Pentraxin-3 as a marker of disease activity in Takayasu arteritis.

BACKGROUND

Because pentraxin-3 (PTX3) is produced by immune and vascular cells in response to proinflammatory signals, it may be a useful biomarker for defining disease activity in patients with Takayasu arteritis.

OBJECTIVE

To compare PTX3 levels in patients who have Takayasu arteritis with those in healthy and infected controls, and to compare accuracy of PTX3 levels with that of C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) for distinguishing active and inactive disease.

DESIGN

Cross-sectional, noninterventional study conducted between September 2005 and October 2008.

SETTING

Immunology and rheumatology clinic at a university hospital in Italy.

PATIENTS

57 consecutive patients with Takayasu arteritis and known disease activity, 57 healthy blood donor controls, and 15 patients with acute infection.

MEASUREMENTS

Disease activity by clinical criteria; plasma PTX3 and CRP levels and ESR.

RESULTS

27 patients had active Takayasu arteritis; 30 had inactive disease. Levels of PTX3 were higher in patients with active disease (median, >2.14 ng/mL [range, 0.57 to 48.18 ng/mL]) than in those with inactive disease (median, 0.63 ng/mL [range, 0.00 to 1.64 ng/mL]) and were higher than in healthy patients (median, 0.11 ng/mL [range, 0 to 1.20 ng/mL]) or those with acute infection (median, 0.26 ng/mL [range, 0 to 0.75 ng/mL]). A plasma PTX3 level greater than 1 ng/mL was more accurate than normal thresholds of CRP or ESR for distinguishing active from inactive disease.

LIMITATION

The study excluded patients with unknown or equivocal disease status.

CONCLUSION

Plasma levels of PTX3 could help distinguish active from inactive Takayasu arteritis but should not be adopted for clinical use until the findings are confirmed in a broader spectrum of patients whose disease activity is unknown or equivocal before testing.