Anti-La/SSB antibody
An autoantibody most often seen in Sjögren's syndrome, and usually alongside anti-Ro/SSA. Adding it helps confirm Sjögren's when dry eyes and dry mouth suggest it. It is rarely found on its own, so it is interpreted together with anti-Ro and the clinical picture.
What it measures
Anti-La/SSB is an autoantibody directed against the La/SSB protein inside cells, and it is one of the extractable nuclear antigen (ENA) antibodies tested after a positive ANA to identify a specific connective-tissue disease. It is closely tied to anti-Ro/SSA and is nearly always found together with it rather than alone. Its main association is Sjögren's syndrome — the autoimmune attack on the tear- and saliva-making glands that causes dry eyes and dry mouth — where the combination of anti-Ro and anti-La is a characteristic pattern that supports the diagnosis. Anti-La is also found in some people with lupus, again usually alongside anti-Ro. Because a positive anti-La on its own (without anti-Ro) is unusual and less clearly meaningful, the two are read together. Like other autoantibodies, a positive result is not a diagnosis by itself: it adds weight to a clinical picture of dry eyes, dry mouth, joint symptoms or other features, and is interpreted by a rheumatologist alongside the ANA, anti-Ro and the person's symptoms and examination.
What a high value can mean
- Sjögren's syndrome — the main association, especially together with anti-Ro/SSA, with dry eyes and mouth.
- Lupus — sometimes present, usually alongside anti-Ro.
- Typically seen with anti-Ro — a positive anti-La almost always accompanies a positive anti-Ro.
- An isolated anti-La positive — uncommon and of less certain significance.
What a low value can mean
- Negative — the expected result; makes Sjögren's less likely but does not exclude it, particularly as anti-Ro can be positive with anti-La negative.
When to discuss with a doctor
Anti-La/SSB is tested as part of the antibody work-up when Sjögren's syndrome or another connective-tissue disease is suspected — for example with persistent dry eyes and dry mouth, joint aches and a positive ANA. A positive anti-La, especially together with anti-Ro, supports Sjögren's, but it is always interpreted with the clinical picture by a rheumatologist rather than in isolation. Diagnosis usually combines the antibodies with symptoms and sometimes eye and gland tests. Mediora.AI can surface a positive anti-La alongside anti-Ro and ANA so the Sjögren's pattern is visible in your results, but confirming the diagnosis and planning care belongs with your doctor and rheumatologist.