Cholesteryl ester transfer activity in liver disease and cholestasis, and its relation with fatty acid composition of lipoprotein lipids

Lipidomic Analysis of Liver Lipid Droplets after Chronic Alcohol Consumption with and without Betaine Supplementation

The earliest manifestation of alcohol-associated liver disease is hepatic steatosis, which is characterized by fat accumulation in specialized organelles called lipid droplets (LDs). Our previous studies reported that alcohol consumption elevates the numbers and sizes of LDs in hepatocytes, which is attenuated by simultaneous treatment with the methyl group donor, betaine. Here, we examined changes in the hepatic lipidome with respect to LD size and dynamics in male Wistar rats fed for 6 weeks with control or ethanol-containing liquid diets that were supplemented with or without 10 mg betaine/mL. At the time of sacrifice, three hepatic LD fractions, LD1 (large droplets), LD2 (medium-sized droplets), and LD3 (small droplets) were isolated from each rat. Untargeted lipidomic analyses revealed that each LD fraction of ethanol-fed rats had higher phospholipids, cholesteryl esters, diacylglycerols, ceramides, and hexosylceramides compared with the corresponding fractions of pair-fed controls. Interestingly, the ratio of phosphatidylcholine to phosphatidylethanolamine (the two most abundant phospholipids on the LD surface) was lower in LD1 fraction compared with LD3 fraction, irrespective of treatment; however, this ratio was significantly lower in ethanol LD fractions compared with their respective control fractions. Betaine supplementation significantly attenuated the ethanol-induced lipidomic changes. These were mainly associated with the regulation of LD surface phospholipids, ceramides, and glycerolipid metabolism in different-sized LD fractions. In conclusion, our results show that ethanol-induced changes in the hepatic LD lipidome likely stabilizes larger-sized LDs during steatosis development. Furthermore, betaine supplementation could effectively reduce the size and dynamics of LDs to attenuate alcohol-associated hepatic steatosis.

Why is elevation of serum cholesterol associated with exposure to perfluoroalkyl substances (PFAS) in humans? A workshop report on potential mechanisms

Serum concentrations of cholesterol are positively correlated with exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in humans. The associated change in cholesterol is small across a broad range of exposure to PFOA and PFOS. Animal studies generally have not indicated a mechanism that would account for the association in humans. The extent to which the relationship is causal is an open question. Nonetheless, the association is of particular importance because increased serum cholesterol has been considered as an endpoint to derive a point of departure in at least one recent risk assessment. To gain insight into potential mechanisms for the association, both causal and non-causal, an expert workshop was held Oct 31 and Nov 1, 2019 to discuss relevant data and propose new studies. In this report, we summarize the relevant background data, the discussion among the attendees, and their recommendations for further research.

ApoE and apoC-III-defined HDL subtypes: a descriptive study of their lecithin cholesterol acyl transferase and cholesteryl ester transfer protein content and activity

Background

The functionality of high-density lipoproteins (HDL) is a better cardiovascular risk predictor than HDL concentrations. One of the key elements of HDL functionality is its apolipoprotein composition. Lecithin-cholesterol acyl transferase (LCAT) and cholesterol-ester transfer protein (CETP) are enzymes involved in HDL-mediated reverse cholesterol transport. This study assessed the concentration and activity of LCAT and CETP in HDL subspecies defined by their content of apolipoproteins E (apoE) and C-III (apoC-III) in humans.

Methods

Eighteen adults (ten women and eight men, mean age 55.6, BMI 26.9 Kg/m², HbA1c 5.4%) were studied. HDL from each participant were isolated and divided into four subspecies containing respectively: No apoE and no apoC-III (E-C-), apoE but not apoC-III (E + C-), apoC-III but no apoE (E-C+) and both apoE and apoC-III (E + C+). The concentration and enzymatic activity of LCAT and CETP were measured within each HDL subspecies using immunoenzymatic and fluorometric methods. Additionally, the size distribution of HDL in each apolipoprotein-defined fraction was determined using non-denaturing electrophoresis and anti-apoA-I western blotting.

