Histopathology of graft versus host disease of the liver

To analyse the histological features of 33 patients (48 biopsy specimens) with a clinicopathological diagnosis of graft vs. host disease of the liver (L-GVHD).

The time of biopsy post-haematopoietic stem cell transplantation (HSCT) ranged from 22 to 1082 days (median 144 days). Bile duct damage (BDD) was present in all biopsies except one. The bile duct to portal ratio ranged from 0.3 to 1 (median 0.8). Moderate/severe lobular hepatitis was present in 11 biopsies. Endotheliitis was present in four biopsies (8%). The majority of the biopsies showed none [25 (52%)] or mild [17 (35%)] fibrosis. The only significant difference between biopsies earlier ("acute") or later ("chronic" GVHD) than 100 days post-HSCT was the presence of portal inflammation in the "chronic" GVHD group.

BDD is the predominant change in L-GVHD. In about a quarter of biopsies the appearance may be of a lobular hepatitis. L-GVHD is not a fibrogenic process. The significance of separating acute versus chronic L-GVHD based on a cut-off of 100 days post-HSCT is questionable. Further studies are needed to understand the relationships between the mechanisms of BDD, bile duct loss and regeneration.