Automated CSF cytology – is conventional cytology still necessary?

Objective: To evaluate precision and clinical applicability of the Bayer „Advia 120“ cytometer for CSF cell count and differentiation.

Methods: 106 analyses of CSF from 98 patients by the ADVIA 120 were compared with routine cell count and microscopic differentiation and correlation coefficients calculated.

Results: In general, the total cell counts of both methods correlated well. The best correlations were seen at higher cell counts over 100 cells/ µL with less than 100 erythrocytes/ µL. The best correlations of cell differentiation were seen for lymphocytes and neutrophils, while the results for monocytes and eosinophils were less precise. In some cases, considerable differences between automated and microscopic cell counts and differentiation were seen that were relevant for the clinical decision-making. The detection of pathological cell types like hemosiderophages, mitoses or neoplastic cells is not provided by automated cytometry.

Conclusions: When experienced personal is not available, a preliminary cell count and differentiation between neutrophilic or lymphocytic reaction by automated cytometry may be valuable to allow for a first therapeutic decision-making. Since the detection of pathological cell types is not provided and the precision at low cell counts is only moderate, a personalised microscopic evaluation of each sample is still indispensable to avoid misdiagnoses.