Effects of Liver Transplantation on Lipids and Cardiovascular Disease in Children With Homozygous Familial Hypercholesterolemia.

Homozygous familial hypercholesterolemia (HoFH) is a rare, inherited, life-threatening, metabolic disorder of low-density lipoprotein (LDL) receptor function characterized by elevated serum LDL cholesterol (LDL-C) and rapidly progressive atherosclerotic cardiovascular disease (ACVD). Since LDL receptors are predominantly found on hepatocytes, orthotopic liver transplantation (OLT) has emerged as a viable intervention for HoFH because LDL receptor activity is restored. This study assessed the effects of OLT on ACVD and ACVD risk factors in pediatric patients with HoFH. We analyzed lipids, lipoproteins, body mass index, glucose, blood pressure, and cardiovascular imaging in 8 pediatric patients who underwent OLT for HoFH. Total serum cholesterol, LDL-C, lipoprotein (a), and apolipoprotein B/apolipoprotein A1 ratio decreased to normal values in all subjects (p values <0.001) at 1 month after OLT and were maintained for the length of follow-up (2 to 6 years). There were few complications related to surgery or immunosuppressive therapy. Two patients developed mild hypertension. In the first 4 subjects monitored for 4 to 6 years after OLT, coronary artery disease did not develop or progress except in 1 minor artery in 1 subject and actually regressed in 2 subjects with >50% stenosis. However, aortic valve stenosis progressed in 2 of 4 subjects. In conclusion, OLT is an effective therapeutic option for patients with HoFH with coronary artery disease and persistently elevated serum LDL-C despite maximum medical therapy. Aortic valvular disease may progress. Long-term data are needed to evaluate the true risk-benefit ratio of this surgical approach.

Surgical portosystemic shunts and the Rex bypass in children: a single-centre experience.

OBJECTIVES: This study aimed to illustrate the indications for, and types and outcomes of surgical portosystemic shunt (PSS) and/or Rex bypass in a single centre. METHODS: Data were collected from children with a PSS and/or Rex bypass between 1992 and 2006 at Mount Sinai Medical Center, New York. RESULTS: Median age at surgery was 10.7 years (range 0.3-22.0 years). Indications included: (i) refractory gastrointestinal bleeding in portal hypertension associated with (a) compensated cirrhosis (n= 12), (b) portal vein thrombosis (n= 10), (c) hepatoportal sclerosis (n= 3); (ii) refractory ascites secondary to Budd-Chiari syndrome (n= 3), and (iii) familial hypercholesterolaemia (n= 4). There were 20 distal splenorenal, four portacaval, three Rex bypass, two mesocaval, two mesoatrial and one proximal splenorenal shunts. At the last follow-up (median 2.9 years, range 0.1-14.1 years), one shunt (Rex bypass) was thrombosed. Two patients had died and two had required a liver transplant. These had a patent shunt at last imaging prior to death or transplant. CONCLUSIONS: Portosystemic shunts and Rex bypass have been used to manage portal hypertension with excellent outcomes. In selected children with compensated liver disease, PSS may act as a bridge to liver transplantation or represent an attractive alternative.

LDL Apheresis: an effective and safe treatment for refractory hypercholesterolemia.

Through the efforts of Edward H. Ahrens, LDL apheresis became available for the treatment of patients, often with familial hypercholesterolemia, who have no alternative therapy for severely elevated LDL cholesterol levels. In the U.S., the FDA has approved this treatment for individuals on maximum diet and drugs with an LDL cholesterol greater than 300 mg/dL or greater than 200 mg/dL with coronary artery disease. Unlike plasmapheresis, apolipoprotein B-containing lipoproteins (LDL, Lp(a), and VLDL) are selectively removed by heparin precipitation or columns containing dextran sulfate cellulose or antibodies to apolipoprotein B. The acute lowering of LDL-cholesterol by a typical 2 - 3 h treatment is up to 80%, and the time-averaged lowering in the 1 to 2 week interval between treatments is up to 50%, with very few side effects. The lowering of LDL-cholesterol and other cardioprotective effects of LDL apheresis have reduced chest pain, prevented new disability and prolonged life. Whole blood compatible columns in development offer the possibility of simpler and less expensive treatments.

Safety and pharmacokinetics of an endotoxin-binding phospholipid emulsion.

BACKGROUND: Lipids and lipoproteins have been shown to bind and neutralize endotoxin and to improve outcomes in animal models of sepsis. OBJECTIVE: To provide safety and pharmacokinetic data for a protein-free, phospholipid-rich emulsion developed as an agent to neutralize endotoxin, and to study the changes in lipids and lipoproteins following emulsion administration. METHODS: Thirty healthy male volunteers (aged 18-45 y) were given an emulsion containing 92.5% soy phospholipid, 7.5% soy triglyceride, and 18 mM sodium cholate using a double-blind, placebo-controlled crossover protocol. Emulsion at 3 escalating doses (75, 150, 300 mg/kg) based on phospholipid content was administered by intravenous infusion over 2 hours in the low- and mid-dose groups and 6 hours in the high-dose group. RESULTS: All subjects completed the protocol without significant toxicities. A slight dose-dependent increase in indirect bilirubin at the 24-hour time point was observed in the emulsion treatment period, with a maximum difference between placebo and emulsion of 0.9 mg/dL. Mean +/- SD peak phospholipid levels were 316 +/- 30, 533 +/- 53, and 709 +/- 86 mg/dL, and phospholipid half-lives were 5.4 +/- 0.6, 5.4 +/- 0.5, and 8.0 +/- 0.8 hours for the low, mid, and high doses, respectively. Increases in total cholesterol, low-density lipoprotein cholesterol and apolipoprotein A-I and B levels were observed. High-density lipoprotein cholesterol decreased immediately following emulsion infusion, but rebounded to above placebo levels by 24 hours. CONCLUSIONS: A unique phospholipid-rich emulsion was shown to have a favorable safety profile and to expand the blood lipid and lipoprotein pool without the use of human-derived blood products. Lipid levels expected to protect against the physiologic effects of bacterial endotoxin were achieved.