Primary biliary cirrhosis is not a clinical condition for increased carbohydrate-deficient transferrin: Experience with four independent CDT analysis methods

Background: Primary biliary cirrhosis (PBC) is considered as an important cause for increased carbohydrate-deficient transferrin (CDT). The underlying pathomechanism is difficult to explain by the pathogenesis and/or consequences of PBC. We tested whether PBC causes increased CDT results with current CDT analysis methods and, if so, whether this depends on the CDT analysis principle. Methods: 48 serum samples from PBC patients were analyzed by HPLC, microcolumn CDT and non-CDT fractionation followed by a turbidimetric immunoassay, particle-enhanced immunonephelometry with monoclonal CDT antibodies, and capillary electrophoresis. The test-specific decision limits were used for categorization of the CDT analysis results into normal and increased values. Results: HPLC: 47 normal/1 increased, microcolumn + TIA: 46 normal/2 increased, particle-enhanced immunonephelometry: 41 normal/7 increased, capillary electrophoresis: 48 normal CDT results. After combining an immunological CDT test (microcolumn + TIA or particle-enhanced immunonephelometry) as the screening method with a physico-chemical CDT test (HPLC or electrophoresis) as the confirmatory method, I case remained with increased CDT values by the screening (value 2.6%, cut-off 2.5%, particle-enhanced immunonephelometry) and confirmatory (value 1.8%, cut-off 1.75%, HPLC) analysis. Conclusions: PBC should no longer be overstressed as an important cause for false-positive CDT results regarding chronic alcohol abuse. In the presence of odd CDT results, PBC should be considered in the anamnestic exploration. However, PBC is not by itself a cause for increased CDT values. (c) 2006 Elsevier B.V All rights reserved.