Is automated platelet counting still a problem in thrombocytopenic blood?
BACKGROUND
Reliable platelet counting is crucial for indicating prophylactic platelet transfusion in thrombocytopenic patients.


OBJECTIVE
To evaluate the precision and accuracy of platelet counting for thrombocytopenic patients, using four different automated counters in comparison with the Brecher & Cronkite reference method recommended by the International Committee for Standardization in Hematology (ICSH).


METHODS
Automated platelet counting assessment in thrombocytopenic patients.


METHODS
Hematology Laboratory, Hospital do Servidor Público Estadual de São Paulo, and the Hematology Division of Instituto Adolfo Lutz, São Paulo, SP, Brazil.


METHODS
Brecher & Cronkite reference method and four different automated platelet counters.


METHODS
43 thrombocytopenic patients with platelet counts of less than 30,000/microliter.


RESULTS
The ADVIA-120 (Bayer), Coulter STKS, H1 System (Technicom-Bayer) and Coulter T-890 automatic instruments presented great precision and accuracy in relation to laboratory thrombocytopenic samples obtained by diluting blood from normal donors. However, when thrombocytopenic patients were investigated, all the counters except ADVIA (which is based on volume and refraction index) showed low accuracy when compared to the Brecher & Cronkite reference method (ICSH). The ADVIA counter showed high correlation (r = 0.974). However, all counters showed flags in thrombocytopenic samples.


CONCLUSIONS
The Brecher & Cronkite reference method should always be indicated in thrombocytopenic patients for platelet counts below 30,000 plt/microliter obtained in one dimensional counters.
Oliveira
Raimundo Antônio Gomes
RA
Hematology Laboratory, Hospital do Servidor Público, Hematology Division, Instituto Adolfo Lutz, São Paulo, Brazil. ocdobarr@usp.br
Takadachi
Maria Mariko
MM
Nonoyama
Kimiyo
K
Barretto
Orlando César de Oliveira
OC
D001938:Brazil; D005434:Flow Cytometry; D006801:Humans; D010976:Platelet Count / Q000295:instrumentation* / Q000379:methods*; D017713:Platelet Transfusion; D012015:Reference Standards; D015203:Reproducibility of Results; D013921:Thrombocytopenia / Q000097:blood*