[Beta 2 microglobulin].

Serum beta 2 microglobulin (beta 2 mu) level was determined in 157 patients followed up for 1 to 38 months. In 42 patients with nonremissional lymphoproliferative malignancies, the observed values (mean 4.35 +/- 2.24 mg/l) were much higher than the beta 2 mu levels obtained either in the 37 healthy subjects (mean 1.86 +/- 0.30 mg/l) or in the 39 patients with various nonmalignant diseases (mean 2.68 +/- 1.76 mg/l). However, for diagnostic purposes serum beta 2 mu level determination is still of very limited value: if the beta 2 mu level is below 2.50 mg/l, the beginning of a hematologic malignancy cannot be excluded; beta 2 mu levels between 2.50 and 5.00 mg/l are observed, in most cases, with lymphoproliferative or myeloproliferative disorders, but these values are also often found in various diseases, particularly of viral or autoimmunological etiology; a serum beta 2 mu level above 5.00 mg/l was obtained only in lymphoproliferative malignancies and in one case of "acquired immuno deficiency syndrome" (AIDS) in a homosexual male. Serum beta 2 mu determination is of chief advantage in follow-up of Hodgkin's disease, of non-Hodgkin malignant lymphoma, of chronic lymphocytic leukemia and of multiple myeloma either during treatment or in remission.