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


METHODS
Platelet rich plasmas (300 x 10(9) 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.


METHODS
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.


METHODS
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.
Cornell
Robert F
RF
Department of Clinical Laboratory Science, Saint Louis University Health Sciences Center, St Louis MO 63104, USA.
Randolph
Tim R
TR
D000244:Adenosine Diphosphate / Q000737:chemistry; D000293:Adolescent; D000328:Adult; D005260:Female; D005340:Fibrinogen / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology*; D010979:Platelet Function Tests / Q000379:methods*
D000244:Adenosine Diphosphate; D005340:Fibrinogen