Changes in carbohydrate-deficient transferrin levels after alcohol withdrawal

Carbohydrate-Deficient Transferrin as a Biomarker for Screening At-Risk Drinking in Elderly Men

Background

Carbohydrate-deficient transferrin (CDT) is a useful biomarker to identify excessive alcohol consumption; however, few studies have validated the %CDT cut-off value in elderly men. This study estimated the optimal %CDT cut-off value that could identify excessive alcohol consumption in men aged ≥65 years.

Methods

This retrospective study included 120 men who visited the department of family medicine at Chungnam National University Hospital for health check-up between January 2010 and August 2013. At-risk drinking included heavy- and binge drinking. Heavy drinking was defined as more than seven standard drinks/wk, and binge drinking was defined as more than three standard drinks/d. The cut-off %CDT values for at-risk drinking were determined using receiver operating characteristic (ROC) curves.

Results

Based on the ROC curves, the optimal %CDT cut-off values in ≥65-year-old men were 1.95% for at-risk drinking, 1.81% for heavy drinking, and 2.07% for binge drinking. The sensitivity, specificity, and positive and negative predictive values were 58.7%, 83.6%, 69.2%, and 76.2% for at-risk drinking, respectively. The AUROC were >0.7 for all three evaluated cut-offs.

Conclusion

Our results suggest that the %CDT cut-off value for at-risk drinking in elderly Korean men (≥65 years) should be readjusted to a lower value of 1.95%.

Alcohol Pathophysiology

There is no specialized alcohol addiction area in the brain; rather, alcohol acts on a wide range of excitatory and inhibitory nervous networks to modulate neurotransmitters actions by binding with and altering the function of specific proteins. With no hemato-encephalic barrier for alcohol, its actions are strongly related to the amount of intake. Heavy alcohol intake is associated with both structural and functional changes in the central nervous system with long-term neuronal adaptive changes contributing to the phenomena of tolerance and withdrawal. The effects of alcohol on the function of neuronal networks are heterogeneous. Because ethanol affects neural activity in some brain sites but is without effect in others, its actions are analyzed in terms of integrated connectivities in the functional circuitry of neuronal networks, which are of particular interest because of the cognitive interactions discussed in the manuscripts contributing to this review. Recent molecular data are reviewed as a support for the other contributions dealing with cognitive disturbances related to alcohol acute and addicted consumption.

Validity of carbohydrate-deficient transferrin (%CDT), gamma-glutamyltransferase (gamma-GT) and mean corpuscular erythrocyte volume (MCV) as biomarkers for chronic alcohol abuse: a study in patients with alcohol dependence and liver disorders of non-alcoholic and alcoholic origin

AIM

To test the clinical performance of carbohydrate-deficient transferrin (%CDT), gamma-glutamyltransferase (gamma-GT) and mean corpuscular erythrocyte volume (MCV) as biomarkers for alcoholism with a special focus on patients suffering from liver diseases.

DESIGN

Well-characterized collectives of alcohol-dependent patients with current consumption (ALC patients, n = 101), and relevant control groups (115 social drinkers, 46 patients with unspecifically increased gamma-GT, 51 hepatitis patients and 20/31 patients with non-alcohol/alcohol-dependent liver cirrhosis) were included into the study. The Positive Alcohol Use Disorders Test (AUDIT) score, International Classification of Diseases version 10 (ICD-10)/Diagnostic and Statistical Manual version IV (DSM-IV) criteria and blood drawn within 4 days of last drinking were inclusion criteria for subjects with regular heavy drinking. %CDT was determined using an automated assay which recently had been completely modified.

FINDINGS

Median AUDIT scores of patients without/with regular heavy drinking were 1-3/27. The following medians/95th percentiles were obtained for %CDT: social drinkers 2.2/3.0, patients with unspecifically increased gamma-GT 2.1/3.0, hepatitis 2.0/4.4, non-alcohol-dependent liver cirrhosis 2.4/4.8, alcohol-dependent liver cirrhosis 3.0/5.9, ALC patients 3.9/14.9. Differences between patients without and with alcohol abuse were highly significant (P < 0.001). No differences in CDT values were found between males and females. There was no correlation between %CDT values, gamma-GT, MCV and the amount of alcohol consumed in ALC patients; 3.0%CDT (95th percentile social drinkers) is proposed as cut-off for the test used (Tina-quant %CDT 2nd-generation). At this cut-off, the sensitivity for ALC patients was 73.3%, whereas gamma-GT/MCV had a sensitivity of 71.3%/64.4%. Multivariate analysis performed at 95% specificity resulted in an improvement of the sensitivity by combining %CDT with gamma-GT (83.2%). A further enhancement of the sensitivity to 88.1% was obtained by combination of %CDT, gamma-GT and MCV. The diagnostic specificity of %CDT calculated at the cut-off of 3% was 93.5% in patients with unspecifically increased gamma-GT, 88.2% in hepatitis patients and 70.0% in patients with non-alcohol-dependent liver cirrhosis. %CDT was more specific in these patient collectives than MCV, and especially more than gamma-GT (specificity in hepatitis 52.9%, and 35.0% in non-alcohol-dependent liver cirrhosis).

CONCLUSION

%CDT is of high diagnostic value to support diagnosis of alcohol-use disorders. The specificity of this marker in patient groups with liver disorders is superior to the biomarkers gamma-GT and MCV.

