Calprotectin (a major S100 leucocyte protein) predicts 10-year radiographic progression in patients with rheumatoid arthritis.

BACKGROUND: Plasma levels of calprotectin, a major S100 leucocyte protein, are cross-sectionally associated with clinical and laboratory markers of inflammation and with radiographic damage in rheumatoid arthritis (RA). High amounts of calprotectin are found in synovial fluid from patients with RA. OBJECTIVE: To examine whether calprotectin might be an independent predictor of joint destruction over time. METHODS: 124 patients with RA were assessed at baseline and after 10 years with inflammatory markers (calprotectin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR)), serological variables (antibodies to cyclic citrullinated peptide (anti-CCP), IgA rheumatoid factor (RF) and IgM RF) and radiographic and clinical assessments of joint damage (hand radiographs and Rheumatoid Arthritis Articular Damage (RAAD) score). Progression of radiographic damage was assessed according to the van der Heijde modified Sharp score. RESULTS: At both examinations the highest calprotectin levels were found in patients positive for anti-CCP, IgA and IgM RF. Calprotectin had moderate to good correlations with inflammatory and serological markers (r = 0.41-0.67). Patients with normal baseline calprotectin levels had a lower degree of joint damage. High univariate associations were found between baseline calprotectin levels and progression in the Sharp score as well as the RAAD score. Baseline calprotectin was independently associated with progression in the Sharp score and with the RAAD score in multiple linear regression analyses, including baseline levels of CRP, ESR, anti-CCP in addition to demographic variables. CONCLUSION: Calprotectin was an independent predictor of clinical and radiographic joint damage after 10 years. These findings support the proposal that calprotectin may be a prognostic biomarker for erosive disease in patients with RA.

The development of a preliminary ultrasonographic scoring system for features of hand osteoarthritis.

OBJECTIVES: Painful osteoarthritis (OA) of the hand is common and a validated ultrasound (US) scoring system would be valuable for epidemiological and therapeutic outcome studies. US is increasingly used to assess peripheral joints, though most of the US focus in rheumatic diseases has been on rheumatoid arthritis. We aimed to develop a preliminary US hand OA scoring system, initially focusing on relevant pathological features with potentially high reliability. METHODS: A group of experts in the fields of OA, US and novel tool development agreed on domains and suggested scaling of the items to be used in US hand OA scoring systems. A multi-observer reliability exercise was then performed to evaluate the draft items. RESULTS: Synovitis (grey scale and Power Doppler) and osteophytes (representing activity and damage domains) were included and evaluated as the initial components of the scoring system. All three features were evaluated for their presence/absence and if present were scored using a 1-3 scale. The reliability exercise demonstrated intra-reader kappa values of 0.444-1.0, 0.211-1.0 and 0.087-1.0 for grey scale synovitis, power Doppler and osteophytes respectively. Inter-reader reliability kappa values were 0.398, 0.327 and 0.530 grey-scale synovitis, power Doppler and osteophytes respectively. Without extensive standardisation, both intra- and inter-reader reliability were moderately good. CONCLUSIONS: The draft scoring system demonstrated substantive to almost perfect percentage exact agreement on the presence/absence of the selected OA features and moderate to substantive percentage exact agreement on semi-quantitative grading. This preliminary process provides a good basis from which to further develop an US outcome tool for hand OA that has the potential to be utilised in multicentre clinical trials.