What is the significance of anti-SSA (Sjögren's syndrome antigen) IgG (Immunoglobulin G)?

From the Guidelines

Anti-SSA/Ro antibodies, also known as anti-SSA KD IgG, are a crucial diagnostic marker for autoimmune disorders, particularly Sjögren's syndrome and systemic lupus erythematosus (SLE), and their presence should prompt further evaluation and management to prevent potential complications, as recommended by the latest guidelines 1.

Key Points

• Anti-SSA/Ro antibodies target the SSA/Ro antigen, a ribonucleoprotein complex involved in cellular RNA processing.
• Testing for anti-SSA antibodies is typically done through blood tests like ELISA or immunoblotting, with positive results indicating potential autoimmune activity.
• The presence of these antibodies is particularly significant in pregnant women, as they can cross the placenta and potentially cause neonatal lupus or congenital heart block in the developing fetus.
• Management depends on the underlying condition and may include immunosuppressive medications, anti-inflammatory drugs, or hydroxychloroquine, as outlined in the EULAR recommendations for the management of Sjögren's syndrome 1.

Diagnosis and Management

• The diagnosis of Sjögren's syndrome is based on a combination of clinical symptoms, laboratory findings, and objective criteria, including the presence of anti-SSA/Ro antibodies.
• The latest classification criteria for Sjögren's syndrome include anti-SSA/Ro antibody positivity, focal lymphocytic sialadenitis, and other objective parameters, as outlined in the dry eye syndrome preferred practice pattern 1.
• Management of Sjögren's syndrome should involve a multidisciplinary approach, with a central role for specialists in autoimmune diseases, and may include topical therapies, systemic therapies, and lifestyle modifications to prevent or address potential complications.

Treatment Options

• Topical lubricants, topical anti-inflammatory therapy, and tear-conserving strategies may be effective in managing dry eye syndrome secondary to Sjögren's syndrome, as suggested by recent studies 1.
• Oral secretagogues, such as pilocarpine and cevimeline, may be effective in treating oral dryness, while topical anti-inflammatories, such as cyclosporine, may be effective in managing moderate or severe dry eye.
• B-cell targeted therapies, such as rituximab, may be considered in patients with severe, refractory systemic disease, as recommended by the EULAR guidelines 1.

From the Research

Anti-SSA Antibodies

• Anti-SSA antibodies are a type of autoantibody associated with various autoimmune diseases, including Sjögren's syndrome and systemic lupus erythematosus (SLE) 2, 3.
• There are two types of anti-SSA antibodies: anti-SSA-52 kDa and anti-SSA-60 kDa, each specific to different antigens 2.
• The presence of anti-SSA antibodies has been linked to an increased risk of congenital heart block (CHB) in fetuses of anti-SSA/Ro-positive mothers 4, 3.

Clinical Significance

• The clinical significance of anti-SSA antibodies is still being researched, with some studies suggesting that they may be associated with a specific clinical form of SLE or SSc 2.
• However, other studies have found that the presence of anti-SSA antibodies is not predictive of a specific clinical outcome 2, 5.
• The prevalence of anti-SSA antibodies in patients with rheumatoid arthritis (RA) is relatively low, and their presence may not be a significant predictor of disease activity or outcome 5.

Treatment and Management

• Hydroxychloroquine (HCQ) has been shown to reduce the recurrence of CHB in fetuses of anti-SSA/Ro-positive mothers 4.
• A combination of leflunomide and HCQ may be effective in treating primary Sjögren's syndrome (pSS) due to their additive immunosuppressive effects 6.
• Further research is needed to fully understand the clinical significance of anti-SSA antibodies and to develop effective treatment strategies for associated autoimmune diseases 2, 3.