AB0111 FAMILIAL RHEUMATOID ARTHRITIS WITH LATE ONSET (50 YEARS AND OLDER) IN CLINICAL PRACTICE ACCORDING TO THE ALL-RUSSIAN ARTHRITIS REGISTER (OREL)
Authors: A. Satybaldyev, O. Rumyantseva, N. Demidova, E. Gerasimova, E. Strebkova, J. Murtazalieva, E. Koltsova, M. Nikolenko, G. Lukina, E. Zhilyaev, E. Nasonov
Journal: Annals of the Rheumatic Diseases (2021)

Background: Relatives of the 1st degree of relationship (RFDR) of a patient with rheumatoid arthritis (RA) have the higher risk for the development of RA, associated with a 2-5 fold increase. Objectives: Clinical characteristics of probands with RA onset at an older age (50 yrs and older) and their RFDR, which had RA, other rheumatic diseases (RD) and other autoimmune diseases (AID). Methods: 2766 RA pts with onset of the disease at the age of 50 yrs and older, residents of Moscow and the Moscow region, were included in the Russian register of arthritis OREL in the period from 01.06.2012 to 31.12.2018. 67 probands with RA (2.4%) had RFDRs with RA, other RDs, other AIDs (86 RFDRs in total). Disease activity (by DAS-28), X-ray stage - (by modified Steinbrocker), functional disorders (by functional class - FC), immunological characteristics (RF, ACPA), etc., characterizing the clinical manifestations of RA were evaluated in accordance with the requirements of the current national working RA classification. RFDRs were divided into groups depending on relation to proband father, mother and siblings with RA, RFDRs withr other RD and RFDR with other AID; serological affiliation to RF and ACPA; association with concordant and discordant RFDR, as well as on number of RFDRs (1 and 2 or more). Results: 67 probands with RA were investigated: 9 men, 58 women, average age in debut (m ± δ) 58.78 ± 6.23 yrs; the average age at the time of the last study was 68.8 ± 6.38 yrs, average duration of RA was 10.14 ± 5.69 yrs. 6 (9%) probands had FC1, 45 (69%) - FC2, 13 (20%) - FC3, 1 (2%) - FC4, 2 - without data; 34 (53%) had high activity, 23 (36%) -medium, 6 (9%) - minimal, 1 (2%) - remission, 3 without data; RF-positive (RF+) - 77.6%, ACPA-positive (ACPA+) - 71.7%. 19 probands (32%) had 1-2a X-ray stage, 27 (46%) - stage 2b, 10(17%) - stage 3, 3 (5%) - stage 4, 8 - without data. 61 (91%) had advanced clinical stage, 6 (9%) - late. Among 86 RFDRs (67 - RF+, 19 - RF-) 10 had father with RA (8 RF+ probands, 2 - RF-), 2 - father with other RDs (all RF+), 10 - mother with RA (all RF+), 7 - mother with other RDs (4 - RF+, 3 - RF-), 26 - siblings with RA (20 - RF+, 6 - RF-), 11 - siblings with other RDs (9 - RF+, 2 - RF-), 20 - RFDR with other AIDs (14 - RF+, 6 - RF-). Probands with concordant RFDRs had more pronounced changes: high activity (56% versus 32%), X-ray erosive stages (67% versus 60%) and stages III and IV (32% versus 6%); FC3 and FC4 (23% versus 12%) and a tendency towards more frequent development of the late clinical stage (11% versus 2%). Comparison of clinical signs in probands with 1 RFDR (49 cases) and probands with 2 or more RFDRs (17 cases) showed a significant predominance of high inflammatory activity (61% versus 41%), erosive arthritis (77% versus 57%), and a tendency to development of a late clinical stage (10% versus 6%) in probands with 1 RFDR. In probands with RF-positive RA, the predominance becomes more significant: high inflammatory activity (69% versus 43%), erosive arthritis (90% versus 54%), late clinical stage (13% versus 7%), and a tendency to severe functional impairment - FC3 and FC4 (22% vs. 15%). ACPA-positive probands showed the same tendency as RF-positive. Conclusion: The clinical picture of probands with RFDRs with RA, other RDs, other AIDs is generally characterized by more pronounced changes in probands with RA who have RFDRs with concordant diseases in the form of more often high inflammatory activity, less often moderate, erosive arthritis, more frequent development of advanced 3 and 4 X-ray stages (every fifth). Also, more pronounced changes develop in probands with RA who have only 1 RFDR compared to probands with 2 or more RPSRs. In this group, the differences are even more pronounced in the case of RF-positive probands. In cases with ACPA-positive probands, the same trends persist. Careful interview of a proband with RA about the presence of RFDRs with RA, other RDs and other AIDs will make it possible to predict its course more correctly and facilitate planning of rational therapy. Disclosure of Interests: None declared