Manufacturers discuss challenges and how they’re addressing them
By Karen Appold
When performing hematology testing, manufacturers cite a number of issues and challenges. In some instances, working through change is necessary.
Proper specimen collection and handling are of the upmost importance in helping to reduce errors that can occur during the preanalytical phase of laboratory testing. Considerations for ensuring test quality are numerous and include, but are not limited to: safety for both the patient/donor and phlebotomist, preventing microbiological contamination, proper venipuncture technique, following the order of draw, thorough mixing, accurate sample identification, and ensuring that optimal storage and transport conditions are met to preserve specimen integrity.
Despite the importance of such issues, Maria Dosseh, MLS(ASCP)CM a technical services manager for Streck Inc, Omaha, Neb, interacts with a number of customers who purchase Streck’s blood collection tubes and are unfamiliar with the practice of phlebotomy. “When customers ask manufacturers for guidance on how to collect patient samples, it makes me concerned about quality,” she says. “I tend to see a lack of regulation and training in the area of phlebotomy in these instances, which leads me to question the scientific reliability of data collected from specimens that may not be handled appropriately.”
Skilled phlebotomists know how to prevent hematomas, nerve damage, and specimen hemolysis. “Even with today’s advanced testing technologies, a good result cannot be produced from a poor specimen,” Dosseh maintains. “Manufacturers can provide guidance on the appropriate collection supplies, proper mixing techniques for preserving specimen integrity, and ideal storage and transport conditions, but it is up to collection centers and affiliate sites to seek education and training in phlebotomy.”
“The lab can serve as advocate for quality and risk management in this area by voicing the costs of repeat draws and associated delays to patient treatment and care,” says Dosseh. A number of publications address the quality of blood specimen collection and the safety of healthcare workers and patients by promoting best practices in phlebotomy.1,2 “I champion comprehensive training programs that produce efficient, well-trained phlebotomists who collect specimens that accurately reflect the patients’ physiology,” Dosseh adds.
Barbara J. Connell, MS, MT(ASCP)SH, senior manager for technical marketing and communications at Sysmex America Inc, Lincolnshire, Ill, says inadequate mixing is another important issue related to sample collection. “When blood is collected into a tube containing ethylenediaminetetraacetic acid (EDTA), it must be mixed thoroughly to prevent specimen clotting or the forming of platelet clumps,” she says. Other problems that can occur in the blood-collection process include tubes that contain an insufficient amount of blood, specimens that are hemolyzed during the drawing process, or samples that are drawn above an intravenous line.
Aged specimens and specimens that are not appropriately stored before they are transported to the lab are also problematic. “Hematology analyzers can flag or alert the operator that there is a problem sample, but there are no hematology analyzers that can correct a poorly collected specimen,” Connell says.
While blood-draw training helps to ensure quality, Connell says it is difficult to maintain that level of quality due to the turnover rate among phlebotomists and the use of blood draws conducted by staff outside the lab. “A stronger solution would be to develop an alternative anticoagulant that would eliminate some of the problems associated with EDTA,” she says.
REDUCING SEPSIS AND OTHER BLOOD-BORNE DISORDERS
Although a number of tests can identify infection or sepsis early on, improvements are still needed. In the hematology lab, the white blood cell (WBC) count is a traditional indicator of infection. Although the sensitivity of this test is high, it is not very specific. “WBC counts can be very high or very low due to a variety of reasons other than just infection or sepsis,” Connell says. “Pediatricians and neonatologists have favored the band count as an indicator of infection or sepsis, but the band count is not always reliable.”
In 2003, Sysmex introduced the first reportable automated immature granulocyte count (IG). “This parameter is more accurate and precise than a manual band count,” Connell says. Studies show that IG count can be an early indicator of infection.3,4 This parameter, along with other indicators, can aid physicians in diagnosing infection. “Reporting the automated differential, including IG, speeds turnaround time and gets this important information to the clinicians faster.” The Sysmex XN-Series automated hematology analyzers come standard with the six-part differential.
