Found in human plasma in concentrations of 55-140 mg per 100 ml. Classical standard glycoprotein for studies on the structure of the oligosaccharide units. Carbohydrate content is 40%. Its biological significance is unknown although it can bind progesterone 15 times as strongly as albumin. Sialic-acid-deficient alpha-1-AG has an affinity for vitamin B-12. Clinically, alpha 1 acid glycoprotein is an acute-phase reactant that together with haptoglobin is an indicator of acute inflammation. The alpha 1 acid glycoprotein: haptoglobin ratio is useful in studies of bone marrow disorders, hemolytic processes and metastases.
