CPT® Code 85175

The CPT® Code 85175 refers to a laboratory test known as clot lysis time, which utilizes whole blood dilution to evaluate the functionality of the fibrinolytic system. This test is crucial for understanding how effectively the body can break down fibrin, a protein that forms the structural basis of blood clots. The process of fibrin breakdown is primarily mediated by the plasmin serine protease pathway, which is essential for maintaining hemostatic balance. An increase in the activity of this pathway can lead to a heightened risk of bleeding, known as hemorrhage, while a decrease can result in the formation of unwanted blood clots, or thrombosis. To perform this test, a sample of whole blood is collected and placed in a test tube, where it is clotted by the addition of thrombin, a clotting factor. The sample is then incubated at a controlled temperature of 37 degrees Celsius. During the incubation period, the test observes and counts the release of erythrocytes, or red blood cells, from the clot at 30-minute intervals. To enhance the clot lysis reaction, substances such as exogenous tissue plasminogen activator (TPA), activated Protein C, or anti-PAI antibodies may be introduced into the test tube. This laboratory test is particularly useful in diagnosing and monitoring conditions associated with atherosclerosis, assessing the coagulation status in patients who have undergone liver transplants, and managing patients during and after cardiovascular surgical procedures.