Carbohydrate-deficient transferrin as an indicator of drinking status during a treatment outcome study

Phosphatidylethanol (B-PEth) and other direct and indirect biomarkers of alcohol consumption

When identifying, preventing and treating alcohol use disorder, a correct estimation of alcohol intake is essential. An objective marker is preferred as self-reported alcohol intake suffers from bias, and the use of alcohol biomarkers is increasing globally. An easy-to-use blood biomarker to correctly assess alcohol consumption is an invaluable asset in alcohol treatment strategies, as well as in alcohol research studies. The specific, cumulative, biomarker phosphatidylethanol, mirroring the past two weeks of consumption, has shown superiority over traditional biomarkers and is an attractive choice of proxy for alcohol intake.

Thirty- Versus Ten-Day Diazepam Treatment for Alcohol Detoxification and a Comparison of Drinking Patterns, Craving, and Anxiety for up to 12 Weeks: A "Proof-of-Concept" Open-Label Randomized Controlled Trial

PURPOSE

The aim of this study was to evaluate whether a prolonged detoxification treatment could decrease the relapse rate at 3 months after alcohol cessation in alcohol-dependent individuals through decreasing the levels of postdetoxification craving and anxiety.

METHODS

Twenty-six adult patients with alcohol dependence (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision) who began an outpatient alcohol cessation program with an initial drinking goal of abstinence were enrolled in a 3-month, parallel, randomized (1:1 ratio), controlled, open-label, pilot trial. Participants were randomized to receive a detoxification treatment of diazepam with a duration of 30 (n = 12) or 10 days (n = 14). All participants received BRENDA-based psychotherapy during follow-up.

RESULTS

No significant between-group difference in relapse to any drinking was found at 3 months (P = 0.20). However, relapse to any heavy drinking at 3 months and regular drinking or heavy drinking during follow-up were significantly lower in the 30-day diazepam group (P = 0.009, P = 0.049, and P = 0.004, respectively). These differences were corroborated by significant differences in the alcohol-specific biological marker carbohydrate deficient transferrin at 3 months. Participants in the 30-day diazepam group also displayed significantly lower scores for alcohol craving (P = 0.007), self-reported anxiety (P = 0.024), and clinician-assessed anxiety (P = 0.002) throughout the follow-up. No serious adverse event was reported during the study.

CONCLUSION

This study provides an evidence-based rationale for a double-blind, randomized, placebo-controlled trial to confirm the efficacy of such a procedure on short-term and mid-/long-term drinking outcomes after alcohol cessation in alcohol-dependent individuals.

Alcohol biomarkers as tools to guide and support decisions about intoxicated driver risk

OBJECTIVES

This article describes the results of a pilot study that used alcohol biomarkers to guide decisions about driving under the influence (DUI) driver risk in the United States, replicating a European best practices model. The pilot tested whether biomarkers (1) can help the assessor identify high-risk drivers who continue to drink heavily after their arrest and (2) detect relapses in drivers enrolled in their drivers' safety plans.

METHODS

These questions were addressed using two biomarkers, carbohydrate-deficient transferrin (CDT), and the Early Detection of Alcohol Consumption (EDAC) test, to evaluate the drinking behavior in repeat offenders during the assessment interview (baseline) and at 3, 6, 9, and 12 months' follow-up. The cutoff used to determine heavy drinking at baseline was 2.2 percent CDT and 40 percent P-positive for EDAC. A 30 percentage point increase in biomarker value from an abstinent baseline signaled a relapse and a 30 percentage point decrease in biomarker value from a previous positive measure signaled reduced drinking/abstinence.

RESULTS

The results show that the EDAC used alone identified 18 percent of drivers as heavy drinkers at baseline compared to 5 percent for CDT and 8 percent for GGT. The best detection rate was achieved with the EDAC-CDT combination, which captured heavy drinking in 20 percent of the repeat offenders at baseline, most of whom (68%) denied drinking at the assessment interview. During follow-up, 52 percent of drivers abstained/reduced their drinking, almost 20 percent experienced a relapse, and 30 percent remained noncompliant with testing. Drivers who relapsed were less likely to be employed full-time (67 versus 84%) or married (17 versus 30%) compared to those who abstained. Of the drivers who relapsed, 80 percent returned to abstinence or reduced their drinking after biomarker information was used as brief intervention by the counselors.

