Differential cell analysis of cytocentrifuged bronchoalveolar fluid samples affected by the area counted.
OBJECTIVE
To investigate variations in the differential cell counts between the quadrants of cytocentrifuged bronchoalveolar lavage (BAL) fluid preparations and to evaluate the diagnostic impact of these differences in interstitial lung diseases (ILD).


METHODS
BAL fluid samples obtained from 30 patients suspected of having ILD or pneumonia were cytocentrifuged and additionally stained with May-Grünwald-Giemsa stain. Two observers differentiated 200 cells in each quadrant as well as in a circular pattern around the center of the cytocentrifuge spot.


RESULTS
Lymphocytes and alveolar macrophages were not randomly distributed on the cytocentrifuge spot. Ten samples of patients with histologically confirmed ILD were selected to test the diagnostic impact using a validated computer program. The predicted diagnosis did not correspond to the histologic diagnosis for one quadrant from 1 of these 10 samples (sarcoidosis instead of idiopathic pulmonary fibrosis), whereas the differential cell counts performed around the center of the cytocentrifuge spot provided the correct diagnosis in all cases.


CONCLUSIONS
BAL fluid differential cell counts varied between the quadrants of the cytocentrifuge spot. The center of the cytocentrifuge spot appeared to be the most reliable area. Therefore, cell counting is recommended in a circular pattern around the center of the cytocentrifuge spot.
De Brauwer
E I
EI
Department of Medical Microbiology, University Hospital, Maastricht, The Netherlands.
Drent
M
M
Mulder
P G
PG
Bruggeman
C A
CA
Wagenaar
S S
SS
Jacobs
J A
JA
D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D002452:Cell Count / Q000379:methods*; D002498:Centrifugation; D003936:Diagnosis, Computer-Assisted; D003937:Diagnosis, Differential; D004804:Eosinophils / Q000166:cytology; D006801:Humans; D016015:Logistic Models; D008214:Lymphocytes / Q000166:cytology; D016676:Macrophages, Alveolar / Q000166:cytology; D009504:Neutrophils / Q000166:cytology; D015588:Observer Variation; D011237:Predictive Value of Tests; D011658:Pulmonary Fibrosis / Q000473:pathology*; D015203:Reproducibility of Results; D017565:Sarcoidosis, Pulmonary / Q000473:pathology*