A new modified gamma-%CDT method improves the detection of problem drinking: studies in alcoholics with or without liver disease

BACKGROUND: The detection of excessive alcohol consumption by laboratory methods continues to lack sensitivity and specificity. Recent studies have suggested that diagnostic improvement may be achieved by combining carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GT) measurements into a marker defined as gamma-CDT. METHODS: We developed a new approach for determining gamma-CDT by using the data obtained from the Axis %CDT turbidimetric assays. Marker results were compared in the assessment of 65 alcoholics, who were either with (n=34) or without (n=31) liver disease, as analysed by clinical, laboratory, and morphological criteria. Reference individuals were 45 healthy volunteers who were either social drinkers or abstainers. RESULTS: Gamma-GT and CDT results derived from both CDTect and %CDT measurements were used to calculate marker ratios as follows 0.8 x ln(GT)+1.3 x ln(CDT). With the established cut-off of 4.0 for the gamma-%CDT, the sensitivity of this method was 94% for men and 82% for women, as compared to 61% and 46% for %CDT and 70% and 73% for GT. The gamma-%CDT method was less dependent on liver status than the various other markers and showed the highest correlation with self-reported alcohol consumption (r=0.7254). CONCLUSIONS: The data indicates that the new gamma-%CDT method yields improved diagnostic accuracy for the detection of excessive ethanol consumption.     

Comparison of Bio-Rad %CDT TIA and CDTect as laboratory markers of heavy alcohol use and their relationships with gamma-glutamyltransferase

BACKGROUND: Carbohydrate-deficient transferrin (CDT) is used as a serum marker for heavy drinking. We compared a new Bio-Rad %CDT TIA assay with the CDTect assay; we also compared both to gamma-glutamyltransferase (GGT) as markers of heavy drinking. METHODS: Serum samples of well-defined alcoholics (n = 404) and matched (age, race, and gender) social drinkers (204) from 10 clinical centers were assayed with both CDT assays. Both assays use microcolumn separation after iron saturation, followed by enzyme immunoassay (CDTect) or turbidimetric immunoassay (Bio-Rad %CDT). In the latter, CDT is expressed as a percentage of total transferrin. RESULTS: The slope and intercept [95% confidence intervals (CIs)] for linear regression of results obtained by the %CDT-TIA (as percentage) and CDTect (units/L) assays were 0.091 (0.088-0.097) and 0.70% (0.54-0.86%), respectively (S(y/x) =1.30%; r = 0.848). The areas under the ROC curves (95% CIs) for CDTect and Bio-Rad %CDT TIA were 0.89 (0.86-0.92) and 0.88 (0.85-0.91), respectively, for men (P, not significant) and 0.76 (0.72-0.80) and 0.72 (0.68-0.76) for women (P, not significant). When CDT (CDTect or Bio-Rad %CDT) was combined with GGT (either one positive), the clinical sensitivity in men was 90% for both assays, and specificities were 81% and 84%, respectively; sensitivities in women were 75% and 76%, respectively, and specificities were 87% and 91%. CONCLUSION: The new Bio-Rad %CDT TIA assay compares favorably to the widely studied CDTect assay in the detection of alcohol-use disorders.     

缺糖基转铁蛋白对酒精性肝病的诊断

目的 检测酒精性肝病(ALD)患者血清中的缺糖基转铁蛋白(CDT)与总TI的比值％CDT,并与GGT、MCV、ALT、AST等指标比较,评价其对ALD的诊断价值。方法 选择健康不饮酒对照组、非酒精性肝病的其他肝病组(NALD组)、ALD组(3组均为男性),分别检测％CDT、GGT、MCV、ALT、AST等指标,各指标在不同组间的比较用F检验;各项目之间的关系研究用直线相关,计算相关系数;同时绘制各指标的ROC曲线。结果 ALD组中的％CDT显著高于对照组、NAID组。％CDT诊断ALD的ROC曲线下面积为0．857,敏感度0．75,特异度0．88,而GGT这三者分别为0．751、0．75、0．76,MCV分别为0．669、0．30、0．78,ALT分别为0．512、0．25、0．72,AST分别为0．426、0．25、0．68。％CDT、与GGT不相关,但两者联合检测敏感度提高到90％。结论 对于ALD的诊断,％CDT、GGT、MCV均具有一定的诊断价值,尤其％CDT是一个很好的辅助诊断指标。％CDT与GGT联用可提高敏感度。     

