SAT0580 ANALYSIS OF ANAS/DFS70 PATTERN IN A LARGE COHORT OF AUTOIMMUNE/AUTOINFLAMMATORY DISEASES COMPARED WITH FIRST DEGREE RELATIVES AND HEALTHY CONTROLS EVALUATED IN A SINGLE HOSPITAL FROM COLOMBIA.
Authors: C. Romero-Sánchez, O. J. Calixto, V. Romero-A, A. Vargas, L. Castro, J. Amador, P. Lopez-Mojica, D. Marin, D. Acero-M, M. Acevedo, D. Rincón-Riaño, J. M. Bello-Gualtero
Journal: Annals of the Rheumatic Diseases (2020)

Background: Autoimmune diseases have a broad phenotypic spectrum, with great variability in clinical manifestations. Anti-DFS70/LEDGFp75 (ANAS/DFS70) antibodies have attracted interest as a positive result in patients without clinical evidence of autoimmune systemic rheumatic disease (SARD). It has been proven in non-rheumatic inflammatory diseases and in “apparently healthy” individuals. Objectives: To assess ANAS/DFS70 performance in a large population with autoimmune/autoinflammatory diseases compared with first degree relatives and healthy controls. Methods: A cross-sectional study was conducted. We analysed 531 individuals between 18-65 years old, 101 rheumatoid arthritis (RA) patients (ACR/EULAR 2010 classification criteria), 137 relatives from RA, 60 psoriasis (Ps) patients (Colombian classification consensus), 47 Undifferentiated connective tissue diseases(UCTD) patients and 186 healthy controls matched by age and sex. The healthy control group were individuals who lived and work similarly like those patients those criteria of exclusion criteria were to present autoimmune or auto-inflammatory disease, infectious, neoplasms, diabetes, antibiotic treatment, pregnancy or lactation, consanguinity with autoimmune entities. Ethical Committee approved. The determination of ANAS-HEp2 antibodies (ANA-Hep-2 AESKU.Dignostic®, Autoantiboy test SYSTEM IMCO DIAGNOSTICS REF 1103® and ANA-Hep-2 AESKU.Dignostic®) was carried out. The positive results (standard AC-2) are used as a confirmatory test the determination of ANAS / DFS70: AUTOANTIBOY TEST SYSTEM IMMCO DIAGNOSTICS (Knocked out, for the psip gene) REF 1108® and CytoBead ANA Generic Assays ref 8065 ® by indirect immunofluorescence-IFI technique. In addition, serum levels of C-reactive protein (PCR), erythrocyte sedimentation rate (ESR), IgG/IgA antibodies against citrullinated peptide (ACPA), and rheumatoid factor (RF). Absolute and relative frequencies were established. Results: 531 participants were included: RA 19%, 25,8% RA relatives, Ps 11,3%, UCTD 8,9%, and 35% healthy controls. RA mean age was 41,8±12,2 years, female 82,2%, with ANA test(+) result 42%. In Ps mean age 49,1±15,7 years, female 53,3%, ANA test(+) 41,7%. UCTD mean age 41,3±15,2 years, female 85,1%, and ANA test(+) 78,7%. Relatives of RA mean age 38,7±12,2 years, female 73%, ANA test(+) 26,3%. And healthy controls mean age 41,3±12,2 years, female 74,7%, and ANA test(+) 26,9%. ANA/DFS70 was positive in a 6,4% in UCTD, 3,2% in healthy controls, 1,7% in Ps, 1,5% in Relatives of RA, no RA had positive results. These 12 participants were negative for acute phase reactants (ESR[-] 83,3% and CRP[-] 66,6%), as well as they were all negative for RF and two were positive for APCA from UCTD. Conclusion: ANAS/DFS70 autoantibodies were present in very low frequency in patients with SARD. Thus, patients with a positive result tend to have a mild or non-progressing phenotype of autoimmune/inflammatory diseases, as UTCD. This is the first time ANA/DFS70 are tested in a large population cohort in Latin American countries which coincide with previous results in RA and RA relatives. Acknowledgments: Hospital Militar Central-Universidad El Bosque-Immco diagnosis-Dizar Ltda and Generic Assay-Medipan. Disclosure of Interests: Consuelo Romero-Sánchez: None declared, Omar-Javier Calixto Employee of: Worked in Janssen Cilag as medical manager from 2016 to 2018, V Romero-A: None declared, A Vargas: None declared, Luis Castro: None declared, Julio Amador: None declared, Pedro Lopez-Mojica: None declared, Daniela Marin: None declared, Diana Acero-M: None declared, M Acevedo: None declared, Diana Rincón-Riaño: None declared, Juan Manuel Bello-Gualtero: None declared