Send to printer »

Feature Articles : Sep 1, 2009 (Vol. 29, No. 15)

Changing the Face of Clinical Medicine

Novel Technologies Take Aim at the Astronomical Cost of Healthcare
  • K. John Morrow Jr., Ph.D.

The annual “American Association of Clinical Chemistry” meeting is the largest conference focusing on the needs of the clinical laboratory. This year the meeting expositions and presentations prominently featured multiplexing technologies and new strategies for developing biomarkers. 

Hycor, a division of Agilent Technologies, offers allergy testing as an aid to diagnosing and treating allergic disease. “Allergic disorders are predicted to worsen as this century moves forward, due to modern living conditions and the swift industrialization of developing nations, adding to the current worldwide incidence of 400 million with allergic rhinitis and 300 million with asthma,” said Mark Van Cleve, Ph.D., applications development manager.

The company offers allergy-evaluation systems, including a broad menu of allergy tests aimed at insects, animals, food, and occupational and environmental allergens, as well as autoimmune testing. The tests, which screen for allergen-specific IgE, have been cleared by the FDA for quantitative detection.

The platform is based on Hycor’s activated cellulose solid-phase technology and has demonstrated equivalence to the fluorescence-enzyme immunoassay. The portfolio includes an inventory of allergy tests which can be run on the Ultra-Sensitive EIA System and the Hytec 288 Plus system, which can handle a half million tests per year.

“This platform offers full walk-away automation for allergy testing,” stated Dr. Van Cleve. “This highly sensitive technology offers clear benefits over the classic pinprick allergy testing.” He also stressed that, in addition to the improved sensitivity, there is a major improvement in patient safety. “When patients are inoculated with potential antigens in the traditional testing for allergens, there is always a risk of anaphylactic shock, which in its most extreme manifestation can lead to death,” he added.

Hycor manufactures and markets allergy and autoimmune testing products widely used in clinical laboratories. The company also produces Kova urinalysis products that help standardize procedures to improve laboratory safety. “The company’s move into an ultrasensitive, fully automated allergy-testing system takes us into a place in the market where we haven’t been,” Dr. Van Cleve commented.

Immune Response

Invitrogen, a division of Life Technologies, announced the global availability of the PlexMark™ 3 renal biomarker panel assay, a new biomarker tool for use in preclinical kidney function research. It is expected to assist in the development of more effective methods to monitor kidney health in transplantation protocols.

This new assay provides researchers with an alternative to the invasive and expensive biopsy procedure by measuring levels of cytokines, chemokines, and receptor levels in urine as proxies for monitoring immune function and response.

The PlexMark assay uses Luminex xMAP® multiplexing technology for bioassay analysis, while the biomarkers in the panel are licensed from Renovar.

Globally, more than 30,000 persons receive kidney transplants each year. These recipients must contend with the intrinsic rejection mechanism triggered by the graft and the cumulative cell and tissue damage caused by the immunosuppressive drugs. Given that kidney damage may already be advanced by the time a biopsy is performed, utilizing urine biomarkers and tracking therapies early in the course of rejection are essential for improving care for transplant patients.

Invitrogen also offers Dynabeads for in vitro diagnostic assays. These uniform magnetic beads are employed for a range of applications and are manufactured according to relevant regulatory requirements. The monodispersity and superparamagnetism of the Dynabeads allows optimal behavior in automated systems, according to Traci Moritz, senior manager for business development at Life Technologies. “Our experience with this technology has enabled us to build in lot-to-lot consistency in the broad range of the Dynabead product line,” she said.

New product introductions include the MyOne product line, which employs a one-micron bead providing increased surface area, as well as Dynabeads Silane for use in molecular diagnostics. The scalability of the beads lends them to automation, noted Moritz. 

New Kits Speed Mass Spec

Waters has addressed the demand for measuring levels of a whole family of immunosuppressive drugs, whose use has greatly expanded in recent years. According to Mark Bruns, Ph.D., senior director for the clinical business operation, the company has introduced a new product for quantitative measurement of tacrolimus, sirolimus, everolimus, and Cyclosporin A. Known as the Waters® MassTrak™ Immunosuppressants XE RUO (Research Use Only) Kit, it provides laboratories an alternative to immunoassay test kits for research laboratory analyses. Included in the kit are reagents, internal standards, and an analytical column for performing up to 500 determinations per kit.

Dr. Bruns stated that the kit performs well in the presence of drug metabolites and addresses some of the analytical weaknesses of immunoassay technology. Currently, FDA-approved clinical tests include a kit to quantify the immunosuppressant tacrolimus in kidney and liver transplant patients by liquid chromatography-mass spectrometry (LC/MS/MS).

Vitamin D deficiency has received much attention in the scientific and lay press in recent years. Associations with an increased risk of osteoporosis, heart disease, diabetes, and other maladies have driven a 90% increase in testing for this condition since 2007. Whereas the mechanisms of the vitamin D protective effects are complex and not completely understood, one overriding explanation resides in the fact that it is a potent inhibitor of the proinflammatory response and slows the turnover of leukocytes.

A National Health and Nutrition Examination Survey caused researchers to conclude that low levels of vitamin D were associated with a generalized increase in mortality. Among many factors that may be responsible for vitamin D’s apparent beneficial effect on all-cause mortality is its effect on telomeres and its potential effect on slowing aging.

