Clinical Aspects and Pathophysiology of Inflammatory Bowel Disease

Abstract

SUMMARY The chronic inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are recognized as important causes of gastrointestinal disease in children and adults. In this review we delineate the clinical manifestations and diagnostic features of IBD. In addition, we summarize important recent advances in our understanding of the immune mediators of intestinal inflammation. This information has led to new therapeutic approaches in IBD. Further, we discuss the considerable data that point to the significance of genetic factors in the development of IBD and the genetic loci which have been implicated through genomewide searches. The commensal bacterial flora also appears to be a critical element, particularly in regards to Crohn's disease, although the precise role of the bacteria in the disease manifestations remains unclear. Current investigations promise to yield fresh insights in these areas.

Molecular-phylogenetic characterization of microbial community imbalances in human inflammatory bowel diseases

“…Current models of human IBD posit that pathogenesis arises from, and is perpetuated by, interactions between host genetic and immune factors, GI microbes, and environmental triggers (8). The net effect is a dysregulated hypersensitive T H 1-type response of the gut-associated lymphoid tissue to luminal microbes and/or their antigens (2,8). Considerable controversy remains, however, as to whether the entire commensal microbiota or individual pathogens [e.g., Mycobacterium avium spp.…”

“…T he human inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD), are chronic gastrointestinal (GI) illnesses of uncertain etiology, with symptoms ranging from diarrhea and weight loss to ulceration, perforation, and complete obstruction of the GI tract (1)(2)(3). Both diseases are incurable and often require extensive medical and surgical management.…”

Therapeutic targeting of α4-integrins in chronic inflammatory diseases: tipping the scales of risk towards benefit?

“…Inflammatory bowel disease (IBD) consists of a heterogeneous group of idiopathic disorders, including Crohn's disease (CD) and ulcerative colitis (UC) [1,2]. While disease mechanisms are unclear, loss of tolerance against the commensal flora is likely a critical event in IBD pathogenesis.…”

“…A mixed inflammatory infiltrate can be transmural, with features that might include fistulas and intestinal obstruction. Increased levels of the T-helper (Th)1-cytokines IL12, IFNc, and TNFa, accompanied by granuloma formation characterize Crohn's disease as Th1 driven immune disease [2,3]. In contrast, ulcerative colitis is confined to the colon, typically with involvement of the rectum extending proximally to variable lengths, presenting as rectum alone (proctitis), involvement of the sigmoid and descending colon (left-sided) or involvement of the entire colon (pancolitis).…”

Low bone mass in children and adolescents

“…Thus different skeletal sites will be affected by different factors. Dietary calcium intake has been shown to affect primarily appendicular bone sites that are predominantly cortical bone (38), whereas hypogonadism and steroid use affect primarily axial bone sites or the ends of long bones, which are predominantly trabecular bones (39,40).…”