POS0494 AN INVESTIGATION OF JOINT INFLAMMATION DEFINED BY COMPREHENSIVE ULTRASOUND ASSESSMENT AND PAIN SENSITISATION IN PATIENTS WITH ACTIVE RA

Abstract

Background:Treat-to-target strategies have improved outcomes in patients with RA. Targets based on clinical assessments of tender (TJC) and swollen joints (SJC) were developed when most patients had active inflammatory disease. It is now recognised some patients have pain sensitisation often termed fibromyalgia (FM), making clinical assessment of inflammatory disease more complex. An indicator of pain sensitisation is the difference between TJC and SJC, an observation we described in a pilot study (1).Objectives:To study patients with RA to describe the relationships between enhanced clinical and patient-reported outcome measures (PROMS) and active inflammatory joint disease detected by comprehensive PDUS.Methods:158 sequential patients with RA with a DAS28ESR score >¬3.2 were enrolled from GSTT Rheumatology after informed consent. They were assessed by a rheumatologist for 66SJC, 68TJC, fibromyalgia tender points & physician global. Recorded PROMS were: patient global, widespread pain index (WPI), symptom severity score (somatic & fatigue), FACIT fatigue, HAQ, EQ5D QoL, GAD7, PHQ9 and PHQ15. All patients had a 44 joint US scored for PD and grey scale by the EULAR scale blind to all patient data. Data were recorded on MedSciNet and statistical analysis used STATA.Results:Patients meeting the ACR 2010 criteria for FM2(n=72) vs those that did not(n=86) had similar demographics. SJC and US doppler scores were higher in the non-FM group, whereas rheumatoid factor, DAS28 and PROMs were higher in the FM group. Analysis of group differences using multinomial logistic regression and subsequent regularised (lasso) logistic regression, showed the FM group related to higher 28TJC, FACIT-F and PHQ15, with the non-FM group related to higher 28SJC, logESR, and lower Differences in 28S/TJC, Physician Global and FACIT-F. Patients were divided into four groups based on presence or absence of at least one PDUS+ joint and FM criteria; -FM-PD, -FM+PD, +FM-PD and +FM+PD, data summarised Table 1. The -FM-PD and -FM+PD groups related to Physician Global and negatively related to FACIT-F, Difference in 28S/TJC, and PHQ15 (-FM-PD). The +FM-PD group related positively to FACIT-F, Difference 28S/TJC, PHQ15, and negatively to Physician Global with +FM+PD related to PHQ9, FACIT-F and DAS28ESR.TABLE 1.-FM -PD -FM +PD +FM -PD +FM +PD p-valueFemale34 (79%)33 (77%)35 (83%)22 (73%)0.77Total power doppler score0.0 (0.0-1.0)16.0 (10.0-25.0)0.0 (0.0-0.0)9.0 (8.0-20.0)<0.001Total gray scale score40.0(34.0-48.0)57.5(45.0-82.0)34.5(20.0-43.0)60.0(46.0-84.0)<0.001Total Swollen JC3.0 (1.0-5.0)6.0 (3.0-9.0)2.0 (0.0-5.0)5.5 (2.0-10.5)<0.001Total Tender5.5 (3.0-12.0)8.0 (4.0-11.0)13.0 (8.0-20.0)15.0 (8.0-20.0)<0.001Tender-Swollen JC Difference4.0 (0.0-8.0)2.0 (0.0-4.0)8.0 (4.0-18.0)5.5 (2.5-13.5)<0.001ESR mm/hour10.0 (8.0-16.0)14.0 (10.0-30.0)12.0 (7.0-23.0)19.5 (11.5-42.5)0.021Pain VAS50.0 (40.0-65.0)50.0 (30.0-60.0)60.0 (47.5-77.5)67.5 (55.0-80.0)<0.001Patient VAS50.0 (30.0-70.0)40.0 (30.0-70.0)60.0 (40.0-80.0)65.0 (50.0-80.0)0.006Physician VAS30.0 (20.0-50.0)50.0 (40.0-60.0)30.0 (20.0-40.0)50.0 (32.5-70.0)<0.001DAS28 (ESR)4.2 (3.7-4.9)4.7 (4.1-5.2)4.7 (3.9-5.8)5.6 (4.9-6.6)<0.001Conclusion:These data using comprehensive US assessment to detect inflammatory joint disease, demonstrate that active inflammation defined as at least 1PDUS+ joint, may account for disease activity in slightly less than half of unselected patients with RA with a DAS28ESR score >3.2. This study shows how frequently pain sensitisation accounts for symptoms and signs in RA. We suggest in addition to central sensitisation, often called FM, another group identified here as -FM-PD, may have pain from joint damage or peripheral pain sensitisation of joints, likely due to different mechanisms than central pain sensitisation.