CONCLUSION

Biomarker testing improved the assessment and monitoring of repeat offenders in this pilot because it provided an objective tool to identify high-risk drivers allowing for better treatment recommendations and helped identified drivers who relapsed during follow-up to facilitate a brief intervention by the counselor that resulted in reduced alcohol consumption. These results contribute to establish evidence based practices in highway safety and are setting up new guidelines in the United States to reduce drunk driving.

The carbohydrate-deficient transferrin test in hospital practice

We report an experience in two hospital populations of the use of a commercially available kit for the detection of carbohydrate-deficient transferrin (CDT). Patients from a drug and alcohol unit and a gastroenterology clinic at two hospitals were selected for the study. Sera were used from blood samples collected for routine biochemical assays. All patients had a specific alcohol history taken by one clinician and CDT results were correlated with reported alcohol intake by the patient and where relevant by their relatives. Sensitivity and specificity of the CDT assay were calculated using an alcohol intake of 60 g/day as the cut-off point for detection of heavy drinking. The CDT assay had a specificity of 95%; a sensitivity of 80% and a 90% positive and 89% negative predictive value. The severity and type of liver disease had little influence on the CDT result and a high alcohol intake was the only predictor of a raised CDT concentration. The assay provided information not available from routine investigations in some patients and also proved useful in monitoring patients over periods of up to 4 years. The test has a role in the evaluation of patients in a hospital practice where routine histories of alcohol intake may lack sensitivity and where other diseases may cause routine liver tests to be unreliable.

Factors Affecting %CDT Status at Entry Into a Multisite Clinical Treatment Trial: Experience from the COMBINE Study

BACKGROUND

Carbohydrate-deficient transferrin (CDT) occurs as a higher percentage of normal transferrin (%CDT) in heavy drinkers. %CDT is used as a marker of both alcohol use disorder severity and treatment outcome both clinically and in treatment trials. Nevertheless, little is known about the parameters that predict which patients are %CDT positives at treatment entry. These parameters might include level of drinking, days of abstinence before testing, and severity of alcohol dependence before evaluation.

METHODS

%CDT levels were collected before randomization from participants of the COMBINE Study, a large federally sponsored multisite clinical trial evaluating medications and behavioral therapies in alcohol-dependent outpatients. %CDT (assayed in a central laboratory) was available in 1,193 individuals for whom drinking history in the 30 days before testing and measures of alcoholism severity were documented. The effects of drinking history and alcohol severity were evaluated for prediction of a %CDT-positive test status.

RESULTS

Less percent days abstinent (PDA) and more drinks per drinking day (DDD) were predictive of higher rates of %CDT-positive patients (maximum 67%). Up to 14 days of continuous abstinence before testing did not appear to significantly affect %CDT status. Rates of %CDT positives remained reasonably steady up to about 40% PDA. Years of drinking at dependence levels had an unexpected negative impact on %CDT-positive rates while previous treatment had a small but positive impact of %CDT-positive rates. ADS and DrInC scores had no predictive value over and above recent drinking amounts on %CDT status.

CONCLUSIONS

%CDT is more likely to be positive in those who have more days of drinking and to a lesser degree in those who drink more per drinking day. It can remain positive even in those alcoholic subjects who stop drinking many days before testing. Alcoholic subjects with more treatment experiences appear to have a marginally higher %CDT-positive rate.

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.

A review of genetic, biological, pharmacological, and clinical factors that affect carbohydrate-deficient transferrin levels

BACKGROUND

Carbohydrate-deficient transferrin (CDT) is an alcohol biomarker recently approved by the U.S. Food and Drug Administration. This test is increasingly being used to detect and monitor alcohol use in a variety of health care, legal, and industrial settings. The goal of this study is to review the genetic, biological, pharmacological, and clinical factors that may affect CDT levels.

METHODS

A review of the literature identified 95 research articles that met the authors' criteria and reported potential interactions of a variety of factors on percent and total CDT levels. The review established 12 categories of variables that may affect CDT levels. These categories include (1) alcohol use, (2) genetic factors, (3) race, (4) gender, (5) age, (6) liver disease, (7) iron levels, (8) tobacco use, (9) medication such as estrogen and anticonvulsants, (10) metabolic factors such as body mass index and total body water, (11) chronic medical conditions such as rheumatoid arthritis, and (12) surgical patients.

