Sjögren's disease is an autoimmune disorder that affects glands that produce saliva and tears, making mouth and eye mucosas dry. An insufficient amount of saliva limits its antibacterial effects, which increases the risk of cavities development, leads to food processing complications, and generally worsens oral health.
This disorder has no cure for now, and doctors can only manage patients' symptoms; however, recently, a group of scientists revealed its biological causes and suggested a possible rheumatology drug that can be used in Sjögren's disease treatment.
How does the disease work?
First of all, scientists looked at the Stim1 and Stim2 genes in salivary gland cells responsible for calcium uptake. This mineral is crucial for organism work, especially cell signaling. In mice model experiments, scientists found that cells without these genes produce a low amount of saliva. However, in these animals, scientists also observed lower levels of inflammatory molecules that associated with autoimmune Sjögren's disease.
In the next study, scientists researched T-cells (involved in immune response) in a similar mouse model to reveal the nature of inflammation. In animals without Stim1 and Stim2 genes, regulatory T-cell functions were disrupted, causing inflammation that resulted in dry eyes, dry mouth, and autoantibodies in salivary glands.
In further analysis, scientists confirmed that the autoimmune response during Sjögren's disease is mainly caused by problems with the regulatory T-cells. Still, this dysfunction may be caused not only by calcium issues and problems with Stim1 and Stim2 genes but also by other factors.
Possible treatment
Disrupted regulatory T-cells cause the production of a substance called interferon-gamma, directly causing dry mouth by an inflammatory process. To manage this issue, scientists tried to use baricitinib – the drug suppressing interferon receptor – usually used for rheumatoid arthritis, alopecia, or COVID patients.
Researchers received promising results – this drug demonstrated salivary gland dysfunction suppression in mice. It means that this medicine may be adapted for therapy, possibly treating Sjögren's disease.
