Objective: To evaluate the effect of Infliximab and Etanercept two types of anti-tumor necrosis factor-alpha (TNF-alpha) inhibitors, on the serum level of matrix metalloproteinase 3 (MMP-3) in the pathogenesis of ankylosing spondylitis (AS).
Method: 47 patients with AS, 40 males and 7 females, aged 17 - 51, were treated with Infliximab (5 mg/kg i.v at weeks 0, 2, and 6); and 26 patients with AS were treated with Etanercept (25 mg, twice a week for 12 weeks). Clinical data including Bath AS indices (BASDAI and BASFI) and sera were collected at baseline and other different times. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were measured. Serum levels of MMP-3 were measured with MMP-3 ELISA kits.
Results: Two, six, and ten weeks after Infliximab treatment the levels of ESR, CRP, and serum MMP-3 of the AS patients were all significantly lower than the baseline level (all P < 0.01), and the serum MMP-3 levels were all significantly correlated with ESR (all P < 0.05). In the Etanercept group 1, 2, 4, 8, and 12 weeks after treatment the levels of serum MMP-3, ESR, CRP, BASDAI, and BASFI were all significantly lower than the baseline levels (all P < 0.01); before the treatment ESR was significantly correlated with CRP (r = 0.80, P < 0.01), BASDAI was significantly correlated with BASFI (r = 0.48, P < 0.05), and MMP-3 was significantly correlated with ESR (r = 0.74, P < 0.01) and with CRP (r = 0.72, P < 0.01); and 12 weeks after the treatment significant correlation still existed between ESR and CRP (r = 0.40, P < 0.05), BASDAI and BASFI (r = 0.89, P < 0.01), and MMP-3 and ESR (r = 0.43, P = 0.029), however, there was no significant correlation between CRP and serum level of MMP-3 (r = 0.37, P = 0.061).
Conclusion: Infliximab and Etanercept, 2 anti-TNF-alpha inhibitors, not only significantly decrease the ESR and CRP, but also decrease the serum level of MMP-3 of patients with AS. MMP-3 is involved in the pathogenesis and disease activity of AS. MMP-3 is also a potentially useful marker of AS disease activity and useful parameter to assess the effectiveness of anti-TNF-alpha inhibitor in treatment of AS.