Normal Beta-2 microgloblulin B2M in a blood test

Each laboratory must establish its own normal range for beta-2 microglobulin B2M in a blood test. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.

Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.

In newborns, beta-2 microglobulin B2M normal ranges may be higher and values up to 5.4 mg/l is considered to be in the normal range.

Beta-2-microglobulin (B2M) or Β-2 microglobulin is a light chain protein with low molecular mass (11.8 KDa).

Beta-2-microglobulin (B2M) is a polypeptide found on the cell surfaces of all nucleated cells, especially lymphocytes and tumor cells.

Beta-2-microglobulin (B2M) is also a component of the class I major histocompatibility complex (MHC).

The beta-2 microglobulin B2M blood test is usually performed for three main purposes:

• Tumor marker: There is an increase in case of suffering certain malignancies such as multiple myeloma, chronic lymphocytic leukemia, and some lymphomas.
• Evaluate renal function: Glomerular kidney damage causes an increase in beta-2 microglobulin B2M in the blood level and a decrease in the urine, while tubular kidney disease causes low blood levels and high urine levels.
• Kidney transplant evaluation: Blood levels of beta-2 microglobulin become high when a kidney transplant is failing.

In addition, an elevation of beta-2 microglobulin in the blood may be caused by drugs (antineoplastic, nephrotoxic, etc.), bacterial or viral infections, myeloproliferative disorders, or inflammatory conditions (lupus, Sjögren's syndrome, rheumatoid arthritis, etc.).

Beta-2 microglobulin is also useful to monitor the efficacy of multiple myeloma treatment. If the level of B2M decreases after the start of the treatment, the prognosis is positive.

It is advisable to perform not only the beta-2 microglobulin blood test, but also the beta-2 microglobulin urine test for a better diagnosis.

The following values are considered to be normal values:

IMPORTANT: These levels are expressed in mg/l. They are an example of a healthy adult of about 40 years old with no known disease, not taking any medication and not pregnant if you are a woman. The ranges can be different depending on the laboratory or on your personal circumstances.