Carbohydrate-deficient transferrin (CDT)--a biomarker for long-term alcohol consumption

Carbohydrate-deficient transferrin (CDT) is a biomarker for chronic alcohol intake of more than 60 g ethanol/d. It has been reported to be superior to conventional markers like gamma-glutamyltransferase (GGT) and mean corpuscular volume MCV). This review covers theoretical and analytical aspects, with data from controlled drinking experiments and from different population subgroups such as subjects with different liver diseases or different drinking patterns. CDT determinations are particularly indicated in (1) cases of chronic alcohol consumption and relapses after withdrawal, (2) license reapplication after driving under alcohol influence, (3) differentiating patients with enzyme-inducing medication from those with alcohol abuse, 4) congenital disorders of glycosylation such as carbohydrate-deficient glycoprotein syndrome Ia (CDGS Ia), and (5) patients treated for galactosemia. The main advantage of CDT is its high specificity, as evidenced in combination with increased alcohol consumption. CDT values are not markedly influenced by medication except in immunosuppressed patients, who may show low CDT values. In general, CDT values appear less elevated after alcohol intake in women. The main disadvantage is the relatively low sensitivity. Hence, this parameter is not suitable for screening for subjects with alcohol abuse in the general population. As CDT, GGT, and MCV are connected with chronic alcohol consumption by different pathophysiological mechanisms, a combination of these parameters will further improve the diagnostic value.

Results of common laboratory tests in solvent-exposed workers

OBJECTIVES

The screening and identification of occupational liver or other organ-system injury related to long-term, low-level solvent exposure are difficult in clinical practice. We studied the feasibility of the use of common laboratory tests combined with a detailed exposure history.

METHODS

The relationships between laboratory tests and exposure to organic solvents were studied in regression modelling adjusted to age, alcohol consumption, gender and body mass index (BMI). The subjects were 29 solvent-exposed workers and 19 referents. Laboratory tests included serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), carbohydrate-deficient transferrin (CDT), alkaline phosphatase (ALP), creatinine, cholesterol, HDL-cholesterol, triglycerides, blood glucose and total and conjugated bilirubin. Positive hepatitis serology, systemic diseases or medications with known hepatic effects and current pregnancy were exclusion criteria. The main exposures of each subject were identified. Current solvent exposure status, exposure during the past 3 months, exposure during the past 5 and 10 years, and total life-time exposure were recorded.

RESULTS

AST (P=0.0031), ALT (P=0.0015) and cholesterol (P=0.0110) correlated positively with cumulative solvent exposure in the past 5 years, total bilirubin with current exposure (P=0.0380), and glucose with exposure in the past 5 (P<0.0001) and 10 (P=0.0003) years. Triglycerides correlated positively with exposure in the past 5 (P=0.0025) and 10 (P=0.0059) years and with life-time exposure (P=0.0005). Creatinine correlated negatively with exposure in the past 10 years (P=0.0300) and life-time exposure (P=0.0005). Most laboratory values were within the normal range.

CONCLUSIONS

These results suggest a multi-system health effect of solvents. The laboratory data had some similarities with those in the metabolic syndrome. The screening and diagnostics of solvent-related conditions should be based on a thorough work history and a set of carefully selected laboratory tests. No single test seems sufficient for this purpose.

Beta-carbolines in chronic alcoholics following trauma

In our society every second polytraumatized patient is a chronic alcoholic. A patient's alcohol-related history is often unavailable and laboratory markers are not sensitive or specific enough to detect alcohol-dependent patients who are at risk of developing alcohol withdrawal syndrome (AWS) during their post-traumatic intensive care unit (ICU) stay. Previously, it has been found that plasma levels of norharman are elevated in chronic alcoholics. We investigated whether beta-carbolines, i.e. harman and norharman levels, could identify chronic alcoholics following trauma and whether possible changes during ICU stay could serve as a predictor of deterioration of clinical status. Sixty polytraumatized patients were transferred to the ICU following admission to the emergency room and subsequent surgery. Chronic alcoholics were included only if they met the DSM-III-R and ICD-10 criteria for alcohol dependence or chronic alcohol abuse/harmful use and their daily ethanol intake was > or =60 g. Harman and norharman levels were assayed on admission and on days 2, 4, 7 and 14 in the ICU. Harman and norharman levels were determined by high pressure liquid chromatography. Elevated norharman levels were found in chronic alcoholics (n = 35) on admission to the hospital and remained significantly elevated during their ICU stay. The area under the curves (AUC) showed that norharman was comparable to carbohydrate-deficient transferrin (CDT) and superior to conventional laboratory markers in detecting chronic alcoholics. Seventeen chronic alcoholics developed AWS; 16 of these patients experienced hallucinations or delirium. Norharman levels were significantly increased on days 2 and 4 in the ICU in patients who developed AWS compared with those who did not. An increase in norharman levels preceded hallucinations or delirium with a median period of approximately 3 days. The findings that elevated norharman levels are found in chronic alcoholics, that the AUC was in the range of CDT on admission and that norharman levels remained elevated during the ICU stay, support the view that norharman is a specific marker for alcoholism in traumatized patients. Since norharman levels increased prior to the onset of hallucinations and delirium it seems reasonable to investigate further the potential role of norharman as a possible substance which triggers AWS.

Biomarkers as aids to identification of relapse in alcoholic patients

Since return to drinking is common in patients recovering from alcoholism, recognition of relapse should be an important component of treatment. Recurrent assessment with biochemical measures can provide clinicians with useful information on the drinking status of their patients. This chapter addresses issues surrounding the importance of early detection of relapse, describes biochemical markers that may assist in this, reviews relevant scientific investigations, and offers recommendations to researchers and clinicians.

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.

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 &lt;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.

