I. Ferraz-Amaro, MD, Division of Rheumatology, Hospital Universitario de Canarias, Tenerife, Spain;
A. Sheikh, MD, Department of Radiology, Division of Nuclear Medicine, Kettering Health, Dayton, Ohio, USA.
J Rheumatol. 2022 Dec;49(12):1315-1319. doi: 10.3899/jrheum.220231. Epub 2022 Aug 15.
Examination and conventional radiography of joints are unable to precisely evaluate and measure disease activity in rheumatoid arthritis (RA). We quantified joint inflammation using F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in people with RA to determine if PET-derived uptake variables were correlated with RA disease activity measures.
We cross-sectionally studied 34 patients with RA in a substudy of the Rheumatoid Arthritis Study of the Myocardium (RHYTHM). All patients underwent F-FDG-PET scanning with CT for attenuation correction and anatomic co-registration. Linear regression was used to model the associations of disease activity scores with articular FDG uptake, calculated as standardized uptake values (SUVs). Weighted joint volume SUVs (wjSUV) representing 25%, 50%, 75%, and maximum (100%) uptake (wj25SUV, wj50SUV, wj75SUV, and wjMaxSUV, respectively) were calculated as global variables of the total volume of joint inflammation in each patient.
Calculated wj25SUV (Spearman ρ = 0.39, = 0.04), wj50SUV (ρ = 0.39, = 0.04), and wj75SUV (ρ = 0.37, = 0.045) measures were significantly correlated with the number of swollen joints. Similar significant correlations were found for the Simplified Disease Activity Index but not Clinical Disease Activity or Disease Activity Score in 28 joints. No associations were found between articular FDG uptake and nonarticular RA-related variables (ie, disease duration, seropositivity, or RA treatments).
Articular FDG uptake in patients with RA was significantly correlated with the number of swollen joints but not with biochemical measures of inflammation.
关节的检查和常规放射摄影无法准确评估和测量类风湿关节炎（RA）的疾病活动度。我们使用 F-氟代脱氧葡萄糖（FDG）正电子发射断层扫描（PET）/计算机断层扫描（CT）对 RA 患者的关节炎症进行量化，以确定 PET 衍生的摄取变量是否与 RA 疾病活动度测量相关。
我们在心肌炎类风湿关节炎研究（RHYTHM）的子研究中对 34 名 RA 患者进行了横断面研究。所有患者均接受 F-FDG-PET 扫描，CT 用于衰减校正和解剖配准。线性回归用于构建疾病活动评分与关节 FDG 摄取之间的关联模型，以标准化摄取值（SUV）表示。计算了关节的加权 SUV（wjSUV），代表每个患者关节炎症总容积的 25%、50%、75%和 100%（分别为 wj25SUV、wj50SUV、wj75SUV 和 wjMaxSUV）。
计算出的 wj25SUV（Spearman ρ=0.39， =0.04）、wj50SUV（ρ=0.39， =0.04）和 wj75SUV（ρ=0.37， =0.045）与肿胀关节数呈显著相关。简化疾病活动指数也存在类似的显著相关性，但在 28 个关节中与临床疾病活动度或疾病活动评分无关。关节 FDG 摄取与非关节 RA 相关变量（即疾病持续时间、血清阳性或 RA 治疗）之间无相关性。
RA 患者关节 FDG 摄取与肿胀关节数显著相关，但与炎症的生化指标无关。
