De Novo Inflammatory Bowel Disease and Its Mimics After Organ Transplantation

Abstract

Diarrhea is a common symptom after solid organ transplantation or hematopoietic stem cell transplantation, with a reported prevalence up to 72%. One of the uncommon causes for diarrhea in the posttransplant setting is development of de novo inflammatory bowel disease (IBD). The incidence of posttransplantation de novo IBD was shown to be higher than that in the general population (206 versus 20 per 100,000 cases annually). The frequency seems to be much higher following orthotopic liver transplantation than the transplantation of other solid organs. De novo IBD has also been described in the setting of bone marrow transplantation though not as commonly as after SOT. While IBD is considered an immune-mediated disorder and responds favorably to immunosuppressive, de novo IBD or IBD-like conditions can occur in the posttransplant period despite antirejection immunosuppressive therapy. Damage or pathogen-associated molecular pattern molecules and their associated ongoing inflammation within the transplanted organ and the recipients' intestine have been implicated as possible etiologies. Various viral, bacterial, and protozoal infections can mimic IBD in postorgan transplantation. Common IBD mimickers in the postbone marrow transplant setting are graft-versus-host disease, infectious enteritis/colitis, and less commonly "cord colitis" that is described in detail below. In this article, we discuss the epidemiology, clinical features, and outcomes of de novo IBD after transplantation and highlight their differences in presentation, diagnosis, and management.

PI3K/AKT/PTEN pathway as a target for Crohn’s disease therapy (Review)

“…When the epithelial barrier is disrupted, they induce an uncontrollable inflammatory condition. The breakdown of this balance by the dysregulation of immune responses may increase susceptibility to chronic inflammatory disorders, such as Crohn's disease (3,4). Uncontrolled mucosal inflammatory responses against gut microbiota due to the disruption of the epithelial barrier hence play important roles in the pathogenesis of Crohn's disease (3,4).…”

“…The breakdown of this balance by the dysregulation of immune responses may increase susceptibility to chronic inflammatory disorders, such as Crohn's disease (3,4). Uncontrolled mucosal inflammatory responses against gut microbiota due to the disruption of the epithelial barrier hence play important roles in the pathogenesis of Crohn's disease (3,4). Crohn's disease is a chronic inflammatory disorder associated with mucosal inflammation of the bowel wall, which is characterized by repetitive active cycles of the disease state (5).…”

A review of liver disorders in inflammatory bowel disease (IBD)

“…Development of De novo IBD after liver transplantation is infrequent; and has been described in various case series [186][187][188][189]. The exact etiology is unknown; though a damage-associated or pathogenassociated molecular pattern has been implicated [188].…”

“…The diagnosis and management is often challenging. Steroids, Azathioprine and anti-TNF therapy have a good therapeutic response [189].…”

“…Presence of a positive CMV donor with a negative recipient [189,190] and use of Tacrolimus post-liver transplant [191] has been identified as risk factors for the development of de novo IBD. It is believed that CMV and Tacrolimus can affect the mucosal immune system (via altering the epithelial barrier system [189] or reducing the interleukin-2 dependent generation of regulatory T cells [192,193] respectively) increasing IBD activity. The diagnosis and management is often challenging.…”