Results

HDL without apoE or apoC-III was the predominant HDL subtype. The size distribution of HDL was very similar in all the four apolipoprotein-defined subtypes. LCAT was most abundant in E-C- HDL (3.58 mg/mL, 59.6% of plasma LCAT mass), while HDL with apoE or apoC-III had much less LCAT (19.8, 12.2 and 8.37% of plasma LCAT respectively for E + C-, E-C+ and E + C+). LCAT mass was lower in E + C- HDL relative to E-C- HDL, but LCAT activity was similar in both fractions, signaling a greater activity-to-mass ratio associated with the presence of apoE. Both CETP mass and CETP activity showed only slight variations across HDL subspecies. There was an inverse correlation between plasma LCAT activity and concentrations of both E-C+ pre-beta HDL (r = − 0.55, P = 0.017) and E-C- alpha 1 HDL (r = − 0.49, P = 0.041). Conversely, there was a direct correlation between plasma CETP activity and concentrations of E-C+ alpha 1 HDL (r = 0.52, P = 0.025).

Conclusions

The presence of apoE in small HDL is correlated with increased LCAT activity and esterification of plasma cholesterol. These results favor an interpretation that LCAT and apoE interact to enhance anti-atherogenic pathways of HDL.

Lipoprotein metabolism in liver diseases

PURPOSE OF REVIEW

The liver is the central hub of lipoprotein metabolism. A complex relationship exists between dyslipidemia and chronic liver diseases (CLDs). Recent advances in the genetics of nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) exemplify the pivotal role of lipoprotein metabolism in the pathogenesis of CLD. We review these relationships in four quintessential forms of CLD: NAFLD, ALD, cholestatic liver disease and cirrhosis, with a focus on recent discoveries.

RECENT FINDINGS

An I148 M variant in patatin-like phospholipase domain-containing protein 3 (PNPLA3) and an E167K variant in transmembrane 6 superfamily 2 (TM6SF2) are major genetic risk factors for the development and progression of NAFLD. These genetic variants also increase the risk of ALD. Both PNPLA3 and TM6SF2 are involved in the hepatic assembly of very low-density lipoprotein. The discovery of these two genetic variants highlights the risk of CLD when environmental factors are combined with functional modifications in the lipoprotein metabolism pathway.

SUMMARY

The relationship between CLD and lipoprotein metabolism is reciprocal. On the one hand, the progression of CLD impairs lipoprotein metabolism; on the other hand, modifications in lipoprotein metabolism can substantially increase the risk of CLD. These relationships are at play among the most common forms of CLD affecting a significant proportion of the population.

Acquired low cholesterol: diagnosis and relevance to safety of low LDL therapeutic targets

PURPOSE OF REVIEW

Acquired hypocholesterolaemia occurs more commonly than inherited hypocholesterolaemia but has received little attention in the literature. In this review, we discuss the causes and underlying mechanisms of acquired hypocholesterolaemia and its relevance to safety of therapeutically induced decreased LDL cholesterol levels.

RECENT FINDINGS

Hypocholesterolaemia is increasingly identified as cholesterol testing becomes more widespread in the assessment of cardiovascular risk. Lower therapeutic targets for LDL cholesterol are also being achieved more regularly with the introduction of more intensive cholesterol-lowering regimens. Acquired hypocholesterolaemia may be the presenting feature of treatable diseases. Understanding its mechanisms may also provide new treatment approaches for neoplastic disease, such as breast cancer, and infections, such as tuberculosis.

SUMMARY

When hypocholesterolaemia is discovered, it is important to identify its cause. Further research into the pathogenesis of hypocholesterolaemia may provide new therapies for primary diseases underlying it.