Waters offers a new MassTrak system platform optimized for 25-Hydroxyvitamin D analysis for clinical research laboratories featuring a robotic liquid-handling system and Waters’ Acquity TQD System for high-throughput measurement of total 25-Hydroxyvitamin, as well as 25-Hydroxyvitamin D2 and D3. The platform is streamlined by a solid-phase extraction sample preparation step that minimizes solvent usage.

Another MassTrak product, the Amino Acid Analysis Solution, is offered as a comprehensive research tool for the analysis of physiological amino acids in urine and plasma. This product incorporates a Waters’ Acquity UPLC system with pre-packaged reagents and consumables, for application in the clinical research laboratory. The platform permits the analysis of amino acids in approximately one-third the time of traditional amino-acid analysis, Dr. Bruns said.

Finally, in the realm of clinical toxicology, LC/MS/MS is now widely used in confirmation analysis, due to its greatly simplified pretreatment requirements. At the meeting, Waters exhibited the Acquity UPLC system and tandem mass spectrometry products for the research and clinical laboratory, with many facilities using the technique for a variety of applications including toxicology, therapeutic drug monitoring, and endocrinology.

Real-Time PCR with FDA Approval

Applied Biosystems, also a division of Life Technologies, presented the 7500 Fast Dx Real-Time PCR Instrument, a flexible, medium-throughput device, designed to facilitate assay development on an in vitro diagnostic platform.

The instrument is devised to meet current health challenges to the identification of influenza strains, especially the strain associated with the recent outbreak of the H1N1 virus (swine flu), according to a Life Technologies official. The FDA has authorized the emergency use of a new CDC rRT-PCR detection panel for the swine flu with instructions that the assay be performed on an Applied Biosystems 7500 instrument.

The company has formed a special 24/7 task force to coordinate the company-wide response to requests for assistance with the outbreak. The task force provides health agencies with support, including instrument training, supply chain management, and monitoring regulatory compliance. The company has also accelerated the manufacture of components that will be used by laboratories to test for and identify influenza.

Other products of relevance to management of a possible H1N1 outbreak include the MagMAX™ viral RNA isolation kits, the SuperScript® III Platinum® One-Step qRT-PCR kit, TaqMan® influenza A detection kit, and several different capillary electrophoresis systems for determining the base-by-base sequence of viral samples.

Last September, the 7500 Fast Dx instrument received 510(k) clearance from the FDA for use with the CDC Human Influenza Virus Detection and Characterization Panel (rRT-PCR Flu Panel). Both products are required to be used together as a system for the detection of influenza.

Stabilizing Tissues

“Tissue over- and underfixing, crosslinking of biomolecules and lack of standardization can lead to loss of morphology and poor quality histological preparations,” according to Lynne Rainen, Ph.D., scientific director at PreAnalytiX, a Qiagen/BD company. Dr. Rainen discussed her company’s PAXgene tissue system, which is designed to overcome the drawbacks of conventional tissues processing. 

The PAXgene tissue system’s first step involves the use of a special container for fixation and stabilization of the tissues under a standardized set of conditions. This allows the formalin-free preservation of nucleic acids along with the histomorphology of the tissues. Dr. Rainen argues that there are marked advantages to her company’s technology.

“It provides details of the histology comparable to classic H&E staining, it is compatible with immunohistochemical applications, it preserves DNA for PCR-based applications, and it allows purification of all nucleic acids from one sample,” she said.

Whereas standard fixation technologies may allow PCR amplification to take place, the company’s studies have shown much better PCR response with the PAXgene system, Dr. Rainen noted. She said that the system is particularly effective at copurification of small RNAs. 

“The excellent preservation of RNA samples means that the system can be used for quantitative downstream measurements of message content in tissues, enabling molecular pathology testing at a level of accuracy not previously attainable,” Dr. Rainen concluded.

Nucleic-Acid Amplification

“Our one-step nucleic-acid amplification technology provides a rapid intraoperative method for assessing metastasis in breast cancer patients,” said Vishal Sikri, marketing manager for life sciences at Sysmex America.

During cancer surgery lymph nodes may be sampled and metastases diagnosed through classical intraoperative methods (frozen section and imprint cytology). However, these types of intraoperative procedures may have a false-negative rate as high as 52%, based on peer-reviewed studies. In studies from Europe and Japan, a one-step nucleic-acid amplification technology has been applied in which multiple mRNA markers are measured.

The amplification step, known as RT-LAMP (loop-mediated isothermal amplification), is an isothermic nucleic-acid amplification technology that is thoroughly documented in the peer-reviewed literature. It can yield results in as little as 30 to 40 minutes, making it suitable for use in cancer surgery. Because it allows for a semiquantitative estimate of cancer-related genes, it is less subjective than the traditional methods of deciding degrees of malignancy.

Some of these markers, such as CK19 (cytokeratin 19), were greatly overexpressed in malignant lymph nodes, so much so that there was no overlap with the profiles of normal lymph nodes.

“The technology has been in clinical use in Europe for 2–3 years and in Japan for the last year,” Sikri stated. “It is currently not available for clinical use in the U.S.” 

Rapid advances in clinical diagnostics are adding to a large portfolio of molecular applications. Faster, easier, and more accurate than technologies in place for years, the new face of clinical medicine promises to be cheaper and more user friendly.

Some, such as the serum-based assessment of allergic reactions, are safer and more accurate, whereas others, in the LAMP technology, are much faster and more accurate.

At a time when a noisy debate is in progress on the astronomical cost of healthcare, the new face of clinical medicine will provide better, more efficient healthcare at a more manageable price.