Inconsistency of different methods for assessing ex vivo platelet function: relevance for the detection of aspirin resistance.
Haematologica
; 95(12): 2095-101, 2010 Dec.
Article
em En
| MEDLINE
| ID: mdl-21123440
ABSTRACT
BACKGROUND:
Assays to evaluate platelet function are often interchangeably used to assess "resistance" to aspirin. We compared different platelet function assays in patients treated or untreated with aspirin. DESIGN ANDMETHODS:
Platelet function was evaluated in 162 subjects, 85 of whom were not being treated with any antiplatelet drug and 77 of whom were receiving chronic therapy with low-dose aspirin. Platelet Function Analyzer collagen/ADP- and collagen/epinephrine closure times, as well as light transmittance aggregometry in response to ADP, collagen and arachidonic acid (this last in 47 aspirin-treated patients) were determined. In 43 aspirin-treated patients, serum thromboxane B(2) levels were also measured.RESULTS:
In untreated patients, collagen/ADP- and collagen/epinephrine-closure times were correlated with each other (r=0.5, P=0.0001), but did not correlate with ADP- or collagen-induced aggregation. In patients treated with aspirin, collagen/ADP-closure time values were not different from those in untreated patients, while the collagen/epinephrine-closure time was prolonged. ADP-induced aggregation was unaffected by aspirin, while collagen-induced aggregation was reduced. Arachidonic acid-induced aggregation was almost completely suppressed (% maximum light transmittance aggregometry =5 ± 13%). There was, however, no correlation between the various platelet function tests. Serum thromboxane B(2), an index of platelet cyclooxygenase-1 activity, was almost completely suppressed (down to 8 ± 17 ng/mL) in treated patients, and was not correlated with arachidonic acid-, ADP- and collagen-induced aggregation or with collagen/ADP-closure time, but was inversely correlated with collagen/epinephrine-closure time.CONCLUSIONS:
There is a high heterogeneity of results of tests evaluating inhibition of platelet function by aspirin, and the results of functional tests do not match biochemical measurement of cyclooxygenase-1 activity. Extreme caution should, therefore, be used in defining "resistance" to aspirin on the basis of the results of these tests.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Testes de Função Plaquetária
/
Plaquetas
/
Agregação Plaquetária
/
Aspirina
Tipo de estudo:
Diagnostic_studies
Limite:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article