Searching to improve the diagnosis and treatment of dry mouth
Today, a minor surgical operation involving extracting a few salivary glands from the lower lip, is one of the steps required to determine whether or not a dry mouth is due to the chronic disorder Sjögren's syndrome. Researchers at the University of Oslo (UiO) are working to simplify the diagnostic process so that a single saliva test may be sufficient.
Although they are not quite there yet, Professor Janicke Liaaen Jensen's multidisciplinary team brings diagnosing Sjögren's syndrome one step closer to a simpler reality in a new scientific article. The team of researchers, utilizing a wide-ranging base of scientific knowledge, has found a correlation between increases in certain types of proteins in saliva and tear fluid in patients with Sjögren's syndrome.
– The findings in this study are not sufficient to turn saliva and tear fluid tests into standalone tools for making this diagnosis. But we have found measurable differences that may be of major significance in terms of enabling us to develop them into full-blown tools, explains Liaaen Jensen of the Institute of Clinical Dentistry at the Faculty of Dentistry.
Multidisciplinary Approach Crucial
In the study, a group of researchers from different fields tested proteins in saliva and tear fluid. The proteins in the vesicles in these body fluids were also examined. Vesicles are small particles found in saliva and tear fluid that are involved in the communication between cells.
Liaaen Jensen is excited about the findings and thinks they are a direct result of researchers from different fields teaming up; dentists, immunologists, physiologists, microbiologists, physicians, ophthalmologists and biochemists. – Together we have arrived at something new. We are not aware of anyone else who has tested both body fluids and vesicles in patients with Sjögren's syndrome. Given that we found significantly upregulated proteins in all of the patients with this diagnosis, it makes us optimistic regarding possibly simplifying the diagnostic process in the future.
Complicated and Uncomfortable Diagnostic Process
The current method for diagnosing Sjögren's syndrome is complicated and involves invasive examinations that can be uncomfortable for the patient. An example of one of the six steps necessary to identify the syndrome is that the attending physician must make an incision on the inside of the patient's lower lip, in order to extract small salivary glands, which in turn have to be carefully examined under a microscope.
Another invasive step involves taking blood samples from the patient. Sjögren's syndrome is an autoimmune disorder where the body's immune system is unable to differentiate between its own and foreign cells. The immune system responds by attacking the body's own tissue by secreting autoantibodies. Blood tests therefore provide valuable information about levels of autoantibodies in patients with Sjögren's syndrome. The other four steps in the diagnostic process involve symptoms and findings of dryness in the mouth and eyes, and lower saliva and tear fluid production.
Chronic Dry Mouth Syndrome
Dry mouth is a relatively common disorder that increases with age: 40% of those aged 55 or older may be affected. It is also a common side effect of a number of medications like those against asthma, allergies, psychiatric illnesses, and depressions. Sjögren's syndrome, on the other hand, is a chronic disorder that also affects the tear glands, meaning that patients feel discomfort from both a dry mouth and dry eyes. At least 2,500 Norwegians suffer from the syndrome; primarily women from the age of menopause onset and older.
What causes Sjögren's syndrome is still unknown. – We are still searching for the cause of this syndrome, says Postdoctoral Fellow Lara Adnan Aqrawi from the Institute of Clinical Dentistry and the first author of the article. – But the strides we have taken towards simpler diagnosis will definitely also be of value when it comes to both finding the cause and better targeted treatment.
There is currently no known treatment for Sjögren's syndrome itself. The available treatment is aimed at alleviating symptoms. – However, if the syndrome has not already completely destroyed the patient's salivary and tear glands, then there is at least a chance that the deterioration can be slowed down, emphasizes Professor Hilde Kanli Galtung from the Department of Oral Biology, who contributes to the study.
The research project is a collaboration between the Dry Mouth Clinic (Institute of Clinical Dentistry) and the Department of Oral Biology at the Faculty of Dentistry, the Department of Rheumatology (Oslo University Hospital), the Dry Eye Clinic, the Department of Medical Biochemistry (Ullevål Hospital) and the Department of Biosciences (UiO).
Aqrawi, Lara A.; Galtung, Hilde Kanli; Vestad, Beate; Øvstebø, Reidun; Thiede, Bernd; Rusthen, Shermin; Young, Alix; Guerreiro, Eduarda M.; Utheim, Tor Paaske; Chen, Xiangjun; Utheim, Øygunn Aass; Palm, Øyvind & Jensen, Janicke Liaaen (2017). Identification of potential saliva and tear biomarkers in primary Sjögren’s syndrome, utilising the extraction of extracellular vesicles and proteomics analysis, Arthritis Research & Therapy, DOI: 10.1186/s13075-017-1228-x.