Crohn disease (CD) is an inflammatory bowel disease whose pathogenesis involves inappropriate immune responses toward gut microbiota on genetically predisposed backgrounds. Notably, CD is associated with single-nucleotide polymorphisms affecting several genes involved in macroautophagy/autophagy, the catabolic process that ensures the degradation and recycling of cytosolic components and microorganisms. In a clinical translation perspective, monitoring the autophagic activity of CD patients will require some knowledge on the intrinsic functional status of autophagy. Here, we focused on monocyte-derived dendritic cells (DCs) to characterize the intrinsic quantitative features of the autophagy flux. Starting with DCs from healthy donors, we documented a reprogramming of the steady state flux during the transition from the immature to mature status: both the autophagosome pool size and the flux were diminished at the mature stage while the autophagosome turnover remained stable. At the cohort level, DCs from CD patients were comparable to control in term of autophagy flux reprogramming capacity. However, the homozygous presence of ATG16L1 rs2241880 A>G (T300A) and ULK1 rs12303764 (G/T) polymorphisms abolished the capacity of CD patient DCs to reprogram their autophagy flux during maturation. This effect was not seen in the case of CD patients heterozygous for these polymorphisms, revealing a gene dose dependency effect. In contrast, the NOD2 rs2066844 c.2104C>T (R702W) polymorphism did not alter the flux reprogramming capacity of DCs. The data, opening new clinical translation perspectives, indicate that polymorphisms affecting autophagy-related genes can differentially influence the capacity of DCs to reprogram their steady state autophagy flux when exposed to proinflammatory challenges.Abbreviation: BAFA1: bafilomycin A1, CD: Crohn disease; DC: dendritic cells; HD: healthy donor; iDCs: immature DCs; IL: interleukin; J: autophagosome flux; LPS: lipopolysaccharide; MHC: major histocompatibility complex; nA: autophagosome pool size; SNPs: single-nucleotide polymorphisms; PCA: principal component analysis; TLR: toll like receptor; τ: transition time; TNF: tumor necrosis factor.

Background and aims We aimed to analyze circulating CD4+ T cell subsets and cytokines during the course of Crohn’s disease (CD). Methods and results CD4+ T cell subsets, ultrasensitive C-reactive protein (usCRP), and various serum cytokines (IL-6, IL-8, IL-10, IL-13, IL-17A, IL-23, TNFα, IFNγ, and TGFβ) were prospectively monitored every 3 months for 1 year, using multicolor flow cytometry and an ultrasensitive Erenna method in CD patients in remission at inclusion. Relapse occurred in 35 out of the 113 consecutive patients (31%). For patients in remission within 4 months prior to relapse and at the time of relapse, there was no significant difference in Th1, Th17, Treg, and double-positive CD4+ T cell subsets co-expressing either IFNγ and FOXP3, IL-17A and FOXP3, or IFNγ and IL-17A. On the contrary, in patients who remained in remission, the mean frequency and number of double-positive IL-17A+FOXP3+ CD4+ T cells and the level of usCRP were significantly higher (p ≤ 0.01) 1 to 4 months prior to relapse. At the time of relapse, only the IL-6 and usCRP levels were significantly higher (p ≤ 0.001) compared with those patients in remission. On multivariate analysis, a high number of double-positive IL-17A+FOXP3+ CD4+ T cells (≥1.4 cells/mm3) and elevated serum usCRP (≥3.44 mg/L) were two independent factors associated with risk of relapse. Conclusions Detection of circulating double-positive FOXP3+IL-17A+ CD4+ T cell subsets supports that T cell plasticity may reflect the inflammatory context of Crohn’s disease. Whether this subset contributes to the pathogenesis of CD relapse needs further studies.

In Crohn’s disease (CD) few data are available on the usefulness of monitoring fecal calprotectin (FC) in the early postoperative setting. We assessed prospectively the accuracy of FC measured 3 months after surgery to predict the risk of endoscopic postoperative recurrence (POR) within 1 year after resection. In 55 consecutive CD patients who had undergone ileocolonic resection samples were collected 3 months after surgery for measuring serum CRP and FC. Endoscopic POR was assessed by ileocolonoscopy within 6–12 months (median 7 months). Receiver operating characteristic (ROC) curves were generated to assess accuracy of the markers, to determine the best threshold and to calculate sensitivity, specificity, positive and negative predictive values. In contrast with median CRP levels, median FC concentrations measured 3 months after surgery were significantly higher in patients who later experienced endoscopic POR (Rutgeerts ≥ i2) compared with those who stayed in endoscopic remission within the following 6–12 months (205 μg/g IQR [106–721] vs. 103 μg/g IQR [60–219], p = 0.008). Area under the ROC curve for FC was 0.71. The best cutoff value of FC to identify patients in subsequent endoscopic remission 3 months after surgery was 65 μg/g (96% sensitivity, 31% specificity, 50% positive and 91% negative predictive values). In multivariate analysis, FC < 65 µg/g at 3 months was the only factor associated with subsequent endoscopic remission. FC measured 3 months after surgery below 65 μg/g is an accurate marker to identify CD patients who will later stay in endoscopic remission within 1 year after resection.

Characterization of colorectal neoplasia with Kudo's [1] and Sano's patterns [2] distinguishes superficial neoplasia (submucosal invasion < 1000 μm) displaying Kudo Vi and/or Sano 3a patterns from deep invasive cancers (DIC) (> 1000 μm) that display Kudo Vn or Sano 3b patterns. Endoscopic submucosal dissection (ESD) is a curative treatment for T1 colorectal cancer with submucosal invasion when the tumor does not display budding, lymphovascular invasion and poorly differentiated components, but depth of invasion over 1000 μm is not an independent risk factor of lymph node metastasis [3]. This leads to a new challenge to distinguish lesions with deep submucosal invasion, which are potentially treatable with ESD, from T2 cancers, for which ESD is unfeasible and dangerous since the submucosa disappears below the lesion. Waiting for optical criteria, Japanese experts have proposed attempting ESD with diagnostic intent [4] to obtain, if successful, a precise pathology evaluation (risk factors) to guide further management.