Importance of HPLC confirmation of problematic carbohydrate-deficient transferrin (CDT) results from a multicapillary electrophoresis routine method

BackgroundThis study presents results from a routine laboratory setup for carbohydrate-deficient transferrin (CDT) measurement, using initial capillary electrophoresis (CE) analysis and, in problematic cases, further investigation by high-performance liquid chromatography (HPLC).MethodsCDT by the Capillarys CDT assay (disialo- and asialotransferrin) was measured on a Capillarys 2 multicapillary CE system (Sebia). In cases of abnormal peak profiles or other interferences in the electropherogram, samples were remeasured following sample cleanup by “Sample treatment” (Sebia). If the problems remained, or otherwise when confirmatory testing was considered important, samples were analysed by an HPLC candidate reference method.ResultsIn about 0.6% of the routine specimens, reanalysis was performed after sample cleanup. Confirmatory HPLC analysis was needed in half of the cases. Quantification problems were observed for genetic transferrin variants and samples showing a variety of abnormal peak profiles. In these cases, HPLC analysis provided accurate quantification, or at least an estimation (positive/negative), of the CDT level. Confirmatory HPLC analysis was also important for evaluation of borderline values, because only part of those cases were indicated to be true positives.ConclusionsThese results indicated that a routine laboratory setup for CDT measurement, using initial high-throughput multicapillary CE analysis with a confirmatory HPLC analysis option, will combine rapid quantitative and qualitative workflow with enhanced patient safety.