Production of beta 2-microglobulin by chronic lymphocytic leukaemia cells in vitro

The in vitro production of beta 2-microglobulin (beta 2m) by leukaemic cells was studied in 22 patients with chronic B-lymphocytic leukaemia (CLL). In addition, the concentration of beta 2m in serum (S-beta 2m) was determined and expressed as percent of the upper normal limit, after a correction for elevated S-Creatinine values. Patients with progressive disease usually had CLL cells with a high rate of in vitro synthesis and an increased S-beta 2m. This was not found in patients with non-progressive disease. The in vitro synthesis of beta 2m X the lymphocyte count correlated with S-beta 2m in the total material (r = 0.65). The increased S-beta 2m frequently observed in CLL may therefore originate from the tumour cells. Hence, S-beta 2m is promising as a clinically useful tumour cell-associated marker in CLL.