Does the immunology specialty deal with elevated Antinuclear Antibodies (ANA)?

From the Guidelines

Yes, immunology specialists deal with elevated antinuclear antibody (ANA) levels, as they are crucial in diagnosing and managing autoimmune diseases such as systemic lupus erythematosus (SLE) and Sjögren's syndrome. Immunologists are physicians who specialize in diagnosing and treating disorders of the immune system, including autoimmune conditions that often present with elevated ANA. When a patient has a positive ANA test, an immunologist can evaluate the clinical significance of this finding, determine if additional autoantibody testing is needed (such as anti-dsDNA, anti-Smith, anti-Ro/SSA, anti-La/SSB antibodies), and assess for specific autoimmune diseases like SLE, Sjögren's syndrome, or mixed connective tissue disease, as recommended by recent studies 1.

Key Considerations

• The EULAR/ACR 2019 classification criteria consider ANA positive when detected at a titer ≥1:80 by the indirect immunofluorescence test on HEp-2 cells (IFI) 1.
• The specificity of ANA detection for SLE is 74.7% (IC 95%: 66.7% - 81.3%) when using the 1:80 cut-off point, which is lower than the specificity observed when using the EULAR/ACR 2019 criteria as a whole 1.
• Elevated ANA can occur in healthy individuals, especially at low titers, and can also be associated with certain medications, infections, or advancing age, making the immunologist's expertise valuable in distinguishing clinically significant elevations from those that don't require treatment 1.
• The use of alternative automated methods for ANA detection, such as ELISA and chemiluminescence immunoassay, has been recommended, but their performance characteristics differ from those of IIFA, and their results should be interpreted with caution 1.

Clinical Implications

• Immunologists work closely with rheumatologists in the diagnosis and management of autoimmune disorders, and their expertise is essential in interpreting ANA test results and determining the clinical significance of elevated ANA levels 1.
• The correct interpretation of ANA test results requires consideration of the clinical context, including the patient's symptoms, medical history, and other laboratory test results, as emphasized in recent studies 1.
• The development of standardized protocols for ANA testing and interpretation is crucial to ensure accurate diagnosis and management of autoimmune diseases, as recommended by international guidelines 1.

From the FDA Drug Label

The trial evaluated BENLYSTA 200 mg once weekly plus standard therapy compared with placebo once weekly plus standard therapy over 52 weeks in patients with active SLE disease Patients had to have a SELENA-SLEDAI score of ≥8 and positive autoantibody test (anti-nuclear antibody [ANA] and/or anti-double-stranded DNA [anti-dsDNA]) results at screening.

• Immunology specialty: deals with conditions related to the immune system, including autoimmune diseases like Systemic Lupus Erythematosus (SLE).
• Elevated ANA: is a common indicator of autoimmune diseases, particularly SLE.
• The immunology specialty does deal with conditions characterized by elevated ANA, as it is a key marker for SLE and other autoimmune diseases. 2

From the Research

Immunology Specialty and Elevated ANA

• The immunology specialty deals with the study of the immune system and its disorders, including autoimmune diseases that can cause elevated antinuclear antibodies (ANA) 3, 4.
• ANA are autoantibodies that attack self-proteins within cell nucleus structures, and their presence in serum may indicate an autoimmune disease 3.
• The presence of ANA in patient blood specimens is detected using a cell-line substrate from human laryngeal carcinoma (HEp-2 cells), and the fluorescence patterns visualized under the fluorescence microscope can be correlated with certain subtypes of ANA and certain autoimmune diseases 3.

Relationship Between ANA and Autoimmune Diseases

• A high ANA titer seems to be a useful biomarker for the diagnosis of autoimmune diseases, especially for patients presenting with joint pain, fever, abnormal urinalysis, or skin rash/skin tightness 4.
• The classification and diagnosis of systemic autoimmune diseases are frequently based on a collection of criteria composed of clinical, laboratory, imaging, and pathology elements that are strongly associated with the respective disease, including the presence of ANA 5.
• Autoantibodies, including ANA, are a distinctive hallmark and have a prominent position in the classification criteria of many autoimmune diseases, such as systemic lupus erythematosus (SLE) and juvenile idiopathic arthritis (JIA) 5.

Management of Autoimmune Diseases with Elevated ANA

• Synthetic drugs, such as hydroxychloroquine, azathioprine, and mycophenolate mofetil, are commonly used to manage autoimmune diseases, including SLE 6, 7.
• Biologic agents, such as belimumab, have also been approved for the treatment of SLE and can play a significant role in the management of SLE-associated chronic serositis 6.
• The use of ANA as a criterion for classification and diagnosis of systemic autoimmune diseases can be improved by restricting the staining patterns accepted for each disease to those relevant to the respective autoantibody specificities 5.