Ristocetin is a chemical compound produced from bacteria and historically used as an antibiotic. Today, it is manufactured for use in lab tests to assess coagulation and platelet aggregation, testing people for a condition called von Willebrand disease, where the blood does not coagulate normally. Certain other coagulopathies, as diseases involving poor coagulation are known, can also be tested for with ristocetin. The compound is available from scientific supply companies and distributors with stocks of supplies for lab tests.
This compound was once used to treat infections with Staphylococcus bacteria. This usage was discontinued out of concerns about the toxicity of the compound, causing potentially serious side effects for patients. Other antibiotics are safer and can be very effective, making the risks of using ristocetin not worth the potential benefit of treating the infection.
In laboratory tests to check coagulation, a sample of blood is fixed to a plate and ristocetin is added. If the blood has a healthy level of von Willebrand factor circulating freely, it will start to clot. The rapidity and degree of clotting can be an important diagnostic clue in the lab test, as the blood may respond partially, indicating low levels of the factor, or a defective version of the factor. People with von Williebrand disease lack this important blood protein, and their blood will not clot as readily in response to injuries.
Testing for other diseases involving clotting may also involve this chemical. If blood clots in response to ristocetin, the patient does not have von Willebrand disease, but may have another medical issue causing problems with clotting. Patients with these conditions are subject to problems like easy bruising, damage to the joints, and free bleeding even from minor injuries. This can put them at risk of serious blood loss, and can complicate things like surgery, where injuries to the tissue can result in losing a high volume of blood.
Management of coagulopathies varies, depending on the disease. For a condition like von Willebrand disease, patients may not need special care. Women are often advised to use hormonal birth control to regulate their menstrual cycles, and patients about to undergo surgery may be given prophylactic treatment with clotting factors to reduce the risks in surgery. These conditions are inherited, and this can be a consideration in people planning to have children. The ristocetin test is one among a family of diagnostic tools a doctor can use to explore the causes of an apparent clotting disorder.