What is Apheresis?
H.E.L.P. LDL Apheresis

 What is Apheresis?
Apheresis essentially means a separation of plasma from the rest of the blood. If the plasma obtained during separation is treated further to remove pathogenic substances, one speaks of therapeutic plasmapheresis. Therapeutic plasmapheresis is always a treatment for chronic metabolic illnesses which cannot or only inadequately be treated with medication. This therapy acts only on symptoms and mitigates their harmful effects.
Roughly 250,000 plasmapheresis therapies are performed worldwide annually. The main purpose of therapeutic plasmapheresis is to treat auto-immune illnesses (e.g. rheumatoid arthritis) and sepsis (blood poisoning) and, in a specialized form, remove high concentrations of lipoproteins (blood lipids such as LDL cholesterol) directly from the blood or plasma. This special form of plasmapheresis is termed LDL apheresis. A direct removal of lipoproteins from the blood is termed full-blood apheresis. If only the plasma is to be treated, a differentiation is made between non-selective and selective LDL apheresis. In the case of semi-selective LDL apheresis (cascade filtration), the plasma is filtered in an additional second stage purely according to the size of the plasma proteins. However, desirable plasma constituents are also eliminated in this process. In the case of the selective variant (H.E.L.P. apheresis), only certain (pathogenic) blood lipids are eliminated from the separated blood plasma. About 2000 patients worldwide are treated annually by means of LDL apheresis, 25% of them receiving the H.E.L.P. therapy. Introduced 25 years ago, H.E.L.P. LDL apheresis has been used to treat 300,000 individual cases to date.

H.E.L.P. LDL Apheresis
Plasma-proteins and blood lipids can be adsorbed by an adsorber or precipitated from the plasma by means of modulation. Plasma modulation is better than plasma adsorption and full-blood adsorption in terms of compatibility with a patient's prescribed medicines. H.E.L.P. LDL apheresis is performed by way of plasma modulation. The abbreviation H.E.L.P. stands for

H eparin-induced
E xtracorporal
L DL
P recipitation.

In a separation process, the plasma in the patient's blood is segregated from its remaining constituents. The separated plasma is mixed with an acetate buffer saturated with heparin. This lowers the plasma's degree of acidity (pH value) to 5.12, causing the LDL cholesterol, Lp(a) and fibrinogen to drop selectively out of the plasma. Together with the heparin additive, the separated constituents form insoluble precipitates which can be removed from the plasma in a single filtration stage. Unused surplus heparin is held back in a separate adsorber, and bicarbonate ultrafiltration is used to restore the purified plasma to the physiologically acceptable level. The selectively treated, purified plasma is then remixed with the remaining blood constituents and supplied back to the patient. During H.E.L.P. apheresis, these four steps (plasma separation, precipitation with subsequent filtration, heparin adsorption and ultrafiltration) are performed by a single device, the PLASMAT Futura.