Should we use carbohydrate-deficient transferrin instead of gamma-glutamyltransferase for detecting problem drinkers? A systematic review and metaanalysis

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

缺糖基转铁蛋白在酒精性肝病中的诊断价值

目的研究酒精性肝病（ALD）患者血清中缺糖基转铁蛋白百分含量（%CDT）,并与肿瘤坏死因子-α（TNF-α）、丙氨酸氨基转移酶（ALT）、天门冬氨酸氨基转移酶（AST）、γ-谷氨酰转肽酶（GGT）、红细胞平均体积（MCV）、平均血红蛋白浓度（MCHC）、红细胞平均血红蛋白含量（MCH）进行比较,评价其对ALD的诊断价值。方法选择ALD患者43例,分为酒精性脂肪肝组、酒精性肝炎组、酒精性肝纤维化组、酒精性肝硬化组共4组。非酒精性肝病患者（NALD组）39例,对照组40例,运用免疫散射比浊法测定%CDT;ELISA法测定TNF-α;速率法测定ALT、AST、GGT;全自动血细胞分析仪测定MCV、MCHC、MCH。结果 4组的%CDT、TNF-α、GGT、MCV、MCHC、MCH明显高于对照组（P〈0.05）;4组的%CDT、TNF-α、GGT、MCV、MCHC、MCH明显高于NAFLD组,ALT、AST明显低于NAFLD组,差异有统计学意义（P〈0.05）。NAFLD组TNF-α、GGT、ALT、AST、MCV明显高于对照组,差异有统计学意义（P〈0.05）。%CDT诊断ALD的敏感度为86.0%,特异度为90.0%。TNF-α诊断ALD的敏感度为76.7%,特异度为80%。%CDT、TNF-α和GGT联合检测在ALD组诊断敏感度提高为95.3%,特异度为97.5%。结论 %CDT在诊断ALD中具有重要的作用,其价值优于TNF-α、ALT、AST、GGT、MCV、MCHC、MCH。联合检测%CDT、TNF-α和GGT,对ALD的诊断及临床治疗具有重要的意义。     

Use of capillary zone electrophoresis for differentiating excessive from moderate alcohol consumption

BACKGROUND: The poorly sialylated transferrin isoforms in serum were analyzed by capillary zone electrophoresis (CZE) to differentiate moderate from heavy alcohol consumption. METHODS: We enrolled 614 volunteers, classified after interviews, self-reported drinking habits, and AUDIT scores as alcohol abusers (consuming >50 g/day ethanol for the previous 3 months or longer; n = 413) or moderate drinkers (<30 g/day ethanol; n = 201). Serum transferrin isoforms were separated at 28 kV and monitored at 214 nm on a P/ACE 5500 CZE with use of fused-silica capillaries and the related CEofix CDT reagent set. Immunosubtraction by anti-human transferrin and electrophoretic migration times identified the isoforms. Previous markers of alcohol abuse and an assay combining anion-exchange minicolumn chromatography with immunoturbidimetry (%CDT) were included in the study. Sensitivities and specificities were compared by ROC analysis. RESULTS: The asialylated isoform was missing in 95% of moderate drinkers but present in 92% of alcohol misusers. Disialotransferrin had a specificity and sensitivity of 0.75 at a cutoff of 0.7% of total transferrin, whereas the sum (asialo- + disialotransferrin) at a threshold of 1.2% had a sensitivity of 0.73 and a specificity of 0.92. Trisialotransferrin values did not distinguish between the two populations. Sensitivities and specificities of %CDT averaged 0.77 and 0.74, respectively, at a 2.6% cutoff; 0.67 and 0.83 at 2.8%; and 0.63 and 0.90 at 3%. CDT data were more sensitive and specific for males. Conventional biomarkers appeared less discriminating. CONCLUSIONS: Asialotransferrin detected by CZE in sera of alcohol abusers offers the highest discrimination between excessive and moderate drinking.     

