Beta 2-microglobulin in the blood and urine

Reference values of the concentration of beta _2- microglobulin: in serum - 660-2740 ng / ml, in urine - 3.8-251.8 ng / ml. Half-life is 40 minutes.

Beta _2- microglobulin is a low-molecular protein of surface antigens of cell nuclei. Its presence in the blood serum is due to the processes of degradation and repair of individual cell elements. β ₂ -Microglobulin freely passes through the membrane of the renal glomeruli, 99.8% of it is then reabsorbed in the proximal part of the renal tubules. Reduction of glomerular filtration helps to increase the level of beta _2- microglobulin in the blood serum, a violation of the renal tubule function leads to the excretion of large amounts of beta _2- microglobulin in the urine. The upper limit of the reabsorption capacity of renal tubules is reached at a concentration of beta _2- microglobulin in serum of 5000 ng / ml. To conditions in which the concentration of serum beta- _2- microglobulin increases, autoimmune diseases, disorders of cellular immunity (eg, HIV infection), conditions after organ transplantation are included. An increase in the concentration of beta _2- microglobulin in the cerebrospinal fluid in patients with leukemia indicates involvement in the CNS process. Determination of beta _2- microglobulin in blood and urine is performed by patients with the diagnosis of glomerulonephritis and tubular nephropathy, as well as to elucidate the prognosis in patients with non-Hodgkin's lymphomas and especially in patients with multiple myeloma (patients with elevated concentrations have significantly lower life expectancy than patients with normal values).

Determination of beta _2- microglobulin is necessary for monitoring the treatment of hemoblastoses, myeloma, control of lymphocyte activation in kidney transplantation.

The concentration of beta- _2- microglobulin in the blood increases with renal failure, acute viral infections, immunodeficiencies, including HIV infection, autoimmune diseases, hemoblastosis (B-cell), myeloma, acute leukemia and lymphomas with CNS damage.

The concentration of beta _2- microglobulin in the urine increases with diabetic nephropathy, intoxication with heavy metals (cadmium salts).