Gent Yoony Y J, Voskuyl Alexandre E, Kloet Reina W, van Schaardenburg Dirkjan, Hoekstra Otto S, Dijkmans Ben A C, Lammertsma Adriaan A, van der Laken Conny J
VU University Medical Center, Amsterdam, The Netherlands.
Arthritis Rheum. 2012 Jan;64(1):62-6. doi: 10.1002/art.30655.
To conduct a prospective pilot study to determine whether macrophage targeting by 11C-(R)-PK11195 positron emission tomography (PET) can visualize subclinical synovitis in arthralgia patients who have anti-citrullinated protein antibodies (ACPAs).
Twenty-nine arthralgia patients who were positive for ACPAs but did not have clinical arthritis were studied. High (spatial)-resolution 11C-(R)-PK11195 PET scans of the hands and wrists were performed. For all metacarpophalangeal, proximal interphalangeal, and wrist joints (i.e., 22 joints per patient), tracer uptake was scored semiquantitatively (0-3 scale) by 2 observers who were blinded with regard to the clinical data. Patients were followed up prospectively for 24 months to investigate the development of clinical arthritis.
Overall agreement and kappa values for the readings of the 2 observers were, respectively, 97% and 0.91 (95% confidence interval [95% CI] 0.74-1) at the patient level and 99% and 0.81 (95% CI 0.65-0.96) at the joint level. In 4 patients, at least 1 and as many as 5 PET-positive joints (score≥1) were found at baseline. Within 2 years of followup, 9 patients had developed clinical arthritis. This included all 4 patients with positive findings on the 11C-(R)-PK11195 scan, who developed clinical arthritis in the hand/wrist region, as identified on PET scans. Of the 5 remaining arthritis patients with negative findings on PET scans, 2 developed arthritis in the hand joints and 3 developed arthritis at locations outside the field of view of the PET scanner.
Subclinical arthritis in ACPA-positive arthralgia patients could be visualized by 11C-(R)-PK11195 PET scanning and was associated with development of arthritis within 2 years of followup. This indicates that 11C-(R)-PK11195 PET may be useful in determining arthritis activity in the preclinical phase of RA.
开展一项前瞻性试点研究，以确定通过11C-(R)-PK11195正电子发射断层扫描（PET）靶向巨噬细胞是否能够使抗瓜氨酸化蛋白抗体（ACPA）呈阳性的关节痛患者的亚临床滑膜炎显影。
对29例ACPA呈阳性但无临床关节炎的关节痛患者进行研究。对手部和腕部进行高（空间）分辨率的11C-(R)-PK11195 PET扫描。对于所有掌指关节、近端指间关节和腕关节（即每位患者22个关节），由2名对临床数据不知情的观察者进行半定量（0-3级）示踪剂摄取评分。对患者进行24个月的前瞻性随访，以调查临床关节炎的发展情况。
在患者层面，2名观察者读数的总体一致性和kappa值分别为97%和0.91（95%置信区间[95%CI]0.74-1），在关节层面分别为99%和0.81（95%CI 0.65-0.96）。4例患者在基线时发现至少1个且多达5个PET阳性关节（评分≥1）。在随访的2年内，9例患者发展为临床关节炎。这包括11C-(R)-PK11195扫描结果呈阳性的所有4例患者，他们在PET扫描所确定的手部/腕部区域发展为临床关节炎。在PET扫描结果呈阴性的其余5例关节炎患者中，2例在手部关节发展为关节炎，3例在PET扫描仪视野之外的部位发展为关节炎。
11C-(R)-PK11195 PET扫描能够使ACPA阳性关节痛患者的亚临床关节炎显影，并且与随访2年内关节炎的发展相关。这表明11C-(R)-PK11195 PET可能有助于确定类风湿关节炎临床前期的关节炎活动情况。
