MLO asked a number of its readers and contributors to tell us what was the “right” test for their labs and why. Here are four varied responses from members of diverse laboratories throughout the country. If you have a particular “favorite” test, perhaps you, too, would like to add your knowledge to this set of suggestions. Go to our website (www.mlo-online.com) and look under CONTACT US for a feedback form.
Flow cytometry technique for LAP to knock your socks off!
“When I discovered the antibody for human leukocyte alkaline phosphatase (LAP) was available for research and testing in flow cytometry, I wanted to improve on the way our lab had traditionally performed LAP procedures using the very subjective and time-consuming Sigma Aldrich (S-A) method. This method has been listed as the 'gold standard' for many years. The challenge was on; and with my efforts and the aid of our hematology pathologist, we devised a working method for the BD FacsCalibur about six years ago. Four years ago, it was adapted to our new BD Canto II. Using comparison studies, we were able to validate this method for FCM, and our VA docs have increased the orders three- to fourfold. To comply with CAP standards, we run it twice a year against the older S-A method and have great correlation! This method was published in the December 2009 issue of MLO.”
—Edna M. Hanson, Retired, Tampa, FL
Impacting patient outcomes
“We were wowed by the new Siemens ExL Loci Module Troponin I assay. The method is a homogeneous sandwich chemiluminescent immunoassay based on the ExL Loci technology. The assay has an ultra-low sensitivity that affords a 99 percentile cutoff value of >0.06 ng/mL and superb precision. (Our in-house precision studies were <1.0% CV). In fact, our chemistry supervisor is so impressed with the precision and accuracy of the ExL Loci Troponin I, she is rolling out a new policy that no longer requires repeating critical troponin values for confirmation in this assay. It is important to have confidence in a Troponin I result, especially when it so greatly impacts our patient outcomes!"
—Brenda Burney, MBA, MT(ASCP)
Administrative Laboratory Director
Blake Medical Center
The test that has insatiable demand: Vitamin D levels
From the NIH office of Dietary supplements: Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced endogenously when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. Vitamin D obtained from sun exposure, food, and supplements is biologically inert and must undergo two hydroxylations in the body for activation. The first occurs in the liver and converts vitamin D to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. The second occurs primarily in the kidney and forms the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D]. Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and to prevent hypocalcemic tetany. It is also needed for bone growth and remodeling by osteoblasts and osteoclasts. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D helps protect older adults from osteoporosis. Vitamin D has other roles in the body, including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. Many cells have vitamin D receptors, and some convert 25(OH)D to 1,25(OH)2D.
“About two years ago, our send-out volume for vitamin D levels was noticeable and increasing on a quarterly basis. We decided to pursue bringing the test in-house. This was one of the best customer-satisfaction procedures we had ever incorporated into our reference lab business. The lab volume increased in a short time, and both patients and physicians were happy with the rapid turnaround time.
“Picking out a methodology depends upon your lab's volume, budget, and scientific demands. We went with the immuno methodology since, for us, it seemed be the most cost-effective and trouble-free as opposed to LC-MS/MS. You need to do your homework on this assay since it is not the easiest assay to get up and running, and some current manufacturers are having problems with hetorphilic antibodies interfering with the assay.
“Because so much exists in the literature and so many consumers are tuned into their vitamin D levels, when a lab gets its assay validated and up and running, it becomes a positive revenue customer-satisfaction procedure that seems to keep increasing in request volume over time.”
—Lawrence Crolla, PhD
Northwest Community Hospital
Arlington Heights, IL
Strengthening partnership in care of lab patients
“Our lab is examining procalcitonin and its potential benefits to our health system. Currently, we send out this low-volume test. Recent hospital-wide efforts to identify and treat severe sepsis and septic shock — with the goal of significantly reducing mortality — however, have led to an increased demand for procalcitonin testing. Rapid results could allow our clinicians to monitor patients' response to antibiotics, thus helping to prevent unnecessary therapy. We are examining ways to bring the test into our core automated chemistry laboratory where our goal is to offer results 24/7 with a STAT turnaround time. Major analyzers include Beckman Coulter DxCs and DxIs, along with Siemens Centaur XPs. We are excited to hear that Siemens has an assay awaiting FDA clearance and look forward to evaluating its performance as soon as it is available. By offering rapid procalcitonin test results, we could meet a need of our clinicians, thus making our lab a stronger partner in the care of our patients.”
—John Frey, MBA, MT(ASCP), Supervisor, Automated Chemistry/Urinalysis
Department of Pathology and Laboratory Medicine
University of California-Davis Health System