To investigate the mononuclear cell (MNC) types from peripheral blood (PB) and synovial fluid (SF) of patients with rheumatoid arthritis (RA) expressing interleukin-1 beta and -1 alpha (IL-1 beta, IL-1 alpha).
PB and SF MNC from 16 patients with classical or definite RA and controls were analyzed by flow cytometry for IL-1 beta and IL-1 alpha staining.
MNC from normal individuals do not stain for either IL-1 beta or IL-1 alpha. By contrast, PB and SF CD14+ monocytes from patients with active RA show significant staining for surface and intracellular IL-1 beta and IL-1 alpha. Furthermore, the erythrocyte sedimentation rate (ESR) correlates with the surface expression of IL-1 alpha (r = 0.52, p < 0.05) while the number of active joints (i.e., tender and/or swollen) correlate with the intracellular expression of IL-1 beta (r = 0.58, p < 0.03) in CD14+ monocytes.
The analysis of IL-1 beta and IL-1 alpha expression on CD14+ monocytes from peripheral blood by flow cytometry could be a potential immunological marker of disease activity in RA and its variation could be used to monitor the effects of therapy.