Is Liver Transplant Curative in Homozygous Familial Hypercholesterolemia? A Review of Nine Global Cases.

INTRODUCTION: Homozygous familial hypercholesterolemia (HoFH) is a rare, life-threatening, inherited condition characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C). Patients are at high risk of atherosclerotic cardiovascular disease, adverse cardiovascular events, and associated early mortality. Liver transplant is sometimes used with curative intent. The objective of the current case series was to evaluate the follow-up of a range of patients who have undergone liver transplant for the treatment of HoFH. METHODS: Patients with clinical and/or genetic diagnoses of HoFH were treated according to local practices in four units in Europe and the Middle East. All patients underwent liver transplantation. Baseline and long-term follow-up data were collected, including LDL-C levels, DNA mutations, lipid-lowering medications, and complications due to surgery and immunosuppressive therapy. RESULTS: Nine patients were included with up to 22 years' follow-up (mean ± SD 11.7 ± 11.7 years; range 0.5-28 years). Three of the patients died as a result of complications of transplant surgery (mortality rate 33%). Among the surviving six patients, four required continued lipid-lowering therapy (LLT) to maintain LDL-C levels and two patients show signs of increasing LDL-C levels that require management. One case (11%) required two consecutive transplants to achieve a viable graft and is awaiting a third transplant because of graft failure. CONCLUSIONS: Liver transplant did not enable attainment of recommended LDL-C targets in most patients with HoFH, and the majority of patients still required post-transplant LLT. Liver transplant was not curative in most of the patients with HoFH followed. Guidelines suggest that transplant is a treatment of last resort if contemporary treatments are not available or possible.

Efficacy and safety of lomitapide in homozygous familial hypercholesterolaemia: the pan-European retrospective observational study.

AIMS: Lomitapide is a lipid-lowering agent indicated as an adjunct therapy for adult homozygous familial hypercholesterolaemia (HoFH). This study evaluated the medium-term effectiveness and safety of lomitapide in a large cohort of HoFH patients in Europe. METHODS AND RESULTS: In a multicentre retrospective, observational study including 75 HoFH patients treated with lomitapide in a real-world clinical setting from 9 European countries, low-density lipoprotein cholesterol (LDL-C) changes, adverse events (AEs), and major adverse cardiovascular events (MACE) were assessed. After a median 19 months (interquartile range 11-41 months) of treatment with a mean dosage of 20 mg of lomitapide. Low-density lipoprotein cholesterol decreased by 60%, from baseline 280.5 mg/dL (191.8-405.0 mg/dL) to 121.6 mg/dL (61.0-190.5 mg/dL). At the last visit, 32.0% of patients achieved LDL-C <100 mg/dL and 18.7% <70 mg/dL. At baseline, 38 HoFH patients were receiving LDL apheresis (LA), but after initiation of lomitapide 36.8% of patients discontinued LA. During follow-up, lomitapide was permanently interrupted in 13% of patients. Gastrointestinal AEs occurred in 40% and liver transaminases increased (3-5 × upper limits of normal) in 13% of patients. Among patients with liver ultrasound evaluation (n = 45), a modest increase in hepatic steatosis was noted during treatment; however, liver stiffness measured by elastography in 30 of them remained within the normal range. Among HoFH patients exposed to lomitapide for at least 2 years, MACE incident rate was 7.4 per 1000 person-years in the 2 years after as compared to 21.2 per 1000 person-years before treatment with lomitapide. CONCLUSION: In this medium-term real-world experience, lomitapide proved to be very effective in reducing LDL-C in HoFH. Gastrointestinal AEs were common, but liver safety was reassuring with no sign of increased risk of liver fibrosis. A signal of cardiovascular protection was also observed.

Variation in Coronary Atherosclerosis Severity Related to a Distinct LDL (Low-Density Lipoprotein) Profile: Findings From a Familial Hypercholesterolemia Pig Model.

