CD4+ CD8+ granular lymphocytic leukemia arising in a patient with acute myeloblastic leukemia

A 59-year-old woman who had an 8-year history of acute myeloblastic leukemia (AML) developed granular lymphocytic leukemia (GLL). She had a small number of granular lymphocytes (GL) in her bone marrow (BM) at the onset of AML. The GL increased during complete remission (CR) of AML, but not at the relapse. During the third CR state of AML, GL increased to 4.0 x 10(9)/l in the peripheral blood (PB). The GL were T-cell receptor (TCR) alpha beta+ T cells and expressed both CD4 and CD8 antigens. Rearrangements of TCR beta and gamma chain genes were detected in the peripheral blood mononuclear cells (PBMNC), confirming that this patient had GLL. The PBMNC from the patient responded weakly to PHA or ConA, yet they responded to her own bone marrow mononuclear cells (BMMNC) or CD4-depleted BMMNC that contained AML cells stronger than her own PBMNC or normal PBMNC. These observations suggest that monoclonal proliferation of GL developed after the reactive proliferation of GL in response to AML cells.