Clinical pictures of poly-myalgia rheumatica (PMR) and remitting seronegative symmetrical synovitis with pitting edema (RS3PE) are often indistinguishable from those of early rheumatoid arthritis (RA). To investigate whether there is a difference in immunological aspects among these 3 disorders, we performed a phenotypic analysis of peripheral blood lymphocytes.
Eleven patients with early RA, 14 with PMR and 11 with RS3PE were enrolled in this study. After separation of mononuclear cells from peripheral blood using the Ficoll-Hypaque method, surface markers and intracellular cytokines of lymphocytes were analyzed by 2- or 3-color flow cytometry.
Both PMR and RS3PE showed a significant decrease in CD8<sup>+</sup>CD25<sup>+</sup> cells (p<0.05), and significant increases in CD4<sup>+</sup>IFN-gamma<sup>+</sup>IL-4- (p<0.05), CD8<sup>+</sup>IFN-gamma<sup>+</sup>IL-4- (p<0.05 and p<0.01, respectively) and CD4<sup>+</sup>TNF-alpha<sup>+</sup> cells (p<0.05) compared with early RA. CD3<sup>+</sup>CD4<sup>+</sup> cells were higher in PMR than in RS3PE (p<0.01), but there were no significant differences in any other phenotypes between these disorders.
A decrease in activated cytotoxic/suppressor T cells and increases in circulating Th1 and Tc1 cells may be common characteristics of PMR and RS3PE in comparison with early RA. Both disorders are clearly different from early RA, and probably belong to the same disease entity with regard to phenotypes of peripheral blood lymphocytes.