RESULTS

There is evidence that %CDT levels are affected by alcohol use, end-stage liver disease, and genetic variants. In addition to these three factors, total CDT levels (CDTect) are also affected by factors that raise transferrin levels such as iron deficiency, chronic illnesses, and menopausal status. Other potential factors such as tobacco and age appear to be confounded by alcohol use. The roles of female gender, low body mass index, chronic inflammatory diseases, and medication on CDT levels require further study. False negatives are associated with female gender, episodic lower level alcohol use, and acute trauma with blood loss.

CONCLUSIONS

This review suggests that a number of factors are associated with false-positive CDTect and %CDT levels. CDT offers great promise to assist physicians in the care of patients to detect and monitor heavy alcohol use.

Current status of carbohydrate deficient transferrin, total serum sialic acid, sialic acid index of apolipoprotein J and serum beta-hexosaminidase as markers for alcohol consumption

AIMS

The purpose of this paper is to present a brief review of the literature and to summarize the current status of four biochemical markers for alcohol consumption, carbohydrate deficient transferrin (CDT), total serum sialic acid (TSA), sialic acid index of apolipoprotein J (SIJ) and serum beta-hexosaminidase (beta-HEX).

FINDINGS

Of these markers, CDT has been the most widely studied, is currently thought to be the most accurate predictor of alcohol consumption, is most readily available and is the only test approved by the FDA for the identification of heavy alcohol use. TSA and SIJ have the potential to be useful markers, but have only recently been discovered, are not readily available and have not yet been studied comprehensively. Finally, the relationship between serum beta-HEX and heavy alcohol consumption has been studied for about 20 years, but the test is not readily available and has not been widely accepted or used as a marker for heavy alcohol consumption.

CONCLUSIONS

These markers have the potential to be included in a combination of measurements to provide an accurate, more exact assessment of alcohol consumption in a variety of clinical and research settings.

Traditional markers of excessive alcohol use

AIMS

The blood tests used traditionally as markers of excessive drinking are the liver enzymes, gamma glutamyltransferase (GGT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and the red blood cell volume (mean corpuscular volume: MCV). Here we review the nature of these markers' association with alcohol use, their practical application in detecting, assessing or monitoring drinking and increases in understanding of these markers in the past 10 years.

DESIGN

Articles were identified via Medline search and perusal of bibliographies.

FINDINGS

The conventional markers have imperfect sensitivity and specificity, but have an added clinical role in the detection of complications of drinking, and of comorbid conditions that may increase risk of drinking. GGT may in part be a marker of the oxidative stress associated with ethanol metabolism. Markers are more likely to be elevated in those aged more than 30 years and in regular drinkers with a longer drinking history. The markers may be useful in opportunistic case finding, in motivating patients to change drinking and in monitoring treatment response. Increased prevalence of obesity and hepatitis C must be considered in interpretation of liver enzyme results. The liver enzymes are prognostic indicators for several medical conditions and for mortality.

CONCLUSIONS

These conventional tests are widely available and relatively inexpensive. While having limited sensitivity and specificity in detection of excessive drinking, they also provide valuable data on complications of drinking, comorbid conditions that may be affected by drinking and, in some cases, prognosis.

Pathogenesis and management of alcoholic hepatitis

Alcoholic hepatitis is a potentially life-threatening complication of alcoholic abuse, typically presenting with symptoms and signs of hepatitis in the presence of an alcohol use disorder. The definitive diagnosis requires liver biopsy, but this is not generally required. The pathogenesis is uncertain, but relevant factors include metabolism of alcohol to toxic products, oxidant stress, acetaldehyde adducts, the action of endotoxin on Kupffer cells, and impaired hepatic regeneration. Mild alcoholic hepatitis recovers with abstinence and the long-term prognosis is determined by the underlying disorder of alcohol use. Severe alcoholic hepatitis is recognized by a Maddrey discriminant function >32 and is associated with a short-term mortality rate of almost 50%. Primary therapy is abstinence from alcohol and supportive care. Corticosteroids have been shown to be beneficial in a subset of severely ill patients with concomitant hepatic encephalopathy, but their use remains controversial. Pentoxifylline has been shown in one study to improve short-term survival rates. Other pharmacological interventions, including colchicine, propylthiouracil, calcium channel antagonists, and insulin with glucagon infusions, have not been proven to be beneficial. Nutritional supplementation with available high-calorie, high-protein diets is beneficial, but does not improve mortality. Orthotopic liver transplantation is not indicated for patients presenting with alcoholic hepatitis who have been drinking until the time of admission, but may be considered in those who achieve stable abstinence if liver function fails to recover.

