Phenotypic heterogeneity displayed by T-non Hodgkin's lymphoma (T-NHL) cells dispersed from diagnostic lymph node biopsies.

In this communication we present the results of the study of the surface antigen expression of cells dispersed from 19 fresh lymph node biopsies. All cases subsequently received a histological diagnosis of T-cell lymphoma (T-NHL). The monoclonal antibody (Mab) panel employed for surface staining of viable cells contained reagents reactive with the sheep red blood cell receptor (OKT11) and T3-receptor associated determinants (UCHT1, OKT3) and a range of surface antigens found on subsets of T-cells. These antibodies are characterized according to their CD group as allocated by the First and Second Monoclonal Antibody Workshops. Cells were also stained with Mabs reactive with MHC class II subregion products. All 19 cases displayed marked heterogeneity for both pan-T-cell and T-subset antigens. An observation which is significant in terms of the routine diagnosis of T-NHL and with regard to the rational classification of node-based tumours of T-cell origin. Unlike resting peripheral blood T-cells, MHC class II subregion products were expressed on most of the cases examined though Tu22, directed towards a monomorphic determinant of HLA-DQ, stained fewer cells than other antibodies. Aberrant expression of MHC class II on lymphoma cells may reflect the activation of the tumour population.