Revealing Alcohol Abuse: To Ask or to Test?

Phosphatidylethanol is superior to carbohydrate-deficient transferrin and γ-glutamyltransferase as an alcohol marker and is a reliable estimate of alcohol consumption level

BACKGROUND

In clinical practice as well as research situations, it is of great importance to get reliable information about a patient's alcohol consumption. The aim of the study was to investigate the correlation of alcohol biomarkers (phosphatidylethanol [PEth], carbohydrate-deficient transferrin [CDT], γ-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase) to retrospective as well as diary-based alcohol self-reports and to examine whether it is possible to correlate a biomarker result to a more precise level of alcohol consumption.

METHODS

One hundred and sixty alcohol-dependent patients were included in a randomized, placebo-controlled clinical trial of pharmacotherapy for alcohol dependence, of which 115 (76 men and 39 women) completed the study. Retrospective alcohol consumption data were collected at baseline, and alcohol diaries were used during the study. Blood samples for determination of alcohol biomarkers were collected on 5 occasions during the study.

RESULTS

PEth and CDT showed a better correlation with alcohol consumption documented in the diary (PEth rs = 0.56 and CDT rs = 0.35) than with retrospective consumption data (PEth rs = 0.23 and CDT rs = 0.22). An even higher correlation (rs = 0.63) was seen between the 2 alcohol biomarkers PEth and CDT. At all consumption levels, PEth had the highest sensitivity of all biomarkers studied.

CONCLUSIONS

PEth was the biomarker with the best correlation to self-reported alcohol consumption. PEth was superior to CDT owing to its substantially higher sensitivity but also due to its closer correlation to self-report. PEth values can be translated into an approximate level of alcohol consumption and PEth appears to be a more reliable measure of alcohol consumption than self-reports.

Alcoholic lung injury: metabolic, biochemical and immunological aspects

Chronic alcohol abuse is a systemic disorder and a risk factor for acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD). A significant amount of ingested alcohol reaches airway passages in the lungs and can be metabolized via oxidative and non-oxidative pathways. About 90% of the ingested alcohol is metabolized via hepatic alcohol dehydrogenase (ADH)-catalyzed oxidative pathway. Alcohol can also be metabolized by cytochrome P450 2E1 (CYP2E1), particularly during chronic alcohol abuse. Both the oxidative pathways, however, are associated with oxidative stress due to the formation of acetaldehyde and/or reactive oxygen species (ROS). Alcohol ingestion is also known to cause endoplasmic reticulum (ER) stress, which can be mediated by oxidative and/or non-oxidative metabolites of ethanol. An acute as well as chronic alcohol ingestions impair protective antioxidants, oxidize reduced glutathione (GSH, cellular antioxidant against ROS and oxidative stress), and suppress innate and adaptive immunity in the lungs. Oxidative stress and suppressed immunity in the lungs of chronic alcohol abusers collectively are considered to be major risk factors for infection and development of pneumonia, and such diseases as ARDS and COPD. Prior human and experimental studies attempted to identify common mechanisms by which alcohol abuse directly causes toxicity to alveolar epithelium and respiratory tract, particularly lungs. In this review, the metabolic basis of lung injury, oxidative and ER stress and immunosuppression in experimental models and alcoholic patients, as well as potential immunomodulatory therapeutic strategies for improving host defenses against alcohol-induced pulmonary infections are discussed.

A search for novel markers of alcohol abuse using magnetic beads and MALDI-TOF/TOF mass spectrometry

Objective markers are required to assess excessive alcohol consumption, which can lead to a various medical and social problems. In this study, we carried out serum peptidome analyses using the ClinProt(™) system, which consists of magnetic beads and MALDI-TOF/TOF MS, to find novel biomarkers of alcohol abuse in 16 chronic alcoholic patients that were hospitalized for a rehabilitation program. A total of 22 peaks were found to be significantly altered during abstinence. Out of these 22 peaks, 3 peaks that had an m/z of 3000 or less and substantial peak intensities were subjected to MS/MS analysis followed by a MASCOT search. The 1466 Da and the 1616 Da peptides were upregulated on admission and were identified as fragments of fibrinopeptide A and phosphorylated fibrinopeptide A, respectively. On the other hand, the 2660 Da peptide, which was downregulated on admission and increased during abstinence, was identified as a fragment of the fibrinogen α C chain. These peaks were not detectable by the SELDI-TOF MS ProteinChip(®) system analysis. The alterations in these peaks induced by alcohol abuse were also seen in γ glutamyltransferase nonresponders. These protein fragments may be additional biomarkers for excessive alcohol drinking.

