Determination Of Carbohydrate-deficient Transferrin Research Articles

Carbohydrate-Deficient Transferrin (CDT) as a Biomarker of Alcohol Abuse: A Retrospective Study of the Italian Drinking Trend among Drivers from 2016 to 2022.

Alcohol abuse is still one of the leading causes of death worldwide. Early diagnosis of alcohol abuse enables preventive intervention on the effects and risks associated with its consumption. Carbohydrate-deficient transferrin (CDT) is one of the most reliable biomarkers of chronic alcohol misuse. We retrospectively studied a population of 12,624 subjects who had their driving license suspended for driving under the influence of alcohol or drugs from 2016 to 2022. The analytical determination of CDT was performed following a certified high-performance liquid chromatography (HPLC) method. Data were split by year, age and gender. The majority of subjects with positive %CDT were male, although the trend of positivity was similar between males and females. A steady increase in both the number of tests performed and the number of positives was observed over the years. Patients aged 41-50 years had the highest prevalence, followed by 51-60, 31-40 and 18-30 years. CDT continues to be a steady marker for diagnosis of alcohol abuse in the majority of cases. Data emerging from our study are in line with the increasing national trends on traffic accidents, injuries and deaths related to alcohol and drug DUI (driving under the influence), requiring the implementation of preventive measures to limit this ever-growing phenomenon.

A novel high-throughput liquid chromatography assay for Carbohydrate-Deficient transferrin (CDT) based on flow-modulated isocratic elution and terbium-induced fluorescence

Transferrin is a glycoprotein containing two bi- or tri-antennary carbohydrate chains ending with sialic acid. Its glycosylation is reduced in chronic alcohol abuse and in inborn glycosylation pathologies, where the carbohydrate-deficient fraction of the protein (CDT) increases significantly. The current methods require a gradient chromatographic separation and time-consuming sample preparation. In comparison, the proposed approach uses a novel flow-modulated liquid chromatography technique (fmLC) and a highly selective and sensitive fluorescence derivatization reaction with terbium ion.A fmLC-FLD method using isocratic anion exchange separation was optimized and validated to resolve disialo-transferrin and trisialo-transferrin from other transferrin glycoforms. Detection took place by recording fluorescence at 550 nm wavelength (excitation at 298 nm). The chromatographic separation needed 5 min, allowing seriate injection every 7.5 min.The method was validated according to the current guidelines of analytical chemistry showing adequate accuracy and precision for the quantitative determination of CDT. The proposed method proved also to be suitable to analyse haemolyzed sera which, because of interference by haemoglobin, fail the standard HPLC-Vis analysis. The method was tested in parallel with HPLC-Vis on 131 sera showing an excellent correlation of results proved by a correlation coefficient of 0.995 (Pearson’s r).The proposed approach proved much simpler than the current methods and cheaper in terms of instrumental costs offering a ground-breaking analytical tool that could likely make available the characterization of CDT outside specialized laboratories, such as in occupational medicine centres, doctor’s offices, small laboratories, alcohol rehabilitation centres, and in developing countries.

Modern approaches to the diagnosis of alcoholic liver disease

The article presents up-to-date information about diagnostic methods for one of the most common and socially significant hepatological diseases-alcoholic liver disease. The most frequent clinical manifestations of this pathology are asthenic, dyspeptic, right hypochondrium, cholestatic, neurological, edematous-ascitic and hemorrhagic syndromes. Validated questionnaires are intended for standardized alcohol use screening, the gold standard among which is the AUDIT questionnaire aimed at identifying alcohol use disorders. Most of the physical signs of chronic alcohol abuse are presented in the modified LeGo grid. Direct indicators (markers) of laboratory diagnosis of alcohol use include the determination of phosphatidyl ethanol and ethyl glucuronide in blood serum and urine; ethyl glucuronide and fatty acid ethyl esters in hair; ethanol, aminotransferase, peroxidase, ethylglucuronide, ethyl sulfate, haptoglobin, etc., in saliva. Indirect markers include macrocytic anemia, neutrophilic leukocytosis, increased activity of gamma-glutamyl transpeptidase, transaminases, de Ritis coefficient, bilirubin, alkaline phosphatase, serum immunoglobulin A and gamma globulins. Determination of carbohydrate-deficient transferrin is recommended as a preferred marker of alcohol intoxication. In order to determine the degree of fibrosis, predictive diagnostic serum tests are used, both non-proprietary (APRI, Forns) and commercial (Fibrometer, Hepascore, Fibrospect etc.). The methods of visual diagnostics of liver diseases include ultrasound, magnetic resonance and computed tomography, which can determine steatosis, exclude other causes of liver damage, reveal signs of severe fibrosis or cirrhosis, as well as their complications, but none of them allows to establish the etiology of the lesion. A promising direction is to determine the degree of steatosis when measuring the controlled parameter of ultrasound attenuation, implemented in the Fibroscan apparatus. The most accurate methods for diagnosing steatosis today are magnetic resonance imaging of the liver in the mode of determining the proportion of fat, weighted by proton density, and proton magnetic resonance spectroscopy. To determine the degree of fibrosis, a transient, two-dimensional shear wave and magnetic resonance elastography are used. Biopsy followed by morphological examination is the gold standard for the diagnosis of alcoholic liver disease, which confirms the presence of liver damage, establishes its stage and often allows confirming alcoholic genesis. However, this procedure has a number of significant drawbacks, so it is advisable to use non-invasive diagnostic techniques for screening, primary examination and further monitoring of the patients condition in dynamics.

