Acarboxy prothrombin (PIVKA-II) as a marker of hepatoblastoma in infants.

We evaluated plasma PIVKA-II (protein induced by vitamin K absence or antagonist-II, acarboxy prothrombin) levels in three infants with hepatoblastoma as a tumor marker. PIVKA-II levels were highly elevated in all three patients. Vitamin K administration, performed in two patients, resulted in only moderate reduction of PIVKA-II levels. Chemotherapy against tumor cells reduced the PIVKA-II levels without exception. Immunohistochemical study of the liver tissue indicated the presence of PIVKA-II in the hepatoblastoma cell. These findings suggest that elevated PIVKA-II in these patients was not due to nutritional vitamin K deficiency, but to excess production of tumor cells. A measurement of plasma PIVKA-II may be useful as a new marker of hepatoblastoma.