The diagnostic accuracy of carbohydrate-deficient transferrin, sialic acid and commonly used markers of alcohol abuse during abstinence

BACKGROUND: The normalization of alcohol abuse markers during the abstinence depends on the time since the last drinking. The aim of this study was to evaluate the diagnostic accuracy (area under the curve-AUC, sensitivity and specificity) of CDT, sialic acid and others biochemical and hematological markers of chronic alcohol abuse during abstinence. METHODS: We studied 75 patients admitted to the treatment of alcohol dependence. The blood samples were collected upon admission to the hospital. CDT was estimated using an immunoturbidimetric assay after anion-exchange chromatography and sialic acid by enzymatic colorimetric method. RESULTS: Mean values of all markers were significantly higher. All tests, except SA, negatively correlated with time of abstinence but not with age, duration of dependence and amounts of weekly alcohol consumption. The area under the curve (AUC) for all tested markers decreased progressively during the abstinence. The highest AUC was obtained for CDT (0.98) and the lowest for ALT (0.78) when alcohol was consumed in the last week. AUC for sialic acid was lower than of CDT but higher than of ALT. CONCLUSIONS: We conclude that the diagnostic accuracy for tested laboratory markers depends on the self-reported time of abstinence being the highest for CDT in the first week of abstinence. The accuracy of sialic acid was observed between GGT and ALT.     

Interference of transferrin isoform types with carbohydrate-deficient transferrin quantification in the identification of alcohol abuse.

BACKGROUND: Isoforms of transferrin interfere with measurement of carbohydrate-deficient transferrin (CDT) as a marker of heavy alcohol consumption. We evaluated the rate of inaccurate CDT results by immunoassays. METHODS: We studied 2360 consecutive sera (1614 individuals) submitted for CDT assay without clinical information as well as samples from 1 patient with a congenital disorder of glycosylation (CDG Ia) and from 6 healthy carriers of CDG Ia. The CDTect, %CDT-TIA, and new %CDT immunoassays were compared with HPLC (%CDT-HPLC). Transferrin isoform pattern were evaluated by isoelectric focusing (IEF). RESULTS: Transferrin BC and CD heterozygotes were found at frequencies of approximately 0.7% and approximately 0.2%, respectively. Another transferrin C subtype, where di- and trisialotransferrin partly coeluted (tentatively identified as C2C3), was observed in approximately 0.6%. Compared with the %CDT-HPLC method, the immunoassays often produced low results for transferrin BC and high results for transferrin CD and "C2C3". A very high trisialotransferrin value (frequency approximately 1%) often produced high CDT immunoassay results. In four of six healthy carriers of CDG Ia, a- and disialotransferrin were highly increased and the HPLC and IEF isoform patterns were indistinguishable from those in alcohol abuse. CONCLUSIONS: Rare transferrin isoform types and abnormal amounts of trisialotransferrin (total frequency approximately 2-3%) may cause incorrect determination of CDT with immunoassays. The observed variants were readily identified by HPLC and IEF, which can be recommended for verification of CDT immunoassay results in doubtful cases. In healthy carriers of CDG Ia, CDT is high by all assays.     

Argininosuccinate lyase deficiency (ASL) and carbohydrate-deficient transferrin (CDT): experience with four independent CDT analysis methods--misleading results given by the %CDT TIA assay

BACKGROUND: Chronic liver disease can cause false-positive carbohydrate-deficient transferrin (CDT) results mimicking chronic alcohol abuse. We tested whether argininosuccinate lyase deficiency (ASL), a genetic disorder of the urea cycle with hepatomegaly and biochemical hepatitis, causes increased CDT results and whether this depends on the analytical method. METHODS: Seven serum samples from four ASL patients without alcohol abuse were analyzed by capillary electrophoresis, HPLC, particle-enhanced immunonephelometry with monoclonal CDT antibodies, and microcolumn CDT and non-CDT fractionation followed by a turbidimetric immunoassay with transferrin antibodies (%CDT TIA). RESULTS: Increased CDT results (two out of four patients or five out of seven samples) were obtained by the %CDT TIA assay, but not by the remaining three CDT tests. The corresponding serum samples showed increased fractions of trisialotransferrin by HPLC (as the IFCC reference method for CDT analysis). One sample contained an elevated trisialotransferrin but a normal CDT also in the %CDT TIA test. One patient had a normal trisialotransferrin and a normal CDT as assayed by each of the four CDT methods. CONCLUSIONS: Argininosuccinate lyase deficiency is not itself a cause for increased CDT values. Increased fractions of trisialotransferrin in ASL patients appear to interfere with CDT analysis by the %CDT TIA assay. This can give false-positive CDT results. Since this can appear not only in ASL patients, microcolumn CDT and non-CDT fractionation followed by a turbidimetric immunoassay using transferrin but not CDT antibodies by the %CDT TIA assay should no longer be used for CDT measurement without confirmatory analysis by HPLC or capillary electrophoresis.     

