What are Anti-Ro (SS-A) antibodies?

From the Guidelines

Anti-Ro antibodies are a significant indicator of autoimmune conditions, particularly in Sjögren's syndrome and systemic lupus erythematosus (SLE), and their presence should be closely monitored, especially in pregnant women, as they can increase the risk of neonatal lupus or congenital heart block 1.

Key Points

• Anti-Ro antibodies, also known as anti-SSA antibodies, are autoantibodies that target the Ro antigen found in certain tissues.
• These antibodies are commonly detected in autoimmune conditions such as Sjögren's syndrome, systemic lupus erythematosus (SLE), and neonatal lupus.
• Testing for anti-Ro antibodies is typically done through blood tests as part of an autoimmune panel.
• The presence of these antibodies is particularly significant for pregnant women, as they can cross the placenta and potentially cause neonatal lupus or congenital heart block in the developing fetus.

Monitoring and Management

• Women who test positive for anti-Ro antibodies during pregnancy often require increased monitoring, including regular fetal echocardiograms starting at 16-18 weeks of gestation.
• Management typically involves close observation rather than specific medication, though hydroxychloroquine may be recommended in some cases to reduce the risk of complications.
• The antibodies target intracellular ribonucleoproteins that play roles in cellular RNA processing, and their presence indicates a breakdown in immune tolerance where the body's immune system mistakenly attacks its own tissues.

Recommendations

• According to the EULAR/ACR 2019 criteria, ANA detection using the IFI or a solid-phase ANA screening immunoassay (SPA) with at least equivalent performance is recommended 1.
• The laboratory report should always detail which method was used; when several methods are used, reporting the results obtained with each method is recommended 1.
• Patients with SLE are at high risk of infections, and prevention should be recommended, including the administration of inactivated vaccines (especially flu and pneumococcus) following the Centers for Disease Control (CDC) guidelines for patients who are immunosuppressed 1.

From the Research

Ant Ro Antibodies

• Anti-Ro antibodies are associated with various connective tissue diseases, including systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) 2, 3, 4, 5, 6
• The presence of anti-Ro antibodies can be used as a diagnostic criterion for Sjögren's syndrome, particularly when combined with anti-La antibodies 4, 5
• Different profiles of anti-Ro antibodies, such as anti-Ro52 and anti-Ro60, are associated with different clinical characteristics and disease manifestations 3, 6
• Anti-Ro52 antibodies are often found in patients with idiopathic inflammatory myopathy and SLE, while anti-Ro60 antibodies are more commonly associated with Sjögren's syndrome and SLE 3, 6
• The presence of combined anti-Ro52 and anti-Ro60 antibodies is associated with a higher risk of xerophthalmia and xerostomia, as well as other clinical features such as hypocomplementemia and hyperglobulinemia 6

Clinical Significance

• The clinical significance of anti-Ro antibodies can vary depending on the specific disease and patient population 2, 3, 4, 5, 6
• Anti-Ro antibodies can be used as a prognostic marker for disease activity and flare-ups in some patients, particularly those with Sjögren's syndrome 2, 5
• The presence of anti-Ro antibodies can also be associated with extraglandular manifestations, such as interstitial lung disease and pulmonary arterial hypertension 6

Disease Associations

• Anti-Ro antibodies are commonly found in patients with SLE and Sjögren's syndrome, as well as other connective tissue diseases such as idiopathic inflammatory myopathy and rheumatoid arthritis 2, 3, 4, 5, 6
• The presence of anti-Ro antibodies can be associated with specific disease manifestations, such as skin vasculitis and oral ulcers 2, 3