Epidemiology, Genetics and Atherosclerosis Research Group on Systemic Inflammatory Diseases, Rheumatology Division, Hospital Universitario Marqués de Valdecilla, IDIVAL, Santander, Spain.
Nuclear Medicine Division, Hospital Universitario Marqués de Valdecilla, Molecular Imaging Group IDIVAL, Santander, and University of Cantabria, School of Medicine, Santander, Spain.
Clin Exp Rheumatol. 2021 Mar-Apr;39 Suppl 129(2):69-75. doi: 10.55563/clinexprheumatol/mjm8fr. Epub 2020 Nov 27.
Clinical improvement following tocilizumab (TCZ) therapy in patients with large-vessel (LVV) giant cell arteritis (GCA) is well established. However, information on TCZ effect on imaging vascular activity is limited. We aimed to determine if clinical improvement correlated with reduction of vascular 18F-fluorodeoxyglucose (18F-FDG) uptake in positron emission tomography (PET/CT) scans.
Observational study of patients with refractory LVV-GCA treated with TCZ who had a baseline and a follow-up 18F-FDG-PET/CT scan. For the visual analysis of 18F-FDG vascular uptake, a total vascular score (TVS) was defined, ranging from 0 to 15. Besides, a semiquantitative analysis was performed as a target to background ratio (TBR)= SUVmax thoracic aorta wall/SUVmax aortic vascular pool. The baseline and follow-up TVS and TBR were compared. Clinical and lab¬oratory outcomes were also assessed.
We included 30 patients (24 women/6 men); mean age± standard deviation 65.7± 9.8 years. Baseline PET/CT scans were performed due to active disease at a median [interquartile range-IQR] of 1.5 [0.0-4.0] months before TCZ onset. Following TCZ therapy, 25 (83.33%) patients achieved clinical remission and reduction of 18F-FDG vascular uptake was also observed after a mean ± standard deviation of 10.8±3.7 months. TBR decreased from 1.70 ± 0.52 to 1.48 ± 0.25 (p=0.005) and TVS from 4.97±2.62 to 3.13±1.89 (p< 0.001). However, only 9 (30.0%) patients showed complete normalisation of TBR and only 3 (10%) normalisation of TVS. TBR and TVS showed a good correlation (r=0.576).
Although most of LVV-GCA patients achieve clinical remission after TCZ therapy, less than one-third show normalisation of 18F-FDG vascular uptake.
托珠单抗（TCZ）治疗巨细胞动脉炎（GCA）大血管（LVV）患者后的临床改善已得到证实。然而，关于 TCZ 对血管 18F-氟脱氧葡萄糖（18F-FDG）摄取的影响的信息有限。我们旨在确定临床改善是否与正电子发射断层扫描（PET/CT）扫描中血管 18F-FDG 摄取的减少相关。
对接受 TCZ 治疗的难治性 LVV-GCA 患者进行观察性研究，这些患者基线时有 18F-FDG-PET/CT 扫描，随访时有 18F-FDG-PET/CT 扫描。为了进行 18F-FDG 血管摄取的视觉分析，定义了总血管评分（TVS），范围为 0 至 15。此外，还进行了半定量分析，即主动脉壁最大标准化摄取值（SUVmax）/主动脉血管池最大标准化摄取值（SUVmax）比值（TBR）。比较了基线和随访时的 TVS 和 TBR。还评估了临床和实验室结果。
我们纳入了 30 名患者（24 名女性/6 名男性）；平均年龄±标准差 65.7±9.8 岁。基线 PET/CT 扫描是在 TCZ 治疗开始前中位数[四分位距-IQR]为 1.5[0.0-4.0]个月时因疾病活动而进行的。接受 TCZ 治疗后，25 名（83.33%）患者达到临床缓解，并且在平均±标准差 10.8±3.7 个月后也观察到 18F-FDG 血管摄取减少。TBR 从 1.70±0.52 降至 1.48±0.25（p=0.005），TVS 从 4.97±2.62 降至 3.13±1.89（p<0.001）。然而，只有 9 名（30.0%）患者的 TBR 完全正常化，只有 3 名（10%）患者的 TVS 正常化。TBR 和 TVS 显示出良好的相关性（r=0.576）。
尽管大多数 LVV-GCA 患者在 TCZ 治疗后达到临床缓解，但不到三分之一的患者显示 18F-FDG 血管摄取正常化。