Vitreous humor carbohydrate-deficient transferrin concentrations in the postmortem diagnosis of alcoholism

Deaths from the effects of alcohol intoxication are encountered routinely in forensic practice. In an important number of cases difficulty may arise in interpreting the significance of results obtained in the autopsy. In clinical practice biochemical markers, particularly serum gamma-glutamyl-transpeptidase (GGT), alanine aminotransferase (ALT), aspartate transaminase (AST), carbohydrate-deficient transferrin (CDT), and erythrocyte mean corpuscular volume are used to diagnose heavy alcohol consumption. CDT is used as a reliable and specific marker. In postmortem diagnosis, because of the difficulty in interpreting blood alcohol levels and relatively non-specific pathological features, biochemical compounds have been studied for use as possible markers. The aim of this study was to evaluate the usefulness of the postmortem determination of CDT in vitreous humor as a confirmation of antemortem alcoholism. CDT levels were studied in 66 male cadavers with a mean age of 55.9 years (S.D. 17.0, range 22-87 years) with a mean postmortem interval of 17.9 h (S.D. 11.4, range 4-72 h). Cases were assigned to two diagnostic groups according to the antemortem diagnosis of alcoholism. Statistically significant differences were found for CDT and ALT concentrations between the two diagnostic groups. The highest vitreous humor levels of CDT and ALT were obtained in the group of cases with a previous diagnosis of alcoholism. Our results suggest that vitreous humor CDT levels are useful in cases where the postmortem diagnosis of alcoholism is hindered by the non-specificity of data.

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.

Limitations of CDT and GGT in detecting relapses in patients attending an alcohol problems clinic

Biochemical markers of alcohol consumption are useful for the detection and monitoring of problem drinking. Blood samples from 37 patients attending an alcohol treatment clinic were analysed for GGT and %CDT, and results were compared with self-reported periods of abstinence and alcohol consumption. Poor correlation was obtained between GGT and %CDT, and between these assays and self-reported alcohol use. The apparent sensitivity and specificity of GGT (57%, 63%) and %CDT (43%, 88%), were considerably lower than those reported by other workers.

Carbohydrate deficient transferrin for detection of alcohol relapse after orthotopic liver transplantation for alcoholic cirrhosis

Early diagnosis and monitoring of an alcohol relapse in patients after orthotopic liver transplantation for alcoholic cirrhosis is of importance for the long-term outcome. A prospective study of 97 patients who underwent orthotopic liver transplant for alcoholic cirrhosis has been performed. All of the recipients considered for analysis survived for at least 3 months and were under the care of one specialist psychologist. Mean follow-up amounted to 48.5+/-1.4 months. The rates of alcohol relapse at 1 and 3 years after orthotopic liver transplant were 6 and 9%, respectively. Carbohydrate-deficient transferrin is a biological marker for alcohol abuse independently of liver disease and has been used for the first time ever in liver graft recipients. A total of 830 values were included prospectively in the study population. Detection of alcohol relapse had a sensitivity of 92% and a specificity of 98%. Changes in carbohydrate-deficient transferrin levels indicated clandestine and sporadic drinking after transplantation. Furthermore, clinical events were not found to influence carbohydrate-deficient transferrin, either in patients with or without alcoholic relapse. In our opinion, carbohydrate-deficient transferrin is a useful screening marker for alcohol relapse in patients after orthotopic liver transplant for alcoholic cirrhosis, to select those patients who need special attention from the psychologist.

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.

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.

Comparison of the Axis %CDT TIA and the CDTect method as laboratory tests of alcohol abuse

Carbohydrate-deficient transferrin (CDT) has been suggested as a specific marker of alcohol abuse. We designed this study to compare the conventional CDTect method (Pharmacia & Upjohn) and the new semiautomated Axis %CDT turbidimetric immunoassay (%CDT TIA) for their diagnostic performance to identify problem drinking. The sensitivities of the %CDT TIA and CDTect for correctly classifying heavy drinkers (n = 90) were 29% and 59% with the thresholds currently recommended by the manufacturers, respectively. In the control group (n = 114), which included hospitalized patients with abnormal serum transferrin concentrations, the CDTect assay gave 21 false-positive values (18%), whereas the %CDT TIA showed 100% specificity. With the cutoff limits based on the present healthy control group (mean + 2 SD), the sensitivities of the %CDT TIA and CDTect were 61% and 86%, respectively. For men, the ROC plot area of the CDTect results in comparisons of alcohol abusers and healthy controls was significantly (P &lt;0.05) higher than that of the %CDT TIA results, whereas for women, there was no significant difference in this respect. The slope and intercept (with 95% confidence intervals) for linear regression between CDTect and %CDT TIA were 0.13 (0.12–0.15) and 1.16 (0.73–1.59), respectively (Sy‖x = 1.51, r = 0.744). CDTect results correlated positively with serum transferrin (r = 0.224, P &lt;0.001), whereas the %CDT TIA results showed a slight inverse correlation with serum transferrin (r = −0.132, P = 0.07). The data suggest that CDTect is more sensitive than %CDT TIA in detecting drinking problems. However, the %CDT TIA method yields more specificity when analyzing samples from patients with high serum transferrin concentrations.

Carbohydrate deficient transferrin in detecting relapse in alcohol dependence

Patients reports together with findings at clinical examination and information from an informant such as a relative were used to categorise patients as relapsed or not relapsed during a 6 month period of out-patient treatment at an alcohol problems clinic. At each fortnightly visit, blood was taken for measurement of serum gamma-glutamyl transferase and carbohydrate deficient transferrin (Pharmacia method). A total of 53 patients attended for at least one follow-up visit. Mean CDT differentiated relapsers from non-relapsers at seven of the 11 visits (P < 0.05), but at no visit did mean GGT differentiate. CDT tended to become elevated after a relapse more quickly than GGT. However, whether using upper limit of normal (ULN), or defining a 'positive test' as > last test and either > 20% above lowest previous test or > ULN, specificity (averaged over the 11 visits) was greater for GGT than CDT. Some of the false positive results for CDT were in patients who, shortly after having a positive test, relapsed, suggesting that a rising CDT can herald a relapse admitted by the patient. This could not be shown for false positive GGT results. Inspection of individual trajectories of alcohol consumption and blood test results shows that for some patients GGT is the more effective marker of relapse, whilst for others CDT operates better.

