HDL in COVID-19 Patients: Evidence from an Italian Cross-Sectional Study

Abstract

A number of studies have highlighted important alterations of the lipid profile in COVID-19 patients. Besides the well-known atheroprotective function, HDL displays anti-inflammatory, anti-oxidative, and anti-infectious properties. The aim of this retrospective study was to assess the HDL anti-inflammatory and antioxidant features, by evaluation of HDL-associated Serum amyloid A (SAA) enrichment and HDL-paraoxonase 1 (PON-1) activity, in a cohort of COVID-19 patients hospitalized at the Cardiorespiratory COVID-19 Unit of Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico of Milan. COVID-19 patients reached very low levels of HDL-c (mean ± SD: 27.1 ± 9.7 mg/dL) with a marked rise in TG (mean ± SD: 165.9 ± 62.5 mg/dL). Compared to matched-controls, SAA levels were significantly raised in COVID-19 patients at admission. There were no significant differences in the SAA amount between 83 alive and 22 dead patients for all-cause in-hospital mortality. Similar findings were reached in the case of PON-1 activity, with no differences between alive and dead patients for all-cause in-hospital mortality. In conclusion, although not related to the prediction of in-hospital mortality, reduction in HDL-c and the enrichment of SAA in HDL are a mirror of SARS-CoV-2 positivity even at the very early stages of the infection.

HDL cholesterol levels and susceptibility to COVID-19

“…HDL was shown to have important immunomodulatory properties beyond cholesterol reverse transportation 11 and could be altered in COVID-19. 30 The anti-inflammatory effects of HDL could be due to both cholesterol effluxdependent 31 and independent mechanisms. 32 A CETP (cholesteryl ester transfer protein) gain-of-function variant was associated with significant reductions in HDL-C levels during sepsis, and increased risk of mortality.…”

Usefulness of the Measurement of Serum Paraoxonase-1 Arylesterase Activity in the Diagnoses of COVID-19

“…An increase in lipid peroxidation therefore produces a decrease in enzymatic activity. Another cause that may explain the decrease in PON1 activity is that the composition of high-density lipoproteins is altered in COVID-19, with a decrease in cholesterol content and an increase in serum amyloid A [ 18 ]. These alterations are common in the acute phase of many diseases and can decrease PON1 activity by modifying its environment [ 15 ].…”

Dyslipidemia and Inflammation as Hallmarks of Oxidative Stress in COVID-19: A Follow-Up Study

“…Although these observations are likely the result of a combination of many factors, we believe that such discrepancies are the result of the initial acute phase response. In this sense, one would expect low initial levels of HDL-c [ 22 , 30 ], given that it is more prone to oxidation until its antioxidant capacity is overwhelmed, leading to LDL-c oxidation at later stages. This concept is supported by recent studies showing that severe COVID-19 patients had a pro-inflammatory oxylipin profile [ 6 ], and a higher degree of LDL-c oxidation is associated with a greater concentration of oxylipins [ 31 ].…”