Disease modification in osteoarthritis: Are drugs the answer?

Doxycycline for osteoarthritis of the knee or hip

BACKGROUND

Osteoarthritis is a chronic joint disease that involves degeneration of articular cartilage. Pre-clinical data suggest that doxycycline might act as a disease-modifying agent for the treatment of osteoarthritis, with the potential to slow cartilage degeneration. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To examine the effects of doxycycline compared with placebo or no intervention on pain and function in people with osteoarthritis of the hip or knee.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library 2008, issue 3), MEDLINE, EMBASE and CINAHL up to 28 July 2008, with an update performed at 16 March 2012. In addition, we checked conference proceedings, reference lists, and contacted authors.

SELECTION CRITERIA

We included studies if they were randomised or quasi-randomised controlled trials that compared doxycycline at any dosage and any formulation with placebo or no intervention in people with osteoarthritis of the knee or hip.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate. We contacted investigators to obtain missing outcome information. We calculated differences in means at follow-up between experimental and control groups for continuous outcomes and risk ratios (RR) for binary outcomes.

MAIN RESULTS

We identified one additional trial (232 participants) and included two trials (663 participants) in this update. The methodological quality and the quality of reporting were considered moderate. At end of treatment, clinical outcomes were similar between the two treatment groups, with an effect size of -0.05 (95% confidence interval (CI) -0.22 to 0.13), corresponding to a difference in pain scores between doxycycline and control of -0.1 cm (95% CI -0.6 to 0.3 cm) on a 10-cm visual analogue scale, or 32% versus 29% improvement from baseline (difference 3%; 95% CI -5% to 10%). The effect size for function was -0.07 (95% CI -0.25 to 0.10), corresponding to a difference between doxycycline and control of -0.2 (95% CI -0.5 to 0.2) on the Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability subscale with a range of 0 to 10, or 24% versus 21% improvement (difference 3%; 95% CI -3% to 10%). The difference in changes in minimum joint space narrowing assessed in one trial was in favour of doxycycline (-0.15 mm; 95% CI -0.28 to -0.02 mm), which corresponds to a small effect size of -0.23 standard deviation units (95% CI -0.44 to -0.02). More participants withdrew from the doxycycline group compared with placebo due to adverse events (RR 2.28; 95% CI 1.06 to 4.90). There was no evidence that participants in the doxycycline group experienced more serious adverse events than those in the placebo group, but the estimate was imprecise (RR 1.07; 95% CI 0.68 to 1.68).

AUTHORS' CONCLUSIONS

In this update, the strength of evidence for effectiveness outcomes was improved from low to moderate and we confirmed that the symptomatic benefit of doxycycline is minimal to non-existent, while the small benefit in terms of joint space narrowing is of questionable clinical relevance and outweighed by safety problems. The CIs of the summary estimates now exclude any clinically relevant difference in improvement of symptoms and the small benefit in terms of joint space narrowing does not outweigh the harms.

Biomechanical modulation of collagen fragment-induced anabolic and catabolic activities in chondrocyte/agarose constructs

INTRODUCTION

The present study examined the effect of collagen fragments on anabolic and catabolic activities by chondrocyte/agarose constructs subjected to dynamic compression.

METHODS

Constructs were cultured under free-swelling conditions or subjected to continuous and intermittent compression regimes, in the presence of the N-terminal (NT) and C-terminal (CT) telopeptides derived from collagen type II and/or 1400 W (inhibits inducible nitric oxide synthase (iNOS)). The anabolic and catabolic activities were compared to the amino-terminal fibronectin fragment (NH2-FN-f) and assessed as follows: nitric oxide (NO) release and sulphated glycosaminoglycan (sGAG) content were quantified using biochemical assays. Tumour necrosis factor-alpha (TNFalpha) and interleukin-1beta (IL-1beta) release were measured by ELISA. Gene expression of matrix metalloproteinase-3 (MMP-3), matrix metalloproteinase-13 (MMP-13), collagen type II and fibronectin were assessed by real-time quantitative polymerase chain reaction (qPCR). Two-way ANOVA and the post hoc Bonferroni-corrected t-test was used to examine data.

RESULTS

The presence of the NT or CT peptides caused a moderate to strong dose-dependent stimulation of NO, TNFalpha and IL-1beta production and inhibition of sGAG content. In some instances, high concentrations of telopeptides were just as potent in stimulating catabolic activities when compared to NH2-FN-f. Depending on the concentration and type of fragment, the increased levels of NO and cytokines were inhibited with 1400 W, resulting in the restoration of sGAG content. Depending on the duration and type of compression regime employed, stimulation with compression or incubation with 1400 W or a combination of both, inhibited telopeptide or NH2-FN-f induced NO release and cytokine production and enhanced sGAG content. All fragments induced MMP-3 and MMP-13 expression in a time-dependent manner. This effect was reversed with compression and/or 1400 W resulting in the restoration of sGAG content and induction of collagen type II and fibronectin expression.

CONCLUSIONS

Collagen fragments containing the N- and C-terminal telopeptides have dose-dependent catabolic activities similar to fibronectin fragments and increase the production of NO, cytokines and MMPs. Catabolic activities were downregulated by dynamic compression or by the presence of the iNOS inhibitor, linking reparative activities by both types of stimuli. Future investigations which examine the signalling cascades of chondrocytes in response to matrix fragments with mechanical influences may provide useful information for early osteoarthritis treatments.

Doxycycline for osteoarthritis of the knee or hip

BACKGROUND

Osteoarthritis is a chronic joint disease that involves degeneration of articular cartilage. Pre-clinical data suggest that doxycycline might act as a disease-modifying agent for the treatment of osteoarthritis, with the potential to slow cartilage degeneration.

