Performance evaluation of platelet counting of Abbott Alinity hq and Sysmex XN-9000 automated hematology analyzer...

Accurate platelet counting is essential for risk assessment of bleeding and thrombosis. Abbott Alinity hq hematology analyzer was recently introduced, and its performance in platelet counting has yet to be evaluated comprehensively. In this study, we evaluated the performance of the optical platelet counting of Abbott Alinity hq (Alinity-PLT) and the impedance and fluorescent platelet counting of Sysmex XN-9000 (XN-PLT-I and XN-PLT-F) compared with the international reference method.

Blood samples were analyzed via Alinity hq and XN-9000 with PLT-F channel. Immuno-platelet (ImmnoPLT) reference method was performed with CD41/CD61 antibodies using FACSLyric^TM flow cytometer (BD). Precision was determined using 10 replicates in a single run, and the platelet counts of Alinity-PLT, XN-PLT-I, XN-PLT-F, and ImmnoPLT were compared.

At a platelet count of 13 × 10⁹ /L, the CVs of Alinity-PLT, XN-PLT-I, and XN-PLT-F were 4.2%, 6.7%, and 4.3%, respectively, and at a platelet count of 44 × 10⁹ /L, all showed a CV of less than 3%. For the total 210 samples, all three methods showed a very strong correlation with ImmunoPLT (r > 0.99). For platelet levels below 20 × 10⁹ /L, XN-PLT-F showed the strongest correlation with ImmunoPLT (r = 0.975), and for platelet levels of 20-100 × 10⁹ /L, Alinity-PLT and XN-PLT-I were comparable to ImmunoPLT. For platelet levels of 100-450 × 10⁹ /L, XN-PLT-I was the most comparable to ImmunoPLT, and for platelet levels above 450 × 10⁹ /L, Alinity-PLT was comparable to ImmunoPLT.

All three methods were highly correlated with ImmunoPLT, and each method had different performance advantages according to the platelet levels.