Pro-inflammatory cytokines in patients with essential hypertension

BACKGROUND: It has been suggested that abnormalities in the immune response play a role in the pathogenesis of essential hypertension (EH). The aim of this study was to assess circulating concentrations and ex vivo production of the pro-inflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and of the anti-inflammatory cytokines IL-1 receptor antagonist (IL-1ra) and IL-6, in patients with EH and compare them with healthy volunteers. PATIENTS AND METHODS: Plasma cytokine concentrations were measured in EH patients and control volunteers by specific radioimmunoassays and ELISA. Ex vivo cytokine production was assessed after stimulation of whole-blood with lipopolysaccharide. RESULTS: Circulating concentrations of TNF, IL-1 and IL-6 did not differ between EH patients and controls. In contrast, IL-1ra circulating levels were higher in EH patients. Hypertensive patients had an increased IL-1 and IL-6 production capacity when whole blood was stimulated ex vivo with lipopolysaccharide, while TNF production was lower. IL-1ra production capacity did not differ between patients and controls. CONCLUSIONS: Patients with EH have an altered profile of pro-and anti-inflammatory cytokines, consistent with monocyte activation in the circulation. The importance of these changes for the pathogenesis of EH and/or its secondary complications remains to be elucidated.