Association versus causation: the relationship of interleukin-1beta and hypertension

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.