Anti-Ro/SSA antibody
An autoantibody found mainly in Sjögren's syndrome and lupus. It helps confirm these connective-tissue diseases when the symptoms fit, and it has a special importance in pregnancy, where it can affect the baby's heart — so it is checked when these conditions are suspected.
What it measures
Anti-Ro/SSA is an autoantibody — the immune system mistakenly making antibodies against one of the body's own proteins (the Ro/SSA proteins inside cells). It is one of the 'extractable nuclear antigen' (ENA) antibodies, usually tested after a positive ANA to work out which connective-tissue disease is present. Anti-Ro/SSA is most strongly linked to Sjögren's syndrome, where the immune system attacks the glands that make tears and saliva, causing dry eyes and dry mouth; it is present in most people with this condition. It is also common in lupus, where it can be associated with sun-sensitive skin rashes and, in some, milder disease. Its most distinctive importance is in pregnancy: anti-Ro/SSA can cross the placenta and affect the baby, causing a temporary rash (neonatal lupus) or, more seriously but rarely, damage the baby's heart's electrical conduction (congenital heart block). For this reason it is checked in women with these conditions who are planning or are pregnant, so the pregnancy can be monitored. A positive result is interpreted alongside symptoms — it is not, on its own, a diagnosis.
What a high value can mean
- Sjögren's syndrome — the strongest association; present in most people with it, with dry eyes and mouth.
- Lupus — common, often with sun-sensitive skin rashes.
- Relevance in pregnancy — can cross the placenta and cause neonatal lupus or, rarely, congenital heart block in the baby.
- Other connective-tissue diseases — sometimes present.
- A low-level positive without symptoms — can occur and may not indicate disease.
What a low value can mean
- Negative — the expected result; makes Sjögren's and anti-Ro-related lupus less likely, though it does not exclude them.
When to discuss with a doctor
Anti-Ro/SSA is tested when a connective-tissue disease such as Sjögren's syndrome or lupus is suspected — for example with dry eyes and mouth, a sun-sensitive rash, joint pains and a positive ANA. A positive result supports the diagnosis but is always read with the clinical picture by a rheumatologist. Its most important practical use is in pregnancy: a woman known to be anti-Ro positive needs her pregnancy monitored, because of the small risk to the baby's heart, and this should be discussed and planned with the specialist team. Mediora.AI can surface a positive anti-Ro/SSA alongside ANA and anti-La so the pattern is visible, but confirming a connective-tissue disease and managing any pregnancy risk belongs with your doctor and rheumatologist.