Although serum concentration of
protein induced
vitamin K absence or antagonist II (
PIVKA-II) has been widely used for diagnosing
hepatocellular carcinoma (HCC), little information is available concerning tissue
PIVKA-II as an immunohistochemical marker for liver histology. In this study, we examined the expression of
PIVKA-II in precancerous nodules (adenomatous
hyperplasia) and various differentiation grades of HCC by immunohistochemical study using the monoclonal anti-
PIVKA-II antibody (MU-3). We examined the relationship between tissue
PIVKA-II staining and serum
PIVKA-II level,
tumor histology and
tumor size.
PIVKA-II was mainly detected in the cytoplasm of the HCC cells. The positive rates of
PIVKA-II were as follows: adenomatous
hyperplasia (AH), 0% (0/9); well-differentiated HCC, 65% (15/23); moderately differentiated HCC, 85% (22/26); poorly differentiated HCC, 54% (7/13). The expression of tissue
PIVKA-II staining in moderately differentiated HCC was significantly higher than in well- or poorly differentiated HCC, whereas the serum
PIVKA-II level in poorly differentiated HCC was higher than well- or moderately differentiated HCC. There was no relationship between the expression of
PIVKA-II in
cancer tissues and serum levels of
PIVKA-II. Immunohistochemical studies revealed that
PIVKA-II was expressed even in small-sized or well-differentiated HCC cells, but expression was not detected in AH. It was concluded that
PIVKA-II is a useful immunohistochemical marker, even in small-sized or well-differentiated HCC.