Association between risk, duration and cause of hospitalisations in people with rheumatoid arthritis and multimorbidity in the UK Biobank and Scottish Early Rheumatoid Arthritis (SERA) cohorts: longitudinal observational study

Objectives: To investigate association between presence of multimorbidity in people with established and early rheumatoid arthritis (RA) and risk, duration and cause of hospitalisations. Design: Longitudinal observational study. Setting: UK Biobank, population-based cohort recruited between 2006 and 2010, and the Scottish Early Rheumatoid Arthritis (SERA), inception cohort recruited between 2011 and 2015. Both linked to mortality and hospitalisation data. Participants: 4757 UK Biobank participants self-reporting established RA; 825 SERA participants with early RA meeting the 2010 ACR/EULAR classification criteria. Participants stratified by number of long-term conditions (LTCs) in addition to RA (RA only, RA + 1 LTC and RA + ≥ 2 LTCs) and matched to five non-RA controls. Main outcome measures: Number and duration of hospitalisations and their causes. Incidence rate ratios (IRR) and 95% confidence intervals (CI) calculated using negative binomial regression models. Results: Participants with RA + ≥ 2 LTCs experienced higher hospitalisation rates compared to those with RA alone (UK Biobank: IRR 2.10, 95% CI 1.91 to 2.30; SERA: IRR 1.74, 95% CI 1.23 to 2.48). Total duration of hospitalisation in RA + ≥ 2 LTCs was also higher (UK Biobank: IRR 2.48, 95% CI 2.17 to 2.84; SERA: IRR 1.90, 95% CI 1.07 to 3.38) than with RA alone. Rate and total duration of hospitalisations was higher in UK Biobank RA participants than non-RA controls with equivalent number of LTCs. Hospitalisations for respiratory infection were higher in early RA than established RA and were the commonest cause of hospital admission in early RA. Conclusions: Participants with established or early RA with multimorbidity experienced a higher rate and duration of hospitalisations than those with RA alone and with non-RA matched controls

Detection of inflammation in vivo by surface-enhanced Raman scattering provides higher sensitivity than conventional fluorescence imaging

The detection of inflammatory changes is a key aim for the early diagnosis and treatment of several autoimmune, infectious, and metastatic diseases. While surface-enhanced Raman scattering (SERS) has the capability to provide noninvasive, in vivo imaging at sufficient depth to achieve this goal, this approach has not been exploited in the study of inflammation. SERS-active nanoparticles were coded with a unique Raman signal that was protected under a wide range of conditions and stimuli. To detect early-stage inflammation, gold nanoparticle clusters containing Raman-active molecules were conjugated to intercellular adhesion molecule 1- (ICAM-1-) specific monoclonal antibodies. SERS allowed noninvasive measurement of ICAM-1 expression in vivo with twice the sensitivity of two-photon fluorescence. This is the first time SERS has been used for in vivo detection of inflammation and is a major advance in the ever-growing toolkit of approaches for use in noninvasive, next-generation in vivo imaging