Background: Patients with Takayasu arteritis (TA) often show recurrence under steroid treatment without an elevation of C-reactive protein (CRP). There is a report that matrix metalloproteinase (MMP)-2, MMP-3, MMP-9 and pentraxin3 (PTX3) could be sensitive biomarkers, but the characteristics of these biomarkers have not been established.
Methods and results: We enrolled 45 consecutive patients; 28 were grouped in an active phase as evidenced by clinical recurrence within 2 years of blood sampling. Circulating levels of high-sensitivity (hs)CRP, MMPs, and PTX3 were determined. Patients in an active phase showed higher levels of hsCRP, MMP-9, and PTX3. Area under the receiving operating characteristics curves of hsCRP and PTX3 were significantly higher than that of MMP-9. Among the 28 patients with active TA, 71% was positive for hsCRP and 82% for PTX3. Patients without recurrence showed significantly higher plasma levels of MMP-9. There was a positive correlation between the plasma MMP-3 level and the prednisolone dose. However, PTX3 and MMP-9 levels did not have such a correlation.
Conclusions: PTX3 and MMP-9, which are not affected by prednisolone, could be sensitive biomarkers for assessing TA activity. Evaluation of MMP-9 may suggest prior existence of TA.