Sjögren's syndrome B (anti-SSB)

Anti‑SS‑B (also called anti‑La) are autoantibodies targeting the La/SS‑B protein. Their presence supports a diagnosis of Sjögren’s syndrome—often alongside anti‑SS‑A/Ro—by indicating autoimmune attack on salivary and tear glands. Anti‑SS‑B is less sensitive but fairly specific, not diagnostic alone; detection prompts further evaluation for systemic involvement and related autoimmune conditions.

A positive anti‑SS‑B (La) antibody indicates an autoimmune response commonly linked to Sjögren’s syndrome and sometimes seen in systemic lupus erythematosus or other connective tissue diseases. It supports—but does not alone confirm—a diagnosis. Clinically it correlates with dry eyes and dry mouth and may signal broader systemic involvement. Further evaluation by a clinician and additional tests are recommended.

The Sjogren's anti‑SSA (Ro) test is a blood test that detects antibodies against SSA/Ro proteins. A positive result supports a diagnosis of Sjogren's syndrome and other autoimmune conditions (like lupus), often linked to dry eyes, dry mouth, and systemic features. It’s not definitive alone—clinical findings and other tests are needed. Positive anti‑SSA may affect treatment and pregnancy counseling due to neonatal risks.

SS‑A (anti‑Ro) and SS‑B (anti‑La) are autoantibodies against cellular ribonucleoproteins, often tested in systemic lupus erythematosus and Sjögren’s syndrome. Anti‑Ro (Ro52/Ro60) links to photosensitive and subacute cutaneous lupus and can cause neonatal lupus with congenital heart block. Anti‑La is more commonly associated with Sjögren’s and milder SLE; both aid diagnosis and risk assessment.

Sjögren’s A (anti‑SSA/Ro) and Sjögren’s B (anti‑SSB/La) are autoantibodies used in diagnosis. Anti‑SSA/Ro is more common, can occur alone, and is linked with systemic features and risks such as neonatal lupus and congenital heart block. Anti‑SSB/La is less frequent, usually appears with anti‑SSA, and is more specific for Sjögren’s; both help predict disease pattern and monitoring.

A normal anti‑SSB (La) antibody result is negative — i.e., below the laboratory’s reference cutoff, commonly reported as <10–20 U/mL depending on the assay. Values above the lab‑specific cutoff are considered positive and may suggest autoimmune conditions (e.g., Sjögren’s syndrome) and require clinical correlation. Review results with your clinician because reference ranges vary by lab and test method.