OBJECTIVES

To examine the effects of doxycycline compared with placebo or no intervention on pain and function in patients with osteoarthritis of the hip or knee.

SEARCH STRATEGY

We searched CENTRAL ( The Cochrane Library 2008, issue 3), MEDLINE, EMBASE and CINAHL up to 28 July 2008, checked conference proceedings, reference lists, and contacted authors.

SELECTION CRITERIA

We included studies if they were randomised or quasi-randomised controlled trials that compared doxycycline at any dosage and any formulation with placebo or no intervention in patients with osteoarthritis of the knee or hip.

DATA COLLECTION AND ANALYSIS

We extracted data in duplicate. We contacted investigators to obtain missing outcome information. We calculated differences in means at follow-up between experimental and control groups for continuous outcomes and risk ratios for binary outcomes.

MAIN RESULTS

We found one randomised controlled trial that compared doxycycline with placebo in 431 obese women. After 30 months of treatment, clinical outcomes were similar between the two treatment groups, with a mean difference of -0.20 cm (95% confidence interval (CI) -0.77 to 0.37 cm) on a visual analogue scale from 0 to 10 cm for pain and -1.10 units (95% CI -3.86 to 1.66) for function on the WOMAC disability subscale, which ranges from 17 to 85. These differences correspond to clinically irrelevant effect sizes of -0.08 and -0.09 standard deviation units for pain and function, respectively. The difference in changes in minimum joint space narrowing was in favour of doxycycline (-0.15 mm, 95% CI -0.28 to -0.02 mm), which corresponds to a small effect size of -0.23 standard deviation units. More patients withdrew from the doxycycline group compared with placebo due to adverse events (risk ratio 1.69, 95% CI 1.03 to 2.75).

AUTHORS' CONCLUSIONS

The symptomatic benefit of doxycycline is minimal to non-existent. The small benefit in terms of joint space narrowing is of questionable clinical relevance and outweighed by safety problems. Doxycycline should not be recommended for the treatment of osteoarthritis of the knee or hip.

An update on osteoarthritis therapeutics

PURPOSE OF REVIEW

This review addresses recent major developments in symptomatic therapy and the principles of disease modification in osteoarthritis. It emphasizes issues that are of importance to the practicing clinician at a time when researchers in the field are trying to improve ways not only to provide symptomatic relief but also to slow disease progression.

RECENT FINDINGS

The past year has led to a reassessment of the role of cyclo-oxygenase-2 inhibitors in osteoarthritis therapy and has yielded new information on nutriceuticals such as glucosamine. The relative efficacy of intra-articular injections of agents such as corticosteroid and hyaluronic acid preparations has been assessed. In addition, reports on trials of potentially disease-modifying agents for osteoarthritis have been published.

SUMMARY

Because the therapeutic options have been reduced over the past year and the role of nutritional supplements remains unclear, the clinician is faced with a need to reassess osteoarthritis therapy. Although no practical disease-modifying agent for osteoarthritis has been identified, reports such as the recent doxycycline trial reviewed herein provide hope that continued research will soon yield a therapeutic model similar to that used in rheumatoid arthritis, for which some therapeutic agents achieve disease modification and other agents can be added as needed for symptomatic relief.

Oral salmon calcitonin reduces Lequesne's algofunctional index scores and decreases urinary and serum levels of biomarkers of joint metabolism in knee osteoarthritis

OBJECTIVE

To evaluate the effects of oral salmon calcitonin (sCT) on Lequesne's algofunctional index scores and on biomarkers of joint metabolism in knee osteoarthritis.

METHODS

In this randomized, double-blind trial, patients received either placebo (n = 18), 0.5 mg of sCT (n = 17), or 1 mg of sCT (n = 18) daily for 84 days. Biomarkers included C-telopeptide of type II collagen (CTX-II), type II collagen neoepitope C2C, collagenases (matrix metalloproteinase 1 [MMP-1], MMP-8, and MMP-13), stromelysin (MMP-3), tissue inhibitors of metalloproteinases 1 and 2, and hyaluronan. Statistical analysis included nonparametric tests.

RESULTS

A total of 41 patients completed the study (13 in the group receiving 0.5 mg of sCT and 14 in each of the other 2 other groups). Although, on day 84, patients in both the placebo group and the group receiving 1 mg of sCT exhibited a similar significant decrease in pain scores, a significant reduction in the function score was observed only in the 2 sCT groups. On day 84, there was no significant decrease in biomarker levels in the placebo group, whereas significant reductions in the levels of both MMP-3 and hyaluronan were observed in the 2 sCT groups. The group of patients receiving 1 mg of sCT exhibited significant decreases in the levels of CTX-II, C2C, and MMP-13.

CONCLUSION

By improving functional disability and by reducing levels of biomarkers that are thought to be predictive of joint space narrowing (and thus cartilage loss), oral sCT at a dose of 1 mg might be a useful pharmacologic agent in human knee OA.

Imaging osteoarthritis: Magnetic resonance imaging versus x-ray

Until recently, imaging evaluation of osteoarthritis has relied primarily on conventional radiography. Using radiography in clinical practice or clinical research, however, has been fraught with difficulty. Techniques for reproducibly acquiring serial radiographs of joints have improved considerably over the past several years. However, the greatest promise for advancing knowledge about osteoarthritis and its treatment lies in MRI and its unique ability to examine the joint as a whole organ. In contrast to conventional radiography, MRI can directly visualize the articular cartilage, synovium, menisci, and other intra-articular structures important to the functional integrity of joints. There have been considerable advances in MRI of articular cartilage in particular over the past several years. However, much of this has come from small cross-sectional studies. Larger, longitudinal studies are ongoing, and publications are just emerging. This paper reviews the current status of x-ray and MRI in osteoarthritis and points to where changes might be anticipated in the future.