Acute phase reaction (APR) is a systemic inflammation triggered by several conditions associated with lipid profile alterations. The Authors evaluated whether APR also associates with changes in cholesterol synthesis and absorption, HDL structure, composition and cholesterol efflux capacity (CEC). They analyzed 59 subjects with APR related to infections, oncologic causes or autoimmune diseases and 39 controls, and detected no difference in markers of cholesterol synthesis and absorption.
Conversely, a significant reduction of LpA-I- and LpAI:AII-containing HDL (-28% and -44.8%, respectively) and of medium sized HDL (-10.5%) occurred in APR. Total HDL CEC was impaired in APR subjects (-18%). Evaluating specific CEC pathways, we found significant reductions in CEC by aqueous diffusion and by the transporters SR-BI and ABCG1 (-25.5%, -41.1% and -30.4%, respectively). ABCA1-mediated CEC was not affected. Analyses adjusted for age and gender provided similar results.
In addition, correcting for HDL-cholesterol levels, the differences in aqueous diffusion, total and ABCG1-CEC remained significant. APR subjects displayed higher levels of HDL serum amyloid A (SAA, +20 folds; p = 0.003). In conclusion, APR does not associate with cholesterol synthesis and absorption changes, but with alterations of HDL composition and a marked impairment of HDL CEC, partly independent of HDL-cholesterol serum levels reduction.
- Zimetti F, De Vuono S, Gomaraschi M, Adorni MP, Favari E, Ronda N, Ricci MA, Veglia F, Calabresi L, Lupattelli G. Plasma cholesterol homeostasis, HDL remodeling and function during the acute phase reaction. J Lipid Res 2017 Aug 22. pii: jlr.P076463. doi: 10.1194/jlr.P076463. [Epub ahead of print] Go to PubMed