Long-term ethanol consumption and macrocytosis: diagnostic and pathogenic implications

Although excessive alcohol consumption is known to elevate the mean cell volume (MCV) of erythrocytes, the relationships among the intensity of ethanol exposure, the generation of abnormal red blood cell indices, and the underlying pathogenic mechanisms have remained unclear. The authors examined 105 alcoholics with a wide range of ethanol consumption (40-500 g of ethanol/day), 62 moderate drinkers (mean consumption 1-40 g/day), and 24 abstainers, who underwent detailed interviews, measurements of blood cell counts, markers of liver status, and circulating antibodies against ethanol-derived protein modifications. Follow-up information was collected from healthy volunteers with detailed records on drinking habits. Data from the NORIP project for laboratory parameters in apparently healthy moderate drinkers or abstainers (n = 845) were used for reference interval comparisons. The highest MCV (P < 0.001) and mean cell hemoglobin (MCH) (P < 0.01) occurred in the alcoholics. However, the values in the moderate drinkers also responded to ethanol intake such that the upper normal limit for MCV based on the data from moderate drinkers was 98 fl, as compared with 96 fl from abstainers. Follow-up cases with carefully registered drinking habits showed parallel changes in MCV and ethanol intake. Anti-adduct IgA and IgM against acetaldehyde-induced protein modifications were elevated in 94% and 64% of patients with high MCV, respectively, the former being significantly less frequent in the alcoholics with normal MCV (63%) (P < 0.05). The data indicate dose-related responses in red blood indices upon chronic ethanol consumption, which may also be reflected in reference intervals for hematological parameters in health care. Generation of immune responses against acetaldehyde-modified erythrocyte proteins may be associated with the appearance of such abnormalities.     

Biochemical markers of alcohol use in pregnant women

OBJECTIVES: To describe the serious health consequences of alcohol (ethanol) use, especially as they relate to pregnancy and the development of fetal alcohol syndrome (FAS) and fetal alcohol effects (FAE). The classic markers of alcohol exposure, including blood/breath alcohol, gamma-glutamyl transferase (gammaGT), mean corpuscular volume (MCV), hemoglobin-associated acetaldehyde (HAA) and carbohydrate deficient transferrin (CDT), are valuable and their methods of analysis are reviewed. CONCLUSIONS: Since both FAS and FAE represent two of the leading preventable causes of mental retardation and birth defects, identification of alcohol use early in pregnancy is important to avoid adverse fetal outcomes. Unfortunately, the diagnosis of FAS and FAE is usually made after birth, when alcohol damage has become irreversible and permanent. The clinical laboratory can help prevent this damage and make a valuable contribution in assessing prenatal alcohol use. The clinical utility of blood/breath alcohol, gammaGT, MCV, HAA and CDT in alcohol use identification, especially in pregnancy, is substantial. Although none of the markers singularly has adequate sensitivity and specificity for screening, their diagnostic utility increases when measured as a panel. This is especially true in detecting alcohol use in pregnancy where the presence of several positive markers was correlated with the presence of alcohol-related fetal effects.     

Biomarkers in alcoholism

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

Development and multicenter evaluation of the N latex CDT direct immunonephelometric assay for serum carbohydrate-deficient transferrin

BACKGROUND: Carbohydrate-deficient transferrin (CDT) is a promising biomarker of alcohol abuse. We describe the development and multicenter evaluation of N Latex CDT (Dade Behring), an automated, particle-enhanced, homogeneous immunonephelometric assay for directly determining CDT. METHODS: N Latex CDT uses a monoclonal antibody that recognizes the structure of transferrin glycoforms lacking 1 or 2 complete N-glycans [i.e., disialo-, monosialo-, and asialotransferrins (CDT glycoforms)] in combination with a simultaneous assay for total transferrin. The Dade Behring BN II and BN ProSpec systems automatically calculate the CDT value as a percentage of total transferrin (%CDT). No preanalytical sample treatment is used. RESULTS: Total imprecision values for serum pools containing 1.8%-8.7% CDT were 3.4%-10.4% (mean, 6.8%). The mean (SD) %CDT for 561 serum samples from healthy control individuals was 1.76% (0.27%; range, 1.01%-2.85%). No marked sex or age differences were noted. The 97.5th percentile was at 2.35%. Transferrin genetic variants did not interfere with measurements. High transferrin concentrations did not falsely increase %CDT values, but increased %CDT values were noted for some samples with transferrin concentrations <1.1 g/L. N Latex CDT results correlated with those of a commercial CDT immunoassay involving column separation (r(2) = 0.862) and an HPLC candidate reference method (r(2) = 0.978). CONCLUSION: N Latex CDT is the first direct immunoassay for quantifying %CDT in serum. The specificity of N Latex CDT for identifying alcohol abuse may be higher than for immunoassays that use column separation, because transferrin genetic variants do not interfere with measurements.     

