The characteristic pain crises and organ failure seen in sickle cell disease results from the abnormal red blood cells adhesion to the endothelium of small vessels and subsequent blood flow cessation. In September 15 Blood, Neil Matsui and colleagues from University of California at San Francisco describe a new cell adhesion mechanism involving the P-selectin molecule that could lead to improved treatments for sickle cell disease.

P-selectin is an adhesion protein present on activated endothelial cells. Matsui et al. found that P-selectin blocking monoclonal antibodies can inhibit the enhanced adherence of normal and sickle red blood cells to thrombin-activated endothelial cells. Both normal and sickle red cells also adhere to immobilized recombinant P-selectin (Blood 2001, 98:1955-1962).

"Animal studies and ultimately clinical trials will help us determine whether inhibiting P-selectin will prevent the clogging that leads to pain crises and organ failure in patients with sickle cell...