Clinical, behavioral and biomarker predictors of PCSK9 levels in HIV-infected patients naïve of statin therapy: A cross-sectional analysis from the Swiss HIV cohort

PCSK9 and ANGPTL3 levels correlate with hyperlipidemia in HIV-lipoatrophy, are regulated by fasting and are not affected by leptin administered in physiologic or pharmacologic doses

BACKGROUND

Medications leveraging the leptin, PCSK9, ANGPTL3 and FABP4 pathways are being developed for the treatment of insulin resistance and/or lipid disorders. To evaluate whether these pathways are independent from each other, we assessed the levels of PCSK9, ANGPTL3 and FABP4, in normal subjects and subjects exhibiting HIV and highly active antiretroviral therapy (HAART) induced metabolic syndrome with lipoatrophy and hypoleptinemia. Studies were performed at baseline and during food deprivation for three days with either a placebo or leptin administration at physiological replacement doses to correct fasting induced acute hypoleptinemia and in pharmacological doses.

METHODS

PCSK9, ANGPTL3, FABP4 levels and their correlations to lipoproteins-metabolites were assessed in randomized placebo controlled cross-over studies: a) in 15 normal-weight individuals undergoing three-day admissions in the fed state, in complete fasting with placebo and in complete fasting with leptin treatment in physiologic replacement doses (study 1), b) in 15 individuals day baseline in a fed and three fasting admissions for three days with leptin administered in physiologic, supraphysiologic and pharmacologic doses (study 2), c) in 7 hypoleptinemic men with HIV and HAART-induced lipoatrophy treated with leptin or placebo for two months in the context of a cross over randomized trial (study 3).

RESULTS

Circulating ANGPTL3, PCSK9 and FABP4 were markedly elevated in HIV-lipoatrophy and not affected by leptin treatment. PCSK9 levels correlated with lipids and markers of lipid utilization and lipolysis. ANGPTL3 levels correlated with HDL particles and their lipid composition. FABP4 levels were negatively associated with HDL diameter (HDL-D) and composition. PCSK9 and ANGPTL3 levels decreased during food deprivation by ~65 % and 30 % respectively. Leptin administration at physiologic, supraphysiologic and pharmacologic doses did not affect PCSK9, ANGPTL3 and FABP4 levels.

CONCLUSIONS

PCSK9, ANGPTL3 and FABP4 levels are associated with markers of lipid metabolism and are higher in HIV-lipoatrophy. PCSK9 and ANGPTL3 but not FABP4 decrease in response to food deprivation. PCSK9 and ANGPTL3 regulation is leptin-independent, suggesting independent pathways for lipid regulation. Thus, combining treatments of leptin with PCSK9 and/or ANGPTL3 inhibitors for metabolic diseases should have additive effects and merit further investigation.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov no. NCT00140231, NCT00140205, NCT00140244.

PCSK9 and inflammation. Maybe a role in autoimmune diseases? Focus on rheumatoid arthritis and systemic lupus erythematosus

Despite a clear epidemiological link between autoimmune disease and cardiovascular (CV) risk exists, pathophysiological explanations are extremely complex and far from being elucidated. Dysregulation of metabolic pathways and chronic low-grade inflammation represent common pathways, but CV risk still remains underestimated in patients with autoimmune diseas. Among different candidate mediators, pro-protein convertase subtilisin/kexin type 9 (PCSK9) is attracting a growing attention, due to a combined effect on lipid metabolism and inflammatory response. Study on PCSK9 inhibitors have established a clear benefit on CV outcome without an established effect on inflammation. Conversely, evidence from sepsis and HIV infection strongly support a pro-inflammatory role of PCSK9. Still uncertain is instead the role of PCSK9 in autoimmune disease. So far reported clinical findings are controversial and likely reflect the poor knowledge of PCSK9 activity on monocyte/macrophage migration and activation. The complex signaling network around PCSK9 synthesis and metabolism may also have a role, especially concerning the involvement of scavenger receptors such as CD36. Such complexity in PCSK9 signaling seems particularly evident in autoimmune disease model. This would also potentially explain the observed independency between lipid profile and PCSK9 levels, the so-called "lipid paradox". In this narrative review we will summarize the current knowledge about the complex network of PCSK9 signaling. We will focus of upstream and downstream pathways with potential implication in autoimmune disease and potential effects of PCSK9 inhibiting strategies.

Association of circulating PCSK9 concentration with cardiovascular metabolic markers and outcomes in stable coronary artery disease patients with or without diabetes: a prospective, observational cohort study

Background

Whether plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) levels is a predictor for cardiovascular outcomes has currently been controversial. No data is currently available regarding the relation of PCSK9 to cardiovascular metabolic markers (CVMMs) and major adverse cardiovascular events (MACEs) in stable coronary artery disease (CAD) patients with diabetes or without diabetes.

