Reptilase time

Reptilase Time (RT) is a blood test used to assess the blood clotting process. It is specifically designed to measure the time it takes for a blood sample to clot after the addition of Reptilase, an enzyme derived from the venom of the Bothrops atrox snake.

Overview

Reptilase is similar to thrombin, a naturally occurring enzyme in the body that converts fibrinogen into fibrin, the protein that forms the framework of a blood clot. However, unlike thrombin, Reptilase is not inhibited by heparin, a medication often used to prevent and treat blood clots. This makes the Reptilase Time test particularly useful in patients who are receiving heparin therapy.

Procedure

The Reptilase Time test is performed on a sample of blood drawn from a vein. The blood is mixed with Reptilase in a test tube, and the time it takes for the blood to clot is measured. The normal range for Reptilase Time is typically between 15 and 20 seconds, although this can vary depending on the laboratory that analyzes the sample.

Clinical Significance

An extended Reptilase Time can indicate a deficiency or abnormality of fibrinogen. This can be seen in conditions such as disseminated intravascular coagulation (DIC), liver disease, and hereditary fibrinogenemia. It can also be extended in the presence of certain abnormal fibrinogen molecules, known as dysfibrinogenemia.

The Reptilase Time test is also used to monitor the effects of heparin therapy. Because Reptilase is not affected by heparin, an extended Reptilase Time in a patient receiving heparin suggests a problem with the fibrinogen itself, rather than an effect of the medication.

See Also

• Thrombin time
• Partial thromboplastin time
• Prothrombin time
• International normalized ratio