[Evaluation of the reproducibility of automated monocyte counting using flow cytometry and monoclonal antibodies].
OBJECTIVE
To compare the results of the monocyte count provided by autoanalysers with those attained with flow cytometry.


METHODS
Fifty-six blood samples (EDTA-K3) from the emergency laboratory were studied. The automatic percentage of monocytes attained by four autoanalysers, STKS (Coulter-IZASA), Technicon H*2 (Bayer Diagnostics), Cell-Dyn-3000 (Abbott Diagnostics) and NE-8000 (TOA-Sysmex) was confronted with that provided by the flow cytometry analysis performed with a FACScan (Becton-Dickinson) using monoclonal antibodies of myeloid-monocytic lineage (CD14, CD16). The morphologic observation of the blood smear in accordance with the H20-A protocol of the National Committee for Clinical Laboratory Standards (NCCLS) was used as a reference method. Descriptive statistics plus linear regression analysis, along with the Student's t test for paired data were used for the statistical evaluation of the results.


RESULTS
Significant correlation was found between the systems under study and the flow cytometry method: Technicon H*2 (y = 1.79 +/- 0.61x; r = 0.91, p < 0.0001), Coulter STKS (y = 0.61 +/- 0.93X; r = 0.89, p < 0.0001), Cell-Dyn 3000 (y = 0.88 + 0.64x; r = 0.78, p < 0.0001) and Sysmex NE-8000 (y = 4.60 +/- 0.33x; r = 0.52, p < 0.0001). When comparing the percentage of monocytes by means of the Student's t test it was found that Coulter STKS provided the closest results with regard to flow cytometry (13.78 +/- 9.27 vs 14.19 +/- 8.88, p = 0.49), while the closest findings with respect to the reference method were given by Technicon H*2 (9.29 +/- 4.78 vs 9.71 +/- 4.77, p = 0.30).


CONCLUSIONS
From this analysis, it was concluded that flow cytometry could be an alternative method to conventional optic observation in the evaluation of the differential count of leucocytes, including monocytes.
Vives Corrons
J L
JL
Servei d'Hematologia Biològica, Hospital Clínic i Provincial, Universitat de Barcelona.
Besson
I
I
Villamor
N
N
Aymerich
M
M
Marín
J L
JL
Jou
J M
JM
D000911:Antibodies, Monoclonal / Q000276:immunology*; D001322:Autoanalysis / Q000295:instrumentation; D048429:Cell Size; D005069:Evaluation Studies as Topic; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping / Q000295:instrumentation / Q000379:methods; D007958:Leukocyte Count / Q000295:instrumentation / Q000379:methods*; D009000:Monocytes; D012015:Reference Standards; D015203:Reproducibility of Results
D000911:Antibodies, Monoclonal
Evaluación de la fiabilidad del recuento automático de monocitos mediante citometría de flujo y anticuerpos monoclonales.