Painless Test Using Teardrops May Speed Diagnosis Of Sjögren's Syndrome

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Painless Test Using Teardrops May Speed Diagnosis Of Sjögren's Syndrome

Researchers in Japan are developing a faster, more accurate diagnostic

test for Sjögren’s (SHOW-grins) syndrome, an incurable autoimmune

disorder characterized by chronically dry eyes and dry mouth. The

noninvasive test, which analyzes multiple protein biomarkers in the

tears using highly sensitive mass spectrometry, shows promise in early

clinical studies as the first simple test for identifying the disease,

the scientists say.

Sjögren’s affects between 1 million and 4 million Americans, primarily

women over age 40. April is Sjögren’s Syndrome Awareness Month.

The study will be described in the June 13 print issue of the American

Chemical Society’s Journal of Proteome Research, a peer-reviewed

publication. ACS is the world’s largest scientific society.

Current methods to diagnose the disease involve a battery of tests,

including painful invasive techniques using needles or biopsies to

analyze bodily tissues and fluids, particularly in the eyes and mouth.

Because of the complexity of the disease and its similarity to other

disease symptoms or drug-induced conditions, Sjögren’s can be difficult

to diagnose. Diagnosis of the disease has been further complicated by

the lack of biomarkers specific for the disease as well as its slow

progress, the researchers say.

According to study leader Naohisa Tomosugi, M.D., of Kanazawa Medical

University in Japan, the new painless technique would require that

patients shed as little as a single teardrop, collected in a doctor’s

office using special filter papers. The teardrop would then be analyzed

in the laboratory for newly discovered protein biomarkers and results

can be obtained in as little as one hour, Tomosugi says. The test,

which is being refined, could be available to consumers in two to three

years, he estimates.

“The development of an accurate and noninvasive diagnostic test [for

Sjögren’s] would be of considerable value in the clinical field,”

Tomosugi says. Early diagnosis is considered key to reducing the

severity of disease symptoms and its complications, which can include

debilitating fatigue and joint pain. Although the disease has no cure,

its symptoms can be minimized with a variety of medications, including

anti-inflammatory drugs and special moisture replacement therapies for

dryness.

In the current study, Tomosugi and his associates analyzed the protein

content of tears obtained from 31 patients diagnosed with Sjögren’s

syndrome (on the basis of conventional tests) and compared the results

to protein markers obtained from the tears of 57 subjects who did not

have the syndrome. Using a new analytical technique called surface

enhanced laser desorption/ionization time-of-flight mass spectrometry

(SELDI-TOF-MS), the researchers identified about 10 protein biomarkers

that appear to be specific for Sjögren’s.

In addition to helping diagnose the disease, the tear biomarkers also

show potential for noninvasive monitoring of disease activity and

progress, the researchers say. The biomarkers may also provide insights

into the underlying mechanisms of the syndrome, such as those involving

inflammation and glandular destruction, they say.

The exact cause of the condition is unknown. In general, researchers

believe that the immune system attacks the glands that produce tears

and saliva, resulting in dry mouth and dry eyes. Although the disease

is generally not life-threatening, it can produce serious symptoms,

including fatigue, difficulty swallowing, joint pain and eye problems.

Because its symptoms often accompany other conditions, such as

arthritis or lupus, and vary among individuals, the disease is often

misdiagnosed or undiagnosed.

Funding for this study was provided by Santen Pharmaceutical Co., Ltd.,

of Japan, which specializes in pharmaceutical treatments for eye

diseases.

The American Chemical Society is a nonprofit organization, chartered by

the U.S. Congress, with a multidisciplinary membership of more than

158,000 chemists and chemical engineers. It publishes numerous

scientific journals and databases, convenes major research conferences

and provides educational, science policy and career programs in

chemistry. Its main offices are in Washington, D.C., and Columbus,

Ohio.