Carbohydrate-deficient transferrin and gamma-glutamyltransferase for the detection and monitoring of alcohol use: results from a multisite study

BACKGROUND

The purpose of this article is to evaluate the biological marker of heavy alcohol use, carbohydrate-deficient transferrin (CDT), in contrast to the older and more widely used gamma-glutamyltransferase (GGT) for the detection and monitoring of heavy alcohol use.

METHODS

In this report, CDT and GGT sensitivity and specificity for heavy alcohol intake are examined in a large multisite study in which 444 recently admitted inpatient alcoholics were compared with 204 matched social drinker controls. In addition, changes in these biomarkers were evaluated during an initial abstinence period and biweekly over 14 weeks of monitoring to compare changes in CDT and GGT during continued abstinence or relapse.

RESULTS

CDT and GGT were comparable in identifying heavy alcohol consumption in men, but GGT appeared to be better for women. For both genders, when these markers were combined, there was better sensitivity than when used alone. CDT and GGT both decreased during 4 weeks of abstinence. When we used a 30% increase from baseline abstinent levels as an indicator, CDT appeared marginally better than GGT at indicating relapse in men but not in women. For men in particular, relapse over the course of the study was best identified by evaluating changes (30% increase) in both markers simultaneously.

CONCLUSIONS

These results support the utility of CDT, especially when used in conjunction with GGT, as an aid in detecting and monitoring heavy alcohol consumption.

Posttreatment results of combining naltrexone with cognitive-behavior therapy for the treatment of alcoholism

Naltrexone, an opiate antagonist medication, has been reported to be efficacious in the treatment of alcohol dependence when added to psychosocial treatments. Although the within-treatment efficacy of naltrexone has received primary attention, there has been little published on the outcome of individuals once the medication is discontinued. Animal studies have led to concern regarding a quick rebound to heavy drinking. This report extends the data previously reported by evaluating the outcome in alcoholic subjects during the 14 weeks after a 12-week treatment with naltrexone or placebo in conjunction with cognitive behavioral therapy. Of the 131 subjects evaluated during the treatment phase, 124 (95%) had up to 14 weeks of posttreatment drinking data available for analysis. Measures of craving and blood markers of heavy drinking were also evaluated. By the end of treatment, naltrexone demonstrated significantly greater efficacy than placebo. However, once the medication was discontinued, there was a gradual increase in relapse rates, heavy drinking days, and drinks per drinking day, and fewer days of abstinence were reported. By the end of the 14-week follow-up period, although naltrexone-treated subjects were, on average, still doing better than control subjects, the effectiveness of naltrexone was no longer statistically significant. There was no evidence that naltrexone subjects had an immediate return to heavy alcohol use as suggested in animals. These data suggest that, for a number of alcoholic subjects, continued treatment with naltrexone, or perhaps psychosocial intervention, for longer than 3 months is indicated. Future research should identify which alcohol-dependent individuals may need prolonged treatment to improve treatment success in the long term.

Current concepts in the treatment of depression in alcohol-dependent patients

This article addresses the comorbidity of depression and alcoholism, including an overview of the epidemiologic evidence available, reasons for the association between depression and alcoholism, and basic mechanisms common to both disorders. Practical evidence and experience-based advice on the management of these patients also are provided.

Should We Use Carbohydrate-deficient Transferrin instead of γ-Glutamyltransferase for Detecting Problem Drinkers? A Systematic Review and Metaanalysis

Background: Carbohydrate-deficient transferrin (CDT) has been used as a test for excessive alcohol consumption in research, clinical, and medico-legal settings, but there remain conflicting data on its accuracy, with sensitivities ranging from <20% to 100%. We examined evidence of its benefit over a conventional and less expensive test, γ-glutamyltransferase (GGT), and compared the accuracy of different CDT assay methods.

Methods: We performed a systematic review using summary ROC analysis of 110 studies prior to June 1998 on the use of CDT in the detection of alcohol dependence or hazardous/harmful alcohol use.

