Decreased catecholamine-induced cell death in B lymphocytes from patients with rheumatoid arthritis

Abstract

The expression of beta2-adrenergic receptors (beta2-R) on B lymphocytes and agonist-induced cAMP production is reduced in patients with rheumatoid arthritis (RA). To further study functional consequences of the diminished beta2-R density on B lymphocytes in RA patients, agonist-induced cell death was evaluated and compared to healthy controls. B lymphocytes from patients with RA and healthy controls were activated with anti-IgM-antibody. Coincubation was carried out with isoprenaline (iso, 0.001-10 microM). Apoptotic and necrotic cells were determined using Annexin-V and propidium-iodide staining. beta2-R-induced cell death in B cells from healthy volunteers was stimulated after 24 h (medium, 21.2 +/- 1.6%; iso, 34.6 +/- 4.4%; increase 59.3 +/- 10.1%). However, in RA patients the increase in cell death following beta2-R stimulation (21.8 +/- 8.9%) was significantly impaired (p = 0.02). Our data demonstrate that catecholamine-induced cell death after stimulation of beta2-R on B lymphocytes is decreased in RA patients, possibly contributing to the pathogenesis of the disease.