Are infections increased in rheumatoid arthritis (RA) prior to diagnosis? Results of a case control study of RA compared to non‐inflammatory musculoskeletal disorders

Time-varying risks of infection in patients as they proceed through the phases of 'pre-RA': results from the Scottish Early RA inception cohort

ObjectiveRheumatoid arthritis (RA) develops after progressing through sequential 'pre-RA' phases. The mechanisms driving progression from one phase to the next remain poorly understood. This study examined the longitudinal rates of community and hospital infections in patients during sequential stages of pre-RA and early arthritis.

METHODS

The Scottish Early RA inception cohort recruited patients with newly diagnosed RA. Incidences of infection were determined from community antibiotic prescriptions and serious infections were determined by hospital discharge coding. Dates of diagnosis and symptom onset allowed identification of asymptomatic/symptomatic pre-RA and early arthritis eras to analyse infection rates over time compared with age- and sex-matched controls.

RESULTS

The incidence rate ratio (IRR) seen in the period 0-6 months prior to symptom onset was 1.28 (95% CI 1.15 to 1.42). In 'symptomatic pre-RA', the IRR was 1.33 (95% CI 1.18 to 1.49) which persisted into 'early arthritis'. The rate of hospital admissions was numerically greater in 'pre-RA' and significantly greater in 'early arthritis' (IRR 1.82, 95% CI 1.32 to 2.46).

CONCLUSION

Antibiotic risk is increased in patients with 'pre-RA' at least 6 months before symptoms develop, and this persists throughout the symptomatic pre-RA phase. Infections may be important in the mechanisms that drive progression to RA or be a manifestation of immune dysfunction (or both). These observations could inform safety and efficacy considerations for interventions in pre-RA to prevent progression. Patients with 'pre-RA' with recurrent antibiotic use may also be an identifiable 'high risk' group that could enrich the study population for intervention studies in pre-RA.

Should tumour necrosis factor antagonist safety information be applied from patients with rheumatoid arthritis to psoriasis? Rates of serious adverse events in the prospective rheumatoid arthritis BIOBADASER and psoriasis BIOBADADERM cohorts

BACKGROUND

Information on the safety of tumour necrosis factor (TNF) antagonists frequently arises from their use in rheumatic diseases, their first approved indications, and is later applied to psoriasis. Whether the risk of biological therapy is similar in psoriasis and rheumatoid arthritis has been considered a priority research question.

OBJECTIVES

To compare the safety profile of anti-TNF drugs in patients with rheumatoid arthritis and psoriasis.

METHODS

We compared two prospective safety cohorts of patients with rheumatoid arthritis and psoriasis that share methods (BIOBADASER and BIOBADADERM).

RESULTS

There were 1248 serious or mortal adverse events in 16 230 person-years of follow-up in the rheumatoid arthritis cohort (3171 patients), and 124 in the 2760 person-years of follow-up of the psoriasis cohort (946 patients). Serious and mortal adverse events were less common in patients with psoriasis than in rheumatoid arthritis (incidence rate ratio of serious adverse events in psoriasis/rheumatoid arthritis: 0·6, 95% confidence interval 0·5-0·7). This risk remained after adjustment for sex, age, treatment, disease, hypertension, diabetes, hypercholesterolaemia and simultaneous therapy with methotrexate (hazard ratio 0·54, 95% confidence interval 0·47-0·61), and after excluding patients receiving corticosteroids. Patients with rheumatoid arthritis showed a higher rate of infections, cardiac disorders, respiratory disorders and infusion-related reactions, whereas patients with psoriasis had more skin and subcutaneous tissue disorders and hepatobiliary disorders.

CONCLUSIONS

Patients with rheumatoid arthritis clinical practice have almost double the risk of serious adverse events compared with patients with psoriasis, with a different pattern of adverse events. Safety data from rheumatoid arthritis should not be fully extrapolated to psoriasis. These differences are likely to apply to other immune-mediated inflammatory diseases.

Integrated neuroendocrine immune risk factors in relation to rheumatoid arthritis: should rheumatologists now adopt a model of a multiyear, presymptomatic phase?

An integrative perspective of neuroendocrine immune (NEI) and related risk factors for the onset of rheumatoid arthritis (RA) is presented, based upon studies of the long-term presymptomatic phase. Besides the recognized genetic markers and familial predisposition, multiple immunological precursors of RA have been identified many years before the clinical onset of inflammatory manifestations. Rheumatoid factors and related antibodies occur in approximately one-half of presymptomatic susceptibles. Cigarette smoking in sufficient amount and duration is a major risk factor for RA, particularly for postmenopausal-onset women and for men. In premenopausal-onset RA, subtle insufficiency of adrenal cortical function is less well recognized. In such women, cytokine imbalance may also precede inflammatory onset of RA. In males alone, multiple hormonal and cytokine correlations were found many years before the onset of RA, implying long-term activation or perturbation of this NEI system. The proposed physiopathogenetic model of RA requires further controlled, prospective studies for validation of the multiyear presymptomatic phase of RA. Such studies promise to clarify the currently unknown causal and sequential chains in this enigmatic disease.