CPT® Code 84449

The CPT® Code 84449 refers to a laboratory test that measures the levels of transcortin, also known as cortisol binding globulin (CBG), in the blood. Transcortin is a type of alpha globulin protein that plays a crucial role in binding steroid hormones, including cortisol, progesterone, aldosterone, and 11-Deoxycorticosteroid. This binding is essential for the regulation and transport of these hormones throughout the body. Transcortin is synthesized in the liver, and its production is influenced by estrogen levels, which can lead to normal physiological increases during pregnancy. Conversely, decreased levels of transcortin may indicate underlying health issues, particularly liver disorders such as cirrhosis, which can impair the liver's ability to produce this protein. The test is performed by obtaining a blood sample through venipuncture, which is a procedure that can be reported separately. The serum obtained from the blood sample is then analyzed using a method known as radioimmunoassay, a sensitive technique that allows for the precise measurement of hormone levels in the serum.