Platelet Aggregation
(Clotting)

Alternative names: Platelet adhesion

Platelets are disk-shaped blood cells that are also called thrombocytes.  They play a major role in the blood-clotting process; platelet aggregation is a crucial step in the process of clot formation, which stops bleeding.

There are many factors involved in blood clotting (coagulation).  One of the first steps in the process involves small cells in the bloodstream called platelets, which are produced in the bone marrow.  Platelets gather at the site of an injury and clump together to form a plug, or aggregate, that helps to limit the loss of blood and promote healing.

Causes and Development

Thrombocytosis is increased platelet count.  This may occur in certain disease states such as cancer, chronic infections, and certain blood diseases, and may cause increased blood clot formation.

Specific causes include: High triglycerides, excessive red meat, stress, caffeine, sodas, chocolate, and others.

Several organic substances may promote platelet clumping which include collagen, ADP, the catecholamines, certain immune complexes and fatty acids.  Cigarette smoking often contributes to "hyperactive" platelet formation.

A high-fat diet should be ruled out as the cause.  Other possible causes include acute phase protein elevation caused by inflammation, tissue necrosis or allergy; a collagen-damaging disease; occult disease processes which may cause collagen damage or neoplastic changes; excessive stress level producing biochemical imbalance.

Signs and Symptoms

Signs and symptoms of possible excess platelet aggregation include poor circulation, capillary blockage, blood clots, heart problems.

Diagnosis and Tests

A platelet aggregation test can be performed to determine how well platelets are sticking together.  The test measures this by using a platelet antagonist to initiate clumping in the patient's blood sample.

Treatment and Prevention

Substances that reduce platelet aggregation include tocotrienols, shark liver oil, curcumin, gingko biloba, grape seed extract, grapes and grape juice, testosterone, Coumadin, fish oils, vitamin E at 300 IU or above, B6 at 150-200mg, EFAs, garlic, taurine and gugulipids.

Bromelain has been shown to decrease aggregation of blood platelets.  It is an effective fibrinolytic agent but this action is more evident in purified fibrinogen solutions than in plasma.

Prognosis; Complications

Severe platelet aggregation can be a potentially serious finding.  Platelet aggregation can contribute to cardiovascular disease which is the number one cause of death in the western world.

Diabetics and patients with hypercholesterolemia usually demonstrate increased platelet aggregation which can predispose them to clotting disorders which may lead to a vascular thrombus and vessel obstruction.