According to a consortium of American scientists, easy, cheap diagnostic tests based on the analysis of saliva are within spitting distance of development.
Researchers claim that the novel protocol could be obtainable as a standard of care as early as 2011 in order to examine for a variety of major diseases.
"The skill to detect and observe diseases through non-invasive means is a very desirable objective in health care," explained Dr David T. Wong, director of the Dental Research Institute at the University of California, Los Angeles. "Saliva, a completely non-invasive fluid, possesses this skill, however is not currently used in (the) mainstream. All of this is just about to alter."
Wong was planned to describe the new tests on Thursday at the International Association for Dental Research annual meeting, in New Orleans.
In order to improve the saliva-based screens, Wong has joined forces with the scientists from the US National Institute of Dental and Craniofacial Research; the University of California, San Francisco; and the Scripps Research Institute.
Interpreting saliva alphabet
Together, the scientists are involved in a painstaking mapping of so-called "diagnostic alphabets" appearing in saliva. Recognizing the components of such alphabets constitutes the key to "reading" the symptoms of the illness.
Up to the present, two such alphabets are considerably decoded: one based on salivary proteins and another based on salivary messenger RNAs (mRNA) - molecules integral to the formation of proteins.
According to the observations of the investigators, over 1 500 salivary proteins have been recognized, together about 3 000 mRNAs.
Effective diagnosis
Based on their detective work, Wong’s team informed that their study has already revealed indicators showing the way toward diagnosing both oral cancer and an autoimmune disease known as Sjogren’s syndrome.
He emphasized that oral cancer may be recognized in saliva by checking for five particular proteins and four mRNAs that mold a inimitable diagnostic signature in over ninety per cent of cases.
Likewise, a small subset of proteins and mRNAs turns out to serve as markers for Sjogren’s syndrome.
Early detection of oral cancer via saliva testing may potentially be helpful in improving survival rates among patients diagnosed with types of oral cancer.
An even larger patient pool now fights Sjogren’s syndrome, a condition in which white blood cells attack moisture-producing glands, leading to dry eyes and dry mouth.
The potential of the work now under way by Wong and his colleagues is facilitated by the specialists from the American Association for Dental Research. They are convinced that saliva, similarly to blood and urine, may be viewed as a repository of relevant information concerning disease and exposure to environmental substances.
Further tests under development
Right now, new tests are being developed that use saliva in order to detect measles, mumps, rubella, hepatitis (A, B and C), breast cancer, Alzheimer’s disease, and cystic fibrosis.
In 2004, a saliva-based test for HIV, the virus that causes AIDS, gained the approval of the US Food and Drug Administration (FDA). Future diagnostic tests may also finally be dependent on saliva for indications of unhealthful exposure to lead, as well as to control drugs or alcohol abuse.
Wong explained that the main goal is to place easy-to-use saliva-screening technologies in the hands of healthcare professionals, dentists and nurses as fast as possible.
"This is really an exciting and revolutionary objective," he explained, adding that current efforts intend "to establish the scientific reliability and clinical utilities of saliva."
Demonstrates real promise
Dr Robert Genco is a distinguished professor of oral biology and microbiology in the Schools of Dentistry and Medicine at the State University of New York in Buffalo. He confirmed that saliva-based diagnostics demonstrates real promise.
"The field is extremely exhilarating, and the search for such diagnostics is essential," he explained. "Due to the fact that if you can take a simple sample like saliva and then perform a test to diagnose the illness - especially for the illnesses that do not show themselves very well - you can probably have some information before the situation gets too serious."
"The crucial matter is what is the predictive value or trustworthiness of such a test in a person. And this is a very high barrier to overcome," he warned. "However, I think the cutting-edge approach these scientists are using is reasonable and holds a great deal of promise."