Methods

A total 1225 untreated patients with stable CAD were consecutively enrolled and their baseline plasma PCSK9 levels were determined by ELISA. Patients were divided into high and low PCSK9 groups according to PCSK9 median. All patients followed up for the occurrence of MACEs and received standard therapy after admission. The associations of PCSK9 with CVMMs and MACEs were evaluated.

Results

PCSK9 levels were positively correlated with multiple CVMMs including total cholesterol, low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol and hemoglobin A_1c at baseline (all p < 0.05). During a median follow-up of 3.3 years, 103 (8.4%) events occurred. PCSK9 levels were higher in patients with events compared to those without (p < 0.05). The Kaplan–Meier analysis displayed that patients in high PCSK9 group had lower event-free survival than that in low group (p < 0.05). Multivariable Cox regression analysis revealed that PCSK9 levels were independently associated with MACEs in diabetic patients (adjusted hazard ratio [HR]: 1.361, 95% confidence interval [CI]: 1.037–1.785, p < 0.05). When added the combination of PCSK9 levels and diabetic status to stratifying factors, patients in high PCSK9 group appeared to have extremely high risk of subsequent MACEs with diabetes (adjusted HR: 5.233, 95% CI: 2.546–10.757, p < 0.01).

Conclusions

The present study firstly showed that elevated PCSK9 levels were related to multiple CVMMs and MACEs in stable CAD with diabetes, suggesting that plasma PCSK9 measurement could help to identify diabetic patients with CAD at higher cardiovascular risk. More studies may be needed to confirm our findings.

Effects of antiretroviral therapy on proprotein convertase subtilisin/kexin 9: focus on lipids, inflammation and immunovirological parameters

OBJECTIVES

Plasma levels of proprotein convertase subtilisin/kexin type 9 (PCSK9), a major regulator of cholesterol metabolism, have been reported to have an increasing trend in people living with HIV (PLWH) compared with controls. We assessed the impact of different antiretroviral (ARV) regimens on plasma PCSK9 levels as well as plasma lipids, systemic inflammation and immunovirological parameters.

METHODS

Eighty HIV-positive ARV therapy (ART)-naïve PLWH and 40 uninfected controls were retrospectively enrolled. At baseline and 3, 6 and 12 months after ART initiation, plasma PCSK9 levels, lipids, high-sensitivity C-reactive protein (hs-CRP), HIV-1 RNA levels and CD4 T-cell count were measured.

RESULTS

Baseline PCSK9 levels were significantly more elevated in PLWH and were associated with HIV-1 RNA levels (P < 0.001), CD4 T-cell counts (P < 0.001), triglycerides (P < 0.001) and high-density lipoprotein (HDL) cholesterol (P < 0.001), but not with total cholesterol, low-density lipoprotein (LDL) cholesterol and lipoprotein(a) levels. The prescription of ART was paralleled by significant decreases in plasma PCSK9 and hs-CRP levels, and increases in total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and lipoprotein(a), independent of regimen.

CONCLUSIONS

PCSK9 levels, along with systemic inflammation, were progressively reduced following the initiation of an effective ART. However, at the end of the study PCSK9 levels remained higher than in controls and did not correlate with any of the lipid variables.

Evolocumab in HIV-Infected Patients With Dyslipidemia: Primary Results of the Randomized, Double-Blind BEIJERINCK Study

BACKGROUND

People living with human immunodeficiency virus (PLHIV) are at increased risk of atherosclerotic cardiovascular disease (ASCVD) and are prone to statin-related adverse events from drug-drug interactions with certain antiretroviral regimens.

OBJECTIVES

This study sought to evaluate the efficacy and safety of evolocumab in dyslipidemic PLHIV.

METHODS

BEIJERINCK (EvolocumaB Effect on LDL-C Lowering in SubJEcts with Human Immunodeficiency VirRus and INcreased Cardiovascular RisK) is a randomized, double-blind, multinational trial comparing monthly subcutaneous evolocumab 420 mg with placebo in PLHIV with hypercholesterolemia/mixed dyslipidemia taking maximally-tolerated statin therapy. The primary endpoint was the percent change (baseline to week 24) in low-density lipoprotein cholesterol (LDL-C); secondary endpoints included achievement of LDL-C <70 mg/dl and percent change in other plasma lipid and lipoprotein levels. Treatment-emergent adverse events were also examined.

