AB1280 Diurnal variation of power doppler signal in metacarpophalangeal joints of patients with rheumatoid arthritis

Background In a preliminary study on 10 patients with active rheumatoid arthritis (RA) we could show for the first time that Power Doppler ultrasonography (PDUS) signal of metacarpophalangeal (MCP) joints has a clear diurnal variation, being higher in the morning vs. early afternoon and evening. We extended our study and involved a total of 36 patients with active RA in order to confirm our preliminary results Objectives To test, in a larger series, whether PDUS signal of MCP joints in RA patients varies according to the time of day Methods A total of 360 MCP joints from 36 patients with active RA (DAS28>3,2) were evaluated for both presence-absence of PDUS signal and according to a semiquantitative score at three different times of day T0: between 7 and 10 a.m.; T1: 4-6 hours after T0; T2: 4-6 hours after T1. The scores at T0, T1 and T2 were compared for each joint. Before each PDUS examination the patient filled out a 100 mm visual scale of pain (VAS). The day of PDUS assessment, factors that could potentially influence PDUS signal or VAS results were minimized. All patients seated in a temperature-controlled room for at least 30 minutes before PDUS examination to stabilize the blood flow. They avoided smoke, alcohol, corticosteroids, NSAIDs, analgesics and vasoactive drugs intake. Room temperature was kept stable. For PDUS examination patients put their hands inside a silhouette drawn on the paper sheet lying on the bench to avoid any change in hands’ position across the three examinations. Results PDUS presence/absence: there was a significant variation in the number of positive MCP joints during the day (p=0.01). There were more PDUS positive MCP joints at T0 (109) vs. T1 (97) (p