Interference of blood leucocytes in the measurements of immature red cells (reticulocytes) by two different (semi-) automated flow-cytometry technologies.
Flow cytometrical methods have been introduced recently as an alternative to the enumeration of reticulocytes by microscopy. Two of these methods have gained widespread use in haematological practice; the multiparametric flow cytometer using thiazole orange staining (Retic-Count, FACScan) and the single-application reticulocyte counter using auramine-O staining (R-series, Sysmex). Several studies have emphasized the excellent correlations between microscopy and these techniques. The purpose of our study has been to examine the specificity of these automated devices with regard to cells classified as 'reticulocytes' and the effect that this may have on measures of reticulocyte maturity. Our results indicate that the specificity of reticulocyte measurements by both the Sysmex R-1000/-3000 and the Retic-Count system is relatively low. This is due to the presence of leucocytes amongst cells classified as reticulocytes. These leucocytes display intense staining with either dye, leading to an erroneous estimation of RMI (thiazole orange) and high fluorescence count (R-1000/-3000). This error is directly correlated with the leucocyte count. The basis for reticulocyte identification should be improved before automated estimation of reticulocyte maturation can be used in clinical practice.
Villamor
N
N
Virchow-Klinikum, Medizinische Fakultat der Humboldt-Universitat zu Berlin, Germany.
Kirsch
A
A
Huhn
D
D
Vives-Corrons
J L
JL
Serke
S
S
D001331:Automation; D001576:Benzophenoneidum; D052160:Benzothiazoles; D004247:DNA / Q000097:blood; D005189:False Positive Reactions; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006801:Humans; D018189:Immunomagnetic Separation; D007962:Leukocytes; D010078:Oxazines; D011804:Quinolines; D012313:RNA / Q000097:blood; D017701:Reticulocyte Count / Q000295:instrumentation / Q000379:methods*; D012984:Software; D013194:Staining and Labeling; D013844:Thiazoles
D052160:Benzothiazoles; D005456:Fluorescent Dyes; D010078:Oxazines; D011804:Quinolines; D013844:Thiazoles; C051000:thiazole orange; D001576:Benzophenoneidum; C006797:Brilliant Cresyl Blue; D012313:RNA; D004247:DNA