AB0351 ELDERLY-ONSET RHEUMATOID ARTHRITIS (EORA): DIFFERENCES ACCORDING TO CLINICAL DEBUT AND SEROLOGICAL POSITIVITY

Abstract

Background In patients with Elderly-onset Rheumatoid Arthritis (EORA) has been described a clinical debut mimicking polymyalgia rheumatica with rhizomelic pseudopolyarthritis, in contrast with the classical profile of patients with Rheumatoid Arthritis similar to younger patients. We compare in our study these two profiles of the disease. Objectives To describe and compare the differences according to clinical debut, serological positivity and its implications in terms of treatment and prognostic factors in patients with Elderly-onset Rheumatoid Arthritis (EORA). Methods Patients with a diagnosis of RA over 65 years of age according to ACR/EULAR 2010 criteria were included. A database was created including the age of onset, the presence of polymyalgia-like symptoms (rhizomelic pseudopolyarthritis), the positivity of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs), elevation of acute phase reactants (APR), the presence of erosions and the treatment required. Finally, data was analyzed according to clinical debut, serological positivity and prognostic factors. Results 83 patients diagnosed of EORA were included, with an average age of 73.8 years. 71.25% had positive RF (58.75% high titers) and 62.5% had positive ACPA (52.3% high titers). 24/83 patients (29%) debuted with a polymyalgia-like symptoms. 47.5% had persistent APR elevation during follow-up. Regarding treatment, 15% were treated only with corticosteroids, 81.5% required treatment with DMARDs and 15% were receiving biological treatment. 42/83 patients (50%) had erosions on plain X-rays. Of those patients with a polymyalgia-like profile, 52.2% (43/83) had positive RF but most of them had low titers (61%). On the other hand, patients without polymyalgia-like symptoms had positive RF in 78% of the cases and most of them at high titers (66%, p = 0.01). In the first group there was less positivity for ACPAs (26%, p = 0.00004) and half of them had low titers. Erosions were observed in only 30% of the patients with polymyalgia-like symptoms, while those without this profile had more erosions (58%, p = 0.02) and higher APR (50%, p = 0.026). Regarding treatment, in the group with polymyalgia-like symptoms only 34% were treated with corticosteroids, 65% required DMARDs and no patients had received biological treatment, whereas in the non-polymyalgic group, 88% required DMARDs and 21% required biologics (p = 0.01 for both results). Analyzing patients with positive RF and ACPAs at high titers, 93% received treatment with DMARDs and 24% required biological treatment. 65% had persistent elevation of APR and 48% presented erosions on plain X- rays. Only 2 patients with positive RF and ACPAs at high titers debuted with a polymyalgia-like symptoms. Conclusion Patients with EORA with polymyalgia-like symptoms tend to have less erosions and a higher prevalence of negative RF and ACPA or at low titers. These patients usually require less DMARDs and biological treatments to control the disease unlike patients with non-polymyalgia symptoms. On the other hand, patients with high RF and ACPA titers have more erosions and elevated APR during follow-up but do not usually experience polymyalgia-like symptoms. Reference [1] Tutuncu Z, Reed G, Kremer J, Kavanaugh A. Do patients with older-onset rheumatoid arthritis receive less aggressive treatment?. Ann Rheum Dis. 2006;65(9):1226-9. Disclosure of Interests None declared