糖缺失性转铁蛋白诊断酒精性肝病准确性的评价

目的对国内外发表的糖缺失性转铁蛋白(CDT)或其相对值(%CDT)诊断酒精性肝病(ALD)的研究进行系统评价,为酒精性肝病的临床诊断提供参考依据。方法计算机检索PubMed、EMBASE、维普、万方、中国期刊全文数据库等文献数据库。按照纳入和排除标准对所检索的文献进行筛选并提取研究中相关的数据,采用MetaDiSc1.4软件对研究进行评价,对诊断的准确性进行Meta分析。结果符合纳入标准的研究共6篇,其中ALD组259例,非酒精性肝病组(NALD)组308例,健康人群组262例。Meta分析结果显示:ALD与NALD组鉴别诊断中,其合并敏感度(Se)、特异度(Sp)、阳性似然比(+LR)、阴性似然比(-LR)、诊断优势比(DOR)和汇总受试者工作特征曲线(SROC)曲线下面积分别为:72%、82%、4.20、0.34、15.46、0.866 7;ALD与健康对照组鉴别中,其合并Se、Sp、+LR、-LR、DOR和SROC曲线下面分别为:73%、89%、5.62、0.35、27.76、0.908 5。结论临床应用CDT或%CDT对ALD进行排除诊断时准确性性较高,但运用在ALD的诊断中需要结合患者的饮酒史进行综合评价。上述研究结果还需要更多设计科学、严谨的临床试验验证。     

Determination of carbohydrate-deficient transferrin in human serum using the Bio-Rad %CDT by HPLC test

BACKGROUND: Carbohydrate-deficient transferrin (CDT) in serum is a biomarker used to identify individuals with sustained, heavy alcohol consumption. This study evaluated the performance of a new commercial method for CDT, the Bio-Rad %CDT by HPLC test, that measures relative amounts of separate transferrin glycoforms in proportion to total transferrin. METHOD: The samples used were two human serum pools (low/high disialotransferrin), 150 clinical sera with low to highly elevated disialotransferrin values, and 18 genetic transferrin variants. Glycoforms are separated on a gradient HPLC system, followed by specific measurement of the iron-transferrin complex at 460 nm. Comparison was made with an HPLC candidate reference method on an Agilent 1100 LC system. RESULTS: The Bio-Rad %CDT by HPLC test allowed for reproducible separation and quantification of the transferrin glycoforms within approximately 6 min. Genetic variants were readily identified. For the low and high serum pool, the total CV was 8.5% and 4.3%, respectively. The relative amounts of disialotransferrin, the main CDT glycoform, were in good agreement with the results of the HPLC candidate reference method (r(2)=0.998, p<0.0001). CONCLUSIONS: The present results demonstrated that the Bio-Rad %CDT by HPLC test is appropriate for confirmatory and routine %CDT testing in human serum, with the added advantage over previously published HPLC methods of an improved serum sample pretreatment and a shorter total analysis time.     

Comparison of HPLC and small column (CDTect) methods for disialotransferrin

BACKGROUND: Current methods for determination of carbohydrate-deficient transferrin (CDT) are based on separation of the CDT fraction by ion-exchange chromatography on minicolumns and quantification by immunoassay. Alternatively, the transferrin isoforms can be separated by HPLC anion-exchange chromatography and quantified by absorbance. This method has been reported to improve the validity of CDT as a marker of chronic alcohol abuse. METHODS: HPLC on either MonoQ or ResourceQ anion-exchange columns was used to separate and quantify isoforms of transferrin with detection at 460 nm. The result was expressed as the percentage of the disialo form (pI 5.7) of total transferrin (DST). The commercial CDTect assay was used as a comparison method. Serum samples from nondrinkers (n = 57), moderate drinkers (n = 77), and heavy drinkers (n = 139) were analyzed. RESULTS: In ROC analysis for differentiation between moderate and heavy drinkers, the area under the curve (AUC) for the HPLC method was 0.87 (95% confidence interval, 0.81-0.93), whereas that for CDTect was 0.72 (95% confidence interval, 0.64-0.80). At 90% specificity, the sensitivity of DST was 63% (95% confidence interval, 53-73%) compared with 33% (22-44%) for CDT. The reference interval of the HPLC method was 0.68-1.7%. CONCLUSIONS: The HPLC anion-exchange method for quantification of CDT provides substantially better separation between moderate and heavy drinkers than the CDTect method.     