The potential of cholesteryl ester transfer protein as a therapeutic target

INTRODUCTION

Over recent decades, attempts to ascertain the pro-atherogenic nature of plasma cholesteryl ester transfer protein (CETP) and to establish the relevance of its pharmacological blockade as a promising high density lipoproteins-raising and anti-atherogenic therapy have been disappointing.

AREAS COVERED

The current review focuses on CETP as a multifaceted protein, on genetic variations at the CETP gene and on their possible consequences for cardiovascular risk in human populations. Specific attention is given to physiological modulation of endogenous CETP activity by the apoC1 inhibitor. Finally, the rationale behind the need for selection of patients to treat is discussed in the light of recent studies.

EXPERT OPINION

At this stage one can only speculate on the clinical outcome of pharmacological CETP inhibitors in high-risk populations, but recent advances give cause to adjust the expectations from now on. The CETP effect is probably largely influenced by the overall metabolic state, and whether CETP blockade may be relevant or not in promoting cholesterol disposal is still questioned. The possible need for a careful stratification of patients to treat with CETP inhibitors is outlined. Finally, manipulation of CETP activity should be considered with caution in the context of sepsis and infectious diseases.

A prospective study on metabolic risk factors and gallbladder cancer in the metabolic syndrome and cancer (Me-Can) collaborative study

OBJECTIVE

To investigate the association between metabolic risk factors (individually and in combination) and risk of gallbladder cancer (GBC).

METHODS

The metabolic syndrome and cancer project (Me-Can) includes cohorts from Norway, Austria, and Sweden with data on 578,700 men and women. We used Cox proportional hazard regression models to calculate relative risks of GBC by body mass index (BMI), blood pressure, and plasma levels of glucose, cholesterol, and triglycerides as continuous standardised variables and their standardised sum of metabolic syndrome (MetS) z-score. The risk estimates were corrected for random error in measurements.

RESULTS

During an average follow-up of 12.0 years (SD = 7.8), 184 primary gallbladder cancers were diagnosed. Relative risk of gallbladder cancer per unit increment of z-score adjusted for age, smoking status and BMI (except for BMI itself) and stratified by birth year, sex and sub-cohorts, was for BMI 1.31 (95% confidence interval 1.11, 1.57) and blood glucose 1.76 (1.10, 2.85). Further analysis showed that the effect of BMI on GBC risk is larger among women in the premenopausal age group (1.84 (1.23, 2.78)) compared to those in the postmenopausal age group (1.29 (0.93, 1.79)). For the other metabolic factors no significant association was found (mid blood pressure 0.96 (0.71, 1.31), cholesterol 0.84 (0.66, 1.06) and serum triglycerides 1.16 (0.82, 1.64)). The relative risk per one unit increment of the MetS z-score was 1.37 (1.07, 1.73).

CONCLUSION

This study showed that increasing BMI and impaired glucose metabolism pose a possible risk for gallbladder cancer. Beyond the individual factors, the results also showed that the metabolic syndrome as an entity presents a risk constellation for the occurrence of gallbladder cancer.

Farnesoid X receptor activation increases cholesteryl ester transfer protein expression in humans and transgenic mice

Cholesteryl ester transfer protein (CETP) activity results in a proatherogenic lipoprotein profile. In cholestatic conditions, farnesoid X receptor (FXR) signaling by bile acids (BA) is activated and plasma HDL cholesterol (HDL-C) levels are low. This study tested the hypothesis that FXR-mediated induction of CETP contributes to this phenotype. Patients with cholestasis and high plasma BA had lower HDL-C levels and higher plasma CETP activity and mass compared with matched controls with low plasma BA (each P < 0.01). BA feeding in APOE3*Leiden transgenic mice expressing the human CETP transgene controlled by its endogenous promoter increased cholesterol within apoB-containing lipoproteins and decreased HDL-C (each P < 0.01), while hepatic CETP mRNA expression and plasma CETP activity and mass increased (each P < 0.01). In vitro studies confirmed that FXR agonists substantially augmented CETP mRNA expression in hepatocytes and macrophages dependent on functional FXR expression (each P < 0.001). These transcriptional effects are likely mediated by an ER8 FXR response element (FXRE) in the first intron. In conclusion, using a translational approach, this study identifies CETP as novel FXR target gene. By increasing CETP expression, FXR activation leads to a proatherogenic lipoprotein profile. These results have clinical relevance, especially when considering FXR agonists as emerging treatment strategy for metabolic disease and atherosclerosis.

