Analysis of the relationship between polymyalgia rheumatica and matrix metalloproteinase-3 levels during the first medical examination and during treatment

In the present study, we assessed the relationship between polymyalgia rheumatica (PMR) and matrix metalloproteinase-3 (MMP-3) levels during the first medical examination and during treatment. We examined 22 patients with PMR in our hospital from 2010 to 2012, in whom the diagnosis was confirmed by the 2012 Provisional Classification Criteria for PMR. The MMP-3 levels were obtained from 19 patients, and the average MMP-3 level was 200.8 ng/mL; this level increased in 15 patients. During the 1 month after treatment initiation, the average dose of prednisolones (PSL) was increased from 2.75 mg/day to 11.3 mg/day, whereas the C-reactive protein level decreased from 6.92 mg/dL to 0.33 mg/dL; however, the average MMP-3 levels increased to 225.1 ng/mL during this period. When comparing the 7 patients in whom PSL withdrawal was achieved within 1 year and the patients in whom PSL withdrawal was difficult, we noted that the MMP-3 levels were higher in the patients in whom PSL withdrawal was difficult, and the MMP-3 level at 3 months after the first medical examination was significantly higher compared to the MMP-3 level during the first medical examination (p = 0.011). Although the MMP-3 level is influenced by PSL use, the MMP-3 levels may be considered to reflect the disease activity of PMR. Thus, MMP-3 levels may be a useful predictive factor for the success of PSL withdrawal in patients with PMR.