Responses Triggered by the Immune System in Hypertensive Conditions and Repercussions on Target Organ Damage: A Review

Background: Hypertension is a chronic, multifactorial clinical condition characterized by sustained high blood pressure levels. It is often associated with functional-structural alterations of target organs, which include heart, brain, kidneys, and vasculature. Objective: This study highlights the recent correlation between the immune system and hypertension and its repercussions on target-organ damage. Methods: The descriptors used for the search of the study were "hypertension", "immunity", and "target organs". The methodology of the study followed the main recommendations of the PRISMA statement. Results: The damage to the vasculature arises mainly from the migration of T cells and monocytes that become pro-inflammatory in the adventitia, releasing TNF-α, IFN-γ, and IL-17, which induce endothelial damage and hinder vascular relaxation. In the renal context, the inflammatory process associated with hypertension culminates in renal invasion by leukocytes, which contribute to the injury of this organ by mechanisms of intense sympathetic stimulation, activation of the reninangiotensin system, sodium retention, and aggravation of oxidative stress. In the cardiac context, hypertension increases the expression of pro-inflammatory elements, such as B, T, and NK cells, in addition to the secretion of IFN-γ, IL-17, IL-23, and TNF-α from angiotensin II, reactive oxygen species, and aldosterone. This pro-inflammatory action is also involved in brain damage through SphK1. In view of the above, the participation of the immune system in hypertension-induced injuries seems to be unequivocal. Conclusion: Therefore, understanding the multifactorial mechanisms related to hypertension will certainly allow for more efficient interventions in this condition, preventing target organ damage.