[Hyperlipoproteinemia in pregnancy]

Physiological changes in lipoprotein levels occur in normal pregnancy. Women with hyperlipoproteinemia are advised to discontinue statins, fibrates already when they consider pregnancy up to and including breast-feeding the newborn, because of the fear for teratogenic effects. Hypertriglyceridemia in pregnancy can rarely lead to acute pancreatitis. Management of acute pancreatitis in pregnant women is similar to that used in non-pregnant patients. Further large cohort studies are needed to estimate the consequence of supraphysiologic hyperlipoproteinemia or extreme hyperlipoproteinemia in pregnancy on the risk for cardiovascular disease later in life.

Aging, age-related macular degeneration, and the response-to-retention of apolipoprotein B-containing lipoproteins

The largest risk factor for age-related macular degeneration (ARMD) is advanced age. A prominent age-related change in the human retina is the accumulation of histochemically detectable neutral lipid in normal Bruch's membrane (BrM) throughout adulthood. This change has the potential to have a major impact on physiology of the retinal pigment epithelium (RPE). It occurs in the same compartment as drusen and basal linear deposit, the pathognomonic extracellular, lipid-containing lesions of ARMD. Here we present evidence from light microscopic histochemistry, ultrastructure, lipid profiling of tissues and isolated lipoproteins, and gene expression analysis that this deposition can be accounted for by esterified cholesterol-rich, apolipoprotein B-containing lipoprotein particles constitutively produced by the RPE. This work collectively allows ARMD lesion formation and its aftermath to be conceptualized as a response to the retention of a sub-endothelial apolipoprotein B lipoprotein, similar to a widely accepted model of atherosclerotic coronary artery disease (CAD) (Tabas et al., 2007). This approach provides a wide knowledge base and sophisticated clinical armamentarium that can be readily exploited for the development of new model systems and the future benefit of ARMD patients.

Apolipoprotein B-containing lipoproteins in retinal aging and age-related macular degeneration

The largest risk factor for age-related macular degeneration (ARMD) is advanced age. With aging, there is a striking accumulation of neutral lipids in Bruch's membrane (BrM) of normal eye that continues through adulthood. This accumulation has the potential to significantly impact the physiology of the retinal pigment epithelium (RPE). It also ultimately leads to the creation of a lipid wall at the same locations where drusen and basal linear deposit, the pathognomonic extracellular, lipid-containing lesions of ARMD, subsequently form. Here, we summarize evidence obtained from light microscopy, ultrastructural studies, lipid histochemistry, assay of isolated lipoproteins, and gene expression analysis. These studies suggest that lipid deposition in BrM is at least partially due to accumulation of esterified cholesterol-rich, apolipoprotein B-containing lipoprotein particles produced by the RPE. Furthermore, we suggest that the formation of ARMD lesions and their aftermath may be a pathological response to the retention of a sub-endothelial apolipoprotein B lipoprotein, similar to a widely accepted model of atherosclerotic coronary artery disease (Tabas, I., K. J. Williams, and J. Borén. 2007. Subendothelial lipoprotein retention as the initiating process in atherosclerosis: update and therapeutic implications. Circulation. 116:1832-1844). This view provides a conceptual basis for the development of novel treatments that may benefit ARMD patients in the future.

