Alteration of beta-2-microglobulin level in malignant lymphoproliferative diseases after a high dose of alpha-2-recombinant interferon

Effects of alpha-interferon on serum beta-2-microglobulin

Beta-2-microglobulin (B2M) forms the small invariable light chain subunit of class I HLA antigens on the cell membrane of all nucleated cells. During the continuous turnover of the HLA molecules, B2M is shed from the cell membrane into blood. Lymphocytes are the main source of serum free B2M. Serum B2M concentration is increased in renal diseases, various malignant diseases and some inflammatory and autoimmune disorders. In lymphatic malignancies serum B2M has significant prognostic value. Interferons (IFNs) have the ability to enhance the expression of class I and II histocompatibility antigens. Accordingly, IFNs cause a rise in formation and release of B2M. Currently, treatment with IFN alpha is used in diseases, like multiple myeloma, where serum B2M measurements are used to assess tumor burden. We have measured serum B2M levels during IFN alpha treatment in patients with both multiple myeloma and chronic myeloproliferative diseases, and IFN alpha caused a significant increase in serum B2M. It can be concluded that use of IFN alpha abolishes the value of serum B2M as an indicator of disease activity.

Alpha interferon raises serum beta-2-microglobulin in patients with multiple myeloma

Serum beta 2-microglobulin (beta 2m) levels were followed in eight patients with multiple myeloma who were treated with leucocyte alpha interferon (alpha IFN) 6 x 10(6) IU daily for 1-2 weeks before chemotherapy. Serial measurements of serum beta 2m were carried out regularly during the first week on alpha IFN. A rise in beta 2m was observed in all patients. with maximum increments ranging from 29% to 185% (mean 109%). The increase in beta 2m was most marked in patients with elevated pretreatment levels of serum beta 2m and creatinine. In six patients the peak value was reached between the third and the fifth day, after which the levels decreased. In two patients serum beta 2m remained elevated for 3 and 4 months, respectively. A marked increase in serum beta 2m can be induced by alpha IFN in myeloma, which should be taken into consideration when using beta 2m for the assessment of tumour response during alpha IFN therapy.