ristocetinkomplex

Ristocetin is an antibiotic that was originally derived from the bacterium Nocardia lurida. It functions by inhibiting bacterial cell wall synthesis. Ristocetin exists in two forms, ristocetin A and ristocetin B, which differ slightly in their chemical structure. While it was initially explored for clinical use, its systemic toxicity, including the risk of ototoxicity and nephrotoxicity, led to its withdrawal from therapeutic applications.

Despite its lack of direct clinical use, ristocetin plays a significant role in laboratory diagnostics, particularly in hematology. It is a key component in the ristocetin cofactor assay, a test used to diagnose and assess the severity of von Willebrand disease. In this assay, ristocetin is added to a patient's plasma and platelets. It acts as an artificial agonist, causing platelets to aggregate by bridging the interaction between the von Willebrand factor (vWF) and platelet glycoprotein Ib (GPIb) receptor. The degree of platelet aggregation observed is directly proportional to the functional level of vWF in the patient's sample. This assay is crucial for differentiating between various types of von Willebrand disease and for monitoring treatment efficacy.