ANTI-SSA RO52 AND ANTI-RO60 AUTOANTIBODIES: ASSOCIATION WITH CLINICAL PHENOTYPES

C. Mazeda, N. Oliveira, C. Abreu, V. Fraga, A. Maduro, A. Saraiva, L. Inês, C. Campinho Ferreira, A. M. Gomes Correia, R. Nicolau, F. Farinha, I. Villanueva, D. Jesus, P. M. Azevedo Abreu, A. Neto, J. Silva-Dinis, A. BarcelosCentro Hospitalar Baixo Vouga, Rheumatology, Aveiro, Portugal Egas Moniz Health Alliance Academic Clinical Center, Egas Moniz Health Alliance Academic Clinical Center, Aveiro, Portugal University of Aveiro, Department of Mathematics, Aveiro, Portugal Hospital Garcia de Orta, Rheumatology, Almada, Portugal Centro Hospitalar e Universitário de Coimbra, Rheumatology, Coimbra, Portugal Universidade da Beira Interior, Faculty of Health Sciences, Covilhã, Portugal Hospital de Braga, Rheumatology, Braga, Portugal Centro Hospitalar e Universitário São João, Rheumatology, Porto, Portugal Hospital Distrital de Santarém, Rheumatology, Santarém, Portugal Hospital Distrital de Santarém, Clinical Pathology, Santarém, Portugal Centro Hospitalar de Leiria, Rheumatology, Leiria, Portugal University of Beira Interior, Faculty of Health Sciences, Covilhã, Portugal ULS Castelo Branco, Rheumatology, Castelo Branco, Portugal Hospital Nélio Mendonça, Rheumatology, Funchal, Portugal Centro Hospitalar Universitário Lisboa Central, Rheumatology, Lisboa, Portugal Universidade NOVA de Lisboa, Comprehensive Health Research Center, Lisboa, Portugal  Background Anti-SSA autoantibodies can be differentiated according to their antigenic target proteins as anti-Ro60 (60 kDa) or anti-Ro52 (52 kDa). Anti-SSA(Ro60) are clearly associated with Connective Tissue Diseases (CTD), but the clinical significance of anti-SSA(Ro52) remains unclear. Objectives To analyze the disease phenotype of patients with anti-Ro52 and/or anti-Ro60. Methods Multicenter, cross-sectional study of anti-Ro52 and/or Ro60 positive patients followed at 10 Rheumatology centers from January 2018 until December 2021. Patients were categorised into 3 groups: group 1 (Ro52+/Ro60-); group 2 (Ro52-/Ro60+); group 3 (Ro52+/Ro60+). Antinuclear antibodies were evaluated by indirect immunofluorescence assay and further screened for anti-extractable nuclear antigen (ENA) antibodies. Demographics and clinical data were compared between the 3 groups, by patients’ medical chart review. Univariate analysis was performed using chi-square, Fisher’s exact or Kruskall-Wallis test. Subsequently, the Bonferroni test was used to identify intergroup differences (level of significance: p<0.0167). Univariate logistic regression was used to calculate the odds ratio with a 95% confidence interval (CI). Results We included 776 patients [female: 83.1%; median age: 59 (46-71) years]. Groups 1, 2 and 3 comprised 31.1%, 32.6%, and 36.3% of the patients, respectively. Characteristics of the groups are presented in Table 1. Anti-Ro52 alone is more frequently associated with non-rheumatic diseases, older age, and men (p<0.05). Among patients with CTD, the diagnosis of systemic lupus erythematosus is 3 and 2 times more prevalent in groups 2 and 3, respectively, than in group 1 [OR 2.8 (95% CI 1.60, 4.97),p=<0.001; OR 2.2 (95% CI 1.28, 3.86), p=0.007]. In group 2, the diagnosis of undifferentiated connective tissue disease is more frequent than in the other groups. The presence of isolated Ro52+ is more frequently associated with inflammatory myositis than in group 2 [OR 0.09 (95% CI 0.01, 0.33), p=<0.001] or group 3 [OR 0.08 (95% CI 0.01, 0.29), p=<0.001]. Group 1 was also more frequently associated with arthritis (p=0.006), interstitial lung disease (p=0.002), and myositis (p=0.009). Table 1. Characteristics of the study population according to the groups of anti-SSA(Ro) positivity. Group 1 (n=241) Group 2 (n=253) Group 3 (n=282) p Age, median (IQR) 64 (52-76) 56 (44-67) 57 (44-69) <0.001 Female, n (%) 185 (76.8) 214 (84.6) 246 (87.2) 0.005 Other anti-ENA, n (%)  Anti-La 24 (10) 50 (19.8) 114 (40.4) <0.001  Anti-RNP 11 (4.6) 23 (9.1) 17 (6.0) 0.115  Anti-Scl70 3 (1.2) 4 (1.6) 6 (2.1) 0.146  Anti-Jo1 7 (3) 1 (0.4) 3 (1.1) 0.070  Anti-Sm 1 (0.4) 7 (2.8) 6 (2.13) 0.098 Anti-dsDNA 11 (4.6) 39 (15.4) 37 (13.1) <0.001 Anti-centromere 12 (5) 3 (1.2) 6 (2.1) 0.026 Lupus anticoagulant 10 (4.2) 32 (12.7) 23 (8.2) 0.008 Anti-cardiolipin 8 (3.3) 10 (3.9) 23 (8.2) 0.024 Anti-β2 glycoprotein 1 6 (2.5) 10 (3.9) 10 (3.6) 0.736 Rheumatoid Factor 46 (19.1) 44 (17.4) 81 (28.7) 0.001 Anti-CCP 11 (4.6) 15 (5.9) 19 (6.7) 0.327 Non-rheumatologic disease, n (%) 77 (32) 35 (13.8) 30 (10.6) <0.001  Infections 11 (14.3) 2 (5.7) 1 (3.3) 0.192  Neoplasms 22 (28.6) 3 (8.6) 6 (20.0) 0.057  Interstitial lung disease 5 (6.5) 4 (11.4) 0 0.168  Other diseases 46 (59.7) 25 (71.4) 22 (73.3) - Immune-mediated rheumatologic disease, n (%) 164 (68.1) 218 (86.2) 252 (89.4) <0.001  Sjögren syndrome 92 (56.1) 88 (40.3) 150 (59.5) <0.001  Systemic lupus erythematosus 20 (12.2) 61 (28) 59 (23.4) 0.001  Systemic sclerosis 11 (6.7) 7 (3.2) 8 (3.2) 0.150  Inflammatory myositis 15 (9.2) 2 (0.9) 2 (0.8) <0.001  Rheumatoid arthritis 18 (11) 17 (7.8) 16 (6.4) 0.234  Undifferentiated connective tissue disease 11 (6.7) 35 (16.1) 21 (8.3) 0.004  Mixed connective tissue disease 6 (3.7) 6 (2.8) 4 (1.6) 0.406  Other diseases 9 (5.5) 8 (3.7) 10 (4.0) - Conclusion Anti-Ro52+ alone is frequently found in patients with non-rheumatic diseases. In addition, anti-Ro52+ is also prevalent in patients with CTD and associated with clinical phenotypes that are different from anti-Ro60+. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests None Declared. Keywords: Diagnostic tests DOI: 10.1136/annrheumdis-2023-eular.1841Citation: , volume 82, supplement 1, year 2023, page 759Session: Diagnostics and imaging procedures (Poster View)