A vaccine for hypertension

A cohort study protocol to analyze the predisposing factors to common chronic non-communicable diseases in rural areas: Fasa Cohort Study

Background

Non-communicable diseases (NCDs) have become the main causes of morbidity and mortality even in rural areas of many developing countries, including Iran. In view of this increased risk, Fasa Cohort Study (FACS) has been established to assess the risk factors for NCDs with the ultimate goal of providing optimal risk calculators for Iranian population and finding grounds for interventions at the population level.

Methods

In a population-based cohort, at least 10,000 people within the age range of 35 to 70 years old from Sheshdeh, the suburb of Fasa city and its 24 satellite villages are being recruited. A detailed demographic, socioeconomic, anthropometric, nutrition, and medical history is obtained for each individual besides limited physical examinations and determination of physical activity and sleep patterns supplemented by body composition and electrocardiographic records. Routine laboratory assessments are done and a comprehensive biobank is compiled for future biological investigations. All data are stored online using a dedicated software.

Discussion

FACS enrolls the individuals from rural and little township areas to evaluate the health conditions and analyze the risk factors pertinent to major NCDs. This study will provide an evidence-based background for further national and international policies in preventive medicine. Yearly follow ups are designed to assess the health events in the participating population. It is believed that the results would construct a contemporary knowledge of Iranian high risk health characteristics and behaviors as well as the platform for further interventions of risk reduction in a typical Iranian population. Constantly probing for future advances in NCDs prevention and management, the accumulated database and biobank serves as a potential for state of the art research and international collaborations.

Hypertension in adolescents

In adults, hypertension has long been perceived as a public health problem. By contrast, its impact in childhood is far less appreciated. In fact, quite often, high blood pressure in children is not even diagnosed. Blood pressure is a vital sign that is routinely obtained during a physical examination of adults, but only very seldom in children. The diagnosis of hypertension in children is complicated because 'normal' blood pressure values vary with age, sex and height. As a consequence, almost 75% of the cases of arterial hypertension and 90% of the cases of prehypertension in children and adolescents are currently undiagnosed. Furthermore, adolescence hypertension is increasing in prevalence as the prevalence of pediatric obesity has increased. Ambulatory blood pressure monitoring is a useful method for risk evaluation in adolescents. In addition to being viewed as an important cardiovascular risk factor in adolescents, elevated blood pressure should prompt a thorough search for other modifiable risk factors that, if treated, might reduce teenagers' risk of developing cardiovascular disease in adulthood. Thus, assessing blood pressure values in children represents one of the most important measurable markers of cardiovascular risk later in life and a major step in preventive medicine.

Angiotensin vaccination: what is the prospect of success?

Over many decades, several attempts have been made to treat hypertension using a vaccination strategy to inhibit the renin-angiotensin system. Renin vaccination successfully inhibited renin activity and reduced blood pressure in animal models, but caused autoimmune disease of the kidney. By contrast, most previous studies of angiotensin vaccination failed to reduce blood pressure in animal models, despite producing high titers of antibodies that prevented the pressor response to exogenous angiotensins. Angiotensin vaccination is being revisited as a strategy for treating hypertension, in the hope that new conjugates of angiotensin I and angiotensin II will produce antibodies of sufficient titer and affinity to reduce blood pressure in patients with hypertension. A recent clinical study of angiotensin II vaccination provided some cause for optimism, but many hurdles remain before this strategy can compete with current oral medications for hypertension.

Angiotensin II vaccine: a novel approach in the treatment of hypertension

BACKGROUND

Hypertension affects approximately 65 million Americans, resulting in 30 million office visits per year. Only about one third of patients have blood pressure below goal. Poor adherence to drug therapy is an important contributor to this statistic. An active immunization, which would induce antibodies against angiotensin, could simplify and improve treatment. An ideal regimen would be a few subcutaneous injections per year, which in turn could vastly improve adherence and subsequent outcomes.

OBJECTIVE

To discuss Cyt006-AngAb, a novel vaccine targeting angiotensin II, which is chemically linked to recombinant virus-like particles. Emphasis is placed on current progress of this vaccine's clinical trials.

METHODS

Relevant literature is discussed.

CONCLUSION

Although advances in hypertension vaccines have faced challenges, the angiotensin II vaccine may provide a promising approach in the control of hypertension.

Vaccination: a novel strategy for inhibiting the renin-angiotensin-aldosterone system

Immunologic approaches to renin-angiotensin-aldosterone system (RAAS) inhibition have been studied for more than 50 years. In animal models, vaccination against renin was effective but resulted in fatal autoimmune renal disease; vaccines directed at small peptides including angiotensin I and II and a segment of the AT(1) receptor reduced blood pressure (BP) without causing autoimmune disease. In humans, angiotensin I vaccination did not reduce BP. More promising is the AngQb vaccine, which uses an immunization technology involving conjugation of angiotensin II to virus-like particles. In a phase 2 trial, hypertensive patients vaccinated with 300 microg showed a difference of 9.0/4.0 mm Hg from baseline in mean daytime ambulatory BP after 14 weeks (P = 0.015 for systolic BP, P = 0.064 for diastolic BP), and a marked reduction in early morning BP. No serious adverse events were attributed to vaccine administration. Although questions remain regarding efficacy and safety, RAAS immunization represents an innovative and promising approach to hypertension treatment.