January 2001, Volume 15, Issue 1, Pages 128 - 133

Original Manuscript

HLA class I antigen cell surface expression is preserved on acute myeloid leukemia blasts at diagnosis and at relapse M Wetzler1, MR Baer1, SJ Stewart2, K Donohue3, L Ford1, CC Stewart2, EA Repasky4 & S Ferrone4 1Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY, USA     2Laboratory of Flow Cytometry, Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY, USA     3Department of Cancer Prevention, Epidemiology and Biostatistics, Roswell Park Cancer Institute, Buffalo, NY, USA     4Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY, USA     Correspondence to: M Wetzler, Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY, 14263, USA; Fax: 716 845 2343

Keywords

acute myeloid leukemia;   HLA class I;   diagnosis;   relapse

Abstract

Human leukocyte antigens (HLA) class I molecules restrict the interaction between cytotoxic T cells and target cells. Abnormalities in HLA class I antigen expression and/or function may provide tumor cells with a mechanism for escaping immune surveillance and resisting T cell-based immunotherapies. The potential for applying T cell-based immunotherapy in the treatment of acute myeloid leukemia (AML) has stimulated interest in analyzing HLA class I antigen expression on leukemic blasts in this disease. Little information is available in the literature. We have analyzed HLA class I antigen expression on bone marrow samples from 25 newly diagnosed AML patients by indirect immunofluorescence staining with monoclonal antibodies. Five of these patients were also studied at relapse. Leukemic blasts were resolved from normal lymphocytes by staining with anti-CD45 antibody; CD45 expression is dim on leukemia cells, but bright on lymphocytes. HLA class I antigen expression was higher on leukemic blasts than on autologous lymphocytes in all but one case. Moreover, there was no significant change in HLA class I antigen expression at relapse. These results suggest that abnormalities in HLA class I antigens are infrequent in AML and should not represent a major obstacle to the application of T cell-based immunotherapies in this disease. Leukemia (2001) 15, 128-133.

Received 10 August 2000; Accepted 1 September 2000

^© Macmillan Publishers Ltd 2001