Changes in PCSK9 and LDL cholesterol concentrations by everolimus treatment and their effects on polymorphisms in PCSK9 and mTORC1

Alirocumab in Adult Patients With Hyperlipidemia After Liver Transplantation: A Short-term Observation

OBJECTIVE

To investigate the clinical efficacy of alirocumab in postoperative hyperlipidemia among liver transplant recipients.

METHODS

We conducted a retrospective analysis of clinical data from liver transplant recipients with postoperative hyperlipidemia who received alirocumab treatment at our institution.

RESULTS

Seventeen cases were observed, with a male-to-female ratio of 12:5. Patient ages ranged from 44 to 65 years, with an average age of 55.47 years. The initiation of alirocumab treatment occurred between 1 and 196 months postliver transplantation, averaging 44.88 months. Treatment duration was a minimum of 3 months. The levels of blood lipids were assessed at 4, 8, and 12 weeks during the treatment regimen. At 8 weeks, a statistically significant reduction in total cholesterol was recorded (P = .012), and this decrease was further pronounced at 12 weeks (P = .004). For LDL cholesterol, significant decreases were evident at 4 weeks (P = .011), 8 weeks (P = .005), and 12 weeks (P = .004). No significant changes were observed in high-density lipoprotein (HDL) cholesterol and triglyceride levels throughout the study period. In addition, all patients maintained stable liver function and immunosuppressant concentrations.

CONCLUSIONS

Alirocumab demonstrated a significant reduction in total cholesterol and low-density lipoprotein cholesterol levels among liver transplant recipients, with no observed increase in the risk of rejection. This suggests the potential effectiveness of alirocumab as a lipid-lowering therapy in liver transplant recipients.

PCSK9 inhibitors in a renal transplant patient complicated with hepatitis B: A case report and literature review

Lipid metabolism disorders are recognized to be one of the most frequent complications of renal transplantation, while dyslipidemia and chronic kidney disease (CKD) are strong risk factors for arteriosclerotic cardiovascular disease (ASCVD). Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are novel lipid-lowering drugs, the safety and efficacy of which are yet to be confirmed in transplanted patients. There have been several small-sample studies using PCSK9i in patients after heart transplantation, while fewer cases use PCSK9i after kidney transplantation. We report a case of a renal transplant recipient complicated with hepatitis B treated with PCSK9i, which achieved a remarkable lipid-lowering efficacy, and no significant adverse effects were found during the follow-up.

Cardiovascular effects of immunosuppression agents

Immunosuppressive medications are widely used to treat patients with neoplasms, autoimmune conditions and solid organ transplants. Key drug classes, namely calcineurin inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and purine synthesis inhibitors, have direct effects on the structure and function of the heart and vascular system. In the heart, immunosuppressive agents modulate cardiac hypertrophy, mitochondrial function, and arrhythmia risk, while in vasculature, they influence vessel remodeling, circulating lipids, and blood pressure. The aim of this review is to present the preclinical and clinical literature examining the cardiovascular effects of immunosuppressive agents, with a specific focus on cyclosporine, tacrolimus, sirolimus, everolimus, mycophenolate, and azathioprine.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors Use for Atherogenic Dyslipidemia in Solid Organ Transplant Patients

Dyslipidemia is a widespread risk factor in solid organ transplant patients, due to many reasons, such as the use of immunosuppressive drugs, with a consequent increase in cardiovascular diseases in this population. PCSK9 is an enzyme mainly known for its role in altering LDL levels, consequently increasing cardiovascular risk. Monoclonal antibody PCSK9 inhibitors demonstrated remarkable efficacy in the general population in reducing LDL cholesterol levels and preventing cardiovascular disease. In transplant patients, these drugs are still poorly used, despite having comparable efficacy to the general population and giving fewer drug interactions with immunosuppressants. Furthermore, there is enough evidence that PCSK9 also plays a role in other pathways, such as inflammation, which is particularly dangerous for graft survival. In this review, the current evidence on the function of PCSK9 and the use of its inhibitors will be discussed, particularly in transplant patients, in which they may provide additional benefits.

Nuclear Receptor PXR in Drug-Induced Hypercholesterolemia

Atherosclerosis is a major global health concern. The central modifiable risk factors and causative agents of the disease are high total and low-density lipoprotein (LDL) cholesterol. To reduce morbidity and mortality, a thorough understanding of the factors that influence an individual’s cholesterol status during the decades when the arteria-narrowing arteriosclerotic plaques are forming is critical. Several drugs are known to increase cholesterol levels; however, the mechanisms are poorly understood. Activation of pregnane X receptor (PXR), the major regulator of drug metabolism and molecular mediator of clinically significant drug–drug interactions, has been shown to induce hypercholesterolemia. As a major sensor of the chemical environment, PXR may in part mediate hypercholesterolemic effects of drug treatment. This review compiles the current knowledge of PXR in cholesterol homeostasis and discusses the role of PXR in drug-induced hypercholesterolemia.

Effects of proprotein convertase subtilisin/kexin type 9 and nilotinib plasma concentrations on nilotinib-induced hypercholesterolaemia in patients with chronic myeloid leukaemia

WHAT IS KNOWN AND OBJECTIVE

The purpose of this study was to investigate the relationships among nilotinib plasma trough concentration (C₀ ), low-density lipoprotein (LDL) cholesterol, and PCSK9 plasma concentration in 31 patients with chronic myeloid leukaemia.

METHODS

Plasma concentrations of nilotinib and PCSK9 were measured by high-performance liquid chromatography and enzyme-linked immunosorbent assays, respectively.

RESULTS AND DISCUSSION

LDL cholesterol concentrations at 1 month after nilotinib treatment were significantly increased compared with those before therapy. The mean C₀ (±SD) of nilotinib at 1, 2, and 3 months after nilotinib treatment were 645 ± 516, 902 ± 623, and 951 ± 1088 ng/mL, respectively. Mean PCSK9 concentrations at 3 months after nilotinib treatment were significantly higher than those at the start of therapy (320 vs 257 ng/mL, respectively, P = .019). When the change rate in the PCSK9 concentration induced by nilotinib was classified with a cut-off value of +40%, the change rate in LDL cholesterol in patients with a change rate in PCSK9 of ≥40% was significantly higher than that in patients with a PCSK9 change rate of <40% (67.1% vs 38.0%, P = .043); however, there were no differences in mean nilotinib C₀ .

WHAT IS NEW AND CONCLUSION

Nilotinib may lead to hypercholesterolaemia by increasing plasma concentrations of PCSK9 after indirect inhibition of mammalian target of rapamycin (mTOR) complex 1. In addition, certain patients seem to have high sensitivity for nilotinib in a signalling cascade of the PI3K/Akt/mTOR pathway, despite low plasma concentrations of nilotinib. Consequently, nilotinib-induced hypercholesterolaemia could not be predicted based on the plasma concentration of nilotinib.