Graft versus host disease
Graft versus host disease (GvHD) is a frequent complication of allogeneic post hematopoietic stem cell transplantation, commonly known as bone marrow transplantation. Anti-rejection drugs have reduced the incidence, although it does still frequently occur.
Graft versus host disease can present early/acute (<100 days) or late/chronic (>100 days) post-hematopoietic stem cell transplantation and is one of the major complications of this treatment. The skin, gastrointestinal tract (especially small bowel), and liver are the principal affected organs. Effects on the gastrointestinal tract are the most commonly described in the radiology literature.
End-organ damage is the result of recipient's immune system (mainly antigen presenting cells) interacting with donor T-cell, leading to the latter's activation with a resultant cell-mediated and inflammatory cascade . The pathophysiology of chronic GvHD is not well understood.
Features depend upon the organ involved.
On small bowel barium studies, the bowel is described as having a "ribbon" appearance with fold thickening. Other described features are :
- edema of mucosal folds in ileum and jejunum
- effacement of folds towards the ileum: can give featureless (atrophic) loops
- thickening of the bowel wall
- spasms and stenosis with prestenotic dilatation
- in the active phase, the bowel can appear shortened
Described CT features include:
- bowel wall thickening:
- considered the most consistent finding
- can affect small or large bowel or both (commonest )
- bowel dilatation
- mucosal enhancement
- engorgement of the vasa recta adjacent to affected bowel segments
- gastric wall thickening
Extraintestinal findings in the abdomen
Reported features include:
- mesenteric stranding: ~60%
- biliary abnormalities
- urinary excretion of orally administered Gastrografin