Immunohistochemical localization of α2-β1-glycoprotein in horses

SUMMARY Alpha 2-(β1-glycoprotein may be found free in horse serum or complexed with α-1-proteinase inhibitor to form pre-α2-elastase inhibitor. There has been little information published concerning α2-β1-glycoprotein and its possible tissue sources in horses. A peroxidase-antiperoxidase technique was used to identify α2-(β1 -glycoprotein in buffy coat and bone marrow neutrophils of healthy horses. Macrophages and neutrophils in bronchoalveolar lavage samples from clinically normal horses and from horses with chronic pulmonary disease also were positive for α2-(β1-glycoprotein. Alpha 2-β1-glycoprotein was identified in some instances in normal equine hepatocytes of formalin- fixed liver sections. In formalin-fixed lung sections from horses with chronic, small-airway disease and chronic bronchointerstitial pneumonia, α2-β1-glycoprotein was observed in some airway secretions and in macrophages.