Hepatology at the Millennium Grading and Staging the Histopathological Lesions of Chronic Hepatitis: The Knodell Histology Activity Index and Beyond

In the last half of the 20th century, use of the liver biopsy has grown to serve multiple purposes: (1) confirmation of clinical diagnosis, (2) assessment of severity of necroinflammation and fibrosis, (3) evaluation of possible concomitant disease processes, and (4) assessment of therapeutic intervention. The current practice for reporting histopathological evaluation of chronic hepatitis involves separate statements for the cause of disease, if known, for severity of necroinflammatory lesions, and for the extent of parenchymal fibrosis. The Knodell histology activity index (HAI), published in HEPATOLOGY in 1981,1 was the first system of its type and is widely regarded as the benchmark for objective, semiquantitative, reproducible description of the various morphological lesions of chronic hepatitis. The report has been cited more than 940 times since its publication. Other proposals for semiquantitative evaluation have followed.2-8 Among these was the consensus report of Desmet et al.,2 which appeared in 1994 in HEPATOLOGY and has been cited more than 440 times. It not only described a modified grading and staging system but also significantly updated the classification of chronic hepatitis to include etiology.