Deficiency of Serum Cholesteryl-ester Transfer Activity in Patients with Familial Hyperalphalipoproteinemia
Year: 1987
Type: article
Study design: Case Report
Abstract: Lipoprotein patterns and cholesteryl-ester transfer activity (CETA) were examined in 2 patients with familial hyperalphalipoproteinemia (FHALP). The proband was a healthy 58-year-old Japanese male who had, an HDL cholesterol of 301mg/dl. His sister's HDL cholesterol was 174mg/dl, which suggested that both were homozygous, carrier of FHALP. In both subjects HDL showed a high cholesterol/apo A-I ratio and appeared to be a large-size particle than normal HDL on agarose gel chromatography. Two of the proband's children showed higher HDL cholesterol levels (67, 83mg/dl) than normal, but another 2 children showed normal levels (57, 54mg/dl). However, the ratios of HDL cholesterol to total cholesterol and to apo A-I in all children were higher than normal. These data suggest, but do not prove, that all his children were heterozygotes. Apo B levels in all of the family members studied were lower than normal (47-80mg/dl).Cholesteryl-ester transfer activity was studied in both patients. When serum or lipoprotein deficient serum (d>1.21) and [3H]cholesteryl ester labeled HDL were incubated in the presence of an LCAT inhibitor, there was no evidence of cholesterylester transfer from HDL to VLDL and/or LDL, unlike normal subjects. The deficiency of CETA in these patients with FHALP presumably accounted for the increase in particle size and cholesterol enrichment of HDL.We studied inhibitors of lipid transfer protein (LTP-I) in S. Y. and Y. S., another patient of FHALP. S. Y. have only one-third of the normal level of LTP-I and an increased level of inhibitor, but Y. S. showed increased level of LTP-I inhibitors and near normal levels of LTP-I activity. Thus, FHALP may be heterogenous in clinical features and in mechanism of pathogenesis.
Institutions: Kanazawa University, Fukui Prefectural Hospital
Language: English
Subfield: Biochemistry
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W628163091