Evaluation of the degree of desialylation of serum C1-inactivator and haemopexin.

The calibration curves for evaluating the degree of desialylation of C1-inactivator (sialic acid content 12.5%) and haemopexin (sialic acid content 4%) have been plotted. No desialylation of either glycoprotein occurs in normal subjects. In the patients (liver damage) studied, C1-inactivator is often desialylated, whereas haemopexin is not. In a previous report, we had shown that alpha1-acid glycoprotein is more often desialylated than alpha1-antitrypsin. Thus, it appears that the degree of desialylation of the sialic acid-rich glycoproteins is a more sensitive index of the severity of hepatic injury than that of the sialic acid-poor glycoproteins. This could be due to a defect in the sialylation process during synthesis.