The impact of peripheral arterial disease on circulating platelets.
BACKGROUND
To test the hypothesis that circulating platelets display evidence of reversible interactions with atherosclerotic lesions, platelet alpha-granule content and propensity for microaggregate formation were measured in samples from normal donors (n=65) and from patients with either peripheral arterial disease (n=47) or renovascular hypertension (n=22). To measure the effect of a defined arterial injury on platelet function, platelet samples were compared before and 30 min after elective angioplasty.


METHODS
P-selectin was measured after strong stimulation of ultra-dilute platelets with thrombin (10 nM). Microaggregation was measured as a platelet count deficit in citrate-anticoagulated platelet-rich plasma (PRP) relative to that predicted from the count in EDTA-anticoagulated blood.


RESULTS
Platelet alpha-granule P-selectin was significantly lower from platelets of patients compared to normal donors. In addition, platelets from patients have a significantly greater propensity to form microaggregates in citrate anticoagulant. In contrast to atherosclerotic renovascular hypertension, platelets from patients with fibromuscular dysplasia, a distinct non-inflammatory cause of arterial stenosis, do not differ significantly from normal donors. Other than the PRP platelet count, which rose transiently following angioplasty, other platelet measures were unchanged by the injury.


CONCLUSIONS
Atherosclerotic arterial disease is associated with an increased share of platelets unable to express P-selectin and an increased fraction of platelets that microaggregate in citrate anticoagulant. These platelet alterations are not completely explained by either focal arterial injury or abnormal rheology associated with arterial stenosis but appear to be an effect of the atherosclerotic process.
McBane
Robert D
RD
Section of Hematology Research, Mayo Clinic and Foundation for Education and Research, Rochester, MN 55905, USA. mcbane.robert@mayo.edu
Karnicki
Krzysztof
K
Miller
Randall S
RS
Owen
Whyte G
WG
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000009:adverse effects; D001161:Arteriosclerosis / Q000097:blood* / Q000209:etiology / Q000473:pathology; D001792:Blood Platelets / Q000502:physiology*; D016022:Case-Control Studies; D003594:Cytoplasmic Granules / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000032:analysis; D016491:Peripheral Vascular Diseases / Q000097:blood* / Q000209:etiology / Q000473:pathology; D010973:Platelet Adhesiveness; D010974:Platelet Aggregation
D019007:P-Selectin