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

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions

BACKGROUND

The quantitative, measurable detection of drinking is important for the successful treatment of alcohol misuse in transplantation of patients with alcohol disorders, people living with human immunodeficiency virus that need to adhere to medication, and special occupational hazard offenders, many of whom continually deny drinking. Their initial misconduct usually leads to medical problems associated with drinking, impulsive social behavior, and drunk driving. The accurate identification of alcohol consumption via biochemical tests contributes significantly to the monitoring of drinking behavior.

METHODS

A systematic review of the current methods used to measure biomarkers of alcohol consumption was conducted using PubMed and Google Scholar databases (2010-2015). The names of the tests have been identified. The methods and publications that correlate between the social instruments and the biochemical tests were further investigated. There is a clear need for assays standardization to ensure the use of these biochemical tests as routine biomarkers.

FINDINGS

Alcohol ingestion can be measured using a breath test. Because alcohol is rapidly eliminated from the circulation, the time for detection by this analysis is in the range of hours. Alcohol consumption can alternatively be detected by direct measurement of ethanol concentration in blood or urine. Several markers have been proposed to extend the interval and sensitivities of detection, including ethyl glucuronide and ethyl sulfate in urine, phosphatidylethanol in blood, and ethyl glucuronide and fatty acid ethyl esters in hair, among others. Moreover, there is a need to correlate the indirect biomarker carbohydrate deficient transferrin, which reflects longer lasting consumption of higher amounts of alcohol, with serum γ-glutamyl transpeptidase, another long term indirect biomarker that is routinely used and standardized in laboratory medicine.

Vitamin B₁₂ and its binding proteins in hepatocellular carcinoma and chronic liver diseases

BACKGROUND

The vitamin B12 (B12)-binding protein haptocorrin (HC) has proven to be a potentially useful biomarker in patients with fibrolamellar hepatocellular carcinoma (HCC). Little is known concerning the level of HC and other B12-related proteins in patients with HCC as compared to patients with other chronic liver diseases (CLDs) and healthy controls. We hypothesized that HC could be a biomarker of HCC.

AIMS

To investigate levels of HC and B12-related proteins in HCC compared to CLDs and healthy controls.

METHODS

We investigated two patient populations: A cross-sectional cohort of HCC patients (n = 130), CLD patients (n = 102) and healthy controls (n = 46) and a cohort of 38 HCC patients studied at baseline and 1, 4, and 12 weeks following ablative treatment. Patients were evaluated by standard biochemistry, Child-Pugh-score and Barcelona Clinic Liver Cancer (BCLC) classification. We analyzed total B12 by routine methods and HC, transcobalamin (TC), B12 saturated TC (holoTC), and the soluble cell surface receptor for holoTC (sCD320) by in-house enzyme-linked immunosorbent assay.

RESULTS

HC showed higher median (range) levels for both HCC (590 [290-5860]) and CLD patients (620 [310-4010]) compared to controls (460 [250-2020]) (p < 0.01). Total B12, TC, holoTC, and sCD320 showed elevated levels in both HCC and CLD compared to controls. Only holoTC changed following treatment, without a concurrent change in TC.

CONCLUSION

B12 and B12-related proteins (total B12, HC, TC, holoTC, and sCD320) show elevations in both HCC and CLD patients compared to controls, suggesting a relation to CLD in general rather than to primary liver cancer. Thus, HC is not useful as a biomarker for HCC.

Detecting alcohol abuse: traditional blood alcohol markers compared to ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) measurement in hair

Alcohol abuse is a common problem in society; however, the technical capabilities of evaluating individual alcohol consumption using objective biomarkers are rather limited at present. In recent years research has focused on alcohol markers using hair analysis but data on performance and reliable cut-off values are still lacking. In this study 169 candidates were tested to compare traditional biomarkers, such as carbohydrate-deficient-transferrin (CDT), gamma glutamyl transferase (GGT), aspartate amino transferase, alanine amino transferase and the mean corpuscular volume of the erythrocytes, with alcohol markers detectable in hair such as ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs). This study revealed that EtG, GGT and CDT showed the best results, demonstrating areas under the curve calculated from receiver operating characteristics of 0.941, 0.943 and 0.899 respectively. The lowest false-negative and false-positive rates were obtained by using a combined interpretation system for hair EtG and FAEEs. All markers demonstrated only low to moderate correlations. Optimum cut-off values for differentiation between social and chronic excessive drinking calculated for hair EtG and FAEEs were 28 pg/mg and 0.675 ng/mg, respectively. The critical values published in the "Consensus on Alcohol Markers 2012" by the Society of Hair Testing were confirmed.

