Comparison of alpha-1-acid glycoprotein isoforms from healthy and cancer patients by capillary IEF.

alpha-1-Acid glycoprotein (AGP) is a glycoprotein that presents different forms in the same individual, depending on the amino acid sequence and/or on the carbohydrate distribution of each form. Changes in these two types of heterogeneities are related to pathophysiological states. The aim of this work is to study the possibility of comparing AGP samples in terms of their CIEF profiles, what would facilitate in a future to perform studies about the role of AGP as a disease marker. In the present study, the CIEF profiles of AGP samples purified from sera of healthy donors and of ovary cancer and lymphoma patients are qualitatively and quantitatively compared. To make possible the comparison of those electrophoretical profiles, reliable assignment of AGP peaks is necessary. A computer program developed in our laboratory is used to select the migration parameters that make possible an accurate assignment of AGP peaks. Percentages of correct assignment of AGP peaks using the migration time of each peak relative to the migration time of an internal standard close to 95% are achieved. After peak assignment, a different distribution of the area percentage of AGP forms is observed when comparing samples from diseased and healthy individuals, the most acidic AGP forms being present in a higher proportion in the samples from cancer patients. Although the number of samples studied is too low to get any clinical significance from these results, this work provides a way to study the role of AGP as a biomarker.