CPT® Code 84120

The CPT® Code 84120 refers to a laboratory test that quantifies and fractionates porphyrins in urine. Porphyrins are organic compounds that play a crucial role in the formation of heme, which is an essential component of hemoglobin in red blood cells and myoglobin in muscle cells. This test is significant for diagnosing various medical conditions, as elevated porphyrin levels can indicate potential health issues such as lead poisoning, liver disease, or porphyria, which is a genetic disorder characterized by a deficiency of enzymes involved in the heme synthesis pathway. The procedure typically involves collecting a 24-hour urine sample, although a random urine sample may be utilized during acute symptomatic episodes. The analysis is performed using quantitative high-performance liquid chromatography, a sophisticated technique that allows for precise measurement of porphyrin levels in the urine. This test is often ordered alongside other tests, such as the urine porphobilinogen test (CPT® Code 84106), to provide a comprehensive assessment of porphyrin metabolism and related disorders.