Therapeutic apheresis in peripheral and retinal circulatory disorders

Abstract

In microcirculation disorders, the therapeutic apheresis seems to have two different effects. The first, achieved after only a few sessions, is acute, consisting of drastic reduction of blood viscosity and obtained with the use of low-density lipoprotein (LDL) apheresis, rheopheresis, or fibrinogen apheresis. The second effect is long term, or chronic, and needs to be evaluated after a long course of treatment. The mechanisms underlying the chronic effect are still objects of debate and take into account the pleiotropic effects of apheresis. However, it is likely that the acute effect of apheresis mainly influences the functional components of the vascular damage, and so the derived rheological benefit might last only for a short period. The chronic effect, on the contrary, by acting on the morphological alterations of the vascular walls, requires the apheresis treatment to be prolonged for a longer period or even cycles of treatment to be programmed.

Therapeutic plasma exchange rapidly improves cardiac allograft function in patients with presumed antibody‐mediated rejection

“…In a previous study, we found that patients with pAMR had significant and sustained reductions in fibrinogen levels when compared to other patient populations who receive daily TPE . Although fibrinogen only accounts for approximately 4% of plasma proteins, its concentration is the major determinant of plasma viscosity and blood rheology owing to its large size . Using 5% albumin as the replacement fluid during TPE causes a rapid reduction in blood viscosity and resistance to blood flow through vessels due to depletion of fibrinogen.…”

“…Using 5% albumin as the replacement fluid during TPE causes a rapid reduction in blood viscosity and resistance to blood flow through vessels due to depletion of fibrinogen. In certain disorders of the microcirculation (e.g., sudden hearing loss, nonarteritic anterior ischemic optic neuropathy, and peripheral arterial disease), reducing blood viscosity by removing fibrinogen results in rapid resolution of the disorder, usually following 1 or 2 treatments . We speculated that the rapid improvement of cardiac allograft function following TPE may be due to changes in the rheologic properties of blood as acute reductions in fibrinogen and viscosity following TPE may improve perfusion of the allograft and increase cardiac contractility.…”

Dynamics of Blood Count after Rheohemapheresis in Age-Related Macular Degeneration: Possible Association with Clinical Changes

“…RHF is used for the treatment of sudden hearing loss, age-related macular degeneration, peripheral arterial disease, and several other microcirculatory diseases [ 6 , 7 , 12 , 13 ]. Data supporting the efficacy of this procedure have been published, but detailed pathophysiological explanations of the positive clinical effects are not clear or are missing.…”

Rheopheresis: A narrative review

“…Hemorheology is determined by the viscosity of the plasma/whole blood as well as the erythrocyte deformability and tendency to aggregate. 1…”

“…Improvement in the mircocirculatory parameters might correct, at least partially, the functional properties of the anatomic entity affected, that is, an improvement in the ischemic symptoms of PAD, or a partial correction/stabilization of visual acuity in patients with AMD. 1…”