CPT® Code 85292

The CPT® Code 85292 refers to a laboratory test known as the prekallikrein assay, also commonly referred to as the Fletcher factor assay. This test is specifically designed to measure the activity of prekallikrein, which is a serine protease coagulation protein. In the context of the clotting cascade, prekallikrein is activated to kallikrein by factor XII, also known as Hageman factor, as part of the intrinsic pathway. The significance of this assay lies in its ability to identify deficiencies in prekallikrein, which, although rare, can lead to abnormal bleeding tendencies. Such deficiencies are typically diagnosed when a patient presents with an abnormal bleeding time test, specifically the partial thromboplastin time (PTT or aPTT). The causes of prekallikrein deficiency can be inherited, stemming from a genetic disorder, or acquired due to conditions such as liver disease, disseminated intravascular coagulation (DIC), or severe infections like sepsis. To perform this test, a blood sample is collected, which is done through a separately reportable venipuncture. The analysis is conducted on platelet-poor plasma using a clotting activity assay, ensuring accurate measurement of prekallikrein activity.