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.

Should we use carbohydrate deficient transferrin as a marker for alcohol abusers?

Carbohydrate deficient transferrin (CDT) is one of the conventional markers for chronic alcohol consumption, is used by researchers and clinicians. A number of enzymes are affected by ethanol intake. The induction or inhibition of sialyl transferase and plasma sialidase may be involved in the CDT level elevation. An alteration of protein transport during post-translational modification could be a primary mechanism in the impairment of protein metabolism associated with chronic alcohol abuse. Transferrin being a steroid responsive protein, sex-based hormonal variations might contribute to the lower sensitivity of CDT. Varying hormonal statuses such as pregnancy, use of contraceptives, menopause/ menstrual cycle can alter iron homeostasis in women. CDT levels are markedly affected by iron homeostasis. Several CDT assay methods appeared promising, but it is not readily apparent which technique is the most accurate. Moreover, false-positive results of CDT have been reported in non-alcohol related hepatic failure and in rare conditions. Therefore clinical interpretation of CDT needs careful assessment in patients with alcohol-related or non-alcohol-related health disorders.

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 in abstaining patients with end-stage liver disease

BACKGROUND

Carbohydrate deficient transferrin (CDT), a biochemical marker of chronic alcohol consumption, is used by researchers and clinicians alike in a variety of populations. Levels of CDT may be affected by certain types of medical illnesses and conditions. Thus the interpretation of CDT results may need to be carefully examined in these populations. Because CDT is synthesized, glycosylated, and secreted by the liver, the use of CDT values in patients with liver disease has been an area of focused interest.

METHODS

We evaluated the CDT values of 79 abstaining patients with end-stage liver disease. These patients were recruited from a liver transplant clinic while they were listed and waiting for transplantation. Patients were determined to be abstaining both by interview and by random blood alcohol levels in those with a diagnosis of alcoholic liver disease. The severity of the liver disease was categorized by the Child-Pugh score. Correlations were determined between CDT values and liver enzymes, and Child-Pugh scores and liver diagnosis.

RESULTS

Nearly 50% of the patients had a CDT value of 2.6% or above, indicating a clinically positive value. There were strong correlations between CDT and a number of biochemical and physical variables, most importantly the Child-Pugh score (r = 0.52, p = 0.000). Specific liver diseases were not associated with absolute CDT values. However, patients with hepatitis C (HCV) had a significantly higher chance of having a clinically positive CDT compared with patients with other types of liver diseases.

CONCLUSIONS

These results suggest that an elevated CDT value may not accurately represent alcohol consumption in patients with advanced liver disease. In fact, in such patients, the CDT may become a marker for the degree of liver impairment in alcoholic and nonalcoholic liver disease. CDT values should be viewed with caution in any patient with liver disease especially when the degree of cirrhosis reaches a Child-Pugh score of C (total score of 10 or above).

Carbohydrate deficient transferrin in abstaining patients with end-stage liver disease

BACKGROUND

Carbohydrate deficient transferrin (CDT), a biochemical marker of chronic alcohol consumption, is used by researchers and clinicians alike in a variety of populations. Levels of CDT may be affected by certain types of medical illnesses and conditions. Thus the interpretation of CDT results may need to be carefully examined in these populations. Because CDT is synthesized, glycosylated, and secreted by the liver, the use of CDT values in patients with liver disease has been an area of focused interest.

METHODS

We evaluated the CDT values of 79 abstaining patients with end-stage liver disease. These patients were recruited from a liver transplant clinic while they were listed and waiting for transplantation. Patients were determined to be abstaining both by interview and by random blood alcohol levels in those with a diagnosis of alcoholic liver disease. The severity of the liver disease was categorized by the Child-Pugh score. Correlations were determined between CDT values and liver enzymes, and Child-Pugh scores and liver diagnosis.

RESULTS

Nearly 50% of the patients had a CDT value of 2.6% or above, indicating a clinically positive value. There were strong correlations between CDT and a number of biochemical and physical variables, most importantly the Child-Pugh score (r = 0.52, p = 0.000). Specific liver diseases were not associated with absolute CDT values. However, patients with hepatitis C (HCV) had a significantly higher chance of having a clinically positive CDT compared with patients with other types of liver diseases.