Cholesterol oxides inhibit cholesterol esterification by lecithin: cholesterol acyl transferase

Cholesterol oxides are atherogenic and can affect the activity of diverse important enzymes for the lipidic metabolism. The effect of 7β-hydroxycholesterol, 7-ketocholesterol, 25-hydroxycholesterol, cholestan-3β,5α,6β-triol,5,6β-epoxycholesterol, 5,6α-epoxycholesterol and 7α-hydroxycholesterol on esterification of cholesterol by lecithin:cholesterol acyl transferase (LCAT, EC 2.3.1.43) and the transfer of esters of cholesterol oxides from high density lipoprotein (HDL) to low density lipoproteins (LDL) and very low density lipoproteins (VLDL) by cholesteryl ester transfer protein (CETP) was investigated. HDL enriched with increasing concentrations of cholesterol oxides was incubated with fresh plasma as source of LCAT. Cholesterol and cholesterol oxides esterification was followed by measuring the consumption of respective free sterol and oxysterols. Measurements of cholesterol and cholesterol oxides were done by gas-chromatography. 14C-cholesterol oxides were incorporated into HDL2 and HDL3 subfractions and then incubated with fresh plasma containing LCAT and CETP. The transfer of cholesterol oxide esters was followed by measuring the 14C-cholesterol oxide-derived esters transferred to LDL and VLDL. All the cholesterol oxides studied were esterified by LCAT after incorporation into HDL particles, competing with cholesterol by LCAT. Cholesterol esterification by LCAT was inversely related to the cholesterol oxide concentration. The esterification of 14C-cholesterol oxides was higher in HDL3 and the transfer of the derived esters was greater from HDL2 to LDL and VLDL. The results suggest that cholesterol esterification by LCAT is inhibited in cholesterol oxide-enriched HDL particles. Moreover, the cholesterol oxides-derived esters are efficiently transferred to LDL and VLDL. Therefore, we suggest that cholesterol oxides may exert part of their atherogenic effect by inhibiting cholesterol esterification on the HDL surface and thereby disturbing reverse cholesterol transport.

Serum lipid levels and the risk of biliary tract cancers and biliary stones: A population-based study in China

Biliary tract cancers, encompassing the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Gallstones, the predominant risk factor for biliary cancers, are linked with hyperlipidemia. As part of a population-based case-control study conducted in Shanghai, China, we examined the associations of serum lipid levels with biliary stones and cancers. We included 460 biliary cancer cases (264 gallbladder, 141 extrahepatic bile duct, and 55 ampulla of Vater), 981 biliary stone cases and 858 healthy individuals randomly selected from the population. Participants completed an in-person interview and gave overnight fasting blood samples. Participants in the highest quintile of triglycerides (>/=160 mg/dl) had a 1.4-fold risk of biliary stones (95% CI = 1.1-1.9), a 1.9-fold risk of gallbladder cancer (95% CI = 1.3-2.8), and a 4.8-fold risk of bile duct cancer (95% CI = 2.8-8.1), compared to the reference group (third quintile: 90-124 mg/dl). Participants in the lowest quintile of high-density lipoprotein (HDL) (<30 mg/dl) had a 4.2-fold risk of biliary stones (95% CI = 3.0-6.0), an 11.6-fold risk of gallbladder cancer (95% CI = 7.3-18.5), and a 16.8-fold risk of bile duct cancer (95% CI = 9.1-30.9), relative to the reference group (third quintile: 40-49 mg/dl). In addition, total cholesterol, low-density lipoprotein (LDL) and apolipoprotein A (apo A) were inversely associated with biliary stones; whereas low levels as well as high levels of total cholesterol, LDL, apo A and apolipoprotein B (apo B) were associated with excess risks of biliary tract cancers. Our findings support a role for serum lipids in gallstone development and biliary carcinogenesis.

