Letter

biopsy of inguinal lymph nodes as a new research tool Rheumatoid arthritis (RA) is a chronic infl ammatory autoim-mune disease affecting mainly the synovial joints. Processes involved in the initiation of infl ammation in RA are largely unknown. Recent work has shown that systemic autoimmu-nity precedes synovial infl ammation in autoantibody positive individuals developing RA1 and animal models have sug-gested that lymph node changes may precede infl ammation in the synovial tissue.2 Ultrasound guided lymph node biopsy under local anaesthesia has previously been used as a diagnos-tic tool in haematology and oncology.3 Therefore, we started to use this technique to provide insight into the pathogenic processes involved in the earliest phases of RA, by analysing lymph node tissue obtained during different phases of th