Alcohol misuse in patients with psoriasis: identification and relationship to disease severity and psychological distress

BACKGROUND

Moderate to severe psoriasis is associated with increased alcohol intake and excessive mortality from alcohol-related causes. Alcohol biomarkers provide an objective measure of alcohol consumption. Carbohydrate-deficient transferrin (CDT) is the single most sensitive and specific alcohol biomarker.

OBJECTIVES

To assess alcohol consumption in a cohort of patients with moderate to severe psoriasis using standard alcohol screening questionnaires and biomarkers. We investigated whether there was an association between alcohol intake, anxiety, depression and disease severity.

METHODS

Consecutive patients with chronic plaque psoriasis were recruited and completed a range of anonymized assessments. Psoriasis severity, anxiety and depression, and the impact of psoriasis on quality of life were assessed. Alcohol screening questionnaires were administered. Blood specimens were taken and γ-glutamyltransferase (γGT) and CDT were measured.

RESULTS

A total of 135 patients completed the study. Using validated questionnaires, between 22% and 32% had difficulties with alcohol. Seven per cent had CDT > 1·6% indicating a heavy alcohol intake. The Alcohol Use Disorders Identification Test (AUDIT) questionnaire was superior to other validated questionnaires in detecting alcohol misuse. There were no significant associations between measures of excessive alcohol consumption and disease severity. Excessive alcohol intake as measured by the CAGE questionnaire was associated with increased depression (P = 0·001) but other measures of alcohol excess did not correlate with psychological distress. Men had significantly more difficulties with alcohol than women (P < 0·001).

CONCLUSION

Alcohol misuse is common in patients with moderate to severe psoriasis. Screening with the AUDIT questionnaire and CDT may allow the identification of patients who are misusing alcohol and allow appropriate intervention.

Analysis of carbohydrate deficient transferrin serum levels during abstinence

An alcohol-associated change in the serum transferrin glycoform pattern, carbohydrate-deficient transferrin (CDT), is used as a biomarker of chronic moderate to heavy alcohol consumption. Furthermore, CDT is employed as a marker of abstinence. Here, we analyzed CDT in patients with chronic excessive alcohol abuse at the beginning and during abstinence. Twenty-nine alcohol dependent patients were recruited from an in-patient abstention program. Reported drinking levels were at least 100 g/d (range up to 450 g/d; mean: 248.9±94.7 g/d) within the last month before study entry. Blood samples were drawn at the beginning and during the abstention program and the relative concentration (%CDT) of CDT was determined using ion exchange followed by immunodetermination of CDT. At study entry, 25/29 patients had a %CDT level above the established cutoff. Although CDT levels declined during abstinence in most patients, in ten patients with %CDT levels just above the cutoff at the start of the program, the CDT values remained elevated 6 weeks after cessation of drinking. Our data indicate that %CDT levels below the cutoff cannot even rule out long lasting excessive alcohol abuse. Further, measurement of %CDT should be interpreted with special care when used as a marker of alcohol abstinence.

Increased serum levels of pigment epithelium-derived factor by excessive alcohol consumption-detection and identification by a three-step serum proteome analysis

BACKGROUND

The search for biological markers of alcohol abuse is of continual interest in experimental and clinical alcohol research. We previously used gel-free proteome analysis methods such as the ProteinChip(®) system and the ClinProt™ system to search for new serum markers for alcoholism and found several novel marker candidates. As serum contains thousands of proteins and peptides that are present in a large dynamic concentration, depletion of the abundant proteins and further fractionation of the remainder is necessary to get into the deep proteome. We recently described a simple and highly reproducible three-step method for identifying potential disease-marker candidates among the low-abundance serum proteins.

