Abstract
The purpose of this paper is to determine what types of circulating immune complex (CIC) assays are the most suitable for monitoring rheumatoid arthritis (RA) patients treated with plasmapheresis (PP).
PP using the double filtration method was carried out in 11 patients with RA. In each PP procedure, 2, 000mll of plasma was passed through the filtration column. Each procedure was performed once a week for 4 weeks. CIC was measured by three different methods, namely Raji cell assay (RJC), anti-C 3 assay (AC 3) and C 1 q solid-phase assay (C 1 q SA). The clinical activities of RA were evaluated using the Lansbury indices.
CIC titers significantly decreased in 4 weeks after PP treatment for 3 patients measured by RJC and for 6 patients by AC 3. A significant decrease of CIC measured by C 1 q SA was also observed for 3 patients in 1 week after treatment.
The decrease of CIC titers measured by AC 3 was associated with a significant improvement of Lansbury index during 8 weeks after treatment. However, there was no relationship between the decrease of CIC titers by RJC or C 1 q SA, and the changes in Lansbury index after PP treatment.
In conclusion, AC 3 assay for CIC in RA patients treated with PP was thought to be best among the 3 different methods.
