Beta 2 microglobulin is a component of major histocompatibility complex (MHC) class I molecules, which are present on almost all cells of the body red blood cells are a notable exception. Beta 2 microglobulin lies lateral to the alpha 3 chain on the cell surface.
Beta 2 microglobulin is a small protein normally found on the surface of many cells, including lymphocytes, and in small amounts in the blood and urine . Testing is done primarily when evaluating a person for certain kinds of cancer affecting white blood cells including chronic lymphocytic leukemia , non-Hodgkin's lymphoma, and multiple myeloma or kidney disease .
beta 2-Microglobulin (beta 2M), an interesting and underutilized metabolite, can be used in assessing renal function , particularly in kidney-transplant recipients and in patients suspected of having renal tubulointerstitial disease . It also can serve as a nonspecific but relatively sensitive marker of various neoplastic, inflammatory, and infectious conditions.(1)
(1) Annals of Clinical and Laboratory Science , Vol 20, Issue 3, 163-168