Electrochemical sensor for the assessment of carbohydrate deficient transferrin: Application to diagnosis of congenital disorders of glycosilation

Carbohydrate deficient transferrin (CDT) is used as biomarker of different health problems as, for example, congenital disorders of glycosylation (CDG). We propose a screen-printed-based electrochemical sensor for the determination of carbohydrate deficient transferrin using an Os (VI) tag-based electrochemistry. When transferrin is labeled with Os (VI) complex, it generates two voltammetric signals: one from carbohydrates (electrochemical signal of osmium (VI) complex at -0.9 V/Ag) and one from the amino acids present in glycoprotein (intrinsic electrochemical signal of glycoprotein at +0.8 V/Ag). The relationship between the two analytical signals (carbohydrate signal/protein signal) is an indicator of the degree of glycosylation (electrochemical index of glycosylation), which has shown an excellent correlation (r = 0.990) with the official parameter %CDT obtained by CE-UV. The suitability of this approach was demonstrated by analyzing serum samples from CDG patients.

Improved detection of alcohol consumption using the novel marker phosphatidylethanol in the transplant setting: results of a prospective study

Phosphatidylethanol (PEth) is a new, highly specific alcohol marker. The aim of this study was to assess its diagnostic value in the liver transplant setting. In 51 pre- and 61 post-transplant patients with underlying alcoholic liver disease PEth, ethanol, methanol, carbohydrate-deficient transferrin (CDT), and ethyl glucuronide in urine (uEtG) and hair (hEtG) were tested and compared with patients' questionnaire reports. Twenty-eight (25%) patients tested positive for at least one alcohol marker. PEth alone revealed alcohol consumption in 18% of patients. With respect to detection of alcohol intake in the preceding week, PEth showed a 100% sensitivity. PEth testing was more sensitive than the determination of ethanol, methanol, CDT or uEtG alone [sensitivity 25% (confidence interval (CI) 95%, 7-52%), 25% (7-52%), 21% (6-45%) and 71% (41-91%), respectively], or ethanol, methanol and uEtG taken in combination with 73% (45-92%). Specificity of all markers was 92% or higher. Additional testing of hEtG revealed alcohol consumption in seven patients, not being positive for any other marker. Phosphatidylethanol was a highly specific and sensitive marker for detection of recent alcohol consumption in pre- and post-transplant patients. The additional determination of hEtG was useful in disclosing alcohol consumption 3-6 months retrospectively.

The Markers for Alcohol Abuse: The Good, the Bad and the Ugly

In the past decades’ different biomarkers for alcohol abuse has been proposed, but, despite this, the research for newly ones is still actual. To overcome the lack of the “perfect” biomarker, at this time, different strategies has been proposed, but none of them has demonstrated the required sensibility and specificity for general population screening. As to date, the determination of carbohydrate deficient transferrin (CDT) alone is the standard serum analysis for forensic examination, despite its chance to be interfered by genetic variants (<3%) and by particular physio-pathological condition. It should be considered the evaluation of ethyl glucuronide on hair coupled with CDT on serum for forensic examination to be able to overcome the intrinsic limits of the laboratory tests and, the combination of the two together with an accurate anamnestic analysis, will give the ability to prevent misinterpretation due to the genetic and metabolic variability providing an accurate patients evaluation.

Carbohydrate-Deficient Transferrin Determination in a Clinical Setting: Consistency Between Capillary Electrophoresis Assays and Utility of HPLC as a Confirmatory Test.

