Serum beta 2-microglobulin in acute and chronic leukaemia.

The serum concentration of beta 2-microglobulin (beta 2-m) was measured in 69 patients with acute or chronic lympho- and myeloproliferative disorders. Serum beta 2-m was found significantly increased in 12 out of 14 patients with chronic lymphatic leukaemia. The serum concentration was proportional to the estimated lymphatic infiltration of tissues but inversely related to the number of circulating lymphocytes. Cytostatic treatment was followed by a decrease in serum beta 2-m, but normalization of the serum concentration was not observed. 11 patients with chronic granulocytic leukaemia all had significantly elevated serum concentrations of beta 2-m and increased serum concentrations were also found in patients with acute leukaemias. Thus, 12 out of 25 patients with acute myeloid leukaemia and all of 5 patients with acute myelomonocytic leukaemia as well as 4 out of 5 patients with acute lymphatic leukaemia had increased serum beta 2-m levels. In acute leukaemia no correlation could be demonstrated between the blood lymphocyte concentration and serum beta 2-m. Also no significant changes in serum beta 2-m were found in either remission or relapse of the acute leukaemia. It is concluded that serum beta 2-m in patients with chronic leukaemia may reflect the total amount or turn-over of leukaemic cells in the body and that repeated determinations of serum beta 2-m in these patients might be useful as an estimate of the residual leukaemic cell mass after therapy. Apart from this the determination of serum beta 2-m seems to be of little, if any, clinical use in leukaemia.