Histological and immunohistochemical features in fatal acute fulminant hepatitis E

Abstract

Hepatitis E is being increasingly recognized as an emerging infection in developed countries. Data on histological findings and nature of inflammatory cell infiltrate in liver in this disease are quite sparse. This study was planned to study the histological features and the type of inflammatory infiltrate in liver biopsies of patients with acute fulminant hepatitis E. We retrieved postmortem liver biopsies of 11 Indian patients with fulminant hepatitis E, and compared these with biopsies from seven patients with fulminant hepatitis B. Biopsies from acute fulminant hepatitis E showed varying degrees of hepatocyte necrosis, mixed portal and lobular inflammation, accompanied by bile ductular proliferation, lymphocytic cholangitis, Kupffer cell prominence, cholestasis, apoptotic bodies, pseudo-rosette formation, steatosis, and presence of plasma cells in portal tracts. Interface hepatitis was more frequent in acute hepatitis B than in acute hepatitis E (100% vs 20%; P<0.05). These findings differ from those reported in cases with autochthonous hepatitis E in Europe. On immunohistochemistry, lymphocyte infiltrate consisted predominantly of CD3 + T cells in both hepatitis E and hepatitis B; these cells contained a predominant cytotoxic (CD8 + ) cell subpopulation in 81.8% of cases with hepatitis E and in 50% of cases with hepatitis B. Our findings suggest that histological changes in HEV infection may vary with geographical location because of prevalent HEV genotypes, and that CD8 + lymphocytes play a role in HEV-induced liver injury.