Dense fine speckled antinuclear antibody patterns: Clinical correlations and implications

Area of Science:

• Immunology
• Rheumatology
• Clinical Diagnostics

Background:

• The clinical significance of Dense Fine Speckled (DFS) pattern anti-nuclear antibodies (ANA) detected by indirect immunofluorescence (IIF) remains incompletely understood.
• Existing research has not definitively established the associations between positive ANA with a DFS pattern and various autoimmune and rheumatic conditions.

Purpose of the Study:

• To investigate the associations between a positive ANA test with a DFS pattern and multiple autoimmune and rheumatic conditions.
• To compare the prevalence of specific diagnoses in patients with DFS pattern ANA versus other ANA patterns.

Main Methods:

• A retrospective analysis of 13,845 patient ANA test results from August 2017 to August 2019.
• Comparison of diagnostic categories and specific diseases among patients with negative ANA, positive ANA (any pattern), and positive ANA with DFS pattern.
• Calculation of relative risk (RR) for diagnostic categories and individual diseases.

Main Results:

• Out of 13,845 ANA results, 34.2% were positive, with 4.6% exhibiting the DFS pattern.
• Among DFS pattern ANA-positive patients, common diagnoses included inflammatory arthritis (10.6%), fibromyalgia/chronic pain syndrome/chronic fatigue (20.6%), and systemic autoimmune rheumatic diseases (SARD) (13.3%).
• Specific diagnoses like seropositive rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and undifferentiated connective tissue disease (UCTD) were less frequent in the DFS pattern group compared to other ANA patterns.

Conclusions:

• The presence of a DFS pattern in ANA testing does not preclude the diagnosis of SARD or other rheumatic diseases.
• Diagnoses such as seronegative RA, idiopathic inflammatory myositis (IIM), Sjögren's syndrome (SS), autoimmune thyroid disorder, and autoimmune hepatitis showed no significant difference between the DFS pattern and other ANA patterns.