M. Galifi et al., INSTRUMENTAL REPORTS AND EFFECT OF ANTICOAGULANTS IN A CASE OF NEUTROPHIL AGGLUTINATION IN-VITRO, Haematologica, 78(6), 1993, pp. 364-370
Background. The aim of this study was to investigate a case of E-DTA-i
nduced polymorphonuclear leukocyte (PMN) agglutination in vitro on Bay
er Technicon H1. Coulter Counter STKS and STKR analyzers. Methods. Ve
nous whole blood was anticoagulated with K-3 . EDTA, sodium citrate, l
ithius heparinate, acid citrate dextrose (ACD) and with two other anti
coagulant mixtures containing citric acid-theophylline-adenosine-dipyr
idamole (CTAD) or citrate-pyridoxal 5'-phosphate-tris (CPT). Results.
PMN agglutination, EDTA - but not temperature - dependent, was found b
y mere chance in an asymptomatic 48-year-old Caucasian male who did no
t show detectable PMN antibodies. Pseudoneutropenia without pseudoleuk
openia was registered on HI exclusively in EDTA anticoagulated blood
with a characteristic higher density PMN population on the BASO cytogr
am. Spuriously low white blood cell (WBC) counts and pseudoneutropenia
appeared on STKR and STI(S in E-DTA anticoagulated blood, but signals
on PMN agglutination were unsatisfactory. Accurate total and differen
tial WBC counts were obtained in CTAD or CPT anticoagulated samples on
the three analyzers. Heparin was the worst choice because it induced
pseudothrombocytopenia and pseudoleukocytosis on STKR and STKS. Conclu
sions. Since PMN agglutination was not observed on peripheral smears a
nd was undetected on EDTA anticoagulated samples processed immediately
by H1, the presence in vivo of PMN clumps should be excluded. Furthe
r hematological investigations will demonstrate in the long run whethe
r the observed PMN agglutination in vitro is a transient occurrence in
an apparently healthy subject not taking drugs at the time of observa
tion.