Does keloid pathogenesis hold the key to understanding black/white differences in hypertension severity?

Repeated national surveys have shown that in the United States hypertension is more common and more severe in the black than in the white population. This discussion presents the hypothesis that the racial difference in hypertension severity is because of differences in growth factors (cytokines) affecting vascular smooth muscle cell growth. This hypothesis is derived from studies of keloids, which occur almost exclusively in blacks. Keloid fibroblasts in culture have growth characteristics that differ substantially from those of normal skin. Furthermore, there is evidence that peripheral blood mononuclear cells from patients with keloids produce different amounts of cytokines than do similar preparations from the blood of individuals without keloids. A growing body of evidence indicates that growth factors play a pivotal role in the pathogenesis of atherosclerosis, in experimental forms of hypertension, and in various renal diseases; it may be that they function in clinical hypertension as well.