Objective: To explore the disorders of the hepatic sinusoids and perisinusoidal space in chronic viral hepatitis B and its relationship to hepatic fibrosis.
Methods: The histopathology, the expression of smooth muscle actin (SMA), fibronectin (FN), laminin (LN) and collagen type IV (C-IV), and deposition of reticular, collagenous and elastic fibers in the sinusoids and perisinusoidal space in 160 liver biopsy specimens of viral hepatitis B were examined by haematoxyln and eosin (HE), immunohistochemistry and special stains techniques, respectively.
Results: The pathological changes of the hepatic sinusoids were collapsing, expansive, occlusive and narrowing. The changes in SMA distribution were characteristic. The spotty activated stellate cells were proliferating, transiting, expressing SMA, and stretching down the wall of sinus or forming fine bundles in G(1) or G(2); they were more active in proliferation, transition, forming bridging and even wide fibrous septa constituted by myofibroblast cells in G(3) or G(4). The other 3 elements, FN, IV-C, LN and reticular, collagenous and elastic fibers deposited in the sinusoids and perisinusoidal space following SMA. The higher the gradings were, the more the depositing elements were. They mainly deposited in the areas of degeneration, inflammation, necroses and fibrous bundles (septa) where the pathologic changes of sinusoids happened.
Conclusion: The sinusoids and perisinusoidal space is the original sites of fibrosis. Special attention should be paid to the pathological changes in the sinusoids and perisinusoidal space when to evaluate the gradings of histopathology and stagings of hepatic fibrosis.