In vitro leukopenia may occur on blood samples. This is similar to EDTA-dependent pseudothrombocytopenia (see above), but has been noted with several types of anticoagulants.


Laboratory features:

(1) The automated white blood cell count on a blood sample indicates leukopenia or is significantly different from previous recent values.

(2) The white blood cell count by a diluted manual leukocyte count.

(3) The peripheral blood smear prepared from the sample with the leukopenia shows clumps of neutrophils which are absent in direct smears of peripheral blood.



• This may not be recognized if the white blood cell count is not low or if there are not other white blood cell counts to compare to.


The reaction occurred with samples collected in:

(1) EDTA

(2) heparin

(3) sodium citrate


To read more or access our algorithms and calculators, please log in or register.