METHODS

Two serum samples-one on admission and one after 8 weeks of abstinence-were obtained from 8 patients with alcohol dependency. The samples were subjected to a three-step serum proteome analysis. The steps were the following: first, immunodepletion of the 6 most abundant proteins; second, fractionation using reverse-phase high-performance liquid chromatography; and third, separation using one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Differences revealed by protein staining were further confirmed by Western blotting and by enzyme-linked immunosorbent assays (ELISA).

RESULTS

Three-step serum proteome analysis revealed that the serum levels of 5 proteins, alpha2-HS glycoprotein, apolipoprotein A-I, glutathione peroxidase 3, heparin cofactor II, and pigment epithelial-derived factor (PEDF), were significantly greater on admission than after 8 weeks of abstinence. We focused on PEDF because alterations in its levels in alcoholic subjects are not well known. Western blotting and ELISA confirmed the upregulation of PEDF. Serum PEDF levels were significantly greater in moderate to heavy habitual drinkers (14.2 ± 7.7 μg/ml) than in healthy subjects without a drinking history (5.5 ± 3.0 μg/ml) (p < 0.001). The serum PEDF levels in subjects with nonalcoholic chronic liver diseases were comparable to the PEDF levels in healthy subjects.

CONCLUSION

  Three-step serum proteome analysis reveals that excessive alcohol drinking increases the PEDF level.

Novel Objective Biomarkers of Alcohol Use: Potential Diagnostic and Treatment Management Tools in Dual Diagnosis Care

Alcohol use disorders are highly prevalent conditions that generate a large fraction of the total public health burden. These disorders are concentrated in mentally ill populations, in which reliability of self-reporting of alcohol consumption may be especially compromised. The application of objective biomarkers for alcohol use may therefore play an important role in these patients. This article provides a description and comparative overview of traditional versus novel biomarkers of alcohol consumption. Greater professional familiarity with and use of novel biomarkers as diagnostic and treatment management tools may enhance clinical standards and research on alcohol use in patients with a dual diagnosis.

Biomarkers in alcoholism

Alcoholism ranks as one of the main current threats to the health and safety of people in most Western countries. Therefore, a high priority should be given to aims at reducing its prevalence through more effective diagnosis and early intervention. The need for objective methods for revealing alcohol abuse in its early phase has also been widely acknowledged. It is postulated here that the diagnosis of alcohol use disorders could be markedly improved by a more systematic use of specific questionnaires and laboratory tests, including blood ethanol, serum gamma-glutamyltransferase (GGT), carbohydrate-deficient transferrin (CDT), and mean corpuscular volume of erythrocytes (MCV). Recent research has provided new insights into the relationships between ethanol intake, biomarkers, and factors affecting their diagnostic validation, including gender, age, and the effects of moderate drinking and obesity. It appears that the concept of reference intervals for several ethanol-sensitive parameters in laboratory medicine needs to be revisited. CDT is currently the most specific marker of alcohol abuse, and when combined with GGT using a mathematically formulated equation a high sensitivity is reached without loss of assay specificity. Possible new biomarkers include minor ethanol metabolites (protein-acetaldehyde condensates and associated autoimmune responses, ethylglucuronide, and phosphatidylethanolamine), 5-hydroxytryptophol, and genetic markers although so far their routine applications have been limited.

Alcohol and the liver

PURPOSE OF REVIEW

To apprise the reader of advances in 2005 in the epidemiology, pathogenesis, prognosis and treatment of alcoholic liver disease. Alcohol use has declined in developed countries, but the opposite is true elsewhere; alcoholic liver disease is a considerable burden worldwide.

RECENT FINDINGS

Genetic mechanisms for alcoholic liver disease are being discovered in addition to aggravating cofactors, such as hepatitis C, obesity and iron overload, and ameliorating ones, like coffee and tea drinking. The involvement of the innate immune system and the mechanisms of apoptosis in alcoholic liver disease are better appreciated, especially the emerging role of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Steroid use and nutrition for alcoholic hepatitis are being refined, and the validity of the model for end-stage liver disease (MELD) score in predicting the outcome of alcoholic liver disease is upheld. Recidivism after liver transplantation for alcoholic liver disease adversely impacts long-term survival.

SUMMARY

Inroads are being made into the genetics of alcoholic liver disease and new phenomena are being uncovered in its pathogenesis, but safe and effective therapies for both alcoholic hepatitis and alcoholic cirrhosis are still wanting.