β2-microglobulin (β2-microglobulin)

β2-microglobulin (β2-M) — a small protein that is a component of major histocompatibility complex class I (MHC I) molecules and is present on the surface of virtually all nucleated cells in the body. It is constantly released into the bloodstream during the process of natural cell renewal.

β2-microglobulin is filtered by the renal glomeruli, after which a significant portion is reabsorbed and broken down in the proximal renal tubules. Therefore, the concentration of this protein can change with impaired renal function.

The study of β2-microglobulin also has clinical significance in some hematological malignant diseases. In particular, the indicator is used in multiple myeloma, as well as as an additional laboratory indicator in certain lymphomas and leukemias.

What does β2-microglobulin show?

Increased concentration of β2-microglobulin in the blood can be observed with decreased kidney function, increased cellular metabolism, some hematological malignant diseases, inflammatory and infectious processes.

In multiple myeloma, β2-microglobulin has an important prognostic value and is included in the disease staging systems. At the same time, an increase in β2-microglobulin is not a specific sign of cancer: its concentration can be significantly affected by kidney function and other conditions.

Main indications for analysis

The study may be prescribed for renal dysfunction and suspected renal tubular damage, as well as for patients with multiple myeloma, lymphomas and chronic lymphocytic leukemia — as an additional indicator for assessing the course of the disease, prognosis, and monitoring over time.

The level of β2-microglobulin can also change in chronic inflammatory, autoimmune, and some infectious diseases, so the result should always be considered together with other laboratory parameters and the clinical picture.

Biomaterial

For research, it is used venous blood (serum).

Preparation for analysis

Special preparation depends on the methodology and rules of a particular laboratory. Before donating blood, it is advisable to avoid significant physical exertion and alcohol consumption. If the patient regularly takes medications, it is worth informing the doctor about this.

You should not stop taking prescribed medications on your own before the test.

Interpretation of the result

The β2-microglobulin result is evaluated according to laboratory reference values. An elevated level does not establish a specific diagnosis and is not an independent confirmation of cancer.

For correct interpretation, kidney function, patient age, clinical symptoms, concomitant diseases, and results of other laboratory and instrumental studies are taken into account.