Modulated serum activities and concentrations of paraoxonase in high density lipoprotein deficiency states

Paraoxonase is a high density lipoprotein (HDL) associated enzyme with a hypothesised role in the protection of low density lipoproteins (LDL) from oxidative stress. The present study examined paraoxonase in several genetically distinct HDL deficiency states. Despite reduction or even absence of detectable HDL, enzyme activity was present in sera from A-I-Pisa, A-I- Helsinki, A-I-Milano and Tangier patients. Both enzyme activities and peptide concentrations were modulated (reduced) but specific activities were broadly similar to controls, suggesting an impact on peptide concentration rather than an inhibition of enzyme activity. Despite the absence of HDL in A-I- Pisa and Tangier subjects, there was no association of paraoxonase with very low density lipoproteins or LDL. Paraoxonase function is maintained in HDL deficient states. It implies that certain HDL-associated anti-atherogenic processes may not be entirely compromised by HDL deficiency. This has important implications for the cardiovascular risk associated with modulated HDL concentrations

Modulated serum acitivities and concentrations of paraoxonase in high density lipoprotein deficiency states

Paraoxonase is a high density lipoprotein (HDL) associated enzyme with a hypothesised role in the protection of low density lipoproteins (LDL) from oxidative stress. The present study examined paraoxonase in several genetically distinct HDL deficiency states. Despite reduction or even absence of detectable HDL, enzyme activity was present in sera from A-I-Pisa, A-I-Helsinki, A-I-Milano and Tangier patients. Both enzyme activities and peptide concentrations were modulated (reduced) but specific activities were broadly similar to controls, suggesting an impact on peptide concentration rather than an inhibition of enzyme activity. Despite the absence of HDL in A-I-Pisa and Tangier subjects, there was no association of paraoxonase with very low density lipoproteins or LDL. Paraoxonase function is maintained in HDL deficient states. It implies that certain HDL-associated anti-atherogenic processes may not be entirely compromised by HDL deficiency. This has important implications for the cardiovascular risk associated with modulated HDL concentrations

Cholesterol lowering with EVOLocumab to prevent cardiac allograft Vasculopathy in De-novo heart transplant recipients : Design of the randomized controlled EVOLVD trial

Background Cardiac allograft vasculopathy (CAV) is characterized by diffuse thickening of the arterial intima. Statins reduce the incidence of CAV, but despite the use of statins, CAV remains one of the leading causes of long-term death after heart transplant. Inhibitors of proprotein convertase subtilisin-kexin type 9 (PCSK9) substantially reduce cholesterol levels but have not been tested in heart transplant recipients. Methods The Cholesterol lowering with EVOLocumab to prevent cardiac allograft Vasculopathy in De-novo heart transplant recipients (EVOLVD) trial ( Identifier: NCT03734211) is a randomized, double-blind trial designed to test the effect of the PCSK9 inhibitor evolocumab on coronary intima thickness in heart transplant recipients. Adults who have received a cardiac transplant within the past 4-8 weeks are eligible. Exclusion criteria include an estimated glomerular filtration rate <20 mL/min/1.73 m(2), renal replacement therapy, or contraindications to coronary angiography with intravascular ultrasound. 130 patients will be randomized (1:1) to 12-month treatment with evolocumab or matching placebo. The primary endpoint is the coronary artery intima thickness as measured by intravascular ultrasound. Conclusion The EVOLVD trial is a randomized clinical trial designed to show whether treatment with the PCSK9 inhibitor evolocumab can ameliorate CAV over the first year after heart transplant.Peer reviewe