This study sought to investigate changes in the expression of activation-dependent
adhesion receptors on neutrophils and platelets after exposure to the balloon-injured
coronary artery plaque.
Activation of blood cells at the balloon-injured coronary artery plaque may contribute
to abrupt vessel closure and late restenosis after percutaneous transluminal coronary
In 30 patients undergoing elective coronary angioplasty, blood specimens were obtained
through the balloon catheter proximal to the plaque before dilation and distal to
the plaque after dilation. Simultaneous blood samples obtained through the guiding
catheter served as control samples. Total surface expression of the inducible fibrinogen
receptor (CD41) and surface expression of the activated fibrinogen receptor (LIBS1)
on platelets as well as Mac-1 (CD11b) and L-selectin (CD62L) surface expression on
neutrophils were assessed by flow cytometry.
After exposure to the dilated coronary artery plaque, surface expression of LIBS1
on platelets increased by 40.5 +/- 11.0 mean (+/-SE) fluorescence (p=0.001) and that
of CD11b on neutrophils increased by 20.1 +/- 4.4 mean fluorescence (p=0.018). Concomitantly,
anti-CD62L binding on neutrophils decreased by 6.6 +/- 2.4 mean fluorescence (p=0.022).
In contrast, surface expression of the adhesion receptors did not change significantly
between the coronary ostium and the prestenotic coronary segment.
The results of this study demonstrate neutrophil and platelet activation at the balloon-injured
coronary artery plaque. This cellular activation may serve as a target for pharmacologic
interventions to improve the outcome of coronary angioplasty.