Accumulation of platelets in the liver may be an important contributory factor to thrombocytopenia and liver fibrosis in chronic hepatitis C.
BACKGROUND
Thrombocytopenia is a marked feature of chronic liver disease and cirrhosis. We tried to clarify whether an accumulation of platelets in the liver contributes to thrombocytopenia and liver fibrosis in chronic liver disease.


METHODS
Thirty-eight patients who underwent hepatectomy for hepatocellular carcinoma (HCC) with hepatitis C virus infection were included. The locations of platelets and Kupffer cells and the expression of platelet-derived growth factor (PDGF) receptor-β and smooth muscle actin (SMA) were identified by immunohistochemistry. Perisinusoidal mesenchymal cells that express PDGF receptor-β and SMA were interpreted as transformed hepatic stellate cells (HSCs).


RESULTS
Patients with cirrhosis had a more extensive platelet area in the liver compared to controls (5601 ± 5611 vs. 564 ± 361 μm(2), p = 0.02), although the blood platelet count significantly decreased along with the progression of liver fibrosis. In cirrhotic liver, most platelets were present in the sinusoidal space of the periportal area with inflammation, where HSCs expressing PDGF receptor-β were frequently observed. In addition, the platelet and Kupffer cell areas were significantly smaller in cancerous tissue than those in noncancerous tissues (platelet area: 492 ± 823 vs. 3643 ± 4055 μm(2), p = 0.001; Kupffer cell area: 450 ± 841 vs. 3012 ± 3051 μm(2), p = 0.001).


CONCLUSIONS
The accumulation of platelets in the liver with chronic hepatitis may be involved in thrombocytopenia and liver fibrosis through the activation of HSCs. In addition, our findings also indicate that both platelets and Kupffer cells decrease in HCC tissues.
Department of Pathology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830-0011, Japan. kondou_reiichirou@kurume-u.ac.jp
Reiichiro
R
Kondo
Hirohisa
H
Yano
Osamu
O
Nakashima
Ken
K
Tanikawa
Yoriko
Y
Nomura
Masayoshi
M
Kage
D000368:Aged; D001792:Blood Platelets / Q000473:pathology* / Q000648:ultrastructure; D006528:Carcinoma, Hepatocellular / Q000601:surgery / Q000821:virology; D005260:Female; D006498:Hepatectomy; D055166:Hepatic Stellate Cells / Q000473:pathology / Q000648:ultrastructure; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000473:pathology; D006801:Humans; D007728:Kupffer Cells / Q000473:pathology; D008099:Liver / Q000648:ultrastructure; D008103:Liver Cirrhosis / Q000473:pathology / Q000821:virology*; D008113:Liver Neoplasms / Q000601:surgery / Q000821:virology; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010976:Platelet Count; D012720:Severity of Illness Index; D013921:Thrombocytopenia / Q000473:pathology / Q000821:virology*