The Minimum Concentration of Fibrinogen Needed for Platelet Aggregation using ADP

Robert F Cornell; Tim R Randolph

doi:10.29074/ascls.15.1.30

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Robert F Cornell II
1. was a student in the Department of Clinical Laboratory Science, Saint Louis University Health Sciences Center, St Louis MO when this research was done
Tim R Randolph, MS⇑
1. is an Assistant Professor in the Department of Clinical Laboratory Science, School of Allied Health Professions, Saint Louis University Health Sciences Center, St Louis MO

Address for correspondence: Tim R Randolph MS, Saint Louis University School of Allied Health Professions, Department of Clinical Laboratory Science, Room 3096, 3437 Caroline St, St Louis MO 63104. (314) 577-8518, (314) 577-8503 (fax). randoltr{at}slu.edu

Abstract

OBJECTIVE: Determine the minimum concentration of plasma fibrinogen needed to stimulate the aggregation of platelets, collected from normal subjects, using ADP.

DESIGN: Platelet rich plasmas (300 x 10⁹ platelets/L) were made and adjusted to final fibrinogen concentrations of 75, 19, 5, and 0 mg/dL using fibrinogen free serum. Each fibrinogen concentration in all twelve subjects was aggregated with ADP.

SETTING: Research laboratory in the Department of Clinical Laboratory Science at Saint Louis University.

PARTICIPANTS: Twelve healthy volunteers of both genders, between the ages of 18 and 60 years who were not pregnant and weighed at least 110 pounds were included in the study. Subjects were excluded from the study if they had ingested aspirin within one week prior to blood collection. In addition, subjects with a history of bleeding disorders such as afibrinogenemia, hypofibrinogenemia, von Willebrand disease, and Bernand-Soulier disease were rejected from the study.

MAIN OUTCOME MEASURES: Platelet aggregation tracings were analyzed for amplitude and compared across plasma fibrinogen concentrations. In addition, the type of curve (monophasic vs. biphasic), smoothness and aggregation stability were also noted.

RESULTS: The results show that aggregation occurred with every dilution of fibrinogen tested and that the amplitude of the aggregation curves appears not to be dependent on plasma fibrinogen.

CONCLUSIONS: The results indicate that platelets from healthy individuals previously exposed to normal fibrinogen levels will aggregate equally well in decreasing plasma fibrinogen concentrations and even in the absence of plasma fibrinogen using ADP as the aggregator.

ABBREVIATIONS: ADP = adenosine diphosphate; PPP = platelet poor plasma; PRP = platelet rich plasma; vWF = von Willebrand Factor.