Antinuclear antibodies in infectious diseases

Area of Science:

• Infectious Diseases
• Rheumatology
• Immunology

Background:

• Antinuclear antibody (ANA) tests are crucial for diagnosing autoimmune conditions.
• However, positive ANA results are also observed in patients with various infections.
• Understanding this overlap is vital for accurate diagnosis and patient management.

Purpose of the Study:

• To investigate the relationship between infections and antinuclear antibody (ANA) status.
• To identify common infectious agents associated with positive ANA findings.
• To explore potential links between infections and the development of rheumatic diseases.

Main Methods:

• Retrospective analysis of 9,320 patients from January 2007 to July 2018 at Inha University Hospital.
• Reviewed ANA test results and rheumatic/infectious diagnoses for 1,111 patients who underwent ANA testing.
• Focused on 110 patients with positive ANA results to identify underlying causes.

Main Results:

• 110 out of 1,111 patients (9.9%) tested positive for ANA.
• Of these, 43 patients were diagnosed with infectious diseases.
• Common pathogens included Mycobacterium tuberculosis, Treponema pallidum, and Orientia tsutsugamushi. Some patients developed autoimmune diseases post-infection.

Conclusions:

• The study highlights significant associations between infections and positive ANA results.
• Intracellular infections such as mycobacterial infections, syphilis, and scrub typhus are frequently linked to positive ANA.
• Positive ANA in the absence of clear autoimmune disease warrants investigation for underlying infections.