Carbohydrate-deficient transferrin (CDT) is used to assess chronic alcohol consumption in administrative and forensic context. The aim of the present study was the optimization of the diagnostic strategy for CDT determination in a clinical laboratory setting. Two capillary zone electrophoresis (CZE) assays, the CEofix CDT (Analis, Suarlée, Belgium) run on single capillary MDQ instrument and the muticapillary (Sebia, Lisses, France), were compared as screening methods and a commercial high-performance liquid chromatography (HPLC) assay (Recipe, Munich, Germany) was used for confirmation. In total, 367 serum samples were analyzed by both CZE assays with concordant classification in 92% of cases. All discordant samples were classified as negative by HPLC, as did 2/3 of those that could not be classified by either CZE assay. Classification of samples with CDT values close to cut-off by CZE was confirmed by HPLC in 95-100% of negative samples but only in 28.6-33.3% of positive samples. Both CZE assays proved suitable for CDT screening. HPLC was useful for discriminating CDT value in most of samples that could not be interpreted by CZE due to analytical interferences. Considering the implication of CDT testing, HPLC assay may also be helpful for the confirmation of positive results close to the cut-off value of CZE assays.

Quantification of total serum transferrin and transferrin sialoforms in human serum; an alternative method for the determination of carbohydrate-deficient transferrin in clinical samples

Carbohydrate deficient transferrin (CDT) is a biochemical marker for congenital disorders of glycosylation (CDG), chronic alcohol consumption, and forensic medicine diagnosis.

Forensic aspects of postmortem serum carbohydrate-deficient transferrin analysis as a marker of alcohol abuse

Carbohydrate-deficient transferrin (CDT) has been suggested as one of alcohol abuse indicators having produced good results in forensic medicine for years. The aim of the study was to identify correlation between present methodology of alcohol abuse diagnosis at autopsy (macroscopic and microscopic findings) and CDT examination using the method of isoelectrofocusing (IEF) in polyacrylamide gel electrophoresis (PAGE). We also analyzed if the time interval between the moment of death and blood sample collection influences CDT findings. The method used for CDTanalysis was IEF-PAGE. Sera of 49 males and 11 females aged 14-87 years, average age 46.85+/-18.53, were used in this study. Control group consisted of five patients who died after medical treatment that lasted longer than 15 days, and five patients who started Disulfiram therapy in controlled hospital environment. The results obtained in CDT examination in dead bodies' sera showed sensitivity 59% and specificity 71%. A high incidence of falsely positive CDT result was noticed in liver failure and cirrhosis of non-alcoholic origin. CDT analysis is also possible to be done in samples collected postmortem up to 76 hours. In forensic medicine, the method of CDT determination is reliable for the diagnosis of alcohol abuse.

Re-assessment of the cut-off levels of Carbohydrate Deficient Transferrin (CDT) for automated immunoassay and multi-capillary electrophoresis for application in a forensic context

BackgroundThe determination of Carbohydrate Deficient Transferrin (CDT) in a forensic context should be based on the use of a screening technique followed, for the “positive samples”, by a confirmatory technique. The aim of this study was to compare the two most used automated screening methods for CDT analysis, immuno-nephelometric assay (INA) and multi-capillary electrophoresis (mCE), with a validated HPLC procedure, used as confirmation test, in order to re-evaluate the cut-off concentrations of the screening methods. Methods195 serum samples underwent CDT analysis by using the N Latex CDT direct immuno-nephelometric assay, the multicapillary system Capillarys™ and an anion exchange HPLC method with UV-visible detection at 460nm developed and validated at our laboratories. Statistical analyses were performed by using Bland–Altman plots and ROC curves. Results and discussionThe 95% limits of agreement were ±0.94% when comparing INA and HPLC and ±0.60% when comparing mCE and HPLC. The ROC analysis of both INA and mCE, using HPLC as the reference method, showed that no false negative results were found when the cut-off was fixed to 1.2% for mCE and to 2.3% for INA. ConclusionsThe study showed a good agreement among CDT determinations carried out either with mCE or INA or HPLC. However, the usual cut-offs of both mCE (1.3%) and INA (2.5%) should be lowered to minimize false negatives at the screening analysis.

