Added sparkle
Xchange newsletter - Autumn 2006
With increasing sample numbers, staff shortages and cost pressures, today’s haematology laboratory is being challenged to use resources more effectively. Key tactics include standardisation, and efficient use of automation and data management.
Heritage
As the CELL-DYN family of haematology instruments celebrates 25 years of innovation Abbott continues to develop CELL-DYN to offer:
- Greater performance – fewer manual differentials, increased first pass efficiency, accurate results and greater ease of use
- Commutable results and maximum reliability across the CELL-DYN family
Unmet needs
At a recent meeting, some currently unmet needs for routine automation were identified (see box). While technological advances have enabled faster blood counting with greater reliability and fewer manual interventions, little has been done to advance our understanding of cellular abnormalities at the functional level and their relation to common haematological diseases. To achieve this, it was argued that it is necessary to integrate and exploit additional technologies.
| Unmet analytical needs for routine automation | ||
|---|---|---|
|
Apoptosis
Neutrophil function Neutrophil killing Neutrophil phagocytosis Neutrophil activation Lymphocyte clonal analysis Lymphocyte immunological status (B, T, NK) Rare event detection (body fluids, CD34 stem cells, QC of leucodepleted products) |
Ultra-rare event detection (circulating tumour cells, tumour marker re-expression on circulating cells)
The immunological differential CD34 stem cell counting Foetal cell counting |
Haemoglobinopathies (Hb S,C,D,E)
CD71 reticulocyte expression (resolving iron deficiency, ACD and thalassaemias) Platelet function testing Platelet associated Ig detection Allergy detection |
Cellular analysis using fluorochrome-conjugated monoclonal antibody probes is well established in flow cytometry and has proven clinical utility. Introducing fluorescence as a primary analyser measurement principle on analysers such as CELL-DYN Sapphire, significantly extends analytical protocols to provide more and more definitive clinical information.
Incorporating fluorescence
For example, effective and reliable automated leucocyte differentials are important for overall lab efficiency but there are limitations in current routine practice. In one study, a simple T- versus B-cell assay was investigated as an extended procedure to determine the nature of abnormal lymphocyte counts. Results differentiate malignant and reactive processes by analysing T- and B- lymphocytes, identifying samples requiring further investigation.
Thirty-seven EDTA-anticoagulated samples were obtained from the routine haematology laboratory. These had a range of absolute lymphocyte counts. Cell population analysis (CD3+ T-cells and CD19+ B-cells) was undertaken with CELL-DYN Sapphire and the files downloaded. Populations were gated using flow cytometry software, and absolute subpopulation numbers obtained by reference to the total WBC count (figure 1).
Figure 1: A sample with a lymphocyte count of 10.1 x 109/L with otherwise normal haematological picture was analysed using conventional blood count (left) and CELL-DYN Sapphire (right) Click here for a larger, clearer chart.
Results correlated well with clinical information. Of the 32 samples with a lymphocyte count exceeding 5.0 x 109/L:
- 11 had increased T-cells and all of these were from patients with infections or from the Infection Department
- 21 had increased B-cells and all of these were from patients with malignancy or from departments with patients with a diagnosed malignancy
Conclusion
Combining optical and immunological measurement principles in haematology analysers provides routine immunofluorescence with automated sample processing and minimal sample manipulation. This represents a significant extension of analytical procedures in haematology.