Serum beta 2-microglobulin in lymphoproliferative and myeloproliferative diseases.

The serum levels of beta 2-microglobulin (beta 2m), which is the light chain moiety of the HLA (-A, -B, -C) antigens, are increased in many of the haematological malignancies. In the lymphoproliferative disorders there is generally an association between serum beta 2m and estimates of tumour load. This relationship is especially close in myelomatosis, where serum beta 2m is a powerful prognostic indicator and can be used in stratification and monitoring. Increases in serum beta 2m are also frequent in the myeloproliferative disorders, notably in myelofibrosis, and in the myelodysplastic syndromes; particularly high levels are seen in chronic myelomonocytic leukaemia. In addition to suggested cellular sources of the beta 2m in these diseases--malignant lymphoid cells and cells of the monocyte-macrophage series--the possibility that T lymphocyte sub-sets could be important contributors to the increased beta 2m production is discussed.