Cell surface expression of β2-microglobulin (β2m) correlates with stages of differentiation in B cell tumours

Abstract

Cell surface β2-microglobulin (β2m) densities of malignant B cells were determined by enzyme immunoassay in 97 cases of immunologically defined lymphoproliferative disease. Absolute β2m 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). β2m 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 β2m densities (mean = 9.3 ng/106 cells; n = 6).