Increased plasma levels of soluble CD40 ligand correlate with platelet activation markers and underline the need for standardized pre-analytical conditions.
OBJECTIVE
To investigate whether sCD40L dosage might represent a useful tool to explore in vivo platelet function.


METHODS
sCD40L and sP-selectin levels and light transmission aggregometry (LTA) were analyzed in 69 healthy donors. Immunoassays were performed on platelet-depleted citrate plasma samples. The effects of in vitro aspirin treatment on the release of sCD40L were investigated in 15 subjects following platelet stimulation. The effects of a 1-month therapeutic course of low-dose aspirin on sP-selectin and sCD40L levels were also investigated.


RESULTS
A significant correlation was observed between sCD40L and sP-selectin (p<0.01). In vitro aspirin treatment remarkably decreased sCD40L levels following platelet activation by exogenous agonists. sCD40L directly correlated with LTA (Rho=0.62, p<0.0001). In vivo aspirin treatment significantly reduced both sP-selectin and sCD40L levels (both p<0.01) in a direct correlation (Rho=0.66, p<0.05).


CONCLUSIONS
Citrated plasma samples reflect sCD40L released from platelets, thus yielding the most valid estimates of in vivo circulating levels of this platelet activation markers.
Riondino
Silvia
S
Department of Laboratory Medicine and Advanced Biotechnologies, IRCCS San Raffaele, Rome, Italy.
Martini
Francesca
F
La Farina
Francesca
F
Spila
Antonella
A
Guadagni
Fiorella
F
Ferroni
Patrizia
P
D000328:Adult; D000368:Aged; D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D023201:CD40 Ligand / Q000097:blood*; D005260:Female; D006801:Humans; D007118:Immunoassay; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood*; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology
D019007:P-Selectin; D010975:Platelet Aggregation Inhibitors; D023201:CD40 Ligand; D001241:Aspirin