Expression of complement receptor type 3 (CR3) by rheumatoid and age/sex-matched control leucocytes. (a) Baseline expression of CR3 expression on peripheral leucocytes in Patients with rheumatoid arthritis and control volunteers. Correlation of neutrophil (b) and monocyte (c) CR3 and erythrocyte sedimentation rate (ESR). There was a trend for a positive correlation between neutrophil expression and ESR; however, this marginally failed to reach statistical significance (p = 0.06). (d) Neutrophil CR3 expression was upregulated in response to TNF-α. MESF, milliequivalents of soluble fluorescein.