Isoelectric focusing (IEF) and immunofixation for determination of disialotransferrin

OBJECTIVES

A new simplified method for detection and quantitation of disialontransferrin in serum is described.

DESIGN AND METHODS

The method is based on polyacrylamide gel isoelectric focusing, direct immunofixation with a specific antibody, and measurement by computerized scanning densitometry. Disialotransferrin levels were determined in 24 teetotallers and 34 alcoholics at 3 moments during detoxification. Three groups of drinkers were arranged: group 1 (without), group 2 (with light), and group 3 (with severe hepatitis).

RESULTS

The metho showed very good reproducibility and accuracy with a coefficient of variation between 5 to 8%. Alcoholic patients could be clearly separated from teetotallers, with a specificity of 100% and a sensitivity of 94%. After 12 days of alcohol withdrawal, disialotransferrin values declined in alcoholics but remained slightly high. They were not influenced by the severity of liver disease. No significant difference was found between the 3 groups.

CONCLUSIONS

An easy-to-perform, sensitive, and inexpensive method has been developed to quantify disialotransferrin that can be used by laboratories almost everywhere.

Carbohydrate-deficient transferrin in alcohol and nonalcohol abusers with liver disease

Carbohydrate-deficient transferrin (CDT) has been demonstrated to be a marker of prolonged heavy alcohol consumption. We compared this marker with gamma-glutamyltranspeptidase (GGT) and mean corpuscular volume (MCV) in alcohol and nonalcohol abusers with liver disease. Our results confirm that the sensitivity of CDT in alcoholics is high, although lower than that of GGT and MCV; however, the specificity of CDT was higher than that of the other two markers. This finding supports the notion that CDT is only partially influenced by the presence of liver damage, whereas increases of GGT and MCV are greatly affected by several factors, including liver damage and drugs. Moreover, we observed that the sensitivity and the specificity of CDT were greater than those of GGT and MCV in younger drinkers.

Serum carbohydrate-deficient transferrin: mechanism of increase after chronic alcohol intake

Carbohydrate-deficient transferrin (CDT) is now considered to be the most sensitive and specific biological marker of alcohol abuse. However, the mechanism by which chronic alcohol consumption causes an elevation of CDT levels in serum is still not understood. Therefore, we fed eight pairs of male rats a nutritionally adequate liquid diet containing either alcohol (36% of energy) or isocaloric dextrose (control) for 4 weeks, after which blood and liver samples were obtained. Serum CDT content in alcohol-treated rats increased by 45% (P < .05) in ethanol-fed animals compared with their corresponding controls. In contrast, in rats fed ethanol, the activities of sialyltransferase (ST), galactosyltransferase (GT), and N-acetylglucosamine transferase (N-AGT), which are glycosyltransferases involved in transferrin carbohydrate side chain synthesis, were diminished by 24% and 40% (P < .05), 23% and 51% (P < .05, .001), and 20% and 26% (P < .05) in total liver homogenates and Golgi fraction (GF) 1, respectively, when expressed as units/100 g body weight. These enzymes were also significantly less active in hepatic GFs 2 and 3. The depression of the transferase activities in ethanol-fed rats appeared to be due, at least in part, to enzyme inactivation by acetaldehyde, whereas ethanol itself was without effect. Similar results were obtained in humans: five alcohol abusers were found to exhibit a 23% decrease in hepatic sialyltransferase and a 41% increase in sialidase activities, respectively, when compared with three nondrinking subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Relevance of carbohydrate-deficient transferrin as a predictor of alcoholism in intensive care patients following trauma

Every second traumatized patient is a chronic alcoholic. Chronic alcoholics are at risk due to an increased morbidity and mortality. Reliable and precise diagnostic methods for detecting alcoholism are mandatory to prevent posttraumatic complications by adequate prophylaxis. The patient's history, however, is often not reliable, and conventional laboratory markers are not sensitive or specific enough. The aim of this study was to investigate whether carbohydrate-deficient transferrin (CDT) is a sensitive and specific marker to detect alcoholism in traumatized patients. One hundred and five male traumatized patients or their relatives gave their written informed consent to participate in this institutionally approved study. All patients were transferred to the intensive care unit after admission to the emergency room, followed by surgical treatment. Diagnostics included an alcoholism-related questionnaire, conventional laboratory markers (mean corpuscular volume, gamma-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase), and CDT sampling (microanion-exchange chromatography, turbidimetry, and radioimmunoassay, respectively). Only patients in whom a reliable history could be obtained were included. Alcoholism was diagnosed if the patients met the Diagnostic and Statistical Manual of Mental Disorders criteria for chronic alcohol abuse or dependence. The administration of fluids before CDT sampling was carefully documented. Patients did not differ significantly regarding age, Trauma and Injury Severity Score, and Acute Physiology and Chronic Health Evaluation score. The sensitivity of the CDT research kit was 70% and of the commercially available kit CDTect was 65%. Early sampling in the emergency room and before administration of large volumes of fluid increased the sensitivity to 83% for the CDT research kit and 74% for CDTect, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Utility of carbohydrate-deficient transferrin as a marker of relapse in alcoholic patients

