Cell surface expression of beta 2-microglobulin (beta 2m) correlates with stages of differentiation in B cell tumours.

Abstract

Cell surface .beta.2-microglobulin (.beta.2m) densities of malignant B cells were determined by enzyme immunoassay in 97 cases of immunologically defined lymphoproliferative disease. Absolute .beta.2m densities were found to depend on disease category with the lowest levels found on cells from chronic lymphocytic leukaemia (mean = 5.6 ng/106 cells, n = 27); atypical chronic lymphocytic leukaemia (mean = 5.9 ng/106 cells, n = 8); and prolymphocytoid chronic lymphocytic leukaemia variant (mean = 6.0 ng/106 cells, n = 16). .beta.2m densities for B non-Hodgkin''s lymphoma (n = 14) and B prolymphocytic leukaemia (n = 17) cases were 8.1 and 10.0 ng/106 cells, respectively, and the highest densities were found on cells from "late-B cell" tumours (mean = 14.3 ng/106 cells). Plasma cells from cases of Ig secreting tumours expressed unexpectedly low .beta.2m densities (mean = 9.3 ng/106 cells; n = 6).