Taking Hematology Testing to Point-of-Care Sites
Review of A New Whole Blood Analyzer
To avoid protracted semantic discourse, point-of-care testing (POCT) is defined as any analytic procedure performed for a patient by: (1) a healthcare professional other than a medical laboratory technologist; (2) operating outside the conventional laboratory; and (3) in close proximity to the patient. Terms synonymous with POCT, therefore, include extralaboratory testing, near-patient testing, and bedside testing. Potential sites for POCT are many and located both in primary and in secondary (hospital) care. POCT systems are categorized as non-instrumental (e.g., disposable reagent test strips), small analyzers (e.g., hand-held devices) or desktop analyzers. Technologic developments have made possible the performance of many clinical chemistry, hematology, hemostasis, and rapid infectious disease tests in a POCT environment. POCT is generally justified if actions affecting clinical management is taken based on the results. Equipment selected by specialists and used by general healthcare staff who have undergone appropriate training, combined with external quality assurance by the central laboratory, may prove to be the most durable must be performed at two levels: (1) the manufacturer’s performance claims for the device must be validated, and (2) the device must be thoroughly tested for robustness, precision, and accuracy in its intended operational environment by non-laboratory (but trained) personnel.
The analyzer and its technology
The pocH-100i is an extremely small, complete blood count (CBC) analyzer providing 19 parameters (including a three-part differential leukocyte count, and red cell, white cell, and platelet volume distribution histograms) when used in whole blood mode and eight parameters (minus three-part differential and histograms) in prediluted mode operation. The analyzer, which integrates all hydraulic and electronic systems and a printer, has a footprint of only 185 x 450 mm and is 350 mm in height. lt weighs 14 kg. An integrated cap piercer exists for closed tube sampling (15 l aspirated from a minimum 1 ml sample) while for prediluted mode operation, 20 l is required (an integrated dilutor exists).
Utility of pocH-100i for POC testing
The analyzer is easy-to-use, which makes it suit-able for non-laboratory personnel. Clear messages and illustrative icons on the color LCD screen guide the user during operation. By simple to use touch-screen technology, blood cell analysis becomes easy, and no specialist personnel is required. Online help is available for each operating step for optimal user support (multilingual software is available).
Maintenance of the blood analyzer is minimal. Only one daily shut down is necessary, and this is accomplished by pushing a single button. The rest of the procedure is fully automatic.
Dade Behring Obtains Factor VII Rights from Aventis Behring
An exclusive license agreement provides worldwide in vitro diagnostic rights for the inventions of Aventis Behring (Marburg, Germany; www.aventisbehring.com) relating to the factor VII activating protease (FSAP) and mutant forms of FSAP, to Dade Behring (Deerfield, IL, USA; www.dadebehring.com).
FSAP has recently been recognized as a potent activator of prourokinase, which plays a major role in human clot degradation. Although substantial research remains to be completed before a development project can be begun for a routine assay, FSAP is the first marker described for arterial occlusion that links coagulation disorders with chronic diseases of the arteries. FSAP is also one of the leading enzymes for cleaving factor VII into factor VIIa and maintaining factor VIIa. One mutant of FASP, the Marburg I SNP (single nucleotide polymorphism), found to exist in 4% of the general population, has shown promise as a significant and independent risk predictor for the progression of carotid stenosis. Dade plans further studies to elucidate the role of FSAP beyond carotid stenosis as a potential marker in a variety of cardiovascular diseases and stroke.
“This agreement is another significant step forward in developing the kinds of diagnostic tests that can led toward the management of cardiovascular disease, the world’s number one health threat,” said Jim Reid-Anderson, chairman, and CEO, Dade Behring.
New Uses for Troponin T Test
A test for troponin T can now be used also as an aid in the differential diagnosis of acute coronary syndrome, for risk stratification in patients with acutecoronary syndrome, and for cardiac risk in patients with chronic renal failure, according to new clearance from U.S. Food Administration (FDA).
The test, called Elecsys Troponin T, measures the level of troponin T, a cardiac-specific protein, in patient’s blood. Troponin T is related into the blood ehen heart cells die, and its presence can help a doctor diagnose a heart attack. Also, the higher the level of troponin T, the more at-risk the patient is suffer another heart attack. Four multicenter trials involving more then 7,000 patients have shown that the test can help identify patients with acute coronary syndromes who may anti-thrombotic therapy.
“The FDA clearance for the expanded indications for troponin T testing in patens with renal failure with change the way we approach the epidemic of cardiovascular disease in the high-risk patient group,” said Benjamin Freda, M.D., department of internal medicine, The Cleveland Clinic Foundation (OH, USA).
The Elecsys test is the product of Roche Diagnostics (Basel, Switzerland; www.roche-diagnostics.com).
Image: The Elecsys Troponin T test, designed to quantify Troponin T in blood (Photo courtesy of Roche Diagnostics).