Results: We identified several potential sources of bias in studies. In studies examining CDT and GGT in the same subjects, subject characteristics were less likely to influence the comparison. In such paired studies, the original Pharmacia CDT assay was significantly more accurate than GGT, but the modified CDTect assay did not perform as well as the original and was not significantly better than GGT. The accuracy of the AXIS %CDT assay was statistically indistinguishable from modified CDTect. Several CDT assay methods appeared promising, in particular, liquid chromatography (chromatofocusing, HPLC, fast protein liquid chromatography) and isoelectric focusing, but there were insufficient paired studies from which to draw firm conclusions.

Conclusions: In studies published before June 1998, the results obtained with commercially available CDT assays were not significantly better than GGT as markers of excessive alcohol use in paired studies. Further high-quality studies comparing CDTect (modified) and other CDT assays with GGT in the same subjects are needed.

Naltrexone and cognitive behavioral therapy for the treatment of outpatient alcoholics: results of a placebo-controlled trial

OBJECTIVE

The opiate antagonist drug naltrexone has been shown in a few studies with limited sample sizes to be effective when combined with psychosocial therapies for the treatment of alcohol dependence. The goal of this study was to obtain additional information regarding its efficacy in pertinent alcoholic populations and with a well-defined therapy.

METHOD

In this study, 131 recently abstinent alcohol-dependent outpatients were treated with 12 weekly sessions of manual-guided cognitive behavioral therapy and either 50 mg/day of naltrexone (N = 68) or placebo (N = 63) (with riboflavin added as a marker of compliance) in a double-blind, randomized clinical trial. Alcohol consumption, craving, adverse events, and urinary riboflavin levels were assessed weekly. Levels of blood markers of alcohol abuse were also ascertained during the trial.

RESULTS

The study completion, therapy participation, and medication compliance rates in the trial were high, with no differences between treatment groups. Naltrexone-treated subjects drank less, took longer to relapse, and had more time between relapses. They also exhibited more resistance to and control over alcohol-related thoughts and urges, as measured by a subscale of the Obsessive Compulsive Drinking Scale. Over the study period, 62% of the naltrexone group did not relapse into heavy drinking, in comparison with 40% of the placebo group.

CONCLUSIONS

Motivated individuals with moderate alcohol dependence can be treated with greater effectiveness when naltrexone is used in conjunction with weekly outpatient cognitive behavioral therapy. Naltrexone increases control over alcohol urges and improves cognitive resistance to thoughts about drinking. Thus, the therapeutic effects of cognitive behavioral therapy and naltrexone may be synergistic.

Carbohydrate-deficient transferrin as compared to other markers of alcoholism: a systematic review

This is a systematic review of the studies in which carbohydrate-deficient transferrin (CDT) has been compared to other laboratory markers in different experimental conditions, clinical settings, and populations. Only the studies (n = 54) in which CDT was compared either to the conventional or new biological markers of alcoholism, heavy drinking, or alcohol use were selected for further evaluation. Two prospective studies indicate that in men CDT is slightly more sensitive than gamma-GT in reflecting changes in these markers caused by drinking of a moderate and fixed amount of alcohol during three to four weeks. In one prospective study, in which the drinking history of male heavy drinking volunteers was as close the golden standard as possible; that is, obtained by a prospective anonymous drinking diary, CDT was slightly but not significantly better marker than conventional laboratory markers (ASAT, ALAT, gamma-GT and beta-Hex) in the identification of men drinking more than 400 g of alcohol daily. Similar prospective studies concerning women have not been done. Six prospective treatment outcome studies indicate that CDT may be a significantly more sensitive marker than gamma-glutamyltransferase (gamma-GT) in the detection of relapses in male alcoholics. However, these two tests can also be considered to be complementary markers. Furthermore, in the detection of relapses the baseline values of CDT and gamma-GT should be measured and compared on individual basis to the pretreatment values. Comparable data are not available from female alcoholics. In selective materials comprising male alcoholics and heavy drinkers, CDT was found to be a slightly more sensitive marker than gamma-GT in seven retrospective studies. In five studies, gamma-GT was slightly better. However, the differences between CDT and gamma-GT in general were not statistically significant. In three studies, the combined use of CDT and gamma-GT improved the sensitivity but with the expense of specificity. Only four studies included women and in three of these the sensitivity of gamma-GT was better than that of CDT, whereas in one study CDT was better than gamma-GT in the detection of female heavy drinkers. Seven studies performed in primary health care settings and among young populations demonstrate that the performance of CDT in the identification of heavy and problem drinkers in this type of populations is very low, although comparable to the poor performance of the conventional laboratory markers, too. According to seven studies, the sensitivity of gamma-GT is slightly better than that of CDT in the identification of excessive alcohol consumption among hospitalized male and female patients. However, in this type of hospital setting, the specificity of CDT is markedly higher than that of gamma-GT. There is some evidence indicating that the performance of the tests can be improved with the combined use of both tests. Eight studies indicate that both in men and women CDT is a better marker than gamma-GT in the identification of alcohol abuse among patients with alcoholic and nonalcoholic liver diseases. This is mostly due to the higher specificity of CDT as compared to that of gamma-GT.

