Cytocentrifugation conditions affecting the differential cell count in bronchoalveolar lavage fluid.
OBJECTIVE
To investigate variations in speed, duration and acceleration rate of the Cytospin 3 cytocentrifuge (Shandon Scientific Ltd., Astmoor, England) on the differential cell count of bronchoalveolar lavage (BAL) fluid samples.


METHODS
BAL fluid samples (n = 51) were cytocentrifuged at various combinations of speed (500, 1,200 and 2,000 rpm), acceleration rate (low, medium and high) and duration (5, 10, 15 and 20 minutes). The preparations were May-Grünwald-Giemsa stained and differentiated on 500 cells. Data were analyzed by mixed model repeated measurements ANOVA.


RESULTS
The mean lymphocyte count was significantly higher at 1,200 rpm than at 500 rpm, whereas the macrophage count decreased. Between 1,200 and 2,000 rpm, the number of both cell types stabilized. Significantly higher numbers of lymphocytes were recorded at 10 and 15 minutes of cytocentrifugation than at 5 minutes. The acceleration rate did not influence the differential cell count. Seventeen BAL fluid samples were selected to test the diagnostic impact of cell damage using a validated computer program. In 1 of 17 samples the predicted diagnosis did not correspond between two different speeds (500 and 2,000 rpm).


CONCLUSIONS
Variations in cytocentrifugation speed and duration affected the mean lymphocyte and macrophage counts of BAL fluid samples.
De Brauwer
E I
EI
Department of Medical Microbiology, University Hospital Maastricht, The Netherlands.
Jacobs
J A
JA
Nieman
F
F
Bruggeman
C A
CA
Wagenaar
S S
SS
Drent
M
M
D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D002498:Centrifugation / Q000379:methods*; D003936:Diagnosis, Computer-Assisted; D003937:Diagnosis, Differential; D006801:Humans; D016015:Logistic Models; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000166:cytology; D016676:Macrophages, Alveolar / Q000166:cytology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results