INTRODUCTION: Acute hepatic allograft rejection remains an important problem following liver transplantation. Liver biopsy specimens show a combination of characteristic changes, first observed by Snover as a diagnostic triad: portal inflammation, bile duct damage, and central or portal vein endothelial inflammation (endothelitis or endothelialitis). The aim of this study was to describe our histopathological assessment of liver transplants. MATERIALS AND METHODS: In the period between September 2000 and June 2004, we evaluated 150 liver biopsy specimens from 105 liver recipients. RESULTS: Acute rejection was diagnosed in 26.6% of liver biopsies taken from 31.4% patients who demonstrated clinical symptoms of liver damage. In 90% of cases the rejection was described as minimal or mild, and in 10% as moderate. There was no episode of severe acute rejection. Only four biopsies (10%) showed nothing but Snover triad changes. In 9 (22.5%) cases only acute rejection was diagnosed; the remaining showed in addition to acute rejection the possibility of other concomitant pathologies: viral infection in 15 cases (37.5%), biliary flow obstruction in 11 cases (28.5%), functional cholestasis in two cases (5%), and ischemic complications in three cases (7.5%). CONCLUSIONS: Histologically confirmed acute rejection episodes were diagnosed in 14.9% liver recipients. Liver biopsy specimens, aside from Snover triad features, often showed other unspecific morphological changes. Differentiation of acute rejection from other accompanying diseases is sometimes difficult, requiring precise clinical data and pathologist experience.
INTRODUCTION: Acute hepatic allograft rejection remains an important problem following liver transplantation. Liver biopsy specimens show a combination of characteristic changes, first observed by Snover as a diagnostic triad: portal inflammation, bile duct damage, and central or portal vein endothelial inflammation (endothelitis or endothelialitis). The aim of this study was to describe our histopathological assessment of liver transplants. MATERIALS AND METHODS: In the period between September 2000 and June 2004, we evaluated 150 liver biopsy specimens from 105 liver recipients. RESULTS: Acute rejection was diagnosed in 26.6% of liver biopsies taken from 31.4% patients who demonstrated clinical symptoms of liver damage. In 90% of cases the rejection was described as minimal or mild, and in 10% as moderate. There was no episode of severe acute rejection. Only four biopsies (10%) showed nothing but Snover triad changes. In 9 (22.5%) cases only acute rejection was diagnosed; the remaining showed in addition to acute rejection the possibility of other concomitant pathologies: viral infection in 15 cases (37.5%), biliary flow obstruction in 11 cases (28.5%), functional cholestasis in two cases (5%), and ischemic complications in three cases (7.5%). CONCLUSIONS: Histologically confirmed acute rejection episodes were diagnosed in 14.9% liver recipients. Liver biopsy specimens, aside from Snover triad features, often showed other unspecific morphological changes. Differentiation of acute rejection from other accompanying diseases is sometimes difficult, requiring precise clinical data and pathologist experience.