Carbohydrate deficient transferrin in alcoholic liver disease: mechanisms and clinical implications

Carbohydrate-deficient transferrin (CDT) is now considered to be the most sensitive and specific biological marker of alcohol abuse. The mechanism by which chronic alcohol consumption causes an elevation of CDT levels in serum is discussed. The sensitivity and specificity of various test procedures are compared, with special emphasis on the impact of liver disease. Clinical applications are reviewed, including the utility of CDT as a marker of relapse in alcoholic patients, and the use of CDT for the systematic screening of drinking in vulnerable populations as part of a public health approach to alcoholism.

Carbohydrate-deficient transferrin in the assessment of harmful alcohol consumption: diagnostic performance and clinical significance

The last decade saw the emergence of carbohydrate-deficient transferrin (CDT) as the most promising marker for the diagnosis of alcohol abuse. Daily alcohol consumption of four beers, four glasses of wine or three standard drinks causes increased concentrations of CDT in serum. CDT is serum transferrin with a reduced content of oligosaccharides due to the detrimental effects of alcohol metabolism on the glycosylation pathway of hepatocytes and/or the increased activity of circulating glycosidases in serum. Most current CDT procedures entail separation of normal transferrin from CDT in a charged matrix-like isoelectric focusing and ion exchange chromatography, followed by detection/quantitation of CDT by a myriad of immunoassays: immunoblotting, radioimmunoassay, enzyme immunoassay and nephelometry. New CDT procedures present the advantages of improved performance, inexpensive automation and CDT results expressed as a percentage of total serum transferrin. CDT's major asset is its high specificity in well-defined populations i.e. individuals ingesting 60 g alcohol daily for at least a week.The sensitivity rates, which vary between 22% and 81%, depend on the amount of alcohol ingested, time of sample collection after the cessation of drinking, age, gender and the cut-off point chosen for analysis of tests' results. Regarding clinical applications, best outcome is achieved when the test is used to confirm a suspicion of alcohol abuse and when monitoring abstinence and relapses.The low prevalence of alcohol abuse in the general population challenges its use as a screening test.With the advent of inexpensive automation and the constant emergence of innovative, improved tests, we are seeing the rise of a new era in alcohol abuse diagnosis as affordability and education allows widespread use of CDT in a variety of settings.

Biological markers as indicators for relapse in alcohol-dependent patients

Although biological markers such as carbohydrate-deficient transferrin (CDT), γ-glutamyl transferase (GGT) and mean corpuscular volume (MCV) have been used as indicators for heavy alcohol consumption and alcoholism little information is available on the utitlity of these markers in detecting relapses. In this study the value of the biological markers CDT, GGT and MCV was examined in monitoring an outpatient treatment programme for alcohol-dependent patients. In 163 male alcoholic patients CDT, GGT and mean corpuscular volume (MCV) were assayed at the beginning and after 6 months during the outpatient programme. All markers distingushed between relapsers and abstainers (p<0.01). The sensitivity for relapses was 55% for CDT, 50% for GGT and 20% for MCV. Combining all markers the sensitivity could be enhanced to 85%, with only a little loss of specificity (85%). The highest positive predictive value was 73% for CDT used as a single marker. The negative predictive value (CDT 93%, GGT 92%, MCV 88%) and the diagnostic efficiency (CDT 91%, GGT 87%, MCV 85%) of all markers were very high. These results indicate that CDT is the most efficient marker for alcohol relapses, followed by GGT. MCV seems to be a marker of second choice.