Carbohydrate-deficient transferrin (CDT) has been proposed as a marker of alcoholism. However, its role in monitoring alcoholic patients for relapse has not been extensively studied. We therefore performed sequential serum CDT measurements using a microcolumn/radioimmunoassay method (Kabi Pharmacia, Piscataway, NJ) in 86 male alcoholics participating in a hepatitis vaccination program who were monitored for relapse using self-report and collateral history (when available). The maximum serum CDT was significantly higher in patients who relapsed (n = 38) (33.1 +/- 3.1 mg/liter), as compared with abstinent subjects with collateral verification (n = 39) (18.8 +/- 1.3, p < 0.001) and abstinent patients without collateral verification (n = 9) (17.4 +/- 1.3, p < 0.01). Using the manufacturer's currently recommended threshold of 20 mg/liter for males, serum CDT was elevated in 29 of 38 patients who relapsed (sensitivity 76.3%). In 16 (42.1%) of the relapsed patients, a serum CDT above this threshold preceded the patient's self-report by at least 28 days. However, serum CDT exceeded 20 mg/liter in 10 of 48 patients who remained sober (specificity 79.2%); three of these patients had clinical and/or pathological evidence of cirrhosis. Using a threshold of 25 mg/liter, 21 of 38 patients who relapsed had an elevated serum CDT (sensitivity 55.3%); 12 (31.6%) of these patients had elevated serum CDT before self-report. Only 4 of 48 subjects who remained sober had serum CDT levels that exceeded 25 mg/liter (specificity 91.7%); three of these patients had clinical and/or pathological evidence of cirrhosis. In conclusion, serial serum CDT testing detects relapses before self-report in male subjects. Values between 20-25 mg/liter suggest relapse, but call for collateral verification, whereas CDT values above 25 mg/liter are usually diagnostic of relapse in the absence of cirrhosis.

Increases and time-course variations in beta-hexosaminidase isoenzyme B and carbohydrate-deficient transferrin in serum from alcoholics are similar

beta-Hexosaminidase B-isoforms (beta-hexosaminidase B, P, and intermediate forms; abbreviated herein as "Hex B") and serum carbohydrate-deficient transferrin (CDT) are two markers of alcohol abuse. In the present study, we have compared "Hex B" with CDT as markers of alcohol abuse in a group of alcoholics hospitalized for detoxification after a period of heavy alcohol abuse. We have also followed the disappearance rate of these two markers from circulation. "Hex B" was elevated in 38 of 42 patients hospitalized for detoxication, whereas CDT was elevated in 35 of 42 patients. A highly significant correlation was noted between "Hex B" and CDT in these patients (p = 0.52, p < 0.001). Neither "Hex B" nor CDT correlated with gamma-glutamyltransferase or AST. The disappearance rates from serum of "Hex B" and CDT were determined in 21 hospitalized patients followed for up to 15 days. "Hex B" and CDT showed similar time-course variation and half-lives, 6.5 +/- 3.7 (mean +/- SD) and 8.6 +/- 4.1 days, respectively. The possible reasons for a relation between these two markers are discussed, and it is concluded that more experience of both "Hex B" and CDT in unselected populations is needed to establish the diagnostic potential of these tests as markers of alcohol abuse.

A comparison between two commercial methods for determining carbohydrate deficient transferrin (CDT)

The performance of CDTect (Kabi-Pharmacia, Uppsala, Sweden) and two versions of AXIS % CDT (AXIS Biochemicals, Oslo, Norway) for determining carbohydrate deficient transferrin (CDT) was examined in 502 consecutive patients admitted to the Department of Medicine, Aker University Hospital. The sensitivity for detecting an alcohol consumption > or = 50 g/day for the last 4 weeks was 69% for CDTect, 65% for AXIS % CDT, version 1 (AX CDT 1) and 50% for AXIS % CDT, version 2 (AX CDT 2). The specificity at the same level of alcohol consumption, markedly differed between the two methods: 92%, 76% and 90% for CDTect, AX CDT 1 and AX CDT 2, respectively. The variation coefficient (day-to-day) was 10%, 22% and 10% for CDTect, AX CDT 1 and AX CDT 2, respectively.

Carbohydrate-deficient transferrin and other markers of high alcohol consumption: a study of 502 patients admitted consecutively to a medical department

An isoform of transferrin, carbohydrate-deficient transferrin (CDT) is increased in a high percentage of abusing alcoholics and has been found superior in its specificity compared with other biological markers. We used serum CDT as a screening parameter in 502 patients consecutively admitted to our medical department during a 4-week period. The intake of ethanol during the last 4 weeks was registrated by personal interviews and the mean daily consumption calculated. Serum CDT was measured at admission (CDTect) and compared with gamma-glutamyltranspeptidase (GGT), AST, ALT, and mean corpuscular volume (MCV). Serum CDT detected 18 of 26 (69%) patients who consumed > 50 g ethanol daily. The clinical sensitivity of CDT of detection ethanol consumption > 50 g daily was 69%, compared with 73%, 50%, 35%, and 52% for increased values of GGT, AST, ALT, and MCV, respectively. Altogether, 38 of 476 patients (8%) with a daily ethanol consumption < 50 g also had increased serum CDT levels. The specificity of CDT was 92%, compared with 75%, 82%, 86%, and 85% for GGT, AST, ALT, and MCV, respectively. In the 60 patients who consumed > 10 g ethanol daily, we found a significantly positive correlation between CDT and ethanol consumption (r = 0.52, p < 0.001). A positive correlation was also found between serum transferrin and CDT (r = 0.51, p < 0.001). In conclusion, the specificity of CDT is much higher compared with GGT in detecting alcohol abuse. Some acute and chronic illnesses may increase the serum level of CDT. False-positive CDT levels may be caused by changes in serum transferrin concentration.

