HDL metabolic activities in a boy with lipoprotein lipase deficiency and his family.

ABSTRACT

BACKGROUND: Lipoprotein lipase (LPL) deficiency is a rare autosomal recessively inherited disease characterized by elevated triglyceride, low total cholesterol and quantitative and qualitative alterations of high-density lipoprotein (HDL). The aim of the present study was to explore HDL metabolic activities in a patient with LPL deficiency and in his family (n = 11). MATERIALS AND METHODS: Subjects were divided into four groups proband (Ser447Stop/Arg170Leu carrier), Ser447Stop carriers, Arg170Leu carriers and silent mutation/wild-type carriers (controls). Cholesterol efflux from Fu5AH cells, lecithincholesterol acyltransferase (LCAT), cholesteryl ester transfer protein (CETP), paraoxonase 1 (PON1) and platelet-activating factor acetylhydrolase (PAF-AH) activities were evaluated. RESULTS: Comparison between the proband and the control group revealed that the boy had significantly reduced cholesterol efflux (P < 0.001), conserved LCAT activity (P > 0.05) and increased CETP activity (P < 0.001). As regards antioxidant enzymes, while PON1 activity was higher in the proband than in the controls (P < 0.0001), PAF-AH activity was reduced (P < 0.05). The other groups did not show relevant differences in comparison with controls. CONCLUSIONS: The presence of one mutation was not enough to introduce important modifications in HDL functions. Markedly reduced HDL levels can keep certain normal enzymatic activities, which probably tend to counteract the deleterious effects of LPL deficiency.