CONCLUSIONS

These results suggest that an elevated CDT value may not accurately represent alcohol consumption in patients with advanced liver disease. In fact, in such patients, the CDT may become a marker for the degree of liver impairment in alcoholic and nonalcoholic liver disease. CDT values should be viewed with caution in any patient with liver disease especially when the degree of cirrhosis reaches a Child-Pugh score of C (total score of 10 or above).

The activity of beta-hexosaminidase (uHex) and gamma-glutamyltransferase (uGGT) in urine as non-invasive markers of chronic alcohol abuse: II. Opiate-dependent subjects receiving methadone substitution

The usefulness of beta-hexosaminidase (uHex) and gamma-glutamyltransferase (uGGT) activity in urine as markers of chronic alcohol abuse was examined in male methadone programme participants. The group consisted of 24 non-abusing and 21 alcohol-abusing men. It has been demonstrated that the uHex test is one of the best alcohol abuse markers for opiate-dependent individuals (Receiver Operating Characteristic (ROC) area under the curve (AUC) 0.82, sensitivity 0.70, specificity 0.82). The uGGT test can be used as a marker of alcohol abuse in opiate-dependent men, however, its parameters are worse than those of uHex (ROC AUC 0.73, sensitivity 0.71, specificity 0.77). Among serum markers, only the relative amount of carbohydrate-deficient transferrin (s%CDT) has parameters sufficient for diagnostic use (ROC AUC 0.74, sensitivity 0.60, specificity 0.86). Factors other than alcohol can render the commonly used sGGT and sHex tests useless (differences between means for abusing and abstinent patients were insignificant, AUC ROC were lower than 0.7-0.65 and 0.69, respectively). Their good parameters, low costs, ease of use and non-invasive character are all features which make uHex and uGGT highly useful tools in the detection of chronic alcohol abuse in opiate-dependent patients participating in a methadone substitution programme.

The activity of beta-hexosaminidase (uHex) and gamma-glutamyl-transferase (uGGT) in urine as non-invasive markers of chronic alcohol abuse: I. Alcohol-dependent subjects

It has been demonstrated that in alcohol-dependent men the uHex test is one of the most powerful discriminating tools, while uGGT has a discriminating power similar to that of sHex but worse than that of uHex, sGGT and s%CDT. Receiver Operating Characteristic (ROC) areas under the curves (AUC) for uHex, uGGT, s%CDT, sHex and sGGT were 0.92, 0.79, 0.88, 0.79 and 0.92, respectively. Due to their good parameters, low cost, ease of use and non-invasive character the uHex and uGGT tests are useful tools for the detection of chronic alcohol abuse.

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.

Sialic acid: new potential marker of alcohol abuse

BACKGROUND

A number of laboratory markers are suggested for the detection and monitoring of alcohol abuse. However, there is still a need to find better indicators of alcohol abuse. Sialic acid (SA) is the name for a series of acyl-derivatives of neuraminic acids that occur as nonreducing terminal residues of glycoproteins or glycolipids in biological fluids and cell membranes. In this study, we investigated the diagnostic value of SA as a marker of alcohol abuse.

METHODS

Sera from social drinkers (n = 38) and alcoholics (n = 77) were analyzed for sialic acid by a colorimetric assay and for carbohydrate-deficient transferrin (CDT) by a radioimmunoassay method. Mean corpuscular volume (MCV), gamma-glutamyltransferase (GGT), aspartate aminotransferase (ASAT), and alanine aminotransferase (ALAT) were determined by using routine methods.

RESULTS

The sialic acid levels of both female and male subjects were significantly (p < 0.001) increased among alcoholic subjects when compared with social drinkers. SA levels were decreased after 3 weeks of treatment. The sensitivity and specificity for SA, respectively, were 57.7 and 95.5 for women and 47.8 and 81.3 for men. The respective values for CDT were 57.7 and 95.5 for women and 78.3 and 100.0 for men; for GGT, 60.0 and 95.5 for women and 60.9 and 87.5 for men; for MCV, 52.4 and 95.5 for women and 47.8 and 100.0 for men; for ASAT, 53.8 and 95.5 for women and 43.5 and 100.0 for men; and for ALAT, 38.5 and 90.9 for women and 39.1 and 87.5 for men. Among women, SA and GGT, and among men CDT, showed the largest area under receiver operation curve.

