The distribution of CD45R, CD29 and CD45RO (UCHL1) antigens in mature CD4 positive T‐cell leukaemias

Abstract

We have studied the expression of antigen characterizing functional T-cell subsets in 32 CD4+ mature T-cell leukaemias. In this analysis we used two monoclonal antibodies (McAb) of the CD45R group (2H4 and GRT22) which have been shown to identify the ''naive/virgin'' T-cell population that functions as ''suppressor-inducer'' cells in vitro, and two McAb, CD29 (4B4) and CD45RO (UCHL1), which characterize non-identical ''memory'' cells that proliferate in response to soluble recall antigens and provide help in antigen-specific IgG synthesis. Four groups of CD4+ cases were identified according to this reactivity: (a) 15 CD45R+, CD29+; (b) 13CD45R-, CD29+; (c) three CD45R-, CD29-; and (d) one case only CD45R+, CD29-. The high incidence of coexpression of CD45R and CD29 (47% of cases) is a new finding which contrasts with the mutual exclusion of these antigens on normal CD4+ T-lymphocytes. There was no correlation between subset phenotypes and pathological disease entities. None of the six cases of adult T-cell leukemia/lymphoma (ATLL), which is known as a disorder of activated ''suppressor-inducer'' cells, had the ''expected'' CD45R+, CD29- phenotype. Reactivity with UCHL1 showed a good correlation with CD29 in the CD45R- CD29+ cases which included three with ATLL. These results may help in the further characterization of T-cell malignancies according to functional subgroups and may clarify further the role of T-differentiation antigens in health and disease.