Expression of the genetic variants of human alpha-1-acid glycoprotein in cancer

Objectives: We have investigated the AAG and its genetic variants concentrations in plasma samples of 61 patients suffering from different types of cancers. Design and methods: The patients were shared out in three groups, breast, lung, and ovary cancers groups. AAG concentration was measured by an immunonephelometric method and the phenotype was determined, after desialylation of plasma by analytical isoelectric focusing. Detection of AAG variants was made by immunoblotting and their proportions were determined by laser densitometry analysis. A population of 74 healthy individuals served as controls. Results: The plasma concentrations of AAG in the breast and lung cancer groups were 2.5 times increased, while in the ovary cancer group, the concentrations were 1.6 times increased. AAG concentrations in the cancer population ranged between 0.45 and 2.85 g/L (mean value 1.12 +/- 0.51 g/L). The proportions of the ORM1 and ORM2 variants were similar to those in the healthy population. In breast and lung cancer groups, the relative concentrations of genetic variants were increased more than 2.5 fold, whereas a 1.6-fold increase was observed in the ovary cancer group. Conclusions: These results show that AAG plasma concentrations are increased in these types of cancers and that changes in the expression of the genetic variants of AAG could also occur according to the type of cancer. Copyright (C) 2000 The Canadian Society of Clinical Chemists.