Anti-SS-B Ab

What is Anti-SS-B Ab?

Antibodies (anti-La) targeting a nuclear protein, most often associated with Sjögren's syndrome and often seen with anti-Ro.

Anti-SS-B (anti-La) antibodies target a ribonucleoprotein involved in RNA processing and are closely linked to Sjögren's syndrome, a condition affecting the glands that produce tears and saliva. They are less common than anti-Ro antibodies but, when both are present together, more strongly support a Sjögren's-related process. Anti-SS-B antibodies can also appear in lupus and, similar to anti-Ro, are relevant during pregnancy due to a small associated risk of fetal heart rhythm changes. Clinicians typically order this test alongside anti-Ro and ANA when dryness, joint symptoms, or lupus-like features are present. A positive result is one clue interpreted together with symptoms and other antibody findings.

Tests often checked alongside this

• Anti-Ro (SS-A) Ab — most often tested and positive together
• ANA Pattern and ANA Titer — commonly reviewed alongside
• Complement C3 and C4 — may be checked in suspected lupus overlap

How this can show up in how you look and feel

• May be associated with dry eyes or dry mouth
• May be associated with joint pain or stiffness
• May be associated with fatigue

What can affect this marker

• Age
• Sex
• Pregnancy
• Medications
• Lab variability between testing methods

What to track over time

• Whether antibody levels remain stable on repeat testing
• How results align with dryness and joint symptoms over time
• Whether monitoring is considered during pregnancy

What to ask your doctor

• How does this result relate to my anti-Ro result and my symptoms?
• Does this finding have any relevance if I am pregnant or planning a pregnancy?
• Should I also be evaluated for Sjögren's syndrome or lupus?
• Is any follow-up testing recommended?

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