What is ristocetin?

Ristocetin is an antibiotic that was originally isolated from the bacterium Nocardia lurida. It is used in the laboratory setting as a reagent to measure the ability of blood to clot, particularly in tests for von Willebrand factor function and for diagnosing von Willebrand disease. Ristocetin works by binding to the von Willebrand factor and inducing platelet agglutination, a necessary step in the clotting process.

Ristocetin has been largely replaced by other, more specific tests for diagnosing von Willebrand disease, but it is still used in some laboratories. It is important to note that ristocetin can cause false positives in von Willebrand factor assays in patients taking certain medications, such as aspirin or nonsteroidal anti-inflammatory drugs.

Ristocetin is not used as an antibiotic in clinical practice due to its potential toxicity and the availability of safer and more effective alternatives. It is primarily used in research and diagnostic testing.