High-molecular intestinal alkaline phosphatase in chronic liver diseases

The presence of high-molecular intestinal alkaline phosphatase (HIALP) different from bone ALP detected in the alpha(2)beta region was recently clarified. In this study we used a novel method in which HIALP was detected after conversion to ALP(5) by protease to investigate the clinical significance of the appearance of HIALP in patients with chronic liver disease. The subjects were 241 patients with chronic liver disease. When a decrease in ALP(3) in the alpha(2)beta region and an increase in ALP(5) in the beta region were noted, the patient was judged HIALP-positive. In the patients with chronic liver disease, the total ALP activity (T-ALP) increased with progression of the pathology in the order of chronic hepatitis (CH), liver cirrhosis (LC), and hepatocellular carcinoma (HCC). HIALP appeared in 22.4% and 49.3% of patients with CH and LC, respectively, but the positivity rate decreased to 30.4% in HCC. As autoimmune liver diseases, primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) were investigated. T-ALP was lower in PBC+AIH than in LC and HCC, but the HIALP-positive rate was high (44.4%). The HIALP-positive rate was dependent on ABO blood groups, and was high in blood groups B and O. In conclusion, the HIALP-positive rate was particularly high in patients with chronic liver disease, and was related to the pathological progression, which suggests that the method is clinically useful.