Evaluation of disease activity in rheumatoid arthritis and other arthritides using 99mtechnetium labeled nonspecific human immunoglobulin.

OBJECTIVE. To determine the usefulness of 99mtechnetium (99mTc) immunoglobulin scintigraphy (99mTc IgG) in rheumatoid arthritis (RA) and in other arthritides. METHODS. Scintigraphic scores were compared with the Ritchie index and biochemical variables of disease activity. RESULTS. In RA, scintigraphic scores were reproducible and seemed to perform better than clinical scores. Moreover, the scores of synovial uptake correlated significantly with systemic variables of inflammation. Other inflammatory arthritides also disclosed uptake of 99mTc IgG but noninflammatory joints did not. CONCLUSION. Although nonspecific for RA, 99mTc IgG scintigraphy is a reliable tool to evaluate the degree and extent of joint inflammation.