Microglobulin β2 is seen in?

It is also important to quantitate serum β2-microglobulin. Serum β2-microglobulin is a protein of 11,000 mol. wt with homologies with the constant region of immunoglobulins that is the light chain of the class I major histocompatibility antigens (HLA-A, -B, -C) on the surface of every cell. Serum β2-microglobulin is the single most powerful predictor of survival and can substitute for staging. Patient with β2-microglobulin levels <0.004 g/L have a median survival of 43 months and those with levels >0.004 g/L only 12 months. Serum β2- microglobulin and albumin levels are the basis for a three-stage International Staging System (ISS). It is also felt that once the diagnosis of myeloma is firm, histologic features of atypia may also exert an influence on prognosis. IL-6 may be an autocrine and/or paracrine growth factor for myeloma cells; elevated levels are associated with more aggressive disease. High labeling index and high levels of lactate dehydrogenase are also associated with poor prognosis.