Carbohydrate-deficient transferrin as an alcohol marker among female heavy drinkers: a population-based study

Carbohydrate-deficient transferrin (CDT) has previously been reported to be an excellent marker of male alcoholics. Less is known of its efficiency among women and especially of early-phase alcohol abuse in nonselected populations. The present population-based study examined the diagnostic value of CDT among consecutive women, including 13 teetotallers, 135 social drinkers (mean alcohol consumption 45 +/- 34 g/week), and 57 nonalcoholic heavy drinkers (197 +/- 97 g/week). Sixty-two women with a well-documented history of chronic alcoholism (942 +/- 191 g/week) were also studied, as well as 36 pregnant women used as a reference group. Two weeks of abstinence among 11 alcoholics was followed. The CDT (containing part of isotransferrin with pI = 5.7, 5.8, and 5.9) was separated by anion exchange chromatography and assayed by radioimmunoassay. In the whole material, CDT correlated significantly with alcohol consumption (r = 0.43, p < 0.001) but not with conventional markers (gamma-glutamyltransferase, AST, ALT, and mean corpuscular volume). The CDT values of alcoholics (34 +/- 20 units/liter) were significantly (p < 0.001) higher than those of teetotallers (19 +/- 6 units/liter), social drinkers (20 +/- 6 units/liter), or pregnant women (16 +/- 3 units/liter). Heavy drinkers also had higher values (25 +/- 13 units/liter), but the difference did not reach statistic significance. The specificity of CDT was on the level of conventional markers when the cut-off value was increased from 26 to 29 units/liter. At a specificity of 95%, CDT found 19% of the heavy drinkers and 52% of the alcoholics; the best traditional marker, AST, with a specificity of 97%, found 7% and 56%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrate-deficient transferrin as a measure of immoderate drinking: remaining issues

A growing body of investigations demonstrate that elevated levels of carbohydrate-deficient transferrin (CDT) effectively distinguishes alcoholics recently consuming large amounts of alcohol from light social drinkers or teetotalers. Nevertheless, important questions still remain concerning the value of CDT as a more generalized marker of alcohol consumption. Most important, the nature of the drinking pattern, including quantity and frequency, necessary to raise levels of CDT significantly remains unclear. Neither has research convincingly demonstrated that CDT is as accurate a marker for women, young adults, or non-Caucasian ethnic groups as for White, middle-aged men. Whereas CDT might serve as a useful outcome measure in trials of alcoholism treatment effectiveness, current research suggests that CDT is of limited value in identifying problematic drinking in general medical or community settings in which a broad continuum of drinkers is represented. Combining CDT with other biochemical or self-report screening measures may, however, improve sensitivity in these contexts. At present, the most accurate laboratory technique to detect CDT seems to be isoelectric focusing. Additional research, however, is needed to resolve the issue of whether CDT is best quantitated as a simple value or if its ratio to total transferrin or non-CDT results in higher predictive validity.

Enzymes and circulating proteins as markers of alcohol abuse

The identification of alcohol abuse is an important social and clinical objective for which various biochemical procedures have been utilized, serum enzymes and circulating proteins being predominant. Tests are required to detect alcohol abuse as screening procedures in the general population as well as for the specific diagnosis of those presenting as hospital inpatients or outpatients, especially when liver disease is present or suspected. The amino-transferases are of limited value, although the mitochondrial isoenzyme of aspartate amino-transferase has been strongly advocated and is quite useful in detecting alcoholics among patients with liver disease. Gammaglutamyl transferase, by contrast, is raised in all forms of liver disease but can identify 30-50% of those consuming excessive amounts of alcohol before organic damage becomes manifest. Serum carbohydrate-deficient transferrin (CDT) is raised in many alcohol abusers without and most with liver damage, but is rarely elevated in other forms of liver disease. Haemoglobin-associated acetaldehyde, the newest biochemical index to be evaluated in alcoholics, is one of several adducts formed by the reaction of acetaldehyde with various proteins, and antibodies to these adducts may contribute, at least in part, to immunological tissue damage provoked by chronic excessive consumption of alcohol. Its assay is technically complex and it appears to be present in higher concentrations in heavy drinkers than in those who fulfill the criteria of addictive alcohol abuse. Many other markers have been introduced in the last decade but the search for a reliable index continues. CDT comes closest at the present time to matching the desired specificity, although it is of limited value in screening unselected non-hospitalized subjects.

New state markers for alcoholism. Comparison of carbohydrate deficient transferrin (CDT) and alcohol mediated (triantennary) transferrin (AMT)

Carbohydrate deficient transferrin (CDTect-RIA, Pharmacia) was compared with an Immunoluminometric assay for isotransferrin separated by a short column Con-A sepharose which we have called alcohol mediated triantennary transferrin (AMT). 101 in-patients with alcohol dependency syndrome (alcohol consumption of more than 60 g/day) were grouped according to the time of abstinence A1 (0-7 days), A2 (8-14 days), A3 (> or = 15 days). Serum samples were obtained at admission (U0) and under abstinent conditions after 10-20 days (U1). All groups were controlled for AMT, CDT, GGT, MCV. Control groups were 30 in-patients with non alcoholic liver disease (NALD) and 31 healthy volunteers (alcohol consumption of less than 20g/day). Results showed for CDT and AMT highly significant differences between short abstinence period (group A1) and more than two weeks abstinence (group A3) alcoholics and between group A1 and healthy controls. In group A1 CDT was significantly elevated (P < or = .001) compared to NALD group whereas AMT showed no differences. CDT (cut off 22 mg/l) showed a high diagnostic specificity (A1/controls 97%, A1/NALD 83%, A1/A3 78%) but only a diagnostic sensitivity of 61%. AMT (cut off 260 mg/l) revealed a diagnostic test sensitivity of 74%. The diagnostic test specificity of AMT was inferior to CDT (A1/controls 74%, A1/NALD 50%, A1/A3 70%). Initial CDT and AMT values in alcoholics were highly correlated (P < or = .001) with time of abstinence. CDT and AMT decline was correlated with time of abstinence. CDT was proved for high significant (P < or = .001) decline over a longer period of abstinence (11-30 days) while AMT decline was significant (P = .008) only in early abstinence (0-10 days). Presence of a withdrawal syndrome was highly correlated (P < or = .01) with CDT values above 22 mg/l and AMT values above 260 mg/l. Furthermore in selected follow up cases it was shown that AMT seemed to be a more sensitive indicator for short alcoholic relapses than CDT.

