Exclusion of trisialo-transferrin from carbohydrate-deficient transferrin measurement: advantage in patients with chronic liver disease?

BACKGROUND

Biological markers for chronic alcohol consumption like MCV or gammaGT or carbohydrate deficient transferrin (CDT) are useful, but far from being perfect. In patients with liver disease a reliable marker for chronic alcohol consumption as the underlying etiology is highly needed. Recently, a new ELISA based version of the carbohydrate-deficient-transferrin (CDT-TRISIALO (-)) assay has been developed, which measures asialo-, monosialo- and disialo transferrin, but excludes trisialo- transferrin; that modification suggests higher sensitivity and specificity in detecting recent alcohol consumption in patients.

AIMS

The study goal was to evaluate the sensitivity, specificity, positive and negative predicitive value of this new carbohydrate-deficient-transferrin assay (CDT-TRISIALO (-)) in a group of patients with liver disease and to compare the results with that of the established CDT assay (CDT-TRISIALO (+)).

PATIENTS AND METHODS

Our study population consisted of 110 consecutive patients (male: n = 80 [72.7 %], female: n = 30 [27.3 %]) with liver disease of the following etiologies: chronic alcohol consumption (n = 51 [46.4 %]; Out of them 30 alcohol abusing patients were assessed by cage = 1 and 21 alcohol dependent patients were assessed by cage = 2, chronic viral hepatitis (n = 33 [30.0 %]) including 25 [22.7 %] patients with chronic hepatitis C infection and 8 [7.3 %] patients with chronic hepatitis B infection), haemochromatosis (n = 4 [3.6 %]), mechanical cholestasis (n = 17 [15.5 %]) and other liver diseases (n = 5 [4.6 %] including autoimmune hepatitis (n = 2) and primary biliary cirrhosis (n = 3)). 27.3 % of our patients (n = 30) had no liver cirrhosis whereas the majority (72.7 %, n = 80) had liver cirrhosis.

RESULTS

In our population of liver disease patients the CDT-TRISIALO (-) assay had a sensitivity of 72.7 % and specificity of 58.1 % for recent alcohol consumption at the published cutoff level of 2.6 %. The positive predictive value was 34.0 % and the negative predictive value was 87.8 %. Sensitivity and specificity of the CDT-TRISIALO (+) assay at the recommended cutoff level of 4.7 % were similar, 77.3 % and 49.3 %, respectively. The positive and negative predictive values were 30.9 % and 88.1 %. CDTTRISIALO (+) and CDT-TRISIALO (-) levels increased significantly with higher Child-Pugh stages.

CONCLUSION

The newly developed carbohydrate deficient transferrin test (CDT-TRISIALO (-)) is of no advantage as compared to the established assay (CDT-TRISIALO (+)) when used in a patient population with liver disease. In that population, normal CDT-TRISIALO (-) helps to exclude recent alcohol consumption; this results from the high negative predictive value of a normal CDT-TRISIALO (-).