Ulcerative colitis and Crohn’s disease are chronic inflammatory intestinal diseases with perplexing heterogeneity in disease manifestation and response to treatment. While the molecular basis for this heterogeneity remains uncharacterized, single-cell technologies allow us to explore the transcriptional states within tissues at an unprecedented resolution which could further understanding of these complex diseases. Here, we apply single-cell RNA-sequencing to human inflamed intestine and show that the largest differences among patients are present within the myeloid compartment including macrophages and neutrophils. Using spatial transcriptomics in human tissue at single-cell resolution (CosMx Spatial Molecular Imaging) we spatially localize each of the macrophage and neutrophil subsets identified by single-cell RNA-sequencing and unravel further macrophage diversity based on their tissue localization. Finally, single-cell RNA-sequencing combined with single-cell spatial analysis reveals a strong communication network involving macrophages and inflammatory fibroblasts. Our data sheds light on the cellular complexity of these diseases and points towards the myeloid and stromal compartments as important cellular subsets for understanding patient-to-patient heterogeneity.

Summary: Background: Effectiveness of vedolizumab in real world clinical practice is unknown.Aim: To evaluate the short and long‐term effectiveness of vedolizumab in patients with inflammatory bowel disease (IBD).Methods: Patients who received at least 1 induction dose of vedolizumab were included. Effectiveness was defined based on Harvey‐Bradshaw index (HBI) in Crohn's disease (CD) and Partial Mayo Score (PMS) in ulcerative colitis (UC). Short‐term response was assessed at week 14. Variables associated with short‐term remission were identified by logistic regression analysis. The Kaplan‐Meier method was used to evaluate the long‐term durability of vedolizumab treatment. Cox model was used to identify factors associated with discontinuation of treatment and loss of response.Results: 521 patients were included (median follow‐up 10 months [interquartile range 5‐18 months]). At week 14, 46.8% had remission and 15.7% clinical response. CD (vs UC), previous surgery, higher CRP concentration and disease severity at baseline were significantly associated with impaired response. The rate of vedolizumab discontinuation was 37% per patient‐year of follow‐up (27.6% in UC and 45.3% in CD, P < 0.01). CD (vs UC), anaemia at baseline, steroids during induction and CRP concentration were associated with lower durability of treatment. Seven per cent of patients developed adverse events, infections being the most frequent.Conclusions: Over 60% of IBD patients respond to vedolizumab. Many patients discontinue treatment over time. CD and disease burden impair both short‐ and long‐term response. Vedolizumab seems to be safe in clinical practice.

Summary: Background: There are limited data of ustekinumab administered according to the doses recommended in the UNITI studies.Aim: To assess the real‐world, short‐term effectiveness of ustekinumab in refractory Crohn's disease (CD)Methods: Multicentre study of CD patients starting ustekinumab after June 2017 at the recommend dose (260, 390 or 520 mg based on weight ~6 mg/kg IV week 0 and 90 mg subcutaneously week 8). Values for Harvey‐Bradshaw Index (HBI), C‐reactive protein (CRP) and faecal calprotectin (FC) were recorded at baseline and at weeks 8 and 14. Demographic and clinical data, previous treatments, AEs and hospitalisations were documented. Possible predictors of clinical remission were examined.Results: Three hundred and five patients were analysed (≥2 previous anti‐TNFα therapies 64% and vedolizumab 29%). At baseline, 217 (72%) had an HBI >4 points. Of these, 101 (47%) and 126 (58%) achieved clinical remission at weeks 8 and 14, respectively. FC levels returned to normal (<250 µg/g) in 46% and 54% of the patients at weeks 8 and 14 respectively. CRP returned to normal (<3 mg/L) in the 35% and 41% of the patients at week 8 and 14 respectively. AEs were recorded in 38, and 40 patients were hospitalised. Intolerance to the most recent anti‐TNF agent and fewer previous anti‐TNF agents were associated with clinical remission at week 14. Endoscopic severity was associated with poor response.Conclusion: This is the first study to show the real‐world effectiveness and safety of ustekinumab administered according to the recommended induction regimen in a cohort of highly refractory CD patients.

Summary: Background: Data on the long‐term administration of ustekinumab in recommended doses are limited.Aim: To assess the real‐world, long‐term effectiveness of ustekinumab in refractory Crohn's disease (CD).Methods: Multi‐centre study of CD patients starting ustekinumab at the recommended dose, followed for 1 year. Values for the Harvey‐Bradshaw Index (HBI), endoscopic activity, C‐reactive protein (CRP), and faecal calprotectin (FC) were recorded at baseline and at weeks 26 and 52. Demographic and clinical data, previous treatments, adverse events (AEs) and hospitalisations were documented. Potential predictors of remission were examined.Results: A total of 407 patients were analysed. The initial maintenance dose of 90 mg SC was administered every 12, 8 and 4 weeks in 56 (14%), 347 (85%) and 4 (1%) patients, respectively. After 52 weeks, treatment was discontinued in 112 patients (27.5%). At baseline, 295 (72%) had an HBI >4 points. Of these, 169 (57%) and 190 (64%) achieved clinical remission at weeks 26 and 52, respectively. FC levels returned to normal in 44% and 54% of patients at weeks 26 and 52, and CRP returned to normal in 36% and 37% of patients at weeks 26 and 52, respectively. AEs were recorded in 60 patients. The use of fewer previous anti‐TNFα agents and ileal localisation were associated with clinical remission, and endoscopic severity was associated with poor response. No factors correlated with endoscopic remission.Conclusion: After 52 weeks, ustekinumab demonstrated effectiveness in inducing clinical and endoscopic remission in patients with refractory CD.

It has been suggested that in doubtful cases of coeliac disease, a high CD3⁺ T-cell receptor gamma delta⁺ (TCRγδ⁺) intraepithelial lymphocyte count increases the likelihood of coeliac disease. Aim: To evaluate the diagnostic accuracy of both an isolated increase of TCRγδ⁺ cells and a coeliac lymphogram (increase of TCRγδ⁺ plus decrease of CD3⁻ intraepithelial lymphocytes) evaluated by flow cytometry in the diagnosis of coeliac disease. Methods: The literature search was conducted in MEDLINE and EMBASE. The inclusion criteria were: an article that allows for the construction of a 2 × 2 table of true and false positive and true and false negative values. A diagnostic accuracy test meta-analysis was performed. Results: The search provided 49 relevant citations, of which 6 were selected for the analysis, which represented 519 patients and 440 controls. Coeliac lymphogram: The pooled S and Sp were 93% and 98%, without heterogeneity. The area under the SROC curve (AUC) was 0.98 (95% CI, 0.97–0.99). TCRγδ⁺: Pooled S and Sp were both 95%, with significant heterogeneity. The AUC was 0.97 (95% CI, 0.95–0.98). Conclusions: Both TCRγδ⁺ count and coeliac lymphogram assessed by flow cytometry in duodenal mucosal samples are associated with a high level of diagnostic accuracy for and against coeliac disease.