B2-microglobulin in serum and urine
Reference concentrations of b2-microglobulin: in serum - 660-2740 ng / ml, in urine - 3.8-251.8 ng / ml. Half-life is 40 minutes.
b2-microglobulin is a low-molecular-weight protein of surface Ag cell nuclei. Its presence in the blood serum is due to the processes of degradation and repair of individual cell elements.b2-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 b2-microglobulin in the blood serum, a violation of the renal tubule function leads to the excretion of large amounts of b2-microglobulin with urine. The upper limit of the reabsorption capacity of renal tubules is reached at a concentration of b2-microglobulin in serum of 5000 ng / ml. To conditions in which the concentration of serum b2-microglobulin increases, autoimmune diseases, disorders of cellular immunity( eg, HIV infection), conditions after organ transplantation are included. An increase in the concentration of b2-microglobulin in cerebrospinal fluid in patients with leukemia indicates involvement in the CNS process. The determination of b2-microglobulin in blood and urine is performed by patients in the diagnosis of glomerulonephritis and tubular nephropathies, 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 thanpatients with normal values).
Determination of b2-microglobulin is necessary for monitoring the treatment of hemoblastosis, myeloma, control of lymphocyte activation in kidney transplantation.
The concentration of b2-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 b2-microglobulin in the urine increases with diabetic nephropathy, intoxication with heavy metals( cadmium salts).