In addition, new laser light scatter capabilities found on hematology analyzers such as the Beckman Coulter UniCel DxH 800 and DxH 600 Coulter cellular analysis systems can help in identifying subtle cellular morphology changes and flag samples for smear review by a technologist, says Bill Bailey, North America senior manager for hematology at Beckman Coulter Diagnostics, Brea, Calif. Performing a smear review allows the technologist to identify and, when appropriate, take action on changes in WBCs consistent with various medical conditions, including infectious processes.
THE CHALLENGES OF CHANGING SITES OF CARE
According to Connell, “bringing the lab to the people” will be a trend of the future. “The need for a full line of standardized products that can easily be adaptable to near-patient testing, mobile health stations, and brick-and-mortar facilities are going to be key,” she says. “Easy-to-use devices that provide accurate results with little operator intervention will be necessary, since some of these analyzers may not be operated by medical technologists.”
Connell envisions medical technologists serving in a consultative capacity to healthcare providers. For example, today there are automated advanced clinical parameters that can provide physicians with information about erythropoiesis and thrombopoiesis, such as extended reticulocyte parameters and the immature platelet fraction, which need to be part of testing protocols for anemia and thrombocytopenia.
TECHNOLOGY INNOVATION IN HEMATOLOGY
Hematology testing still contains an element of manual science with reflex testing and the manual differential review, which have an element of subjectivity. State-of-the-art technology not only incorporates science at the analytic level to minimize these manual processes by reducing unnecessary reflex, rerun, and reviews but also helps to provide accurate results to physicians in a timely manner. “Today’s labs don’t have the resources to do morphologic reviews of their samples, so they must rely on the cellular science in their instruments to fill that need, such as Beckman Coulter’s automated intelligent morphology (AIM), which impacts the entire complete blood count workload in the lab,” Bailey says. “Additionally, analyzer technology can minimize and automate maintenance to benefit technologists and lab operations.”
Testing technologies that offer a more complete diagnostic picture for the physician will be important moving forward in healthcare. “The combination of hematology and flow cytometry will bring that capability into the laboratory,” Bailey says. The ability to identify cells of undetermined origin will supply the physician with results that can impact diagnosis and treatment of a patient in an expedient manner.
Connell says the numbers of true hematology morphologists are dwindling, and generalists or techs who occasionally work in hematology are not always confident calling abnormal cells on smear. As such, the science of hematology needs technologies that can provide standardized automated enumeration of abnormal cells, as well as the incorporation of more flow cytometry techniques into routine hematology analyzers. “Molecular diagnostics in hematology will continue to grow as we move toward more personalized medicine,” Connell says.
Today, more research is aimed at bringing flow cytometric methods to the routine hematology analyzer for the identification of normal and abnormal cells, Connell says. Scientists are also refining methodologies to reduce or eliminate interferences such as hemolysis and lipemia so that more reportable results are available with less manual confirmation procedures. Also in development is more cost-effective molecular testing.
A combination of hematology and specific flow cytometry panels are already in use in Europe. A specific panel of CD markers has been developed to identify abnormal and immature cells. Advanced algorithms and alerts are used for gating, allowing certain aspects of flow cytometry to be used in hematology. “Coupled with hematology results, this information now supplies a more complete diagnostic picture for the physician,” Bailey says.
For more information, visit the sidebar on Clinical Testing Issues in Hematology.
Karen Appold is a contributing writer for CLP. For further information, contact chief editor Steve Halasey via [email protected]
1. Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture, approved standard GP41-A6, 6th ed. Wayne, PA: Clinical and Laboratory Standards Institute, 2010.
2. WHO Guidelines on Drawing Blood: Best Practices in Phlebotomy. Geneva: World Health Organization, 2010.
3. Ansari-Lari MA, Kickler TS, Borowitz MJ. Immature granulocyte measurement using the Sysmex XE-2100. Relationship to infection and sepsis. Am J Clin Pathol. 2003;120(5):795-799.
4. Briggs C, Kunka S, Fujimoto H, Hamaguchi Y, Davis BH, Machin SJ. Evaluation of immature granulocyte counts by the XE-IG master: Upgraded software for the XE-2100 automated hematology analyzer. Lab Hematol. 2003;9(3):117-124.