[The correlation between osteopontin and metastasis of hepatic Echinococcus multilocularis infection].

Objective: To investigate the expression and distribution of osteopontin (OPN) in Echinococcus multilocularis cyst, and explore the role of OPN in the metastasis of hepatic E. multilocularis infection.

Methods: Forty gerbils were infected with 20% E. multilocularis suspension (0.1 ml per gerbil) through abdominal opening injection in liver. Gerbils were sacrificed at 100 days postinfection for observing the growth and metastasis of hepatic echinococcus cyst. The liver, hepatic echinococcus cyst and metastasis tissue were observed on HE stain; the expression of OPN were measured by immunohistochemistry staining (SP method).

Results: E. multilocularis were spread over the liver and abdominal cavity. Expression of OPN was found at different degree in echinococcus cysts. The positive expression rate of OPN in echinococcus cysts was 70% (28/40). OPN was mainly distributed in the germinal layer, inflammatory cells and some liver cells. 60% (24/40) occurred thoracic lymph node metastases. The OPN expression rate in hepatic echinococcus cysts with thoracic lymph node metastases (83%, 20/24) was significantly higher than that of hepatic echinococcus cysts without thoracic lymph node metastases (50%, 8/16) (P < 0.05). The positive expression of OPN in lymph node metastases (92%, 22/24) was higher than that of hepatic echinococcus cyst (70%, 28/40) (P < 0.05).

Conclusion: Osteopontin mainly distributes in the germinal layer of hepatic echinococcus cyst and inflammatory cells, which might be involved in metastasis of hepatic E. multilocularis infection.