Cross-evaluation of five slidemakers and three automated image analysis systems: The pitfalls of automation?

Automated slidemakers and stainers and digital microscopes are coupled with haematology analysers to achieve better efficiency and cost-effectiveness. This study evaluates the integrated performance of slidemakers and digital microscopes commonly available on the market.

We compared the percentage of neutrophils for five slidemakers (two Siemens Advia Autoslides, a SysmexSP-10 and SP-50 and an Abbot Alinity hs) and a Horiba Hemaprep to the corresponding haematology analyser data (Siemens Advia 2120i, Sysmex XN and Abbot Alinity hq). Differential leucocyte counting (DLC) was performed on three different CellaVision digital microscopes (DM96, DM1200 and DI-60) and manually. The quality of the smears was assessed using a CellaVision SmearChecker.

We observed a significant positive absolute bias (P < .05) for the percentage of neutrophils with the Autoslide and Alinity hs smears on the digital microscopes, but not when DLC was performed manually. The SP-10 and SP-50 showed no bias regardless of the DLC method. No bias was observed for the Hemaprep smears. All the smears had an acceptable monolayer quality, stain intensity and colour. All smears, except those from Sp-10, were of an acceptable length.

Users should be aware of a potential lack of accuracy that can be encountered when using some slidemakers and digital microscopes. All laboratories should validate or verify the differential counts from slidemakers and digital microscope with automated cell differential counters. Manual count validation should only be considered if a significant proportion of clinically relevant abnormal cells are present. Otherwise, haematology analyser results should be favoured.