Variables that Influence Platelet Function Analyzer-100™ Closure Times in Healthy Algerian Adults

CONTEXT: The Platelet Function Analyzer (PFA-100™) assesses primary hemostasis in vitro under high shear stress to simulate the conditions to which platelets are exposed at the site of an injured blood vessel wall. AIMS: We investigated preanalytical variables in healthy Algerian adults, and we also assess the performance of the test. SUBJECTS AND METHODS: Closure time (CT) was measured in 302 well-characterized healthy Algerian adults with the collagen/epinephrine (CEPI) and the collagen/adenosine diphosphate (CADP) cartridges. RESULTS: Age and sex did not affect CT values. Blood group O was associated significantly with longer CEPI CT and CADP CT than non-O groups (P ≤ 0.0001 for both). CTs were shorter in samples collected in the morning vs the afternoon (P < 0.0001 for both). We found a strong positive correlation between CT CEPI and CT CADP with r = 0.72 and P < 0.001 and an inverse mean correlation between von Willebrand factor level and CT with r = −0.56, r = −0.45 for CT CEPI and CT CADP, respectively P < 0.001. Duplicate analysis of PFA-100™ CT revealed a mean difference of 3.6% ±19.1% for the CEPI cartridge and 1.5% ±10% for the CADP cartridge. The mean coefficient of variation was 7.4% for the CADP CT and 7.6% for the CEPI CT. No marked difference between test positions. CONCLUSIONS: The PFA-100™ showed good reproducibility. The variables influencing the test in healthy Algerian adults are similar to Western and Asian populations. Standardization of preanalytical and analytical conditions is essential for obtaining reliable PFA-100™ results.