Table 2 Deposition of K7 in hepatocytes in a liver biopsy specimen and stage of fibrosis according to Nakanuma classification. Deposition of orcein-positive granules in Nakanuma classification has been replaced with a similar model, along with applying the deposition of K7-positive hepatocytes in the evaluation of chronic cholestasis. Adapted from [Nakanuma, Y., Zen, Y., Harada, K., Sasaki, M., Nonomura, A., Uehara, T., et al. [19]. Application of a new histological staging and grading system for primary biliary cirrhosis to liver biopsy specimens: Interobserver agreement. Pathology International, 60(3), 167–174, [19]
Deposition of K7-positive hepatocytes (score 0–3) | Scoring protocol |
0 | No K7-positive hepatocytes |
1 | K7 positivity in at least ten hepatocytes in one periportal area (zone 1) |
2 | K7 positivity in at least ten hepatocytes in 1/3–2/3 of periportal areas |
3 | K7 positivity in at least ten hepatocytes in more than 2/3 of periportal areas |
Nakanuma classification - stage of fibrosis in a liver biopsy specimen | |
Stage of fibrosis (0–3) | Scoring protocol |
0 | No portal fibrosis or fibrosis limited to portal tracts |
1 | Portal fibrosis with periportal fibrosis or incomplete septal fibrosis |
2 | Bridging fibrosis with variable lobular disarray |
3 | Liver cirrhosis with regenerative nodules and extensive fibrosis |