ISR Autumn Meeting 2018

1st Place Poster Award

Dr Candice Low

TBA (18A149)

Arthroscopic Synovitis and Vascularity and C-reactive Protein Predict the Future Development of Rheumatoid Arthritis in Patients with Seropositive Arthralgia.

Author(s)

Candice Low, Richard Conway, Francis Young, Eamonn S Molloy, Anne Barbara Mongey, Oliver FitzGerald, Gerry Wilson, Ursula Fearon, Douglas J Veale

Department(s)/Institutions

Centre for Arthritis and Rheumatic Disease, St. Vincent’s University Hospital, University College Dublin, Ireland, and Department of Molecular Rheumatology, School of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland

Introduction

Arthralgia in patients who are seropositive for rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) is a precursor to rheumatoid arthritis (RA) in some but not all patients. The factors which influence progression and outcomes in these patients remain to be fully defined.

Aims/Background

To evaluate outcome and prognostic factors in a consecutive cohort of patients with seropositive arthralgia undergoing arthroscopy.

Method

We performed a prospective study of consecutive patients with seropositive arthralgia presenting to our outpatient clinic who underwent arthroscopy. All patients were seropositive for RF and/or ACPA. Demographic and clinical characteristics were collected on all patients. Synovial biopsy was performed by needle arthroscopy, and macroscopic and histologic features recorded. The degree of synovitis and vascularity were recorded on a 0–100-mm visual analog scale, and chondropathy on a semi-quantitative scale from 0-3. Diagnosis at last follow-up was recorded in all patients. Mann-Whitney U test was used to compare groups. Spearman’s Rank Correlation Coefficient was used to assess for associations with outcomes.

Results

33 patients were recruited. Mean (SD) age was 54 (12) years. 22 (67%) were female. 27 (82%) were positive for RF and 30 (91%) for ACPA with 24 (73%) dual positive. Mean (SD) follow-up was 29 (10) months. Baseline characteristics are shown in Table 1. Final diagnosis was RA in 24 (73%), psoriatic arthritis in 2 (6%), connective tissue disease in 1 (3%), calcium pyrophosphate arthritis in 1 (3%), and remained seropositive arthralgia in 5 (15%). Baseline CRP was significantly higher in patients who developed rheumatoid arthritis than those who remained seropositive arthralgia, mean (SD) 9.63 (16.63) vs 1.40 (0.55) mg/dL (p=0.005). Macroscopic synovitis and vascularity at arthroscopy were both significantly higher in those who developed RA than in those who remained as seropositive arthralgia, mean (SD) 60 (25) vs 28 (13) mm (p=0.009) and mean (SD) 56 (26) vs 26 (13) mm (p=0.012) respectively. Baseline DAS28-CRP, tender joint count, swollen joint count, and patient global assessment were not different between the groups. All patients who had plasma cells or lymphoid aggregates on baseline synovial biopsy progressed to RA over the course of the study.

Conclusions

Most but not all patients with seropositive arthralgia develop RA. Elevated baseline CRP and macroscopic synovitis and vascularity scores at arthroscopy predict the future development of RA.


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