From the Guidelines
A homogeneous ANA pattern is a significant indicator of systemic lupus erythematosus (SLE) and should be further investigated with specific antibody testing, such as anti-dsDNA, anti-histone, or anti-nucleosome antibodies, to confirm the diagnosis 1. The homogeneous ANA pattern is characterized by uniform staining of the entire nucleus in immunofluorescence testing, with a smooth, even fluorescence throughout the nucleus, and is typically seen with antibodies against DNA, histones, and nucleosomes. Some key points to consider when interpreting a homogeneous ANA pattern include:
- The pattern is commonly associated with SLE, but may also be seen in other autoimmune conditions, such as drug-induced lupus, juvenile idiopathic arthritis, and mixed connective tissue disease 1.
- The titer level is important for interpretation, as low titers may occur in healthy individuals, while higher titers (typically >1:80) are more likely to be clinically significant 1.
- Further specific antibody testing is usually recommended to confirm the diagnosis when a homogeneous pattern is identified, and a double-screening strategy using a last-generation SPA and CLIFT as the confirmation test is recommended for anti-dsDNA testing 1.
- The presence of anti-dsDNA antibodies is a key diagnostic criterion for SLE, and the detection of these antibodies can help confirm the diagnosis, especially in patients with a high degree of clinical suspicion 1.
- The use of antiphospholipid antibodies, such as anticardiolipin, anti-β2GP1, and/or lupus anticoagulant, can also increase the likelihood of SLE in patients with a homogeneous ANA pattern and clinical suspicion of the disease 1.
From the Research
Homogeneous ANA Pattern
- The homogeneous ANA pattern is one of the standard patterns in immunofluorescence antinuclear antibodies (ANA) 2
- This pattern is seen in 5-9% of ANA in various conditions, including autoimmune diseases and malignancies 2
- The homogeneous pattern is classified as AC-8 in the International Consensus on ANA Patterns (ICAP) classification 2
- Specificities known to show the AC-8 homogeneous pattern include anti-Th/To, -PM-Scl, -nucleophosmin/B23, -nucleolin/C23, -No55, and others 2
Clinical Significance
- The clinical significance of antinucleolar antibodies (ANoA) remains to be established, although they have been associated with scleroderma (SSc) and other systemic autoimmune rheumatic diseases (SARDs) 2
- ANoA have also been reported in malignancies, graft versus host disease (GVHD), and other conditions 2
- The characterization of nucleolar antigens has identified several autoantigens recognized by SSc autoantibodies, including anti-Th/To, PM-Scl, fibrillarin/U3RNP, and RNA polymerase I 2
Treatment and Diagnosis
- The diagnosis and treatment of systemic autoimmune diseases, including systemic lupus erythematosus (SLE), often involve the detection of autoantibodies such as ANA 3
- Belimumab, a human immunoglobulin G1λ monoclonal antibody, has been approved for the treatment of non-renal SLE and has been shown to be effective in reducing disease activity and improving health-related quality of life 4, 5
- The use of belimumab in combination with standard therapy has been associated with a low incidence of organ damage and a decrease in disease activity and severe flares 5, 6