Background The main goal of rheumatoid arthritis (RA) treatment is to maximize the patient’s long-term QOL. In addition to achievement/maintenance of clinical remission, prevention of structural change such as joint destruction is essential for this goal. Serum matrix metalloproteinase 3 (MMP-3) has been reported to be a potential prognostic predictor for joint destruction.¹²³ However, most of the available data were collected from treatment-naive RA patients or those treated with non-biological disease modifying anti-rheumatic drugs (DMARDs); data with the use of biologicals are limited.

Objectives Study the relationship between serum MMP-3 levels and joint destruction resulting in total knee arthroplasty (TKA) in RA patients receiving etanercept (ETN).

Methods Our research data on the relationship between MRI findings of the knee and TKA in RA patients who started ETN treatment at our site (presented at the conference in 2012)⁴ were used to retrospectively investigate the relationship between TKA and MMP-3 at baseline and post-implementation of ETN. Patients were followed after initial ETN dose until TKA or, in those without TKA, up to Week 104 to compare change in MMP-3 levels. Also, the association between knee MRI findings and MMP-3 change after starting ETN treatment was examined.

Results A total of 116 patients were analyzed; 28 underwent TKA. The mean observation period was 74.7 and 100.8 weeks in patients with and without TKA, respectively. Patient background characteristics were similar between groups. No significant difference in the rate of concurrent use and mean dose of glucocorticoid, which is known to affect MMP-3, was observed. TKA patients had significantly higher mean MMP-3 of post-dosing ETN than non-TKA patients (210.0 vs 112.0 ng/ml, p=0.0002) and significantly lower reduction in MMP-3 from baseline (12.5 vs 65.0 ng/ml, p=0.0246). There was also a significant difference in the proportion of patients with normal MMP-3 levels at the final observation between groups (TKA, 10.7%; non-TKA, 33.0%; p=0.0278). (Table) Moreover, patients with worsening of knee MRI findings (synovitis, T1 low/T2 high signals) were significantly more likely to have elevated MMP-3 relative to baseline than those without worsening.

Conclusions Serum MMP-3 levels were associated with TKA. In patients without sufficient reduction in MMP-3 after starting biologicals, joint destruction is likely to progress. Serum MMP-3 measurement can be considered as a useful predictor of TKA and should be performed to monitor structural change.

References

1. Mamehara A, et al. Kobe J. Med. Sci 2010;56:E98-E107

2. Yamanaka H, et al. Arthritis Rheum 2000;43:852-858

3. Green MJ, et al. Rheumatology 2003;42:83–88

4. Tsuchida T. Ann Rheum Dis 2012;71(Suppl3):524

Disclosure of Interest None Declared