HPLC analysis of carbohydrate deficient transferrin isoforms isolated by the Axis-Shield %CDT method

BACKGROUND: Carbohydrate-deficient transferrin (CDT) is elevated during prolonged overconsumption of alcohol and CDT is considered to be the most specific biochemical marker for alcohol overconsumption. However, an accurate method for analysing CDT is necessary because the test is frequently used for example in legal matters. METHODS: Patient serum samples were analysed with the Axis-Shield %CDT and eluates were pooled together. Transferrin was purified from the pool by affinity chromatography and further analysed with HPLC to determine the ratios of different transferrin isoforms. RESULTS: In the eluates using the Axis-Shield %CDT method, a substantial amount of trisialo transferrin was found, which is generally not considered a CDT isoform. CONCLUSIONS: The fact that trisialo transferrin is present may generate falsely elevated CDT results and it could at least partly explain the discrepancy between results of the Axis-Shield %CDT assay and HPLC in routine analysis.     

Markers for excessive alcohol use (screening)

It is well-known that early diagnosis in addiction leads to a better outcome and prevents psychosocial and medical illness and disability as well as costs. It would be important to have a gold standard for the diagnosis for alcoholism because of the consequences of this diagnosis for both the patient and the physician. In the last 15 years there were world-wide efforts to find biological markers for alcoholism and alcohol abuse. The results, however, were rather poor. With the exception of the relatively new and expensive CDT TEST (Carbohydrate-deficient transferrin) and some changes in established questionnaires (shortenings) we have used the same screening tests for decades. The relationship between the patient and the physician, a detailed medical history and experience of the physician cannot be replaced by tests. The Plinius Major Society recommends in its Guidelines the CAGE questionnaire. In medical settings and in primary care the MALT or AUDIT are more informative. As laboratory markers the Plinius Major Society still recommends: gamma-GT, MCV, GOT/GPT (ASAT/ALAT) and CDT. These tests are only useful if normal values of the particular laboratory are given.     

Improved diagnostic classification of alcohol abusers by combining carbohydrate-deficient transferrin and gamma-glutamyltransferase

BACKGROUND: Biochemical markers can provide objective evidence of high alcohol consumption. However, currently available markers have limitations in their diagnostic performance. METHODS: The diagnostic values of the most frequently used markers [carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume] were studied in an analysis of six different clinical studies (n = 1412) on alcohol abusers and social drinkers. The purpose of the analyses was to determine whether a combination of markers would improve the diagnosis of subjects. RESULTS: Discrimination between alcohol abusers and social drinkers, as measured by the areas under nonparametric ROC plots, was significantly better (P<0.001) for the new combined marker [gamma-CDT = 0.8. ln(GGT) + 1.3. ln(CDT)] than for any of the separate markers or combination of CDT or GGT with other markers. The cutoff values for gamma-CDT (6.5) can be taken to be the same among males and females. CONCLUSIONS: The combined variable gamma-CDT is a powerful tool to discriminate alcohol abusers from social drinkers and is recommended for clinical use.     

Ethanol elimination-rates determined by breath analysis as a marker of recent excessive ethanol consumption

The rate of ethanol elimination was studied in two groups of men by means of an Alcotest 7010 breath analyser. The experimental group consisted of 15 skid-row alcoholics undergoing detoxification. Their median daily ethanol consumption was 211 (range 26-476) g pure ethanol during the last year. The control group was made up of 12 age-matched healthy social drinkers consuming 9 (range 4-23) g day-1 pure ethanol during the last year. The median ethanol elimination-rate in the elimination phase was 0.25 (range 0.13-0.31) g 1-1 h-1 during the detoxification period in the experimental group. This value was approximately 70% higher than in the control group (0.14(0.12-0.17) g 1-1 h-1). Some correlation was found between reported ethanol intake, and the calculated ethanol elimination-rate, as well as gamma glutamyl transferase (GGT), alanine amino transferase (ALAT), aspartate amino transferase (ASAT), glutamate dehydrogenase (GLDH), mean corpuscular volume (MCV) and HDL-cholesterol. Of these measures, ethanol elimination-rate showed highest sensitivity and efficiency for detection of ethanol consumption above the limit of 50 g per day.