Factors influencing transfusion-associated HLA sensitization in patients bridged to heart transplantation using ventricular assist device.

Background: Bridging heart failure patients with mechanical ventricular assist devices (VAD) enables access to transplantation. However, VAD is associated with increased risk for anti-HLA antibodies associated with rejection of subsequent allografts. Factors determining alloantibody formation in these patients remain undefined.

ADP receptor P2Y12 is expressed in vascular smooth muscle cells and stimulates contraction in human blood vessels.

Objective: ADP plays an important role in platelet aggregation by activating P2Y12 receptors. We assessed the hypothesis that P2Y12 receptors are expressed in vascular smooth muscle cells (VSMC).

Methods And Results: P2Y12 receptor mRNA was found to have a high expression among the P2 receptors in human VSMC, significantly higher than the other 2 ADP receptors (P2Y1 and P2Y13, real-time polymerase chain reaction).