Diagnosis of carbohydrate-deficient glycoprotein syndrome by matrix-assisted laser desorption time-of-flight mass spectrometry

Serum transferrin from patients with carbohydrate-deficient glycoprotein syndrome was analysed by matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF mass spectrometry). Abnormal molecular species with a defect of one or two oligosaccharide chains of 2200 Da were clearly identified. MALDI-TOF mass spectrometry will serve to diagnose this aetiologically unknown, metabolic disease.

Detection of relapses in alcohol-dependent patients: comparison of carbohydrate-deficient transferrin in serum, 5-hydroxytryptophol in urine, and self-reports

In this study, detection of relapses in male alcohol-dependent patients by biochemical markers and self-reports of alcohol consumption were examined. The patients were trying to stay abstinent from alcohol for 6 months. Four of 15 patients dropped out from treatment after 50-110 days. Ratios of urinary 5-hydroxytryptophol (5-HTOL)/5-hydroxyindole-3-acetic acid and 5-HTOL/creatinine were measured daily and serum carbohydrate-deficient transferrin (CDT) once a week. Clinical ratings and self-reports about alcohol consumption were performed three times a week. According to the self-reports, 3 of the patients drank alcohol frequently, 5 of them sporadically, and 7 of the patients reported no alcohol intake at all. According to the 5-HTOL marker, 4 of the patients drank alcohol frequently, and 11 of them sporadically. No one had all urinary levels of 5-HTOL marker below the reference level. According to the CDT, 3 of the patients drank alcohol frequently, 3 sporadically, and in 9 of the patients no elevated levels of CDT were found. Elevated levels of CDT were preceded by increased values of 5-HTOL marker. The combined results suggested that no one of the patients was totally abstinent from alcohol during the treatment period. The 5-HTOL marker seemed to be useful to reveal recent alcohol drinking, and CDT proved to be useful to validate the patients' self-reports. Together the two biochemical markers showed complementary properties in early detection of relapse and treatment monitoring.

Serum carbohydrate-deficient transferrin as a marker of alcohol consumption in patients with chronic liver diseases

We measured serum levels of carbohydrate deficient transferrin (CDT) in 420 subjects: 100 healthy blood donors, 82 healthy employees, 70 abstaining patients with different chronic nonalcoholic liver disease, 16 abstaining patients with alcoholic fatty liver, 50 abstaining patients with alcoholic liver cirrhosis, 25 abusing patients with alcoholic fatty liver, 41 abusing patients with alcoholic liver cirrhosis, and 36 patients with alcohol dependence syndrome with a daily ethanol consumption of 173 +/- 120 g the last 4 weeks before blood was drawn. In controls the serum level of CDT was significantly higher in females compared with males (17.7 +/- 5.1 and 13.7 +/- 3.8 units/liter, respectively), and the upper normal limit was defined as 27 and 20 units/liter. Sixty-two of 102 (60.8%) abusing patients with alcoholic liver disease had increased levels of CDT compared with 1 of 66 abstaining (1.5%) patients with alcoholic liver disease, and 10 of 70 (14.3%) abstaining patients with nonalcoholic liver disease among them 3 with primary biliary cirrhosis and 2 with chronic autoimmune hepatitis. No correlation was found between serum CDT and gamma-glutamyltranspeptidase (GGT), AST, ALT, and mean red cell volume (MCV). The sensitivity and specificity for serum CDT was 61 and 92%, respectively, compared with 85 and 18% for GGT and 70 and 66% for MCV. No advantage was gained by using the CDT/transferrin ratio. Our study confirms that CDT is a specific marker for chronic alcohol abuse, except in few patients with other chronic liver diseases. Serum CDT seems to be a better indicator of abstention than GGT; AST and MCV in patients with alcoholic liver disease. However, in our hands CDT is not so sensitive for alcohol abuse in patients with liver disease as reported earlier in unselected alcoholics.

Orosomucoid system: 17 additional orosomucoid variants and proposal for a new nomenclature

There are two forms of orosomucoid (ORM) in the sera of most individuals. They are encoded by two separate but closely linked loci, ORM1 and ORM2. A number of variants have been identified in various populations. Duplication and nonexpression are also observed in some populations. Thus, the ORM system is very complicated and its nomenclature is very confusing. In order to propose a new nomenclature, ORM variants detected by several laboratories have been compared and characterized by isoelectric focusing (IEF) followed by immunoprinting. A total of 57 different alleles including 17 new ones were identified. The 27 alleles were assigned to the ORM1 locus, and the others to the ORM2 locus. The designations ORM*F1, ORM1*F2, ORM1*S and ORM2*M were adopted for the four common alleles instead of ORM1*1, ORM1*3, ORM1*2 and ORM2*1 (ORM2*A), respectively. The variants were designated alpha numerically according to their relative mobilities after IEF in a pH gradient of 4.5-5.4 with Triton X-100 and glycerol. For the duplicated genes a prefix is added to a combined name of two alleles, e.g. ORM1*dB9S. Silent alleles were named ORM1*Q0 and ORM2*Q0 conventionally. In addition, the effects of diseases to ORM band patterns after IEF are also discussed.

