There is no single test that can definitively diagnose Sjögren syndrome. Usually a health practitioner will order laboratory tests and other types of tests, and the results are considered with other factors such as signs and symptoms and results of a physical exam to make a diagnosis.
Laboratory tests to detect autoantibodies may include:
- Antinuclear antibodies (ANA) — a primary test for autoimmune disorders; this test is also positive in most cases of Sjögren syndrome.
- Antibodies specific to Sjögren syndrome — Anti-SS-A (also called Ro) and Anti-SS-B (also called La); the tests for these antibodies are often performed as part of an ENA panel and are frequently positive.
- Rheumatoid factor (RF) — may be positive
- Anti-dsDNA — also used to evaluate people for autoimmune diseases; this test is usually specific for lupus, but low levels may sometimes be seen with Sjögren syndrome.
Other general laboratory tests may include:
- Erythrocyte sedimentation rate (ESR) — detects inflammation and is often elevated in autoimmune diseases like Sjögren syndrome
- C-reactive protein (CRP) — another common test for inflammation, usually elevated
- Comprehensive metabolic panel (CMP) — evaluates the function of various organs, including the kidneys
- Complete blood count (CBC) — may be done to evaluate for anemia or low white blood count, which are sometimes seen in this disease
- Mouth (salivary gland) biopsy — a few small salivary glands may be removed surgically from a lip and then examined under a microscope. This is done to look for inflammation (accumulation of white blood cells called lymphocytes) in the gland. This is characteristic of Sjögren syndrome. (For more on biopsies, see the article on Anatomic Pathology.)
- Schirmer test — to measure tear production
- Rose Bengal or lissamine green staining of eye (cornea or conjunctiva) — to evaluate the extent to which dryness has damaged the surface of the eye
- Salivary flow — measures the amount of saliva produced over a specific time period
- Salivary scintigraphy — a nuclear medicine test in which a radioisotope is injected into a vein and tracked for how long it takes to reach salivary glands