Objective: Giant cell arteritis (GCA) has a variable course. We assessed whether intensity of initial systemic inflammatory response (ISIR) can predict the course of GCA.
Methods: Charts of 130 GCA patients were reviewed. ISIR intensity at presentation was determined by 5 parameters of inflammation: sedimentation rate >100 mm/h, thrombocytosis >400,000/microl, hemoglobin <11 g/dl, leukocytosis >11000/microl, and fever >37.5 degrees C. Patients were divided into 3 groups according to ISIR intensity: strong (4-5 parameters present, n=24), moderate (2-3 parameters, n=55) and weak ISIR (0-1 parameter, n=51).
Results: There were no significant differences between these groups regarding mean age, female:male ratio and the initial prednisone dose. At 1 year, 75% of patients in the strong ISIR group required >5 mg/d of prednisone, compared to 54% and 37% of patients with moderate or weak ISIR, respectively (p=0.015). Disease flares were more common in patients with strong ISIR during a 3-year period, compared to patients with moderate or weak ISIR (77%, 67% and 43%, respectively, p=0.013). Only 33% of patients with strong ISIR were able to discontinue steroids after 3 years, compared to 49% and 77% of patients with moderate and weak ISIR, respectively (p=0.003).
Conclusion: GCA Patients with strong ISIR have prolonged disease course with more flares, requiring higher steroid doses. ISIR intensity should be taken into consideration when planning studies evaluating potential steroid-sparing agents, as response to treatment may vary in patients with different ISIR intensities.