Long-Term Benefits of Induction Therapy for GCA
Induction therapy with high intravenous doses of methylprednisolone suppresses inflammation and hastens remission in patients with giant cell arteritis (GCA), according to a new study in Arthritis & Rheumatism (2006;54(10):3310-3318).
Perhaps the most important finding was that the induction therapy had long-term benefits with a higher frequency of patients in sustained remission off treatment and less smoldering disease after one year, senior author Jorg J. Goronzy, MD, PhD, professor of medicine at Emory University School of Medicine in Atlanta, tells The Rheumatologist.
In the study, 27 patients with biopsy-proven GCA were randomized to receive daily infusions of methylprednisolone in a dose of 15 mg/kg or a saline placebo for three days. All patients also took oral prednisone, starting with a dose of 40 mg/day and tapering as long as disease activity was controlled. After the infusions, the patients were followed every four weeks by physicians who were blinded to each patient’s infusion status. They reported their findings at 36, 52, and 78 weeks after the start of therapy.
For all patients, the mean erythrocyte sedimentation rate and C-reactive protein values returned to normal by the first four-week follow-up visit. This was unexpected, given that the doses were lower than those conventionally recommended, says Dr. Goronzy.
This suggests that patients without evidence of severe vascular manifestations could do well initially with a lower dose and more rapid tapering of prednisone. However, without methylprednisolone induction therapy, the disease may smolder and require a higher cumulative dose of oral prednisone to keep it under control, says lead author Mehrdad Mazlumzadeh, MD, assistant professor of medicine at the Mayo Clinic in Scottsdale, Ariz.
Ten of the 14 patients (71%) who received methylprednisolone achieved the primary outcome of staying in remission at 36 weeks on oral prednisone in doses of 5 mg/day or less, compared with only two of the 13 (15%) control patients (p=0.003). Six patients in the methylprednisolone group were off treatment entirely by the three-week point, compared with none of the control patients.
What’s more, patients who received the methylprednisolone required much lower median doses of oral glucocorticoids at every follow-up period. Over the length of the study, they took a median of 5,636 mg of prednisone, compared to a cumulative median of 7,860 mg taken by patients in the control group (p=0.001). The relapse rate was also significantly lower among patients in the IV glucocorticoid group, although there was no significant difference in the rate of adverse effects.