AUTHOR=Freudenhammer Mirjam , Salzer Ulrich , Heselich Aileen , Hufnagel Markus , Janda Ales 

TITLE=Low Prevalence of Anti-DFS70 Antibodies in Children With ANA-Associated Autoimmune Disease

JOURNAL=Frontiers in Pediatrics

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.839928

DOI=10.3389/fped.2022.839928

ISSN=2296-2360

ABSTRACT=<sec><title>Introduction</title><p>Anti-DFS70 antibodies occur in healthy individuals with various medical conditions. Unlike other anti-nuclear autoantibodies (ANA), they are not associated with systemic autoimmune disease in adult patients. To date, only a few studies have addressed the prevalence and/or clinical relevance of anti-DFS70 autoantibodies in children with and without autoimmune disease.</p></sec><sec><title>Methods</title><p>Included in this retrospective cross-sectional mono-centric study were 308 pediatric patients with suspected or known autoimmune conditions who had a positive ANA in indirect immune fluorescence (IIF) screening and who were screened for anti-DFS70 antibodies by extractable nuclear antigen antibodies (ENA) immunoblot. Patients were assigned to four different diagnostic categories according to their diagnosis in the corresponding medical record: (a) absence of autoimmune or rheumatic disease (noARD, <italic>n</italic> = 116); (b) suspected autoimmunity without definitive diagnosis (sAI, <italic>n</italic> = 48); (c) other rheumatic disease (ORD) (<italic>n</italic> = 115); and (d) ANA-associated autoimmune disease (AARD, <italic>n</italic> = 29).</p></sec><sec><title>Results</title><p>The prevalence of anti-DFS70 antibodies in the overall cohort was 33.8%. Among children without ARD (46.6%, 54/116), prevalence was significantly higher than among children with ORD (23.7%, 27/115, <italic>p</italic> = 0.0003) or AARD (17.2%, 5/29, <italic>p</italic> = 0.0054). Among all of the anti-DFS70 positive patients with AARD, other autoantibodies were found in the ENA immunoblot. In contrast, among anti-DFS70 positive patients with ORD (11.5%, 4/27), sAI (33.3%, 6/18) and noARD (16.7%, 9/54), other autoantibodies infrequently were detected (<italic>p</italic> = 0.0005). Patients with uveitis rarely were positive for anti-DFS70 antibodies (7.7%, 1/13). No association was found between anti-DFS70 antibodies and a history of allergic conditions (<italic>p</italic> = 0.51). The concordance between a typical DFS pattern in IIF and the detection of anti-DFS70 antibodies by immunoblot was 59.3%.</p></sec><sec><title>Conclusion</title><p>As with adults, the higher prevalence of anti-DFS70 among children without autoimmune disease confirms the mutual exclusion for this autoantibody in the pathogenesis of ARD. Among ANA-positive children, monospecific anti-DFS70 antibodies may help to discriminate between AARD and not-AARD-related conditions.</p></sec>