The usefulness of advanced lipid and oxidative stress testing for diagnosis and management of low HDL-cholesterol phenotype: A case report

Abstract Objective Plasma high-density lipoprotein cholesterol (HDL-C) level is a strong inverse predictor of cardiovascular disease (CVD) development. Tangier disease, a consequence of mutations in the ATP binding cassette transporter 1 ( ABCA1 ) gene, is associated with very low HDL-C levels. Still, the relationship between Tangier disease and CVD is not always evident. The study investigates usefulness of lipoprotein subfractions, oxidative stress and paraoxonase 1 (PON1) status assessment for evaluation and management of patient with low HDL-C phenotype. Patient and methods A 12-year-old boy was hospitalised due to hypertension. Laboratory evaluation revealed low HDL-C level, and subsequent molecular diagnostic confirmed Tangier disease. Lipoprotein subfractions were assessed by gradient-gel electrophoresis. Oxidative stress status was estimated by measuring total antioxidative status, total oxidative status, prooxidative-antioxidative balance, malondialdehyde and advanced oxidation protein products levels. Activity of paraoxonase 1 in serum and its distribution within HDL subclasses was also determined (ten healthy boys aged 13.1 ± 3.4 years served as the reference group). Results Analysis of oxidative stress status biomarkers revealed a state of prolonged prooxidants activity. In turn, serum PON1 activity was substantially reduced. The majority of PON1 activity was present on HDL 2 particles. Conclusion Impaired antioxidative potential of HDL may point toward hidden cardiovascular risk in isolated low HDL-phenotype.