Scintigraphic evaluation of synovial inflammation in rheumatoid arthritis with 99mtechnetium-labelled human polyclonal immunoglobulin G

Abstract

The aim of this study was to investigate whether ^99mtechnetium-labelled polyclonal human immunoglobulin G (^99mTc-IgG) scintigraphy reflects synovial inflammation in patients with rheumatoid arthritis (RA). We evaluated 29 patients with RA for this reason and found a highly significant correlation between total scintigraphic scores and total tenderness scores (r=0.781, P < 0.001). A significant correlation was also found between ^99mTc-IgG scintigraphic scores and tenderness in all joints other than the shoulders. The ^99mTc-IgG scintigraphy had a sensitivity of 69% and specificity of 88% in cases with tenderness and 72% and 81%, respectively, in cases with swelling. Total scintigraphic scores were correlated with serum levels of C-reactive protein (r=0.401, P < 0.05) but not with erythrocyte sedimentation rate (r=0.149, P > 0.05). The correlation between disease activity scores and total scintigraphic scores was also found to be significant (r=0.812, P < 0.001). We suggest that ^99mTc-IgG scintigraphy is a reliable and objective method in detecting synovial activity and can be appropriate for observing disease prognosis in clinical trials with RA.