Ultrasonographic abnormalities and inter-reader reliability in Danish patients with systemic lupus erythematosus – a comparison with clinical examination of wrist and metacarpophalangeal joints

Abstract

Objectives We aimed to determine 1) ultrasound (US) abnormalities in patients with systemic lupus erythematosus (SLE) with and without hand arthralgia at the day of examination compared with clinical evaluation and healthy controls, and 2) inter-observer reliability of the US abnormalities. Methods Thirty-three female SLE patients were twice examined with US by three trained examiners. Using B-mode and Doppler US, unilateral wrist and metacarpophalangeal (MCP) joints were examined for synovitis and erosions as well as signs of hand tenosynovitis using a GE Logiq 9 US machine with Doppler settings for slow flow. All patients also underwent clinical joint evaluation and were compared with 11 healthy controls (HC). Results Among the patients with SLE 16 (48%) had signs of wrist synovitis, which was only observed in one HC ( p = 0.03). Corresponding figures for any MCP joint were 12 (36%) and 0 ( p = 0.06). In SLE patients, 18% had hand tenosynovitis and 6% bone erosions. Wrist synovitis was detected by US in 16 SLE patients (81%) with arthralgia compared with 17 patients without (18%) ( p = 0.0005). Any US abnormalities were observed in 44% of 25 wrists without tenderness at clinical examination and in 46% of 26 wrists without swelling. Corresponding percentages for MCP2 joints were 27% and 21%. Inter-observer reliability of the US findings was good to excellent for examination of hand joints and tendons. Conclusions A majority of SLE patients with hand arthralgia showed US signs of synovitis, erosions and tenosynovitis indicating subclinical disease. Even SLE patients without clinical signs of joint inflammation demonstrated US abnormalities. Good to excellent inter-observer reliability was found in US evaluation of hands in patients with SLE.