Treating axial and peripheral spondyloarthritis, including psoriatic arthritis, to target: results of a systematic literature search to support an international treat-to-target recommendation in spondyloarthritis

BACKGROUND

Current recommendations for the management of axial spondyloarthritis (SpA) and psoriatic arthritis are to monitor disease activity and adjust therapy accordingly. However, treatment targets and timeframes of change have not been defined. An international expert panel has been convened to develop 'treat-to-target' recommendations, based on published evidence and expert opinion.

OBJECTIVE

To review evidence on targeted treatment for axial and peripheral SpA, as well as for psoriatic skin disease.

METHODS

We performed a systematic literature search covering Medline, Embase and Cochrane, conference abstracts and studies in http://www.clinicaltrials.gov.

RESULTS

Randomised comparisons of targeted versus routine treatment are lacking. Some studies implemented treatment targets before escalating therapy: in ankylosing spondylitis, most trials used a decrease in Bath Ankylosing Spondylitis Disease Activity Index; in psoriatic arthritis, protocols primarily considered a reduction in swollen and tender joints; in psoriasis, the Modified Psoriasis Severity Score and the Psoriasis Area and Severity Index were used. Complementary evidence correlating these factors with function and radiographic damage at follow-up is sparse and equivocal.

CONCLUSIONS

There is a need for randomised trials that investigate the value of treat-to-target recommendations in SpA and psoriasis. Several trials have used thresholds of disease activity measures to guide treatment decisions. However, evidence on the effect of these data on long-term outcome is scarce. The search data informed the expert committee regarding the formulation of recommendations and a research agenda.

Arthroscopic surgical tools: a source of metal particles and possible joint damage

PURPOSE

Our goals were (1) to characterize metal microparticles created by standard arthroscopic instruments and (2) to examine the in vitro cellular responses induced by those particles, including possible synergistic effects with local anesthetic.

METHODS

We applied standard surgical tools to 16 foam bone blocks immersed in saline solution (plus 3 non-instrumented controls). Eight specimens underwent 4 minutes of exposure to a 4.0-mm full-radius shaver rotating forward at 6,000 rpm. In the other blocks, 4 holes were created with a 3.0-mm drill through a sleeve. Particles were isolated onto silicon wafers by density gradient ultra-centrifugation, and scanning electron microscopy was used to analyze a minimum of 1,000 particles per wafer. Metal particles were then isolated and purified. Aliquots of sterilized micro-particles were applied to cultured bovine chondrocytes (with or without local anesthetic) and to cultured human or bovine synoviocytes. Chondrocyte viability was assessed with live/dead cell assay by flow cytometry. Synoviocyte responses were assessed with quantitative polymerase chain reaction.

RESULTS

Stainless steel or aluminum particles were found in each sample (the same composition as surgical instruments). The mean particle size was 1 to 2 μm (range, 50 nm to 20 μm). Chondrocyte exposure (1 hour) to metal debris induced a small but statistically significant increase in cell death, without any synergistic effect of local anesthetic. Proinflammatory chemokines were consistently upregulated in both human and bovine synoviocytes exposed to metallic microparticles for 3, 24, and 48 hours.

CONCLUSIONS

This study shows that metallic microdebris is liberated by common arthroscopic instruments, at scales much smaller than previously recognized. These particles are bioactive, as shown by the in vitro synoviocyte responses initiated by metallic microparticles.

CLINICAL RELEVANCE

Our findings suggest that metallic microparticles could induce intra-articular damage through a synoviocyte-mediated cytokine response if their concentrations reach clinically significant levels.