Is biopsy-positive GCA different from high index of suspicion biopsy-negative GCA?
It seems patients with negative biopsies are excluded from several observational cohorts. Of course the biopsy-negative patients may be imaging positive (and some studies allow for inclusion of this group) or have a very high index of suspicion for the diagnosis of GCA. Thus I can't determine if biopsy-negative patients are different.
What dose should I start with for initiation of treatment of GCA?
You can get an overall lower prednisone dose if you start at 40 mg/day (i.e. higher induction dosing vs. maintenance). Patients treated with an initial oral prednisone dose of >40 mg/day had higher cumulative doses of steroids but achieved earlier discontinuation without an increased risk of steroid-associated adverse events (Koster FRI0251). Time to first relapse based on initial oral prednisone dose did not differ [HR 1.18 .3]
How often do people with GCA relapse?
Relapses are common. Half of patients seem to relapse and some of the relapsers have several relapses.
Dr. G. Restuccia (OP0233) presented information from a cohort of Italian GCA patients. 1/3 relapsed into biopsy-proven GCA over 6.5 years of follow-up and obviously they found increased inflammatory markers, anemia and/or thromboses at the time of relapse. Approximately 40% relapsed with PMR as the diagnosis of the relapse.
Similarly, 40% of GCA positive and negative biopsy relapsed at 1 year in a single site US study (Koster FRI0251).
So the answer is that patients will likely relapse (30 to 40%). Maybe this suggests we don't treat the disease effectively to sustain remission in many patients.
Can I identify who will relapse?
Interestingly in the TCZ RCT of GCA, PMR symptoms were present in 33% of relapsing patients but only in 10% with new-onset GCA. C. Labarca (FRI0256) reported relapses were more common in women, patients with hypertension, diabetes, and VTE. Perhaps concomitant PMR increases the likelihood of relapse or accompanies relapses.
Should I use a steroid-sparing drug?
Many of the presentations about GCA did not have concomitant steroid-sparing drug use but reserved methotrexate or other drugs for steroid failures. A meta-analysis done in the past did show that methotrexate could allow for overall steroid-sparing in GCA.1
Do GCA patients suffer more strokes?
A single site study from Rochester Minnosota (Olmsted County) looked at GCA diagnosed patients compared to age- and sex-matched population controls. Dr. A. Lo Gullo compared 244 cases and 240 controls with a mean age of 76 years (#FRI0244). Mostly there were no significant differences in rates of CVA, TIAs and clots (venous thromboemolic events; VTE). The 10-year cumulative incidence of VTE was 6.3% in GCA and 3.7% among non-GCA patients (p=0.22), so VTE were nearly twice as high. Amaurosis fugax was reported in 1.2% vs none in controls (p=0.045). Others have shown that vasculitis increases VTEs.2
What should I do if usual treatment fails?
Meta-analyses have shown that methotrexate can be steroid-sparing in the treatment of GCA. However, if steroids (with an immune suppressive / steroid-sparing drug such as methotrexate) fail, there are more data emerging on tociluzimab.
Toussirot et al presented a poster (#FRI0253) on PMR treatment with TCZ (only 1 case had GCA) with rapid improvement and steroid tapering, but the study did not answer the question, if failing treatement, will TCZ help in GCA? K.
Tuckwell described baseline characteristics of the TCZ RCT in GCA (#FRI0248) that is evaluating approximately half the patients who relapsed and half are new onset.
1. Mahr AD, Arthritis Rheum 2007;56(8):2789-97.
2. Lee JJ, Arthritis Res Ther. 2014 Sep 25;16(5):435.
Dr. Janet Pope is Professor of Medicine at Western University and Division Head of Rheumatology. Dr. Pope's research interests include epidemiologic studies in scleroderma, classification criteria in systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis.View Full Bio