Clinical significance of abnormal lipoprotein patterns in liver diseases

We analyzed lipids in liver diseases by agarose gel electrophoresis, and differential staining and simultaneous analysis of the cholesterol (Chol) and triglyceride (TG) fractions. Liver diseases were classified into chronic hepatitis (CH), liver cirrhosis (LC), hepatocellular carcinoma (HCC), and metastatic liver cancer, and each fraction was compared among these diseases. Atypical patterns that were unclassifiable according to the WHO classification of hyperlipidemia phenotypes were classified, and their clinical importance was evaluated. With progression of the pathologic conditions of CH, LC, and HCC, the T-Chol level, each Chol fraction, and the TG fraction decreased while the LDL-TG fraction increased. Metastatic liver cancer showed a lower HDL-fraction level but higher levels of the other parameters than HCC. When the subjects were classified into survivors and patients who died, the HDL fraction level in HCC and metastatic liver cancer, and the LDL level in LC and metastatic liver cancer differed between survivors and patients who died. Phenotypes of hyperlipidemia also differed among diseases, and atypical patterns were frequently observed in patients who died. There were 6 atypical patterns, of which 4 (slow alpha HDL, abnormal LDL, Lp-X, and Lp-Y) were associated with liver diseases. Slow alpha HDL appeared during slight bile stagnation and was accompanied by increases in the apo E level and the HDL particle size. Abnormal LDL appeared with severe liver dysfunction; a TG peak appeared at the position of LDL, and the HDL and VLDL fractions were negligible. Lp-X was a Chol-rich band, occurring on the cathode side of LDL in the presence of marked bile stagnation such as that in obstructive jaundice, and was accompanied by appearance of abnormal LDL. Lp-Y was similar to Lp-X in terms of mobility and associated diseases but contained Chol and TG. Abnormal LDL, Lp-X, and Lp-Y were often observed in patients with poor outcomes. Lipid analysis in liver diseases by this method showed results reflecting the pathologic conditions and may be clinically useful.