Microheterogeneity of orosomucoid in pathological conditions.

Studies of orosomucoid (alpha 1-acid glycoprotein) in human serum have revealed that orosomucoid is a mixture of molecules with differences in the glycan chains. This microheterogeneity has been studied using crossed affinoimmuno-electrophoresis with the lectin concanavalin A which binds to biantennary glycans. The relative proportions of the three orosomucoid subtypes are altered in various pathological conditions independently of the total serum orosomucoid concentration. There are reproducible differences in microheterogeneity patterns between some pathological conditions: Acute tissue injury or inflammation results in a high proportion of orosomucoid with biantennary glycans. Conditions with increased estrogen levels are associated with a high proportion of orosomucoid with tri- or tetraantennary glycans and a low total serum orosomucoid concentration. Chronic inflammation also seems to be associated with a high proportion of orosomucoid with tri- or tetraantennary glycans but with a high total serum concentration of orosomucoid. Other diseases, such as cancer, can not be associated with any specific microheterogeneity pattern. The microheterogeneity pattern in these conditions seems to be determined by disease activity and unspecific inflammation in surrounding tissues.