[Prognostic importance of beta-2-microglobulin in multiple myeloma].

Beta 2 microglobulin is a low molecular weight protein found on the surface of all nucleated cells: it is the light chain of the HL-A histocompatibility complex. The increased levels of serum beta 2 microglobulin in patients with multiple myeloma have been associated with a poor prognosis. Pretreatment levels of serum beta 2 microglobulin were estimated in 70 previously untreated patients with multiple myeloma. In a multivariate analysis, serum beta 2 microglobulin levels and stage were the most significant prognostic factors for survival independent of other risk factors associated with a worse prognosis. There was a clear difference in survival duration observed between the patients with a high pretreatment level of beta 2 microglobulin and stage III (none alive at 5 years) compared with patients with normal levels and stage I (80% alive at five years) (p less than .001). We conclude that pretreatment-beta 2 microglobulin level is one of the most useful prognostic factors in patients with multiple myeloma.