Sonoelastography, a fast and non-invasive imaging technique that detects increases in tissue rigidity in salivary glands, may help to diagnosis of primary Sjögren’s syndrome, a study suggests.
The study, “Is sonoelastography a helpful method of evaluation to diagnose Sjögren’s syndrome?,” was published in the International Journal of Rheumatic Diseases.
Sjögren’s syndrome is an autoimmune disease characterized by the infiltration of immune cells into certain glands, including those that produce tears or saliva. As a consequence, glands are damaged and patients often experience dry eyes and mouth.
Currently, the disease is diagnosed through the evaluation of ocular and oral symptoms and damage, by levels of autoantibodies, and tissue biopsy analysis. A need exists for a less-invasive, quicker and low-cost procedure that accurately identifies patients affected with Sjögren’s syndrome.
Sonoelastography is a simple non-invasive tool that uses acoustic radiation force impulses, a type of ultrasound, to create three-dimensional patterns that can be used to measure tissue stiffness and elasticity.
Because Sjögren’s syndrome causes inflammation and scarring of the salivary glands, sonoelastography is seen as a promising approach in identifying these changes and helping to diagnose patients.
With this in mind, a Spanish team tested the procedure in 41 Sjögren’s patients and 18 people with dry eyes and mouth but not this autoimmune disease. An additional 29 healthy volunteers were used as controls.
Participants underwent oral examination and blood tests for autoantibodies, along with a detailed analysis of eye symptoms, saliva production, and saliva gland biopsy. (Autoantibodies are antibodies, or immune system proteins, that mistakenly target and react with a person’s own tissues or organs.)
Data revealed that Sjögren’s syndrome patients had higher shear wave velocities in their salivary glands — indicating scarred, stiffer glands — compared to controls. The most affected glands were the submandibular (located beneath the mouth’s floor), and the parotid glands, the largest of the salivary glands, located on either side of the mouth and in front of both ears.
People with primary Sjögren’s syndrome had stiffer glands than those with secondary disease — when Sjögren’s is caused or associated with another autoimmune condition — or those with dry eye or mouth symptoms alone.
“It is known that inflammation and fibrosis increase shear wave velocity,” the investigators wrote. “Different combinations of inflammation and fibrosis produce varying but relatively stable shear wave velocities that can be used to monitor the disease progress.”
No significant differences were reported between patients with secondary disease and those with dry eye/mouth symptoms, but researchers believe that sonoelastography “may provide a non‐invasive, simple, quick and economical diagnostic method within the foreseeable future.”