SCINTIGRAPHIC EVALUATION OF DISEASE-ACTIVITY IN RHEUMATOID-ARTHRITIS - A COMPARISON OF TC-99M HUMAN NONSPECIFIC IMMUNOGLOBULINS, LEUKOCYTES AND ALBUMIN NANOCOLLOIDS

Technetium-99m-labelled, non-specific, polyclonal, human immunoglobulin G (Tc-99m-hIG) has been used to quantify synovial inflammation in rheumatoid arthritis. A comparison was carried out between the scintigraphic results obtained with this tracer, Tc-99m-hexamethylpropylene amine oxime-labelled white blood cells (Tc-99m-WBC) and Tc-99m-albumin nanocolloids (Tc-99m-NC). Twenty patients affected by rheumatoid arthritis and suffering from clinically active synovitis were studied with Tc-99m-hIG. The number and sites of the involved joints had been previously assessed on the basis of the presence of pain and/or swelling. A radiological examination had already been carried out on all the joints. Two days after the Tc-99m-hIG scan, 10 patients (group 1) underwent Tc-99m-WBC scintigraphy and the other 10 (group 2) underwent a Tc-99m-NC scan. The results show that the results of Tc-99m-hIG and99m Tc-NC scans are in agreement with clinical examinations in the majority of cases. However, a certain number of positive joint scans corresponding to negative clinical examinations was found. The numerical distribution of these results according to the radiological stages seems to show that Tc-99m-hIG is more useful than Tc-99m-NC in the initial phases of the disease. The Tc-99m-WBC scan was negative in a consistent percentage of the joints previously assessed as clinically and Tc-99m-hIG scan positive.