Background The relationship between systemic rheumatic diseases such as rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosing spondylitis (AS) and various comorbidities has long been debated, and it has also been observed that patients with RA and SpA develop adverse events during anti-TNF therapy.
Objectives The primary aim of this multicenter study was to identify the most frequent comorbidities and adverse events (AEs) in RA, PsA and AS patients on the basis of the data in the LORHEN register. The secondary aim was to identify the effect of biological anti-TNF on adverse events development.
Methods The study involved 2253 patients with RA (mean age 46.21±14.7 years; mean disease duration 14.8±8.9 years; F(%)=82.0%), 372 with long-standing PsA (mean age 41.2±13.5 years; mean disease duration 11.6±7.6 years; F(%)=38.3%), and 410 with AS (mean age 36.8±13.3 years; mean disease duration 11.6±8.9 years; F(%)=47.7%), all of whom had been treated with biological drugs for at least six months or had discontinued therapy due to serious adverse events. Of the RA patients, 34.4% had been treated with two DMARDs before receiving biological therapy, whereas the majority of PsA and AS patients had been treated with only one DMARD (respectively 40.22% and 39.85%). Many patients were treated with low-dose corticosteroids (<7.5 mg/day): 94.72% of the RA patients, 75.41% of the PsA patients, and 55.92% of the AS patients. Most of the patients were treated with the anti-TNF agents ADA, IFN, ETN, GOL and CTZ, but some RA patients were treated with ABA or TCZ. Logistic regression analysis corrected by age, gender, disease duration, smoking habit, study centre and therapy or diagnosis if appropriate were used.
Results Many of the patients suffered from comorbidities, particularly hypertension (20.13% of the RA patients, 10.36% of the PsA patients, and 7.28% of the AS patients), cardiovascular diseases (CVD; respectively 2.15%, 0.35% and 1.53%), dyslipidemia (4.05%, 3.93% and 1.92%), osteoporosis (12.53%, 3.21% and 5.75%). The most frequent adverse events were infections (48.7%, 34.15% and 30.32%), neoplasias (5.03%, 5.28% and 4.07%), and CVD (4.82%, 2.85% and 1.81%). The odds ratios (ORs) for the risk of a comorbidity between the different disease groups were: PsA vs RA: 0.35 (95% CI 0.24-0.50); PsA vs AS: 0.81 (95% CI 0.53-1.23); and RA vs AS: 2.33 (95% CI 1.59-3.39). The ORs of developing an adverse event were: PsA vs RA: 0.48 (95% CI 0.35-0.66); PsA vs AS: 0.96 (95% CI 0.66-1.41); and RA vs AS: 1.99 (95% CI 1.38-2.86). The ORs of the effect of anti-TNF vs no anti-TNF therapy on adverse events were 0.68 (95% CI 0.42-1.10) in the RA group; 5.49 (95% CI 1.12-26.92) in the PsA group; and 3.38 (95% CI 0.42-27.11) in the AS group.
Conclusions Our results suggest that patients with RA are at greater risk of having comorbidities and developing adverse events than those with AS, but not those with PsA. The effect of anti-TNF therapy on the development of adverse events is greater in AS and PsA patients than in RA patients.
Disclosure of Interest None declared