Detection of sarcolectin-specific receptors like the cytokine macrophage migration inhibitory factor in rheumatoid nodules

The objective of this study was the evaluation of the relation between the N-acetyl-neuraminic acid-binding endogenous lectin sarcolectin and the cyto kine macrophage migration inhibitory factor (MIF) during development of rhe umatoid nodules (RN) in seropositive rheumatoid arthritis (RA). Sarcolectin was purified and biotinylated. The binding patterns of this probe were ana lyzed in RN from patients with RA (n=23) and compared with the distribution of antibodies with specificity for MIF, fibrin, fibronectin. In early RN, all areas of the inflammatory tissue displayed presence of receptors for sa rcolectin. Macrophages were especially positive. In mature rheumatoid nodul es binding of sarcolectin was restricted to the periphery of necrotic areas , to endothelial cells and perivascular connective tissue of marginal zones . Distribution patterns of MIF were similiar but not identical. The histolo gical staining characteristics demonstrate sarcolectin-binding receptors in RN that are altered upon disease progression. The finding suggests that sp ecific interactions between this endogenous lectin and MIF may be involved in the course of RA.