OBJECTIVE: In an adult porcine model of familial hypercholesterolemia (FH), coronary plaque development was characterized. To elucidate the underlying mechanisms of the observed inter-individual variation in disease severity, detailed lipoprotein profiles were determined. Approach and Results: FH pigs (3 years old, homozygous LDLR R84C mutation) received an atherogenic diet for 12 months. Coronary atherosclerosis development was monitored using serial invasive imaging and histology. A pronounced difference was observed between mildly diseased pigs which exclusively developed early lesions (maximal plaque burden, 25% [23%-34%]; n=5) and advanced-diseased pigs (n=5) which developed human-like, lumen intruding plaques (maximal plaque burden, 69% [57%-77%]) with large necrotic cores, intraplaque hemorrhage, and calcifications. Advanced-diseased pigs and mildly diseased pigs displayed no differences in conventional risk factors. Additional plasma lipoprotein profiling by size-exclusion chromatography revealed 2 different LDL (low-density lipoprotein) subtypes: regular and larger LDL. Cholesterol, sphingosine-1-phosphate, ceramide, and sphingomyelin levels were determined in these LDL-subfractions using standard laboratory techniques and high-pressure liquid chromatography mass-spectrometry analyses, respectively. At 3 months of diet, regular LDL of advanced-diseased pigs contained relatively more cholesterol (LDL-C; regular/larger LDL-C ratio 1.7 [1.3-1.9] versus 0.8 [0.6-0.9]; P=0.008) than mildly diseased pigs, while larger LDL contained more sphingosine-1-phosphate, ceramides, and sphingomyelins. Larger and regular LDL was also found in plasma of 3 patients with homozygous FH with varying LDL-C ratios. CONCLUSIONS: In our adult FH pig model, inter-individual differences in atherosclerotic disease severity were directly related to the distribution of cholesterol and sphingolipids over a distinct LDL profile with regular and larger LDL shortly after the diet start. A similar LDL profile was detected in patients with homozygous FH.

Sex differences in cholesterol levels from birth to 19 years of age may lead to increased cholesterol burden in females with FH.

BACKGROUND: The increased risk of cardiovascular disease in familial hypercholesterolemia (FH) is caused by increased cholesterol burden from birth. Even small elevation in cholesterol level accumulates over time and aggravates atherosclerosis. OBJECTIVES: The aim of the present study was to describe the lipid profile across sex and age in a large cohort of untreated children and adolescents with FH, as this have not clearly been described. METHODS: FH children (438 girls, 452 boys) not receiving lipid-lowering therapy, aged 0 to 19 years were included and divided into 4 age groups (<5, 5-9, 10-14, and 15-19 years). Information was retrieved from the medical records. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and non-HDL cholesterol (non-HDL-C) were studied in relation to sex and age by multiple linear regression analysis. RESULTS: Girls with FH as compared to boys had significantly higher TC, LDL-C, and non-HDL-C (P < .001 for all) levels with mean (95% confidence interval) differences of 0.48 mmol/L (0.28, 0.68) (18.6 g/dL), 0.39 mmol/L (0.19, 0.59) (15.08 mg/dL), and 0.42 mmol/L (0.22, 0.63) (16.24 mg/dL), respectively. These estimates did not change after adjustment for age. We also observed sex differences for HDL-C; girls had higher HDL-C in the youngest (<5 years, P = .05) and oldest age groups (15-19 years, P < .001). CONCLUSIONS: FH girls have higher levels of TC, LDL-C, and non-HDL-C levels than boys from birth up to 19 years of age. This may contribute significantly to the total lifelong cholesterol burden in FH women.

Maternal inheritance does not predict cholesterol levels in children with familial hypercholesterolemia.

BACKGROUND AND AIMS: Pregnancy exerts metabolic changes with increasing levels of total cholesterol and triglycerides as prominent features. Maternal hypercholesterolemia may thus contribute to an unfavorable in utero environment potentially influencing the susceptibility of adult cardiovascular disease in the offspring. We investigated the impact of maternal familial hypercholesterolemia (FH) on pre-treatment plasma lipids and C-reactive protein (CRP) levels in non-statin treated FH children. METHODS: Children with FH (n = 1063) aged between 0 and 19 years were included. Of these, 500 had inherited FH maternally, 563 paternally and 97.6% had a verified FH mutation. Information about inheritance, mutation type and pretreatment levels of blood lipids and CRP was retrieved from the medical records. RESULTS: There were no significant differences in the plasma levels of lipids and C-reactive protein (CRP) in children with maternal FH compared with children with paternal FH, (0.12 ≤ P ≤ 0.90). Independent of which parent transmitted FH, children with LDL receptor negative mutations had significantly higher levels of total and LDL cholesterol and Apolipoprotein (Apo) B, and lower levels of HDL cholesterol and ApoA1, compared with children with other LDL receptor mutations (P < 0.001). CONCLUSION: Maternal inheritance of FH was not associated with detectable long-term effects in the offspring's phenotype measured by adverse lipid profiles and increased CRP levels, whereas a LDL receptor negative mutation was associated with an unfavorably phenotype in FH offspring. Our findings do not support the fetal origin of adulthood disease hypothesis, while at the same time not excluding the hypothesis since other pathways leading to atherosclerosis may be involved.