Digital Public Defence: Heidi Annett Eilertsen
M.Sc Heidi Annett Eilertsen at Institute of Clinical Medicine will be defending the thesis The Ability of Hematology Analyzers to Detect Pathological Cells in Blood – with Special Focus on Blasts and Immature Granulocytes for the degree of PhD (Philosophiae Doctor).
The public defence will be held as a video conference over Zoom.
The trial lecture and defence will be conducted in Norwegian.
The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.
Due to copyright reasons, an electronic copy of the thesis must be ordered from the faculty. In order for the faculty to have time to process the order, it must be received by the faculty no later than 2 days prior to the public defence. Orders received later than 2 days before the defence will not be processed. Inquiries regarding the thesis after the public defence must be addressed to the candidate.
Digital Trial Lecture – time and place
- First opponent: Professor Ole Lars Brekke, Nordlandssykehuset HF
- Second opponent: Professor emeritus Axel Brock, Aalborg Universitetshospital
- Third member and chair of the evaluation committee: Associate Professor Ulla Randen, University of Oslo
Chair of the Defence
Associate Professor Anders Erik Astrup Dahm, University of Oslo
Professor emeritus Tor-Arne Hagve, University of Oslo
Automated hematology analyzers generate flags to alert for the possible presence of abnormal cells in peripheral blood samples. The flags may be useful markers for the selection of samples that need additional investigation to clarify if the samples contain blasts and/or immature cells. International societies recommend that such flags are followed up by manual microscopy of blood smears. This method is imprecise, time-consuming, and cumbersome.
In this thesis, Eilertsen et al. show that the blast-related flags have low ability to distinguish positive blast-containing samples from negative samples. High proportions of false-positive, and also high proportions of false-negative flags, were observed. The repetitive measurements used to measure the inter- and intra-instrumental variability demonstrated low precision and random reporting of the flags. The manual microscopy and digital image analysis of blood smears identified substantially less samples with blasts than immunophenotyping by flow cytometry (IFCM). Using digital image analysis, a significant difference between blast counts of preclassification vs reclassification was observed. However, the digital image analyzer was able to classify blasts as blasts, and misclassification of blasts into other cell classes was not observed.
In conclusion, the work 0f this thesis has contributed to call into question the usefulness of blast-related flags as valuable sources of information for medical decisions, and it is also doubtful whether it is useful to follow up the flag messages with examination of blood smears. The work has provided new information on the repeatability and inter-instrumental reproducibility of the blast-related flags, and also demonstrated the value of using IFCM instead of blood smear methods in studies evaluating the performance of the hematology analyzers.
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