Transferrin immunoextraction for determination of carbohydrate-deficient transferrin in human serum by capillary zone electrophoresis

CZE-based assays for carbohydrate-deficient transferrin (CDT) in which serum is mixed with an Fe(III) ion-containing solution prior to analysis are effective approaches for the determination of CDT in patient samples. Sera of patients with progressed diseases, however, are prone to interferences comigrating with transferrin (Tf) that prevent the proper determination of CDT by CZE in these samples. The need of a simple and economic approach to immunoextract Tf from human serum prompted us to investigate the use of a laboratory-made anti-Tf spin column containing polyclonal rabbit anti-human Tf antibodies linked to Sepharose 4 Fast Flow beads. This article reports extraction column manufacturing and column characterization with sera having normal and elevated CDT levels. The developed procedure was applied to a number of relevant hepatology and dialysis patient samples and could thereby be shown to represent an effective method for extraction and concentration of all Tf isoforms. Furthermore, lipemic sera were delipidated using a mixture of diisopropyl ether and butanol prior to immunoextraction. CDT could unambiguously be determined in all pretreated samples.

Carbohydrate deficient transferrin in doping and non-doping sportsmen

The determination of carbohydrate deficient transferrin (CDT) concentration is primarily used in social security studies as a proof of regular alcohol consumption exceeding the amount of 60 grams per day. Aims: The present study was performed to investigate into how carbohydrate deficient transferrin CDT values in serum are affected by the so-called food supplements and chemicals included in doping lists. Methods: The investigation was carried out in 15 bodybuilders of two sport clubs and in 10 boxers. All sportsmen were males. In both groups serum carbohydrate deficient transferrin (CDT%), median red blood cell volume and (MCV) gamma-glutamyl-transpeptidase (GGT) values were measured. Results: The authors found a significant difference between the two groups only in carbohydrate deficient transferrin CDT% that was the CDT% value in bodybuilders was twice as high as in boxers. Conclusion: Not all the details of the specificity of carbohydrate deficient transferrin (CDT) concentration are known, however, the remarkably high sensitivity of the method makes it suitable and probably cost-financially effective for serving as a pre-screening tool in doping tests. Orv. Hetil., 2012, 153, 514–517.

Comparative evaluation of capillary zone electrophoresis and HPLC in the determination of carbohydrate-deficient transferrin

Transferrin (Tf) glycoform lacking one or two complete or incomplete glycan chains (i.e., asialo-monosialo- and disialo-Tf) typically appear in blood after chronic alcohol consumption, though recently it was reported that monosialo-Tf is associated with trisialo-Tf but not with alcohol consumption. These glycoforms are collectively known as carbohydrate-deficient transferrin (CDT). Since samples from alcoholic patients are characterized by decreased sialic acid content in serum transferrin, the assessment of CDT is thereby widely used for laboratory evaluation of chronic alcohol abuse. CDT analysis has been performed in 6011 consecutive subjects undergoing national mandatory testing after the confiscation of driving license for driving under the influence of alcohol. Out of the 6011 specimens, 539 (9%) displayed values exceeding the specific cut-off (>1.3%) on multicapillary electrophoresis (MCE) (Capillarys2 Sebia, France), and were further analyzed with a routine high-pressure liquid chromatography (HPLC) technique. The overall correlation between the methods in the total 539 samples was satisfactory, displaying a correlation coefficient (r) of 0.960. Nevertheless, the correlation was lower in the group with CDT values comprised between 1.3% and 1.9% (group 1; r=0.60) than in those with CDT values >2.0% (group 2; r=0.98). Moreover, the discordance between values exceeding the method-specific threshold in the former group of samples was also remarkably high (62% of samples in group 1 vs. 0.6% in group 2). Finally, a significant difference of CDT values was observed in group 1 (p<0.001), and in group 2 (p<0.0001) by Wilcoxon test. The MCE is characterized by a high throughput and it seems a suitable approach for laboratory monitoring of alcohol abuse when CDT is used as medical parameter in the diagnosis and follow-up of heavy drinking. However, CDT measured by screening techniques must be confirmed by a confirmatory technique, in particular for forensic purpose.

