Giant cell arteritis (GCA) has a variable course. We assessed whether intensity of initial systemic inflammatory response (ISIR) can predict the course of GCA.
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).
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).
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.