The ability of blood
tests to precisely measure very low doses of anti-rejection drugs in kidney
transplant patients may make a significant difference in assuring long-term
viability and survival, according to research presented at the
American Association for Clinical Chemistry (AACC) annual meeting.
The current thinking in transplant medicine favors reducing doses of
tacrolimus and other immune-suppressive drugs as much as possible after
kidney-transplant procedures. “Even though we are succeeding in preventing
organ rejection, we haven’t made much progress to improve long-term
survival,” said Sudarshan Hebbar, M.D., senior medical director, Abbott
Diagnostics. “Unfortunately, most kidney transplant patients will go back
on dialysis in eight to ten years, in part because the anti-rejection drugs
can be toxic to the kidneys.”
Dr. Hebbar added that kidney-transplant patients have high incidence of
heart attacks and other cardiovascular disorders from long-term effects of
renal disease. Therefore, minimizing drug toxicity over time is considered
one way to help improve long-term graft survival and preserve quality of
life for transplant patients.
To minimize long-term toxicity of transplant medications, physicians
frequently aim to taper down doses of immunosuppressive drugs to as low a
level as possible without risking rejection. “Successful low-dose regimens
of tacrolimus and other anti-rejection medications require highly precise,
ultra-sensitive drug-monitoring assays,” said Daniel Levine, Ph.D.,
director of the clinical laboratory, Iris and B. Gerald Cantor Clinical
Research Laboratory at The Rogosin Institute in New York City.
Dr. Levine emphasized the importance of using an accurate and precise
test to monitor patients on low-dose treatment regimens. “At low doses,
even the slightest variation in blood-level readings could be devastating
to transplant patients. The consequence for the laboratory is twofold: it
must have accurate, precise testing for immunosuppressive drugs, and
tacrolimus tests that are accurate to 4 ng/mL are no longer adequate,” he
explained.
Dr. Levine reported results of his studies evaluating the performance
of the Abbott ARCHITECT assay for tacrolimus, the most widely used
immunosuppressant drug. He said the usual dosing range for the medication
is between 2 and 15 ng/mL, with lower doses preferred. “The challenge for
the laboratory, therefore, is to assure with the utmost confidence to the
physician that a tacrolimus blood level of 3 ng/mL is exactly right and not
5,” Levine said.
In the trials, the Abbott ARCHITECT tacrolimus assay was accurate and
precise at low levels and showed consistent results. “The functional
sensitivity in our hands was 0.9 ng/mL, exceeding the package insert claim
of 2 ng/mL. We are fully confident the ARCHITECT tacrolimus assay meets our
requirement for low-level tacrolimus monitoring,” Levine said.
“The ARCHITECT tacrolimus assay is the only automated transplant
monitoring test that meets international standards for low-level
monitoring,” according to Dr. Hebbar.
The ARCHITECT tacrolimus assay is used for the quantitative
determination of tacrolimus in human whole blood, as an aid in managing
liver and kidney transplant patients receiving tacrolimus therapy.
About the ARCHITECT Family
With its extensive menu of diagnostic tests, user-friendly software and
advanced sample management capabilities, the ARCHITECT family and the
currently marketed flagship analyzer, ARCHITECT(R) ci8200(R), meet the
needs of today’s diagnostics laboratory by enhancing workflow and
productivity. ARCHITECT instruments are designed with laboratory-focused
features such as the capability to prioritize emergency tests, the ability
to use common reagents among platforms and sample monitoring. These
features not only minimize training, but also reduce inventory costs and
sample contamination potential, leading to better results for laboratories,
physicians and, ultimately, patients.
About Abbott’s Diagnostics Businesses
Abbott is a global leader in in vitro diagnostics and offers a broad
range of innovative instrument systems and tests for hospitals, reference
labs, molecular labs, blood banks, physician offices and clinics. With more
than 65,000 institutional customers in more than 100 countries, Abbott’s
diagnostic products offer customers automation, convenience, bedside
testing, cost effectiveness and flexibility. Abbott has helped transform
the practice of medical diagnosis from an art to a science through the
company’s commitment to improving patient care and lowering costs. Abbott’s
history is filled with examples of first-of-a-kind diagnostic products and
significant technological and research advancements.
About Abbott
Abbott is a global, broad-based health care company devoted to the
discovery, development, manufacture and marketing of pharmaceuticals and
medical products, including nutritionals, devices and diagnostics. The
company employs more than 68,000 people and markets its products in more
than 130 countries.
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