To develop a new technique to assess the primary lesion in early rheumatoid arthritis (RA).
Ten patients with early RA and radiographically or MRI confirmed erosions had a needle introduced into the base of the erosion under sonographic guidance. Material was then aspirated from this site.
The procedure was well tolerated with no complications. Small samples of necrotic bone and tissue were obtained in five out of 10 cases. In one case, a distinctive population of pleomorphic CD34 + cells with characteristics of bone marrow progenitors was isolated. Tissue invading bone with a characteristic appearance of pannus was not seen.
A new method of sampling the earliest lesion in RA is described. The findings raise questions about the nature of bone damage in early RA.