RESULTS

A total of 464 patients were analyzed (mean age of 56.4 years, 82.5% male, mean duration with HIV of 17.4 years). ASCVD was documented in 35.6% of patients, and statin intolerance/contraindications to statin use were present in 20.7% of patients. Evolocumab reduced LDL-C by 56.9% (95% confidence interval: 61.6% to 52.3%) from baseline to week 24 versus placebo. An LDL-C level of <70 mg/dl was achieved in 73.3% of patients in the evolocumab group versus 7.9% in the placebo group. Evolocumab also significantly reduced other atherogenic lipid levels, including non-high-density lipoprotein cholesterol, apolipoprotein B, and lipoprotein(a) (all p < 0.0001). Evolocumab was well tolerated, and treatment-emergent adverse events patient incidence was similar among evolocumab and placebo groups.

CONCLUSIONS

Evolocumab was safe and significantly reduced lipid levels in dyslipidemic PLHIV on maximally-tolerated statin therapy. Evolocumab is an effective therapy for lowering atherogenic lipoproteins in PLHIV with high cardiovascular risk. (Safety, Tolerability & Efficacy on LDL-C of Evolocumab in Subjects With HIV & Hyperlipidemia/Mixed Dyslipidemia; NCT02833844).

Evolocumab treatment in patients with HIV and hypercholesterolemia/mixed dyslipidemia: BEIJERINCK study design and baseline characteristics

BACKGROUND

People living with human immunodeficiency virus (PLHIV) are at higher risk of atherosclerotic cardiovascular disease (ASCVD) due to traditional and HIV- or antiretroviral treatment (ART)-related risk factors. The use of high-intensity statin therapy is often limited by comorbidities and drug-drug interactions with ART. Herein, we present the design and baseline characteristics of the BEIJERINCK study, which will assess the safety and efficacy of evolocumab in PLHIV and hypercholesterolemia/mixed dyslipidemia.

METHODS

Randomized, double-blind, placebo-controlled, multinational trial that investigates monthly subcutaneous evolocumab 420 mg versus placebo in PLHIV with hypercholesterolemia/mixed dyslipidemia who are treated with maximally-tolerated statin therapy. The primary outcome is the baseline to week 24 percent change in low density lipoprotein cholesterol (LDL-C). Secondary outcomes include achievement of LDL-C < 70 mg/dL and percent change in other plasma lipid and lipoprotein levels. Safety will also be examined.

RESULTS

This study enrolled and dosed 464 patients who had a mean age of 56.4 years and were mostly male (82.5%). Mean duration with HIV was 17.4 years, and, by design, HIV viral load at screening was ≤50 copies/mL. ASCVD was documented in 35.6% of patients. Mean LDL-C of enrolled patients at baseline was 133.3 mg/dL. Statin use was prevalent (79.3% overall) with 74.6% receiving moderate or high-intensity statins. In total, 20.7% of patients did not receive statins due to intolerance/contraindications.

CONCLUSIONS

The BEIJERINCK study is the first clinical trial to examine the lipid-lowering efficacy and safety of a fully human PCSK9 monoclonal antibody inhibitor in a moderate/high cardiovascular risk population of PLHIV.

PCSK9 inhibition and inflammation: A narrative review

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality despite excellent pharmacological and revascularization approaches. Low-density lipoproteins (LDL) are undoubtedly the most significant biochemical variables associated with atheroma, however, compelling data identify inflammation as critical for the maintenance of the atherosclerotic process, underlying some of the most feared vascular complications. Although its causal role is questionable, high-sensitivity C-reactive protein (hs-CRP) represents a major biomarker of inflammation and associated risk in CVD. While statin-associated reduced risk may be related to the lowering of both LDL-C and hs-CRP, PCSK9 inhibitors leading to dramatic LDL-C reductions do no alter hs-CRP levels. On the other hand, hs-CRP levels identify groups of patients with a high risk of CV disease achieving better ASCVD prevention in response to PCSK9 inhibition. In the FOURIER study, even in patients with extremely low levels of LDL-C, there was a stepwise risk increment according to the values of hs-CRP: +9% (<1 mg/L), +10.8% (1-3 mg/L) and +13.1% (>3 mg/L). Likewise, in the SPIRE-1 and -2 studies, bococizumab patients with hs-CRP> 3 mg/L had a 60% greater risk of future CV events. Most of the patients enrolled in the PCSK9 trials were on maximally tolerated statin therapy at baseline, and an elevated hs-CRP may reflect residual inflammatory risk after standard LDL-C lowering therapy. Moreover, data on changes in inflammation markers in carriers of PCSK9 loss-of-function mutations are scanty and not conclusive, thus, evidence from the effects of anti-inflammatory molecules on PCSK9 levels might help unravel this hitherto complex tangle.