Hematology — the study of blood cell components —provides a wealth of data and clues that lead to diagnoses such as infection, anemia, blood cancers, and clotting disorders. As a result, orders for a complete blood cell count (CBC) and differential are one of the most frequently ordered in-patient tests.
The steady development of the current hematology workflow
Before the age of automation, CBCs were performed under a microscope. Cell components were stained and counted manually under the microscope, then plugged into mathematical formulas to determine blood parameters. As the principles of manufacturing started to infiltrate the healthcare industry to improve efficiency and productivity, the industry started examining the hematology workflow to determine automation points that could increase output and standardization of results.
In the 1960s, the Coulter counter brought about counting automation by detecting and counting cells that were electrically resistant. By the 1980s, most laboratories were utilizing some form of impedance or flow cytometry to determine parameters such as red cell count, white cell count, platelet count, and hemoglobin and hematocrit levels.
Breaking the bottleneck
However, confirmation outside of normal automation parameters and white cell differentiation still required additional blood for slide preparation, stain, and microscopic review. It remains a bottleneck in the hematology workflow. In response, automated slide makers and stainers were developed and connected to the cell counters. Manual review with a lab scientist confirming, counting, and sorting cells under the microscope still takes place in many hospital laboratories and is considered the gold standard.
With the development of artificial intelligence and image recognition, CellaVision software brought about automation to blood component morphology detection and differentiation. What was previously left to the human eye could be determined by software algorithms and image database correlation. It provided a more objective approach to microscopy workups and allowed lab scientists to focus on more difficult imagery cases.
Bloodhound technology: challenging the traditional workflow
In 2013, Roche acquired Constitution Medical Investors, Inc. (CMI) to obtain the technology patent on the Bloodhound system. Five years later, the FDA approved the sale of Roche’s m511 hematology analyzer, currently the only hematology analyzer utilizing the Bloodhound technology for sale in the U.S.
Bloodhound technology. Image courtesy of Roche Diagnostics.
The Bloodhound technology brings all the hematology workflow steps into one unified integrated workflow. It eliminates the flow cytometry counter and depends solely on digital imaging technology to perform the blood cell counting and classification. It challenges the traditional thought of peripheral blood smear preparation with its own proprietary smear and staining technique and allows for a CBC with 5-part white cell differential and reticulocyte count to be done in one imaging step.
A traditional hematology CBC with differential has a turnaround time of 20–30 minutes, with the slide preparation and stain taking roughly 80% of that time. According to Roche, a CBC with differential with Bloodhound technology takes 6 minutes to completion.
Whether Bloodhound technology will change the landscape of the hematology workflow remains to be seen. Not all hematology samples require a full workup with microscopic cell classification. A CBC without differentials by traditional methods takes less than 3 minutes to completion, whereas as Bloodhound technology will still require 6 minutes.
For mid-volume laboratories that have limited personnel, the extra 3 minutes has limited impact. However, for high-volume laboratories with dedicated hematology sections, the utility of this technology is limited because personnel tasks are more segregated, and the additional 3 minutes would delay the release of results that are within normal ranges.