CONCLUSION

This study indicated that sialic acid levels were elevated by high alcohol consumption and reduced during abstinence, especially among women. Thus, sialic acid seems to be an interesting marker that needs further evaluation as a diagnostic tool for alcohol abuse.

Serum and saliva levels of sialic acid are elevated in alcoholics

BACKGROUND AND METHODS

Recently, sialic acid has been suggested as a potential marker for alcohol abuse. In this study, social drinkers and alcoholics were analyzed with a modified version of Warren's method for sialic acid and traditional markers of alcohol abuse in serum (n = 38; n = 87), saliva (n = 36; n = 29), and urine (n = 37; n = 83), respectively. The alcoholics were participating in an alcohol dependency treatment program and were followed in this study for 5 weeks.

RESULTS

The sialic acid concentrations in female and male alcoholics were significantly higher in serum (p < 0.001;p < 0.001 respectively) and saliva (p < 0.05; p < 0.05) but not in urine, compared with social drinkers. The diagnostic efficiency of serum sialic acid was higher than that for traditional markers: 77% for female subjects and 64% for male subjects. The corresponding results for saliva were 72% and 53%. The sialic acid concentrations were significantly decreased during the alcohol dependency treatment program (after 5 weeks of treatment) in both females and males.

CONCLUSIONS

This study confirms that serum sialic acid is a valuable marker for detecting and monitoring alcohol abuse. This work also indicates that sialic acid in saliva could be used possibly as a noninvasive marker for alcohol abuse.

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.

Carbohydrate-deficient transferrin, a sensitive marker of chronic alcohol abuse, is highly influenced by body iron

Carbohydrate-deficient transferrin (CDT), a microheterogeneous form of serum transferrin (Tf), has been proposed as the most reliable marker of chronic alcohol consumption, although unexplained false-positive and -negative results have been reported. We investigated whether body iron influenced CDT serum levels by studying alcohol abusers with or without iron overload and nonabusers with iron deficiency or iron overload caused by genetic hemochromatosis (GH). In alcohol abusers, CDT was significantly lower in the presence of iron overload than in the absence (24.6 +/- 16.5 U/L vs. 33.3 +/- 11.7 U/L; P <.01), with false-negative results almost exclusively in patients with iron overload. Similarly, in nonabusers with GH, CDT was lower than in normal controls (9.6 +/- 2. 2 U/L vs. 15.7 +/- 3.3 U/L; P <.0001), whereas, patients with iron deficiency anemia had significantly higher levels than controls (28. 1 +/- 5.8 U/L vs. 15.7 +/- 3.3 U/L; P <.0001). In nonabusers, iron supplementation therapy significantly decreased CDT levels in patients with iron deficiency anemia (33.7 +/- 6.6 U/L vs. 21.7 +/- 5.2 U/L; P =.0007), while iron-depletion treatment significantly increased CDT levels in patients with GH (9.7 +/- 2.0 U/L vs. 14.7 +/- 4.0 U/L; P =.001). Alcohol abusers had a significant relationship between liver iron concentration (LIC) and the reciprocal of CDT (r =.65; P <.0001), while in nonabusers, there was a significant correlation between Tf and CDT (r =.72; P <.0001). In conclusion, CDT serum levels are markedly affected by the patient's iron status, with iron overload reducing its sensitivity in alcohol abusers and iron deficiency its specificity in nonabusers. CDT can be considered a reliable marker of alcohol abuse only when iron stores are normal.

Carbohydrate-deficient transferrin: diagnostic efficiency among patients with end-stage liver disease before and after liver transplantation

