β2-microglobulin is a low weight protein (MW = 10.8 kDa) non-covalently bound to the HLA class I antigens and can be detected on the cell membranes of virtually all normal nucleated cells. The surface of lymphocytes and monocytes is particularly rich in β2-microglobulin. The protein is eliminated via the kidneys by glomerular filtration, subsequently more than 99.9% is reabsorbed and degraded in the proximal tubules. The serum level of β2-microglobulin is determined by the glomerular filtration rate and the rate of synthesis.
Determination of β2-microglobulin is used to monitor lymphoproliferative diseases (multiple myeloma, chronic lymphocytic lymphoma, non-Hodgkin’s lymphoma, Hodgkin’s disease) and to assess the renal function. In infectious diseases and inflammations serum β2-microglobulin values can be elevated