Clonal disease of natural killer large granular lymphocytes in Taiwan

Lymphoproliferative diseases of large granular lymphocytes (LDGL) may arise from either CD3(+) T cells or CD3(-) natural killer (NK) cells. LDGL with clonal proliferation of large granular lymphoeytes (LGL) is defined as LGL leukaemia. The number of patients with NK-LGL leukaemia reported is limited and the pathogenesis of the disease is not yet clear. From 1991 to 1998 si x patients with cytogenetically proved clonal disease of NK-LGL were identi fied in our institute. All were seropositive far Epstein-Barr virus (EBV). EBV RNA or DNA could be detected in LGL from four patients by EBV in situ h ybridization or Southern blot analysis. Most patients ran an aggressive cli nical course and five died of the disease. Nonrandom clonal chromosomal abn ormalities, including duplication of 1q, rearrangement at 3q and loss of ch romosomes Y, 13 or 10, were noted in the six patients from this study and i n eight from the literature. The implications of these recurrent cytogeneti c aberrations in the development and progression of the disease deserve fur ther studies.