Laboratory markers of ethanol intake and abuse: a critical appraisal

Laboratory markers for ethanol intake and abuse and chronic alcoholism currently in use have been critically reviewed. The merits and pitfalls of each test have been evaluated. The clinical use of the new test of carbohydrate-deficient transferrin has been particularly emphasized. Carbohydrate-deficient transferrin currently provides the highest specificity and sensitivity of all commonly used markers of alcoholism.

Carbohydrate-deficient transferrin (CDT) in serum as a possible indicator of heavy drinking in young university students

Carbohydrate-deficient transferrin (CDT) in serum was studied as a possible marker of heavy drinking in a sample of 187 female and 102 male 1st year university students from Finland. CDT was measured by a new radioimmunoassay (Pharmacia CDT RIA). Alcohol consumption was measured on a quantity-frequency scale. For female students CDT was 18.2 +/- 0.45 units/liter (mean +/- SEM) and for male students 13.3 +/- 0.48 units/liter. 9.6% of female students and 7.8% of male students had elevated CDT with a cut-off level of 26 units/liter for females and 20 units/liter for males. The correlation between CDT and reported alcohol consumption was 0.30 (p less than 0.001) for females and 0.25 (p = 0.014) for males. Those reporting a consumption of at least 10 kg of pure ethanol per year were considered as heavy drinkers (3.7% of females and 22.5% of males). In female students the average CDT of heavy drinkers did not differ significantly from that of social drinkers but in teetotalers CDT was significantly (p less than 0.03) lower than in female alcohol users. In male students the average CDT of heavy drinkers was higher than the average of social drinkers (p less than 0.1) and significantly higher than the average of teetotalers (p less than 0.001). In the detection of heavy drinking among male students elevated CDT had a specificity of 96.2% and a sensitivity of 21.7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Utility and evaluation of biochemical markers of alcohol consumption

Biochemical markers of alcohol consumption have a variety of clinical and research applications. Currently available markers such as the serum gamma-glutamyl transpeptidase (GGT), serum transaminases, and the mean corpuscular volume (MCV) lack sufficient sensitivity and specificity to be used for screening of alcoholism in ambulatory patients. However, these tests can be helpful in corroborating a clinical suspicion of alcoholism. A number of special laboratory markers of alcoholism recently have been developed which may have increased diagnostic accuracy. Promising potential markers include serum carbohydrate-deficient transferrin (CDT), red blood cell acetaldehyde, and acetaldehyde adducts. The application of reliable and practical markers of alcohol consumption could lead to significant improvements in the treatment of alcoholism and in the assessment of clinical trials.

New Alcohol Markers-How Useful Are They in Population Studies: The Svalbard Study 1988-89

Regular high consumption of alcohol in selected populations have, with high precision, been identified by two new alcohol markers; carbohydrate-deficient transferrin and mitochondrial aspartate aminotransferase. To test these markers in an unselected population, gamma-glutamyltransferase (GGT), carbohydrate-deficient transferrin (CDT), and mitochondrial aspartate aminotransferase (mAST) were measured in the Norwegian population, 310 males and 171 females, aged 18 to 60 years, living at Svalbard. Using self-reported alcohol intake as gold standard, sensitivity, specificity, positive predictive value, and likelihood-ratio were estimated according to different cutoff-points for alcohol intake and for the tests. In contrast to earlier studies, the sensitivity was in general low. With a specificity of 90% or higher, the sensitivity did not exceed 26% for any of the tests. Whereas CDT showed its best discriminatory power at lower intake of alcohol, GGT discriminated best at higher levels. Parallel and serial analysis of CDT and GGT indicated a conditional independence between the tests, as well as at higher and at lower levels of alcohol consumption. mAST was judged as not suitable in population studies.

Isoelectric focusing/western blotting: a novel and practical method for quantitation of carbohydrate-deficient transferrin in alcoholics

Carbohydrate-deficient transferrin (CDT) has been described as the single, most accurate marker of chronic alcohol consumption. Rapid, sensitive, and specific measurement of serum CDT levels can thus provide important clinical information concerning patient diagnosis and treatment. To date, however, methods used for assessing CDT concentrations [e.g., analytical isoelectric focusing combined with immunofixation and micro anion-exchange chromatography followed by radioimmunoassay (RIA)] have not been practical enough for widespread laboratory application. In the present study, we examined the use of a different technique, namely isoelectric focusing (IEF) combined with Western blotting (IEF/WB). Serum proteins (20-40 micrograms) were first focused according to isoelectric points (pI) on high-resolution agarose IEF gels (ampholyte pH range of 5-8) containing nonionic detergent. The focused proteins were transferred electrophoretically to nitrocellulose filters, and then stained immunochemically with antihuman transferrin IgG. IEF/WB completely resolved CDT (focusing at pI 5.7 and 5.9) from other serum transferring isoforms, as assessed with neuraminidase-generated CDT standards. Computerized densitometric scanning of the immunoblots allowed CDT levels to be quantitated directly rather than as a quotient. Serum CDT content determined by IEF/WB was highly correlated (r2 = 0.962; n = 17) with values determined previously by RIA. In a larger subject group, CDT levels (mg/liter) measured by IEF/WB were 139 +/- 54 in recently-drinking alcoholics (n = 58), 81 +/- 8 in abstaining alcoholics (n = 7), and 68 +/- 16 in healthy control subjects (n = 16).(ABSTRACT TRUNCATED AT 250 WORDS)