The right
diagnosis means everything.
In some
cases, it can be a matter of life and death.
A recent study in the Journal of Evaluation in
Clinical Practice found that more than 20 percent of patients who went for a
second opinion at the Mayo Clinic had, in fact, been misdiagnosed by their
primary care doctors.
Doctors are
human and ailments are complex, so misdiagnoses are nothing new.
What can
prevent patients from being inaccurately diagnosed?
Read more: New blood test may pinpoint cancer tumors »
Accuracy of
new blood tests
One tool is
a blood test.
There’s not
always been a test for everything out there.
However,
there are a few new pathology exams (and more on the horizon) that can help
doctors better detect diseases and conditions.
Here are
three recent developments:
Viral vs. bacterial infections: Wouldn’t it be great to know if you
really need an antibiotic or if you should just let a cold run its course?
A Duke
University team is looking into the efficacy of a test that could distinguish
viral from bacterial infections.
Dr. Geoffrey S. Ginsburg previously told Healthline that
he would love to have the “pregnancy test equivalent to viral infections.”
Heart attack: Researchers at King’s College London created a blood
test
that better detects heart muscle damage due to a heart attack.
When
a doctor suspects that a patient has had an attack, only some incidents show
changes on a heart trace or ECG. Those exams test levels of cardiac troponin,
which is a protein released by the heart that is common after heart attacks or
inflammation. When doctors can’t find cardiac troponin in the blood, patients
are labeled as low-risk and typically discharged.
Researchers,
however, looked at 4,000 patients and found that 47 percent of those actually
had an intermediate risk and required more tests. Their test for myosin-binding
protein C is a better indicator of how much heart muscle has been damaged.
Dr.
Tom Kaier, a cardiologist with Kings College London, told Healthline that the
myosin-binding protein C is present in greater abundance and may rise quicker than troponin
after a heart attack. That could change the way heart attacks are diagnosed.
“Troponin is
an excellent test, but it has its limitations. It takes over three hours to
appear in adequate levels in the bloodstream to be measured reliably,” Kaier
noted.
Considering that only 14 to 17 percent of patients that go
to emergency rooms with chest pain have a heart attack, the other 80 percent
want reassurance as soon as possible. A quicker diagnosis may also improve
patient outcomes.
The detection of myosin-binding protein C “appears in the
circulation quicker, and thus could rule out heart attacks in more patients at
an earlier time point than currently possible,” Kaier added.
Concussions/traumatic
brain injuries: Accurately diagnosing
a concussion or traumatic brain injury can be a bit of a guessing game when it
comes to specifying the severity of the impairment.
But Dr. Linda Papa, an emergency medicine
physician and researcher at Orlando Health released a study in JAMA Neurology
detailing a blood test that measures a protein released by brain cells upon an injury.
More of the
protein indicates a higher severity of brain injury, she explained.
Symptoms of a brain injury can be subtle and may
not come on for several days. She told Healthline that
diagnosing a concussion can be “very subjective” and is “often based on the
experience of the clinician.”
If a person doesn’t see a brain expert, they may not be
accurately diagnosed, so having a concrete test to confirm injury would be a
big step. A CAT scan can give an assessment of a brain injury, but it only
detects lesions and cannot detect all of them.
Having a definitive blood test could help doctors
make better treatment decisions sooner —hopefully leading to better patient
outcomes, Papa said.
If approved by the Food and Drug Administration (FDA),
Papa’s test would be the first of its kind.
“We’re just a couple of years from it being available,” she
added. “We’re hoping the blood test will find injury where it couldn’t be seen
before.”
Papa noted that it was also tested in patients of all ages
with severe traumatic brain injury and seems to “cover the spectrum” of brain
injuries.
Read more: High-tech blood test may detect cancer early »
The future
of precision pathology
Dr. Michael
J. Donovan, a pathologist and researcher at The Mount Sinai Hospital in New
York, said there are many new innovations happening with blood tests.
There are
also developments in tests to evaluate urine, saliva, and cerebrospinal fluid.
In the
oncology field, for instance, researchers are looking at cell-free DNA, which
is the deoxyribonucleic acid (DNA) in blood that can be isolated and sequenced
to identify cancer-related genes with mutations in them.
Doctors then
can tell if a cancer drug will work on the patient. The blood acts as a
companion diagnostic to gauge the efficacy of a drug before it’s even given.
“That’s one
of the very practical ways in which the field has advanced,” Donovan told
Healthline.
Other blood
test innovations include evaluations that can predict how a kidney transplant
patient will respond. This can replace an invasive biopsy. Researchers are also
targeting urine tests in this area.
Donovan said
that blood tests in the future may also be able to determine if a patient is
building a response to human papillomavirus (HPV) in a lesion instead of having
to biopsy it or conduct an intrusive cell scraping.
Blood tests
are also a pathway to evaluate the possibility of neurodegenerative diseases
such as Alzheimer’s disease.
“We’re
always looking for ways to detect the manifestation of Alzheimer’s prior to
actual clinical manifestations,” Donovan said.
Other liquid
biopsy options could evaluate a patient’s immune system via bloodwork so
doctors can monitor an individual’s state via a simple blood draw.
Assessing
DNA isn’t the only research pathway, either, as researchers are looking to
evaluate peptide fragments in the blood. Peptides are amino acids that are
linked via peptide bonds and in some ways are similar to DNA and ribonucleic
acid (RNA).
DNA gives a
blueprint of genes, while RNA helps to execute the DNA’s guidelines.
Donovan said
that the field of liquid biopsies will continue to evolve — again, not just via
bloodwork but through spinal fluid, saliva, and urine. That will give doctors
multiple tools to better diagnose patients and hopefully improve outcomes.
“What we see
in blood under a microscope, that will pull together a more comprehensive
genotype of a person,” Donovan said.
“That’s the
future of precision pathology,” Donovan added.
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