated Patients With Inflammatory Bowel Disease.

Introduction: Patients with Inflammatory Bowel Disease (IBD) frequently receive immunomodulating treatment, which may render them at increased risk of an attenuated immune response upon vaccination. In this study, we assessed the effects of different types of commonly prescribed immunosuppressive medications on the serological response after vaccination against SARS-CoV-2 in patients with IBD. Methods: In this prospective observational cohort study, IgG antibody titers against SARS-CoV-2 were measured 2-10 weeks after completion of standard vaccination regimens in patients with IBD. Clinical characteristics, previous history of SARS-CoV-2 infection, type of vaccine (mRNA- or vector-based) and medication use were recorded at the time of sampling. Subsequently, a chemiluminescent microparticle immunoassay was used for the quantitative determination of IgG antibodies against the receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2. Results: Three hundred and twelve (312) patients with IBD were included (172 Crohn's disease [CD] and 140 ulcerative colitis [UC]). Seroconversion (defined as titer of >50 AU/ml) was achieved in 98.3% of patients. Antibody concentrations were significantly lower in patients treated with TNF-α-antagonists vs. non-users of TNF-α-antagonists (geometric mean [95% confidence interval]: 2204 [1655-2935] vs. 5002 [4089-6116] AU/ml, P<0.001). In multivariable models, use of TNF-α-antagonists (P<0.001), vector vaccines (P<0.001), age (>50 years) (P<0.01) and CD (P<0.05) were independently associated with lower anti-SARS-CoV-2 antibody titers. In patients who received mRNA vaccines, users of thiopurines (either prescribed as monotherapy or in combination with biologicals) demonstrated significantly lower antibody titers compared to thiopurine non-users (P<0.05). Conclusion: Despite reassuring findings that most patients with IBD have detectable antibodies after anti-SARS-CoV-2 vaccination, TNF-α-antagonists were found to be strongly associated with an attenuated IgG antibody response after vaccination against SARS-CoV-2, independent of vaccine type, the time elapsed after vaccination and blood sampling, prior SARS-CoV-2 infection and patient age. Patients treated with thiopurines and receiving mRNA-based vaccines demonstrated lower anti-SARS-CoV-2 antibody titers compared with non-users.