AB1484 THE SIGNIFICANCE OF ANTI-DFS70 ANTIBODIES IN HEALTHY POPULATION AS A MARKER OF EXCLUSION OF SYSTEMIC AUTOIMMUNE RHEUMATIC DISEASES

Background The prevalence of anti-DFS70 antibodies in healthy volunteers (HV) by various methods ranges from 0 to 22% [1]. This pattern, which is rare patients with systemic autoimmune rheumatic diseases (SARDs), has been described as the second most common serum HV [2]. Objectives To study frequency detection HV, (pts) undifferentiated SARDs and lupus erythematosus (SLE). Methods A total 45 17 pts 81 SLE were included study. Groups comparable gender age among themselves. diagnosis was performed according ACR/EULAR 2019 classification criteria. Serum samples tested for (ANA HEp-2 ELITE/DFS70 knock-out IFA, “Trinity Biotech”, Ireland). Fluorescence titers ≥1:160 considered positive ANA cell patterns. Results Positive results found (100.0%) SLE, 16 (94.0%) 7 (15.6%) (Table 1). Abs DFS70 isolated, detected 4 (57.1%) 9 (56.2%) SARDs, but not pts. Classical patterns (homogeneous AC-1, speckled AC-4.5, homogeneous+speckled AC-1,4,5, cytoplasmic AC-19,20,21) without deficient 3 (42.9%) (43.8%) (100%) 2). Therefore, monospecific groups, a reliable SLE. Conclusion Monospecific can potentially be possible marker exclusion sign benign autoimmunity. References [1]Conrad K, Röber N, Andrade LEC, Mahler M. Clinical Relevance Anti-DFS70 Autoantibodies. Clinic Rev Allerg Immunol (2017) 52:202–216. [2]Mariz HA, Sato EI, Barbosa SH, Rodrigues Dellavance A, LEC (2011) Pattern on antinuclear antibody-HEp-2 test critical parameter discriminating antibody-positive individuals diseases. Arthritis Rheum 63:191–200. Disclosure Interests None declared