Improved capillary electrophoresis determination of carbohydrate-deficient transferrin including on-line immunosubtraction

The instrumental analysis of carbohydrate-deficient transferrin (CDT), a recognized marker of chronic alcohol abuse, is most commonly carried out by high-performance liquid chromatography (HPLC) or capillary zone electrophoresis (CZE). Between these two techniques, CZE shows higher efficiency and productivity, but is often reported to be inferior to HPLC in terms of selectivity, because of a less specific ultraviolet detection wavelength than HPLC. On these grounds, the present work was aimed at the development of an improved CZE method for CDT determination, including an on-line immunosubtraction step specifically aimed at enhancing the analytical specificity of CZE determination. The analytical conditions were as follows: uncoated fused silica capillary, 30 microm x 60 cm (L = 50 cm to detector); running buffer, 100 mmol/L borate and 6 mmol/L DAB (1,4-diaminobutane), pH 8.3; voltage, 30 kV; temperature, 25 degrees C; detection, 200 nm. Under the described CZE conditions, a baseline separation between all the CDT related peaks was achieved with good analytical performances in terms of both precision and accuracy. In order to achieve unequivocal recognition of the CDT peaks, an in-capillary immunosubtraction step was included by loading a plug of anti-human transferrin antibody solution after the sample plug. This analytical approach was applied successfully to recognize CDT peaks in the presence of potential interferences.

Determination of asialotransferrin in the cerebrospinal fluid with the HPLC method

Background: Identification of the content of asialotransferrin in the cerebrospinal fluid is a diagnostic method for childhood-onset ataxia and central nervous system hypomyelination (CACH), also known as vanishing white matter disease (VWM), and also for other types of CNS disorders. Methods: In our work, we have determined the value of the ratio of the asialo form of transferrin to the total transferrin in the CSF using the commercially used VariantTM Bio-Rad system for the determination of carbohydrate-deficient transferrin (CDT) in serum. The peak corresponding to the asialo form of transferrin was identified with electrophoresis with subsequent immunofixation and mass spectrometry (MALDI-TOF/TOF). Results: The intra-assay and inter-assay variations of the asialotransferrin value in CSF were 6.8% and 10.2%, respectively. Analysing CSF samples of 60 subjects (23 men aged 22–68 years and 37 women aged 18–77 years) with normal transferrin values and normal cytology as well as biochemistry parameters in the cerebrospinal fluid, and without apparent signs of neurological disorders, we have found the presence of 25.2 ± 8.2% asialotransferrin. Conclusion: Except for the need to obtain approximately 1.5 mL of cerebrospinal fluid and a tenfold concentrating of the sample, there is no need to conduct any modifications of the preparation procedure for the analytic sample and chromatographic separation normally used for serum samples. The HPLC method of asialotransferrin determination in CSF provides clinically useful results.

Diagnosis of alcohol-related neurological diseases by analysis of carbohydrate-deficient transferrin in serum.

Analysis of carbohydrate-deficient transferrin (CDT) in serum has been shown to be a good marker of current regular alcohol consumption at levels that are potentially harmful both to the liver and the nervous system. In this study CDT was analyzed by anion exchange chromatography and the results were evaluated in 134 consecutively examined patients with neurological symptoms of possible or probable alcohol-related etiology. A total of 22% of the patients were regarded as current alcohol abusers and 93% of them had elevated CDT values. The majority of these cases suffered from diseases such as epilepsy, neuropathies, cerebral atrophy/dementia and cerebellopathy. Most of them were still in a socially functioning condition. Low alcohol consuming patients and abstaining patients with a previous history of alcohol abuse had CDT levels within the normal range. The results demonstrated that determination of CDT is a valuable tool in the diagnosis of alcohol-related neurological disorders provided that its biological turnover is taken into account.

Determination of carbohydrate‐deficient transferrin in human serum by two capillary zone electrophoresis methods and a direct immunoassay: Comparison of patient data

Data obtained with two CZE assays for determining carbohydrate-deficient transferrin (CDT) in human serum under routine conditions, the CAPILLARYS CDT and the high-resolution CEofix (HR-CEofix) CDT methods, are in agreement with patient sera that do not exhibit interferences, high trisialo-transferrin (Tf) levels or genetic variants. HR-CEofix CDT levels are somewhat higher compared to those obtained with the CAPILLARYS method and this bias corresponds to the difference of the upper reference values of the two assays. The lower resolution between disialo-Tf and trisialo-Tf observed in the CAPILLARYS system (mean: 1.24) compared to HR-CEofix (mean: 1.74) is believed to be the key for this difference. For critical sera with high trisialo-Tf levels, genetic variants, or certain interferences in the beta-region, the HR-CEofix approach is demonstrated to perform better than CAPILLARYS. However, the determination of CDT with the HR-CEofix method can also be hampered with interferences. Results with disialo-Tf values larger than 3% in the absence of asialo-Tf should be evaluated with immunosubtraction of Tf and possibly also confirmed with another CZE method or by HPLC. Furthermore, data gathered with the N Latex CDT direct immunonephelometric assay suggest that this assay can be used for screening purposes. To reduce the number of false negative results, CDT data above 2.0% should be confirmed using a separation method.