Fluctuation of lipoprotein metabolism linked with bile acid-activated liver nuclear receptors in Alagille syndrome

Alagille syndrome (AGS) is a rare hereditary disorder exhibiting fluctuating cholestasis and dyslipidemia. Farnesoid X receptor (FXR) and liver X receptor (LXR) are hepatic nuclear receptors that regulate bile acid and lipoprotein metabolism. To investigate whether cholestasis is related to dyslipidemia and hepatic nuclear receptor expression in AGS patients, we determined the blood levels of total bile acid (TBA) and lipoprotein parameters, and examined hepatic nuclear receptor expression in three AGS children and their three incomplete AGS parents repeatedly over several years. In the AGS children, TBA level showed significant positive correlations with low-density lipoprotein-cholesterol, apolipoprotein E (apoE)-rich high-density lipoprotein-cholesterol (HDL-C), apoA-I, apoE, and cholesteryl ester transfer protein (CETP) concentrations, but negative correlation with apoE-poor HDL-C concentration. Western blot analysis of liver biopsy specimens revealed that FXR and LXR expression increased in parallel with TBA level. CETP- and ATP-binding cassette transporter A1 expression also increased with TBA level, while scavenger receptor class B type-I expression showed the opposite response. However, apoA-I expression was similar to the control level at any TBA level. In the incomplete AGS parents, TBA and lipoprotein parameters showed little fluctuation. In summary, cholestasis is closely related to dyslipidemia and hepatic nuclear receptor expression in AGS patients.

Maternal lipid metabolism and placental lipid transfer

During early pregnancy, long-chain polyunsaturated fatty acids (LC-PUFA) may accumulate in maternal fat depots and become available for placental transfer during late pregnancy, when the fetal growth rate is maximal and fetal requirements for LC-PUFAs are greatly enhanced. During this late part of gestation, enhanced lipolytic activity in adipose tissue contributes to the development of maternal hyperlipidaemia; there is an increase in plasma triacylglycerol concentrations, with smaller rises in phospholipid and cholesterol concentrations. Besides the increase in plasma very-low-density lipoprotein, there is a proportional enrichment of triacylglycerols in both low-density lipoproteins and high-density lipoproteins. These lipoproteins transport LC-PUFA in the maternal circulation. The presence of lipoprotein receptors in the placenta allows their placental uptake, where they are hydrolysed by lipoprotein lipase, phospholipase A(2) and intracellular lipase. The fatty acids that are released can be metabolized and diffuse into the fetal plasma. Although present in smaller proportions, maternal plasma non-esterified fatty acids are also a source of LC-PUFA for the fetus, their placental transfer being facilitated by the presence of a membrane fatty acid-binding protein. There is very little placental transfer of glycerol, whereas the transfer of ketone bodies may become quantitatively important under conditions of maternal hyperketonaemia, such as during fasting, a high-fat diet or diabetes. The demands for cholesterol in the fetus are high, but whereas maternal cholesterol substantially contributes to fetal cholesterol during early pregnancy, fetal cholesterol biosynthesis rather than cholesterol transfer from maternal lipoproteins seems to be the main mechanism for satisfying fetal requirements during late pregnancy.

Clinical practice guidelines for managing dyslipidemias in kidney transplant patients: a report from the Managing Dyslipidemias in Chronic Kidney Disease Work Group of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative

The incidence of cardiovascular disease (CVD) is very high in patients with chronic kidney (CKD) disease and in kidney transplant recipients. Indeed, available evidence for these patients suggests that the 10-year cumulative risk of coronary heart disease is at least 20%, or roughly equivalent to the risk seen in patients with previous CVD. Recently, the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) published guidelines for the diagnosis and treatment of dyslipidemias in patients with CKD, including transplant patients. It was the conclusion of this Work Group that the National Cholesterol Education Program Guidelines are generally applicable to patients with CKD, but that there are significant differences in the approach and treatment of dyslipidemias in patients with CKD compared with the general population. In the present document we present the guidelines generated by this workgroup as they apply to kidney transplant recipients. Evidence from the general population indicates that treatment of dyslipidemias reduces CVD, and evidence in kidney transplant patients suggests that judicious treatment can be safe and effective in improving dyslipidemias. Dyslipidemias are very common in CKD and in transplant patients. However, until recently there have been no adequately powered, randomized, controlled trials examining the effects of dyslipidemia treatment on CVD in patients with CKD. Since completion of the K/DOQI guidelines on dyslipidemia in CKD, the results of the Assessment of Lescol in Renal Transplantation (ALERT) Study have been presented and published. Based on information from randomized trials conducted in the general population and the single study conducted in kidney transplant patients, these guidelines, which are a modified version of the K/DOQI dyslipidemia guidelines, were developed to aid clinicians in the management of dyslipidemias in kidney transplant patients. These guidelines are divided into four sections. The first section (Introduction) provides the rationale for the guidelines, and describes the target population, scope, intended users, and methods. The second section presents guidelines on the assessment of dyslipidemias (guidelines 1-3), while the third section offers guidelines for the treatment of dyslipidemias (guidelines 4-5). The key guideline statements are supported mainly by data from studies in the general population, but there is an urgent need for additional studies in CKD and in transplant patients. Therefore, the last section outlines recommendations for research.

