From the Guidelines
A positive ANA with a speckled pattern at a titer of 1:160 suggests possible autoimmune disease, and the next step should be a comprehensive clinical evaluation and additional laboratory testing, including specific autoantibody tests such as anti-dsDNA, anti-Smith, anti-SSA/Ro, anti-SSB/La, anti-RNP, and anti-Jo-1, as recommended by recent guidelines 1. The differential diagnoses for a positive ANA with a speckled pattern at a titer of 1:160 include Systemic Lupus Erythematosus (SLE), Sjögren's syndrome, Mixed Connective Tissue Disease, Polymyositis/Dermatomyositis, and drug-induced lupus.
- The pattern and titer provide clues to potential diagnoses, with the speckled pattern often associated with SLE and Sjögren's syndrome 1.
- It's essential to note that a positive ANA at 1:160 can be found in approximately 5% of healthy individuals, so clinical correlation is crucial 1.
- Referral to a rheumatologist is recommended for patients with positive ANA and clinical symptoms suggestive of autoimmune disease for specialized evaluation and management, as they can provide guidance on the interpretation of autoantibody test results and the diagnosis of autoimmune diseases 1.
- The use of anti-dsDNA autoantibodies in the diagnosis and follow-up of SLE is recommended, with a double-screening strategy using a last-generation SPA in the first place, and subsequently, the CLIFT as the confirmation test 1.
- The laboratory report should always detail which method was used for ANA detection, and when several methods are used, the results obtained with each method should be reported 1.
From the Research
Differential Diagnosis
- Systemic lupus erythematosus (SLE) 2
- Other ANA-associated rheumatic diseases 2
- Chronic inflammatory conditions 3, 4
- Infections 4