There is evidence that corticosteroid treatment may alter platelet adhesion, in a study of spontaneously hypertensive rat (SHR) increased circulating glucocorticoid, suppressed p-selectin expression. p selectin is a transmembrane protein present in the α granules of platelets. P selectin has a crucial role in platelet aggregation and platelet-leukocyte interactions, which are both potentially important mechanisms in the initiation and/or progression of tissue injury and development of thrombosis. In a study of patients with chronic obstructive pulmonary disease (COPD) exacerbation these were treated with either β agonists alone or β agonist and 40mg prednisolone and compared with a control group. At presentation the COPD patients had higher pulmonary artery pressure (PAP) higher p selectin and fibrinogen levels but lower Antithrombin III levels (AT III). The pulmonary artery pressure and fibrinogen levels were found to be significantly decreased in the steroid treated group whilst the p-selectin levels further increased in the non steroidal therapy patients.