Onset of Suspected Ulcerative Colitis After Treatment With Tocilizumab in Patient With Celiac Disease and Juvenile Idiopathic Arthritis

Role of interleukin-6-mediated inflammation in the pathogenesis of inflammatory bowel disease: focus on the available therapeutic approaches and gut microbiome

Inflammatory bowel disease (IBD) is considered a chronic inflammatory and multifactorial disease of the gastrointestinal tract. Crohn's disease (CD) and ulcerative colitis (UC) are two types of chronic IBD. Although there is no accurate information about IBD pathophysiology, evidence suggests that various factors, including the gut microbiome, environment, genetics, lifestyle, and a dysregulated immune system, may increase susceptibility to IBD. Moreover, inflammatory mediators such as interleukin-6 (IL-6) are involved in the immunopathogenesis of IBDs. IL-6 contributes to T helper 17 (Th17) differentiation, mediating further destructive inflammatory responses in CD and UC. Moreover, Th1-mediated responses participate in IBD, and the antiapoptotic IL-6/IL-6 receptor (IL-6R)/signal transducer and activator of transcription 3 (STAT3) signals are responsible for preserving Th1 cells in the site of inflammation. It has been revealed that fecal bacteria isolated from UC-active and UC-remission patients stimulate the hyperproduction of several cytokines, such as IL-6, tumor necrosis factor-α (TNF-α), IL-10, and IL-12. Given the importance of the IL-6/IL-6R axis, various therapeutic options exist for controlling or treating IBD. Therefore, alternative therapeutic approaches such as modulating the gut microbiome could be beneficial due to the failure of the target therapies so far. This review article summarizes IBD immunopathogenesis focusing on the IL-6/IL-6R axis and discusses available therapeutic approaches based on the gut microbiome alteration and IL-6/IL-6R axis targeting and treatment failure.

Therapeutic agents affecting the immune system and drug-induced inflammatory bowel disease (IBD): A review on etiological and pathogenetic aspects

In recent years, therapeutic agents affecting the immune system have been largely implemented in the treatment of various hematological, rheumatological and dermatological disorders. Their clinical use has offered important benefits for affected patients and has also ameliorated clinical outcome and prognosis in many cases. Nonetheless, as any treatment, the use of these drugs may be associated with side effects. One of the target organs in such cases is the gastrointestinal tract. In particular, the exacerbation or the onset of inflammatory bowel disease (IBD) in treated patients is not infrequent, although the mechanism of action of these agents may be different. In this review we will focus on the use of therapeutic agents affecting the immune system and the development or exacerbation of IBD, with a mention on the possible underlying pathogenetic mechanisms.