# Clinical implications of seropositive and seronegative autoantibody status in rheumatoid arthritis patients: A comparative multicentre observational study

## TL;DR

This study compares disease characteristics in rheumatoid arthritis patients based on their autoantibody status, finding that dual antibody-positive patients have higher disease activity and risk of metabolic syndrome.

## Contribution

The study provides new insights into how autoantibody status correlates with disease severity and metabolic syndrome in rheumatoid arthritis patients.

## Key findings

- Dual seropositive RA patients show higher disease activity and functional impairment.
- Dual seropositive patients have a higher risk of developing metabolic syndrome.
- Single RF positivity is associated with fibromyalgia and longer disease duration.

## Abstract

Rheumatoid factor (RF) and anti-cyclic citrullinated protein (anti-CCP) have been used to improve the diagnosis and prognosis of rheumatoid arthritis (RA). However, their association with RA disease phenotypes, individually and in combination, is not well studied. The aim of the study was to compare patients’ and disease characteristics, activity and severity in double seronegative (DNRA), single seropositive RF, single seropositive anti-CCP and double seropositive (DPRA) patients.

Adults subjects with RA from Egyptian College of Rheumatology (ECR) database who had RF and anti-CCP results available were included. Demographic, clinical features, disease activity score 28 (DAS28), Health Assessment Questionnaire (HAQ) and laboratory data were collected and compared among different RA groups.

5268 RA patients with mean age of 44.9±11.6 years, and 4477 (85%) were females. 2900 (55%) had DPRA, 892 (16.9%) had single positive RF, 597 (11.3%) had single positive anti-CCP while 879 (16.7%) had DNRA. Patients with DPRA had significantly high percentage of metabolic syndrome (19.3%, P < 0.001), and functional impairment using HAQ (P = 0.01). Older age (RRR [relative risk ratio]: 1.03, 95%CI: 1.0, 1.0, P = 0.029), greater DAS28 (RRR: 1.51, 95%CI: 1.2, 1.9, P < 0.001), higher steroid use (RRR: 2.4, 95%CI: 1.36, 4.25, P = 0.002) were at higher risk of DPRA while longer disease duration (RRR: 1.08, 95%CI: 1.01, 1.16, P = 0.017) and fibromyalgia syndrome (RRR: 2.54, 95%CI: 1.10, 5.88, P = 0.028) were associated with higher odds of single positive RF status.

Dual antibody-positive status has higher disease activity and severity, and higher chance of development of metabolic syndrome; highlighting the implicated role of inflammation, atherogenesis and cardiovascular disease risk in RA.