Urinary β2-Microglobulin is a Sensitive Indicator for Renal Tubular Injury

β2-microglobulin is a single-chain, low molecular weight (MW=11.8kDA) polypeptide [1,2] and has similar structure to the CH 3 domain of the immunoglobulin molecule [3].β2-microglobulin forms the invariant light chain portion of major histocompatibility complex (MHC) class I molecules [4-6], which can be found on the membrane of all nucleated cells [7].Thus, cellular membrane turnover is the main source of serum β2-microglobulin [3].Because of its small size, β2-microglo- Urinary β2-Microglobulin is a Sensitive Indicator for Renal Tubular Injury