Tachykinin activation of human monocytes from patients with rheumatoid arthritis: in vitro and ex-vivo effects of cyclosporin A

Three types of tachykinin receptors, namely NK1, NK2 and NK3, are known to preferentially interact with substance P (SP), neurokinin A (NKA) and neurokinin B (NKB), respectively. We previously demonstrated that NK1 and NK2 receptors are present on human monocytes, SP and NKA inducing superoxide anion production and tumor necrosis factor- alpha (TNF-alpha) mRNA expression. NK2 receptor stimulation also triggered an enhanced respiratory burst in monocytes isolated from rheumatoid arthritis (RA) patients. This study was aimed to evaluate the in vitro and ex-vivo effects of cyclosporin A (CsA) on tachykinins-evoked TNF-alpha release from monocytes of healthy donors and RA patients. CsA (100 ng/ml) potently inhibited phorbol ester- and tachykinin-evoked TNF-alpha secretion. In RA patients treated with CsA (Sandimmun(R) Neoral(R)) 2.5 mg/kg/die, a significant time-dependent reduction in TN F-or secretion from monocytes was measured. This may contribute to the CsA therapeutic activity in RA.