Progressive familial intrahepatic cholestasis: partial biliary diversion normalizes serum lipids and improves growth in noncirrhotic patients

OBJECTIVES

Progressive familial intrahepatic cholestasis (PFIC) usually presents with pruritus, jaundice, hepatomegaly, and growth failure. A group of PFIC is recognized by marked elevation of total serum bile acids, decreased serum apolipoprotein A-1, and high-density lipoprotein, but normal gamma-glutamyltranspeptidase and cholesterol. Although medical therapy generally fails, partial external biliary diversion (DIV) has been used with promising results for cholestasis. However, little has been reported of its effect on linear growth, synthetic liver function, and lipid metabolism.

METHODS

DIV was performed on six noncirrhotic children with PFIC, all suffering from severe pruritus and cholestasis, refractory to medical treatment. Stature was below -1 (median, -2.3) standard deviation score (SDS) for height in all cases. All patients had markedly enhanced bile acids (307 +/- 72 microl/L), markedly decreased high-density lipoprotein (20 +/- 7 mg/dl), and apolipoprotein A-1 (58 +/- 37 mg/dl), but normal gamma-glutamyltranspeptidase and cholesterol. In addition, cholinesterase activity, monoethylglycinexylidide test, and Fischer's ratio indicated a significantly reduced synthetic liver function in all children but the youngest.

RESULTS

After DIV, all patients were consistently relieved of pruritus, and experienced normalization of all liver function tests, including cholinesterase activity, monoethylglycinexylidide test, and Fischer's ratio, as well as the serum lipid profile within 1 yr. In addition, a marked catch-up growth (median, +/- 1.3 SDS) was evident after 1 yr in all cases.

CONCLUSIONS

This report shows an excellent result of DIV in noncirrhotic PFIC patients and compares favorably with other reports. All patients experienced complete remission, including normalization of synthetic liver function and lipid metabolism. For the first time we have shown that DIV can also be associated with an accelerated growth in these patients.

Determination of biological markers for alcohol abuse

Alcoholism is one of the most frequent addictions and an important subject in forensic medicine and clinical toxicology. Several laboratory abnormalities are associated with excessive alcohol consumption. They are useful in the diagnosis of alcoholism especially during the follow-up of various treatment programs. The biological markers mostly used for diagnosis of alcoholism are presented. Especially, methods for the determination of the following diagnostic tools are reviewed: congener alcohols, gamma-glutamyltransferase, aspartate and alanine aminotransferase, beta-hexosaminidase, erythrocyte aldehyde dehydrogenase, alpha-amino-n-butyric acid to leucine ratio, macrocytosis, carbohydrate-deficient transferrin, (apo)lipoproteins, fatty acid ethyl esters, blood acetate, acetaldehyde adducts, 5-hydroxytryptophol, dolichol and condensation products. No laboratory test exists that is reliable enough for the exact diagnosis of alcoholism. The combination of physician interview, questionnaire and laboratory markers is necessary for the diagnosis of alcoholism.