We tested the diagnostic validity of carbohydrate-deficient transferrin (CDT) as an indicator for relapse into elevated alcohol consumption among patients who were examined under follow-up treatment before (n = 147) and after (n = 102) orthotopic liver transplantation (OLT) in the outpatient-department of the University Hospital Department of Surgery in Hamburg-Eppendorf. CDT measurements were performed with two commercial kits in parallel (CDTect-RIA and CDT%-RIA). Short-term parameters of alcohol consumption (ethanol, methanol) indicated relapses into elevated alcohol consumption in 11.4% of the evaluated patients with alcoholic liver disease (ALD) before transplantation. Before OLT, median CDT values were determined to be elevated among patients with alcoholic as well as nonalcoholic end-stage liver diseases (NALD). Among patients with ALD, we found elevated CDT medians even in those who were successfully scheduled for OLT after long-term evidence of abstinence proved by biochemical short-term parameters and psychological tests. Both CDTect and CDT% assays had comparable low specificities in selected patient groups before transplantation. CDT% and CDTect were negatively correlated with the albumin level. Before the study ended, CDT was no longer implemented in the evaluation of whether an OLT should be administered. This was due to inconsistent results of CDT in ALD as well as NALD. After OLT, patients with ALD, as well as NALD, had statistically significant lower CDT medians than before OLT, which ranged within reference levels. We determined, according to CDT, elevated alcohol consumption subsequent to OLT in 4 of 13 patients with ALD who underwent transplantation during the study (median observation period: 10 months). CDT does not appear to be useful in evaluating patients before OLT. With regained specificity and high sensitivity in patients after OLT, CDT could be recommended as a standard instrument for quality control in patients with ALD after liver transplantation.

Carbohydrate deficient transferrin in alcoholic and non-alcoholic liver disease: a comparison of two assay methods

Carbohydrate-deficient transferrin (CDT) was assayed in 105 patients with non-alcohol-related liver diseases, 50 patients with alcohol-induced liver disease and 40 alcohol misusers with minimal hepatic dysfunction. The patients with liver disease were hospitalized for assessment of suitability for orthotopic liver transplantation. CDT was measured by two commercially available micro anion exchange methods; CDTect (Pharmacia) and %CDT (AXIS). Additionally, total transferrin was measured to allow expression of the CDTect results as 'relative' measurements. Overall, 41/105 (39%) of patients with non-alcohol-related liver diseases had a raised CDTect result, 13/105 (12%) had a raised %CDT result and 26/105 (25%) an abnormal CDTect/total transferrin ratio. In general, patients with cholestatic liver disease, primary biliary cirrhosis or primary sclerosing cholangitis had more 'false positive' results by CDTect than did those with viral or autoimmune hepatitis. The sensitivity of the two methods for the detection of alcohol misuse was similar; CDTect 77%, %CDT 65% and CDTect/total transferrin ratio 70%. This was, however, lower than the sensitivity of the conventional marker GGT (82%). In patients with severe liver disease, where up to 30% of the serum total transferrin concentrations fall outside the reference range, 'relative' CDT methods have greater specificity than 'absolute' measurements.

A comparative study between carbohydrate-deficient transferrin and gamma-glutamyltransferase for the diagnosis of excessive drinking in a liver unit

AIM

To compare the efficacy of carbohydrate-deficient transferrin and gamma-glutamyltransferase for the diagnosis of excessive alcohol intake in patients admitted in a liver unit.

METHODS

The 346 patients were divided into three groups of alcoholics: 57 patients (31 men, 26 women) with a normal liver, 77 patients (51 men, 26 women) with non-cirrhotic alcoholic liver disease, and 61 patients (43 men, 18 women) with alcoholic cirrhosis; and three groups of non-alcoholics: 35 abstainers (21 men, 14 women), and 58 healthy blood donors (26 men, 32 women), and 58 patients (32 men, 26 women) who had a non-alcoholic liver disease. Carbohydrate-deficient transferrin and gamma-glutamyltransferase were measured at admission using commercially available kits.

RESULTS

Carbohydrate-deficient transferrin was more sensitive than gamma-glutamyltransferase in patients without alcoholic liver disease, in both men (85 vs 54%) and women (64 vs 36%). Carbohydrate-deficient transferrin sensitivity decreased slightly but not significantly according to the severity of the liver disease in men and women. The sensitivity of gamma-glutamyltransferase which was low in men and women without alcoholic liver disease, improved in groups with moderate or severe alcoholic liver disease: not less than 80% in men and up to 100% in women. The specificity of carbohydrate-deficient transferrin in patients with non-alcoholic liver disease was consistently higher than that of gamma-glutamyltransferase (80% vs 60%).

CONCLUSIONS

In liver units, carbohydrate-deficient transferrin can help to identify excessive drinkers without liver disease with a higher efficacy than that of gamma-glutamyltransferase; carbohydrate-deficient transferrin can also be used to distinguish between alcoholics with moderate liver disease and patients with non-alcoholic liver diseases.