Carbohydrate-deficient transferrin and alcohol use in medical examiner cases

Carbohydrate-deficient transferrin (CDT) has been studied as an index of heavy alcohol use. The present study evaluates the utility of CDT as a marker for chronic alcohol use in medical examiner cases. Over a 5-month period, serum specimens were collected in consecutive deaths that were referred to the medical examiner's office (N = 25). Manner of death was accidental in nine cases, homicide/suicide for eight cases, and natural causes for seven cases. Fifteen of the 17 cases having alcohol abuse had positive CDT levels above threshold, indicating chronic use (sensitivity 88%). Eight cases had no evidence of alcohol abuse but three of these cases had CDT levels also above threshold (specificity 63%). There was no correlation between serum CDT levels and the time of death to blood collection for the total sample, indicating that CDT is stable postmortem for at least 36 h. CDT appears to have value as a marker of ante-mortem alcohol use prior to time of death in medical examiner cases.

The effect of drinking intensity and frequency on serum carbohydrate-deficient transferrin and gamma-glutamyl transferase levels in outpatient alcoholics

Whereas heavy alcohol consumption is known to elevate serum carbohydrate-deficient transferrin (CDT) and gamma-glutamyl transferase (GGT) levels, the contribution of drinking pattern to these effects is not completely understood. We present data on 423 men and 146 women evaluated 1 year after treatment in a large-scale alcoholism treatment study (Project MATCH). Relationships between drinking frequency (number of days drinking), intensity (drinks per drinking day), and blood levels of CDT and GGT were analyzed by using response surface regression models and thin-plate spline-smoothing techniques. Both models indicated differences between CDT- and GGT-drinking pattern relationships in men and, also, a difference between men and women in CDT drinking-pattern relationships. For men, CDT levels appeared to respond primarily to frequency of drinking, whereas GGT was influenced primarily by drinking intensity. For women, both CDT and GGT were influenced more by drinks per drinking day (intensity) than by number of days drinking (frequency). The data confirm both the independent nature of these biological markers of alcohol consumption and gender differences in alcohol-induced CDT response reported previously.

Intra- and interindividual variability of carbohydrate-deficient transferrin, γ-glutamyltransferase, and mean corpuscular volume in teetotalers

Blood samples for determination of the biochemical alcohol markers carbohydrate-deficient transferrin (CDT) in serum, γ-glutamyltransferase (GGT) in serum, and erythrocyte mean corpuscular volume (MCV) were collected once every 1–2 weeks over ∼5 months from 10 female and 4 male teetotalers. Mean values for serum CDT (using the CDTectTM assay) ranged from 9.9 to 29.4 units/L (median, 14.2 units/L), and the highest results were obtained in the women. The mean values for serum GGT ranged from 0.15 to 0.49 μkat/L (median, 0.30 μkat/L, or 18 U/L) except for one woman with a very high mean of 3.07 μkat/L. For MCV, the mean values ranged from 79.5 to 91.5 fL. Two women showed several CDT results above the upper reference limit (mean values, 27.6 and 29.4 units/L, respectively); however, their GGT and MCV values fell within the reference intervals. One of these women exhibited an increased total transferrin concentration (mean value, 5.38 g/L), which was possibly related to the use of oral contraceptives and/or a low serum iron concentration. When the CDTect value was expressed relative to total transferrin, a ratio within the reference interval was observed for this woman but not for the other woman with increased CDTect values. The present study demonstrates a considerable variation between individuals in CDT, GGT, and MCV without drinking any alcohol. The results also show that these baseline values are fairly constant over time within the same individual.

New methodologies for pharmacological treatment trials for alcohol dependence

As the number of pharmacological agents for the treatment of alcoholism continues to proliferate, there is an increasing need to design studies that accurately measure the efficacy of these agents. Key study design issues include selecting subjects, calculating patient retention, determining medication compliance, maintaining adequate sample size to ensure that a clinically meaningful therapeutic effect will not be missed, and measuring the study outcome, including the amount of alcohol consumed and levels of craving. Because there is evidence that self-report of alcohol consumption and medication compliance can be unreliable in subjects, biological methods have been used. One type of direct measurement, carbohydrate-deficient transferrin levels, has been found to be a reasonably sensitive indicator of alcohol consumption that may provide meaningful outcome information. The ingestion of riboflavin with medication and its urinary measurement is an accepted method of compliance detection. Improved study design will lead to continued advances in pharmacotherapy for the treatment of patients with alcoholism.