Background The goal of the treatment of rheumatoid arthritis (RA) is remission, however the remission induction for established RA (eRA) patients with long disease duration and significant radiographic damage is difficult. One of the reasons for this is that Patient Global Assessment score (PtGA) continues to be high even after the synovitis resolves through appropriate treatment, because of disability or pain from the structural damage. Although such high PtGA of eRA patients is thought to be acceptable, there is little evidence which supports this concept.
Objectives To evaluate whether high PtGA of eRA patients is acceptable by assessing synovitis using ultrasound sonography (US).
Methods Three hundred and thirty two RA patients were recruited with informed consent. Bilateral 2–5 MCP, wrist, ankle, and 2–5MTP joints were scanned by using the Aplio500 (TOSHIBA) with a 12 MHz transducer. Power Doppler (PD) images were obtained by Superb Micro-vascular Imaging (SMI). Gray scale (GS) and PD images were scored using a 0–3 semi-quantitative scale. Clinical information was obtained from the Kyoto University Rheumatoid Arthritis Management Alliance (KURAMA) database, which is based on the assessment by physicians who were blind to the US results. We defined “Semi-Boolean remission (SBR)” as the condition which is composed of 3 elements of Boolean remission (BR) criteria, excluding PtGA. All the patients were classified into 1–4 Steinbrocker stages according to their joint X-rays.
Results The number of patients who fulfilled BR or SBR criteria were 99 and 122, respectively. As shown in table 1, age, disease duration, total GS score, and total PD score were virtually the same between the two groups. PtGA become higher in accordance with the stages (P<0.01, Jonckheere-Terpstra trend test. Mean values of PtGA of stage I, II, III, and IV were 13.6±15.6, 19.6±21.0, 26.6±26.1, and 28.0±22.0, respectively). PtGA and total PD score showed no correlation in BR+SBR patients, or in each of the stages (Spearman's rho=0.14, 0.16, 0.04, 0.03, or 0.07, respectively). The median values of total GS scores of each stage were, 10.0 (8.0–15.0), 12.0 (9.0–16.0), 11.0 (8.0–15.0), and 12.0 (7.5–17.0). There is no significant difference between stages. On the other hand, the median values of total PD scores of each stage were 0.0 (0.0–2.0), 1.0 (0.0–2.0), 1.0 (0.0–3.5), and 2.0 (1.0–6.5), respectively (figure 1). There was significant accordance between total PD score and stages (P<0.01, Jonckheere-Terpstra trend test).
Conclusions PtGA did not always reflect the activity of synovitis. This was not limited to eRA but also to RA without radiographic damage. However, we must be careful as higher total PD scores were seen in eRA patients even though they were thought of as being in BR or SBR. This result means that a certain portion of active eRA patients are misclassified as being in remission. Before accepting the high PtGA, we should use US for correct evaluation of eRA.
Disclosure of Interest None declared