Intestinal strictures in Crohn’s disease: a 2021 update

Abstract

Intestinal strictures remain one of the most intractable and common complications of Crohn’s disease (CD). Approximately 70% of CD patients will develop fibrotic strictures after 10 years of CD diagnosis. Since specific antifibrotic therapies are unavailable, endoscopic balloon dilation and surgery remain the mainstay treatments despite a high recurrence rate. Besides, there are no reliable methods for accurately evaluating intestinal fibrosis. This is largely due to the fact that the mechanisms of initiation and propagation of intestinal fibrosis are poorly understood. There is growing evidence implying that the pathogenesis of stricturing CD involves the intricate interplay of factors including aberrant immune and nonimmune responses, host-microbiome dysbiosis, and genetic susceptibility. Currently, the progress on intestinal strictures has been fueled by the advent of novel techniques, such as single-cell sequencing, multi-omics, and artificial intelligence. Here, we perform a timely and comprehensive review of the substantial advances in intestinal strictures in 2021, aiming to provide prompt information regarding fibrosis and set the stage for the improvement of diagnosis, treatment, and prognosis of intestinal strictures.

Neutrophil-fibroblast crosstalk drives immunofibrosis in Crohn’s disease through IFNα pathway

“…Since fibrotic complications are a prominent feature of Crohn’s disease (CD) ( 2, 3 ) and recent data have shown that profibrotic activity of human lung fibroblasts is associated with downregulated KLF2, elevated CCN2 levels, and increased collagen production ( 13 ), we aimed to investigate whether intestinal fibroblasts in CD share similarities with this fibrotic phenotype.…”

“…Crohn’s disease (CD) is characterized by chronic relapsing inflammation that, in contrast to ulcerative colitis (UC), may lead to intestinal fibrosis causing lifelong disabling illness with a large impact on the quality of life and the healthcare systems ( 1, 2 ). Therefore, understanding the mechanisms of initiation and propagation of intestinal fibrosis in CD is crucial to providing knowledge for diagnosis and better care of patients ( 3, 4 ).…”

Crohn's disease: An enigmatic variant with gastritis and ileal obstruction

“…10 Intestinal strictures form part of the natural history of Crohn's disease and will occur in up to 70% of patients over a 10-year period. 11 The strictures are classified as inflammatory, fibrotic, primary, or anastomotic. 12 Inflammatory strictures result from edema of the intestinal lining, while fibrotic ones are caused by chronic inflammation that results in the accumulation of extracellular matrix and hyperproliferation of smooth muscle cells.…”

“…Intestinal strictures form part of the natural history of Crohn's disease and will occur in up to 70% of patients over a 10‐year period 11 . The strictures are classified as inflammatory, fibrotic, primary, or anastomotic 12 .…”

Developments in Checkpoint Inhibitor Therapy for the Management of Deficient Mismatch Repair (dMMR) Rectal Cancer

“…While a rectal stricture may represent residual tumor scar tissue, its formation may be increased by ICI-induced inflammation and colitis in and around the tumor bed. Similarly, strictures have been reported in patients diagnosed with inflammatory bowel disease (IBD) [ 53 , 54 ], which can be associated with an increased risk of severe GI adverse events [ 55 , 56 ] when treated with immune checkpoint inhibitors. The patient in our cases study had no prior history of IBD and in follow-up had no further symptoms of colitis.…”