AB0155 COMPARATIVE ANALYSES OF SEROLOGICAL BIOMARKERS AND DISEASE CHARACTERISTICS BETWEEN ELDERLY ONSET RHEUMATOID ARTHRITIS (EORA) AND YOUNGER ONSET RHEUMATOID ARTHRITIS (YORA)
Authors: S. Rajalingham, S. S. Shaharir, H. Mahadzir
Journal: Annals of the Rheumatic Diseases (2021)

Background: Several studies have reported differences in disease characteristics between elderly onset RA (EORA: age of onset &gt; 60 years) and younger-onset RA (YORA). However, the findings across the studies have been rather inconsistent owing partially to the genetic variation across the populations studied. While a few studies have looked into the clinical aspects of EORA, there is a profound lack of comparative data on serological findings between EORA and YORA. Seropositive RA is known to be associated with more aggressive disease and the titres of the autoantibodies may predict the disease activity and the severity of radiographic progression. Objectives: The main aim of this study was to compare the levels of the autoantibodies namely anti–CCP (cyclic citrulinated peptide), IgA, IgM, IgG rheumatoid factors(RF) and disease characteristics between the EORA and YORA groups. Methods: We consecutively recruited a total of 151 female RA patients who were tested for IgA RF, IgG RF, IgM RF and anti CCP antibodies. Participants were aged above 18 years and met the 2010 ACR/EULAR RA criteria. Data on the disease characteristics (age at onset, disease activity at onset, disease duration and medications)were obtained by reviewing the medical records of the subjects. Subjects were divided into 2 groups i.e EORA and YORA based on age at onset of RA. All subjects were assessed for the severity of radiographic joint damage and functional disability based on Modified Sharp Score (MSS) and Health-assessment questionnaire-disability index (HAQ- DI), respectively. The EULAR response criteria was used to determine the subjects’ response to disease-modifying anti-rheumatic drugs. Results: The EORA group had 69 patients whereas the YORA group had 82 patients. The mean anti-CCP and IgA RF levels were significantly higher in the YORA group with p values of 0.002 and 0.035, respectively. The YORA group had significantly more severe disease at onset (p value for DAS 28 at onset was 0.009) with worse radiographic joint damage (p value for MSS was 0.006). In parallel with these findings, the YORA group had significantly higher ESR and CRP at onset with higher frequency of subjects requiring advanced therapies. The differences in frequency of RF positivity, disease duration, number of DMARDs, prednisolone dose and HAQ-Di scores between the groups did not reach statistical significance. Conclusion: EORA is characterized by lower levels of anti-CCP and IgA autoantibodies with less aggressive disease as compared to YORA. References: [1]Calvo-Alen J, Corrales A, et al.Clinical rheumatology 2005;24:485-9. [2]Huscher D, Sengler C, Ochs W, et al. Clinical and experimental rheumatology 2013;31:256-62. [3]Mueller RB, Kaegi T, et al. Rheumatology 2014;53:671-7. Table 1. Comparison of disease characteristics between EORA and YORA Parameter EORA (n=69 ) YORA(n=82 ) p value Age (years)* 67.19± 2.49 31.93± 5.10 &lt;0.050 Disease duration (years)* 8.06±5.04 8.70± 3.63 0.365 DAS28 at onset* 3.29± 1.37 3.96± 1.68 0.009 RF positive at onset 47 (68.11) 62 (75.61) 0.306 Anti CCP titre* 84.52±117.97 151.14±138.02 0.002 IgA RF titre* 24.15±39.54 43.14±64.82 0.035 IgM RF titre* 68.58±97.65 72.74±93.28 0.789 IgG RF titre* 64.36±66.01 70.88±69.58 0.558 ESR at onset(mm/hr)* 54.20± 20.50 67.04± 23.60 0.001 CRP at onset(mmol/L)* 1.33± 1.37 3.79± 8.11 0.019 No. of DMARDS 1 45 (65.21) 41 (50.00) 2 16 (23.19) 32 (39.02) 0.106 3 8 (11.59) 9 (10.98) On biologics &amp; tsDMARD 12 (17.39) 35 (42.68) 0.008 Prednisolone dose (mg)* 2.83 ± 3.32 2.77 ± 3.02 0.920 Treatment Response Good 50 (72.46) 54 (65.86) 0.487 Moderate 15 (21.74) 19 (23.17) None 4 (5.80) 9 (10.98) MSS* 10.04±12.79 17.49±19.04 0.006 HAQ-DI* 1.47±0.87 1.58±0.71 0.397 Data presented as either counts (percentages) or mean ± SD* Disclosure of Interests: None declared