CPT® Code 84166

The CPT® Code 84166 refers to a laboratory test that involves the electrophoretic fractionation and quantitation of proteins found in various body fluids, specifically those with concentration such as urine and cerebrospinal fluid (CSF). This procedure is essential for measuring the levels of proteins present in these fluids, which can provide critical insights into a patient's health status. Elevated protein levels in CSF may indicate serious conditions such as central nervous system tumors or various neurological disorders, while increased protein levels in urine can suggest kidney disease or damage. The test utilizes quantitative electrophoresis, a technique that separates proteins based on their size and charge, allowing for precise measurement and analysis. It is important to note that CSF is typically collected through a lumbar puncture, also known as a spinal tap, which is a separate procedure that must be reported independently. In contrast, urine samples are usually collected over a 24-hour period to ensure accurate assessment of protein concentration. This test is particularly valuable in diagnosing and monitoring conditions that affect protein levels in these critical body fluids.