Recipient perioperative cholesterolaemia and graft cholesterol metabolism gene expression predict liver transplant outcome

An observational study on the effect of hypercholesterolemia developed after living donor liver transplantation on cardiac event and graft failure

This study sought to evaluate the association between newly-developed significant hypercholesterolemia within one year following living donor liver transplantation (LDLT) and long term outcomes in light of cardiovascular events and graft failure. From October 2003 to July 2017, 877 LDLT recipients were stratified according to development of significant hypercholesterolemia within one year following LDLT. The primary outcome was occurrence of a major adverse cardiac event (MACE), defined as a composite of cardiac death, myocardial infarction, and coronary revascularization after LDLT. The incidence of graft failure, defined as all-cause death or retransplantation, was also compared. A total of 113 (12.9%) recipients developed significant hypercholesterolemia within one year. The differences in incidences of cardiac related events and graft related events began emerging significantly higher in the hypercholesterolemia group after 24 months and 60 months since the LDLT, respectively. After adjustment using the inverse probability of weighting, the hazard ratio (HR) for MACE was 2.77 (95% confidence interval (CI) 1.16–6.61; p = 0.02), while that for graft failure was 3.76 (95% CI 1.97–7.17, p < 0.001). A significant hypercholesterolemia after LDLT may be associated with cardiac and graft-related outcome; therefore, a further study and close monitoring of cholesterol level after LDLT is needed.

Liver and the defects of cholesterol and bile acids biosynthesis: Rare disorders many diagnostic pitfalls

In recent decades, biotechnology produced a growth of knowledge on the causes and mechanisms of metabolic diseases that have formed the basis for their study, diagnosis and treatment. Unfortunately, it is well known that the clinical features of metabolic diseases can manifest themselves with very different characteristics and escape early detection. Also, it is well known that the prognosis of many metabolic diseases is excellent if diagnosed and treated early. In this editorial we briefly summarized two groups of inherited metabolic diseases, the defects of cholesterol biosynthesis and those of bile acids. Both groups show variable clinical manifestations but some clinical signs and symptoms are common in both the defects of cholesterol and bile acids. The differential diagnosis can be made analyzing sterol profiles in blood and/or bile acids in blood and urine by chromatographic techniques (GC-MS and LC-MS/MS). Several defects of both biosynthetic pathways are treatable so early diagnosis is crucial. Unfortunately their diagnosis is made too late, due either to the clinical heterogeneity of the syndromes (severe, mild and very mild) that to the scarcity of scientific dissemination of these rare diseases. Therefore, the delay in diagnosis leads the patient to the medical observation when the disease has produced irreversible damages to the body. Here, we highlighted simple clinical and laboratory descriptions that can potentially make you to suspect a defect in cholesterol biosynthesis and/or bile acids, as well, we suggest appropriate request of the laboratory tests that along with common clinical features can help to diagnose these defects.

Cholesterol metabolism in cholestatic liver disease and liver transplantation: From molecular mechanisms to clinical implications

The aim of this review is to enlighten the critical roles that the liver plays in cholesterol metabolism. Liver transplantation can serve as gene therapy or a source of gene transmission in certain conditions that affect cholesterol metabolism, such as low-density-lipoprotein (LDL) receptor gene mutations that are associated with familial hypercholesterolemia. On the other hand, cholestatic liver disease often alters cholesterol metabolism. Cholestasis can lead to formation of lipoprotein X (Lp-X), which is frequently mistaken for LDL on routine clinical tests. In contrast to LDL, Lp-X is non-atherogenic, and failure to differentiate between the two can interfere with cardiovascular risk assessment, potentially leading to prescription of futile lipid-lowering therapy. Statins do not effectively lower Lp-X levels, and cholestasis may lead to accumulation of toxic levels of statins. Moreover, severe cholestasis results in poor micellar formation, which reduces cholesterol absorption, potentially impairing the cholesterol-lowering effect of ezetimibe. Apolipoprotein B-100 measurement can help distinguish between atherogenic and non-atherogenic hypercholesterolemia. Furthermore, routine serum cholesterol measurements alone cannot reflect cholesterol absorption and synthesis. Measurements of serum non-cholesterol sterol biomarkers - such as cholesterol precursor sterols, plant sterols, and cholestanol - may help with the comprehensive assessment of cholesterol metabolism. An adequate cholesterol supply is essential for liver-regenerative capacity. Low preoperative and perioperative serum cholesterol levels seem to predict mortality in liver cirrhosis and after liver transplantation. Thus, accurate lipid profile evaluation is highly important in liver disease and after liver transplantation.

Transmission of LDLR mutation from donor through liver transplantation resulting in hypercholesterolemia in the recipient

Donor-transmitted disease in organ transplantation is uncommon, but possible. The LDL receptor (LDLR), a key regulator of lipoprotein metabolism, is abundant in the liver. Mutations in the LDLR gene, leading to reduced LDLR activity, are the main cause for familial hypercholesterolemia (FH). The estimated prevalence of FH is 1/200-1/500 in the population indicating that there are 14-34 million individuals with FH worldwide. We describe a patient who developed severe hypercholesterolemia after liver transplantation (LT). The 42-year-old female, who was transplanted because of hepatic epithelioid hemangioendothelioma with normal liver function, exhibited an increase in plasma total cholesterol from 5.6 mmol/L (217 mg/dL) pretransplant to 11.7 mmol/L (452 mg/dL) at 6 months posttransplant. The respective increase in LDL cholesterol was from 3.30 (128 mg/dL) to 8.99 mmol/L (348 mg/dL). At 1 year, total and LDL cholesterol levels were 11.0 (425 mg/dL) and 7.81 (302 mg/dL), respectively. Sequencing of the coding region of LDLR from a liver graft biopsy revealed a splicing heterozygous mutation of LDLR, whereas no FH-related mutation was found in DNA extracted from the patient's blood white cells. This confirmed the first reported case of a patient receiving a mutation in LDLR through LT. The case shows that a donor-transmitted disorder should not be overlooked as a possible cause for severe hypercholesterolemia.