Platelet Reactivity and Non-Reactivity in Native Americans — 19a — Mikayla Bendix, Pierce Cunningham

Platelets are cellular components of the blood that activate in response to vascular damage and maintain hemostasis via their role in clot formation to prevent blood loss. Under pathological conditions, platelet activation can lead to obstructive clots that prevent blood flow and can lead to thrombosis. Previous research has shown that certain ethnicities have enriched genetic polymorphisms that correlate to heightened platelet reactivity, which in turn leads to an increased risk of thrombosis. Native Amercians are another ethnicity with increased risk of cardiovascular disease; however, there has never been a systematic approach to studying their platelet reactivity. We set out to replicate the results of a previous pilot study that showed approximately one third of a small sample of Native Americans had much higher platelet reactivity in response to treatment with various agonists. We also wanted to establish demographic and genetic factors behind this higher level of response. We sampled 60 Native American subjects and incubated their diluted whole blood with high and low dose concentrations of four agonists present after vascular damage and two platelet activation markers before flow cytometric analysis. Our findings correlated with those of the previous pilot study, with approximately one third of subjects showing an elevated platelet response to both markers. This data will allow us to make future correlations to demographic and genetic factors. However, about 50% of the subjects surprisingly did not show any response to the agonists. Non-responders were much more likely to be male. This suggests the presence of at least two populations of differing platelet reactivity in Native Americans: one of which shows individuals with heightened platelet responses to agonists, while the other doesn’t respond at all.

Augustana University
Dr. Mark Larson