RESUMEN
OBJECTIVES: The aim of this study is to analyse the diagnostic value of positron emission tomography (PET) in patients with giant cell arteritis (GCA) despite glucocorticoid (GC) therapy before PET acquisition. METHODS: Consecutive patients with strongly suspected GCA according to 2022 EULAR/ACR criteria were included. The physician diagnosis of GCA after 6 months of follow-up was the gold standard. PET was performed at baseline and 6 months later. In patients with negative results at 60 min, delayed imaging was performed at 180 min. RESULTS: Twenty-six patients were included with a median (IQR) age of 70.5 (57-88) years. Baseline PET was positive in all but one: 18 patients at 60 min and 7 patients after delayed imaging at 180 min. The median (IQR) GC dose at the time of baseline PET was 45 mg/d (26.2-45) of prednisone equivalent with a median exposure of 14 days (7-76.2). At 6 months of follow-up, PET was performed in 22 patients, with positive results in 16. Delayed imaging was performed in 6 patients due to negative PET at 60 min, with positive results in all cases, despite treatment with GC and/or biological therapy. CONCLUSIONS: In patients on GC therapy, delayed imaging protocols applying procedural recommendations for vascular quantification could improve diagnostic accuracy. Therefore, we suggest performing imaging only at 180 min in patients who have been on GCs for more than 3 days as well as in those with highly suspected GCA but negative findings in baseline PET at 60 min.
RESUMEN
OBJECTIVE: Aortitis in Giant Cell Arteritis (GCA-aortitis) is a frequent complication that may lead to aneurysms. Tocilizumab (TCZ) was approved in GCA, but the efficacy in GCA-aortitis and aneurysms has not been analyzed to date. Our aim was to assess the effectiveness and safety of TCZ in a wide series of GCA-aortitis and aneurysms. METHODS: Multicentre observational study with GCA-aortitis treated with TCZ. GCA was diagnosed by: a) ACR criteria, b) temporal artery biopsy, and/or c) imaging techniques. Aortitis was diagnosed mainly by PET/CT. Main outcomes were EULAR and imaging remission. Others were clinical remission, analytical normalization, corticosteroid-sparing effect, and the prevention and improvement of aneurysms. RESULTS: 196 patients with GCA-aortitis treated with TCZ. After 6 months, 72.2% reached EULAR remission but only 12% an imaging remission; increasing up-to 81.4% and 31.8%, respectively, at 24 months. A rapid clinical remission, ESR and CRP normalization was observed in 47.4%, 84.3% and 55.6%, at 1 month, increasing to 89.6%, 85.3% and 80.3% at 24 months, respectively. Aneurysms were present in 10 (5%) patients. Five of them required early surgery, while 3 others enlarged. No patient on TCZ therapy developed aneurysms during follow-up. CONCLUSION: In patients with GCA-aortitis treated with TCZ, a rapid and maintained clinical and analytical improvement was observed. However, there was an uncoupling between clinical and EULAR remission with imaging remission.