Determination of carbohydrate-deficient transferrin in human serum with capillary zone electrophoresis: Sample preparation strategies for the removal of interferences caused by increased levels of immunoglobulins

Capillary zone electrophoresis (CZE) in fused-silica capillaries is an effective analytical approach for the separation and determination of the transferrin (Tf) isoforms and thus carbohydrate-deficient transferrin (CDT) in human serum. Sera of patients with progressed liver cirrhosis are prone to interferences in the β region which prevent the proper determination of CDT by CZE without additional sample preparation. Efforts to identify, reduce or even eliminate these interferences have been undertaken. Data obtained by ultrafiltration, affinity subtraction procedures using protein A, protein L and antibodies against immunoglobulins or Tf, and immunopurification of Tf suggest that the interferences in the patient sera are caused by increased levels of IgA and IgM and are best eliminated by immunopurification. Avian IgY antibody spin column immunocapture of serum Tf followed by CZE analysis of the stripped and concentrated fraction is shown to provide an attractive approach for CDT monitoring in sera with β region interferences.

Analysis of Carbohydrate-Deficient Transferrin: Comparative Evaluation of Turbidimetric Immunoassay, Capillary Zone Electrophoresis, and HPLC

Most assays for carbohydrate-deficient transferrin (CDT) (1)(2)(3) use cartridge extraction of CDT isoforms followed by immunoassay (4)(5). In 2001 the US Food and Drug Administration cleared the %CDT turbidimetric immunoassay (TIA; Axis Shield Plc) for detection of sustained and harmful alcohol use. Another method, based on anion-exchange HPLC separation of the CDT isoforms with direct detection at 460 nm [selective for the iron–transferrin (Tf) complex], was first developed by Jeppsson et al. (6) and adopted with minor changes by several authors, who reported advantages over immunoassays in terms of analytical selectivity, accuracy, and precision (7)(8)(9)(10). Recently released commercial reagents for HPLC analysis (Recipe®) offer advantages in interlaboratory analytical standardization. Capillary zone electrophoresis (CZE) with dynamically coated capillaries and direct ultraviolet detection at 200 nm (11)(12)(13)(14)(15)(16)(17) has also been successfully applied to CDT determination in human serum (2), and a CZE method with a proprietary capillary coating is commercially available (CEofix® CDT; Analis). Validation studies for each of these techniques have been reported in the literature, but no direct comparison studies have been published. We compared 3 commercial methods, based on TIA, CZE, and HPLC, focusing on their application to the diagnosis of chronic alcohol abuse in the forensic environment and in other areas requiring high diagnostic reliability and objectivity. CDT immunoassays were performed with a commercial reagent set (%CDT TIA) from Axis Shield on a BN2 nephelometer (Dade Behring), according to the manufacturer’s instructions. The procedure included iron saturation followed by CDT extraction onto anion-exchange disposable cartridges and a TIA. CZE was performed on a P/ACE MDQ capillary electropherograph (Beckman Coulter) with uncoated fused-silica capillaries [50 cm (total length) × 50 μm (i.d.)] obtained from Polymicro …

Determination of carbohydrate deficient transferrin (CDT) with capillary electrophoresis: an inter laboratory comparison

Carbohydrate deficient transferrin (CDT) is currently the most specific laboratory marker of chronic or sustained alcohol abuse. CDT is increasingly being used as a diagnostic tool in the areas employment, traffic safety and forensic medicine. In recent times, capillary electrophoresis (CE) has been proposed as a convenient tool for rapid, precise and accurate CDT determination, not only for research but also for routine analyses. Quite recently, commercial kits have been introduced which, reportedly, could simplify and standardize CDT analysis with capillary electrophoresis. The present work was aimed at testing the ruggedness of a capillary electrophoretic method based on a commercial kit (CEofix, Analis), by comparing the results obtained with different instruments in different laboratories, on a panel of sera randomly collected and exchanged. The results showed, notwithstanding few outliers, excellent correlation of the results obtained in the two laboratories (R=0.974). Also high concordance was found when results were classified as positive or negative on the basis of a cut-off (1.25%) established from a control group of teetotalers. In conclusion the present data support the usefulness of capillary electrophoresis for CDT determination for clinical, forensic and administrative diagnosis of chronic alcohol abuse.