Renin-angiotensin vaccine: old story, new project 'efficacy versus safety'.

In the present issue of Clinical Science, Brown and co-workers report preliminary results of Ang I (angiotensin I) immunization in humans. They demonstrate the presence of antibodies in human plasma and report that the procedure is well tolerated, but the blood pressure does not fall. The first attempts to actively immunize against components of the renin-angiotensin system were performed by Goldblatt in the 1950s. In our experience, active immunization against renin was associated with a complete inhibition of endogeneous plasma renin activity and a decrease in blood pressure, followed by the progressive development of a juxtaglomerular autoimmune nephritis. In contrast neither blood pressure nor aldosterone secretion were significantly modified by Ang I immunization. Moreover, Ang I-immunized animals continued to respond to the pharmacological inhibition of renin-angiotensin system. These data provide evidence of the inability of antibodies to target Ang I within tissues.