The cellular infiltrate in the liver of patients with fulminant hepatitis: analysis of paraffin-embedded tissue sections.

Intrahepatic infiltrate from 18 patients who died of fulminant hepatitis, was analyzed by an immunohistochemical method using formalin-fixed, paraffin-embedded liver sections and monoclonal antibodies. Inflammatory cells were characteristically located in the portal and periportal areas adjoining resting hepatocytes, but were infrequently found in the perivenular areas where hemorrhagic hepatocyte necrosis predominated. In the inflammatory infiltrate, T cells were the most predominant cell type, composing about two-thirds of the total hepatic infiltrate, followed by lysozyme-positive macrophages which composed about one-third of the total hepatic infiltrate, irrespective of the etiology of the fulminant hepatitis. On the other hand, B cells made up less than 2% in all cases, and plasma cells were also few, less than 2% in 12 of 18 cases. Furthermore, an enhanced display of beta 2-microglobulin on hepatocyte membranes was demonstrated in all cases with remaining hepatocytes, indicating an increased expression of class I MHC antigens on these cells. These results suggest that T cells may play an important role in the pathogenesis of the portal and periportal lesions of fulminant hepatitis, probably with a help of MHC class I antigens on hepatocytes, while hemorrhagic necrosis of hepatocytes around the central veins may be caused by a different mechanism, most likely a circulatory disturbance secondary to cell-mediated immune reactions in the periportal areas.