What is β2-MG?

β2-MG is a small-molecule globulin produced by lymphocytes, platelets, and polymorphonuclear leukocytes, with a molecular mass of 11,800 and a single-chain polypeptide consisting of 99 amino acids. It is the β-chain (light chain) portion of the human leukocyte antigen (HLA) on the cell surface, and contains a pair of disulfide bonds within the molecule and no sugar.

β2-MG is similar in structure to the stabilisation region of immunoglobulin. β2-MG is widely found in plasma, urine, cerebrospinal fluid, saliva, and colostrum.

The synthesis rate and release of β2-MG from the cell membrane are fairly constant in normal humans. β2-MG can be freely filtered from the glomerulus, 99.9% of which is absorbed in the proximal tubule and broken down and destroyed by the epithelial cells of the renal tubule; therefore, β2-MG is normally excreted in very small amounts.

Clinical application of β2-MG

Clinical detection of β2-MG concentration in blood or urine provides an early, reliable and sensitive indicator for the clinical diagnosis of kidney function, renal transplantation survival, diabetic kidney disease, heavy metal cadmium and mercury poisoning and certain malignant tumours.

Specific clinical applications of β2-MG are shown below:

Blood β2-MG(Estimation of kidney function)

① Blood β2-MG is a sensitive indicator of glomerular filtration function, and various primary or secondary glomerular pathologies that involve glomerular filtration function can result in elevated blood β2-MG.

② Sensitive indicators of impaired renal function in hypertension and diabetes mellitus.

③ Elevated blood β2-MG in long-term haemodialysis patients is associated with the development of amyloidosis, amyloid osteoarthropathy and carpal tunnel syndrome.

④ Dynamic observation and diagnosis of early kidney transplant rejection.

⑤ β2-MG is a major marker of lymphoproliferative disorders and can be used to evaluate the prognosis and treatment of myeloma

⑥ Blood β2-MG can be used to assess the activity of autoimmune diseases and as an indicator of drug efficacy.

Factors affecting β2-MG

Increased β2-MG levels may also be due to:

Renal Failure

(Inadequate blood supply to the kidney, chronic drug use,decrease in glomerular filtration function)

Systemic Lupus Erythematosus(SLE)

(Genetics, environment, increased oestrogen)

Kidney Transplant Rejection

Congenital defects of proximal tubular function

Malignant tumours, autoimmune diseases, chronic hepatitis, diabetic kidney disease

Summary

In conclusion, blood β2-microglobulin is of great significance in clinical practice, not only as one of the effective detection indicators of impaired renal function and glomerular filtration rate, but also help to dynamically observe and diagnose early renal transplantation rejection, which is of great significance and value for our current assessment of renal function.

The ReLIA β2-MG Immunoassay is CE-marked cleared. For more details on ReLIA β2-MG Immunoassay products and prices please contact us at  marketing@ReLIAchina.com

References

[1] Wong J, Sridharan S, Berdeprado J, Vilar E, Viljoen A, Wellsted D, et al. Predicting residual kidney function in hemodialysis patients using serum beta-trace protein and beta2-microglobulin. Kidney international. 2016;89(5):1090-8. doi: 10.1016/j.kint.2015.12.042.

[2] Trailin AV, Pleten MV, Ostapenko TI, Iefimenko NF, Nikonenko OS. High Serum Level of beta2-Microglobulin in Late Posttransplant Period Predicts Subsequent Decline in Kidney Allograft Function: A Preliminary Study. Disease markers. 2015;2015:562580. doi: 10.1155/2015/562580.

[3] Hu S, Wu J, Lu D, Dai Y, Mai M, Wei R, et al. Reference values of fetal serum beta2-microglobulin in the Chinese: evaluation of its clinical usefulness. Clinical chemistry and laboratory medicine. 2014;52(3):413-7. doi: 10.1515/cclm-2013-0505.

[4] Astor BC, Muth B, Kaufman DB, Pirsch JD, Michael Hofmann R, Djamali A. Serum beta2-microglobulin at discharge predicts mortality and graft loss following kidney transplantation. Kidney international. 2013;84(4):810-7. doi: 10.1038/ki.2013.172.

[5] Matokovic D, Haspl M, Petric P, Skorvaga S, Rajic MT. Value of beta2-microglobulin in the serum of healthy subjects older than 40 years. Therapeutic apheresis and dialysis : official peer-reviewed journal of the International Society for Apheresis, the Japanese Society for Apheresis, the Japanese Society for Dialysis Therapy. 2011;15(3):315-8. doi: 10.1111/j.1744- 987.2011.00908.x.