In medicine

Medicine

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

, LDL apheresis is a form of apheresis

Apheresis

Apheresis is a medical technology in which the blood of a donor or patient is passed through an apparatus that separates out one particular constituent and returns the remainder to the circulation...

, resembling dialysis

Dialysis

In medicine, dialysis is a process for removing waste and excess water from the blood, and is primarily used to provide an artificial replacement for lost kidney function in people with renal failure...

, to eliminate the cholesterol

Cholesterol

Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...

-containing particle low-density lipoprotein (LDL) from the bloodstream.

Uses

It is used in diseases featuring high LDL, such as the rare

Rare disease

A rare disease, also referred to as an orphan disease, is any disease that affects a small percentage of the population.Most rare diseases are genetic, and thus are present throughout the person's entire life, even if symptoms do not immediately appear...

 homozygous familial hypercholesterolemia

Familial hypercholesterolemia

Familial hypercholesterolemia is a genetic disorder characterized by high cholesterol levels, specifically very high levels of low-density lipoprotein , in the blood and early cardiovascular disease...

, when the heterozygous form does not respond to medical treatment, or when the treatment has led to dangerous side-effects

Adverse effect (medicine)

In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...

 (such as rhabdomyolysis

Rhabdomyolysis

Rhabdomyolysis is a condition in which damaged skeletal muscle tissue breaks down rapidly. Breakdown products of damaged muscle cells are released into the bloodstream; some of these, such as the protein myoglobin, are harmful to the kidneys and may lead to kidney failure...

).

The procedure takes 2-4 hours and must be repeated every several weeks to keep the LDL levels from accumulation and causing cardiovascular disease

Cardiovascular disease

Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...

.

It is an expensive procedure, limiting its use to severe cases of hyperlipidemia

Hyperlipidemia

Hyperlipidemia, hyperlipoproteinemia, or hyperlipidaemia is the condition of abnormally elevated levels of any or all lipids and/or lipoproteins in the blood...

.

Principles

LDL apheresis works by leading venous blood

Venous blood

Venous blood is deoxygenated blood in the circulatory system. It runs in the systemic veins from the organs to the heart. Deoxygenated blood is then pumped by the heart to lungs via the pulmonary arteries, one of the few arteries in the body that carries deoxygenated blood .Venous blood is...

 through a column coated with antibodies

Antibody

An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...

 to apolipoprotein B

Apolipoprotein B

Apolipoprotein B is the primary apolipoprotein of low-density lipoproteins , which is responsible for carrying cholesterol to tissues. While it is unclear exactly what functional role APOB plays in LDL, it is the primary apolipoprotein component and is absolutely required for its formation...

 (the main protein of LDL particles), dextran

Dextran

Dextran is a complex, branched glucan composed of chains of varying lengths...

 sulfate or polyacrylate, or by precipitating LDL with heparin

Heparin

Heparin , also known as unfractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule...

 at low pH

PH

In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

. In all cases (apart from polyacrylate absorption), plasma

Blood plasma

Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...

 is separated from cells

Blood cell

A blood cell, also called a hematocyte, is a cell normally found in blood. In mammals, these fall into three general categories:* red blood cells — Erythrocytes* white blood cells — Leukocytes* platelets — Thrombocytes...

 by a cell separator.

External links

• http://www.apheresis.org American Society for Apheresis
  American Society for Apheresis
  The American Society for Apheresis is an organization of physicians, scientists, nurses, and allied health professionals whose mission is to advance apheresis medicine for patients, donors and practitioners through education, evidence-based practice, research and advocacy...
  
  
• LDL apheresis information on from Cedars-Sinai Medical Centre.

• LDL apheresis information on from Liposorber.