Liver biopsy findings in patients with hematopoietic cell transplantation.

Liver dysfunction is a frequent complication after hematopoietic cell transplantation. Liver biopsy has an important role for confirming the diagnosis of graft-versus-host disease (GVHD) or other liver diseases. The histological features of GVHD are not specific, and GVHD and other coexisting diseases may be present in the same biopsy, which makes the histologic interpretation of the liver biopsy more complex and challenging. The aim of the study is to improve the present diagnostic criteria. Fifty-two liver biopsies were studied. Most biopsies (47, 92%) showed some features of GVHD. Five (9.6%) had no GVHD, 20 (38.5%) had possible GVHD, and 27 (51.9%) had likely GVHD. Histologic features were analyzed semi-quantitatively and scored. Bile duct damage and intraepithelial lymphocytes were significantly more frequent in likely GVHD groups. Bile duct injury score calculated as the sum of bile duct damage and intraepithelial lymphocytes score was 2.3 in no GVHD and possible GVHD groups, and 4.2 in likely GVHD group (P<.001). A bile duct injury score ≥4 correlated well with a diagnosis of GVHD, with sensitivity 74% and specificity 88%. Many cases (36; 70.6%) had a concurrent disease process. Drug-induced liver injury (8, 16%) and sinusoidal obstruction syndrome (6, 12%) are particularly important causes of liver dysfunction. Moderate degree of bile duct injury and intraepithelial lymphocytes were the most helpful histologic findings to confirm the diagnosis of GVHD. In addition, it is important for the pathologist to be aware of the etiologies of liver dysfunction other than GVHD.