CPT® Code 82232

The CPT® Code 82232 refers to a laboratory test specifically designed to measure the levels of beta-2 microglobulin (B2M) in various biological samples. Beta-2 microglobulin is a small protein that is present on the surface of certain cells, including B lymphocytes, which are a type of white blood cell, as well as tumor cells. This protein can shed into the bloodstream and may also be detected in urine and cerebrospinal fluid (CSF). While B2M testing is not classified as a differential test, it serves a significant role in providing additional clinical insights regarding the progression of various diseases. The test is particularly relevant for patients diagnosed with conditions such as multiple myeloma, lymphoma, multiple sclerosis, liver and kidney diseases, chronic inflammatory disorders, HIV/AIDS, and cytomegalovirus (CMV) infections. The collection of samples for B2M testing involves obtaining a blood sample through a separately reportable venipuncture, a CSF sample via a separately reportable lumbar puncture, and a urine sample which can be collected either as a voided specimen or through catheterization. For urine collection, it is important to discard the first specimen, ensure the patient is hydrated by providing water, and then collect a second urine sample within one hour for accurate analysis. The testing methodologies employed for serum/plasma and CSF samples include quantitative immunoturbidimetry, while urine samples are analyzed using a quantitative chemiluminescent immunoassay.