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Preferential suppression of trisomy 8 compared with normal hematopoietic cell growth by autologous lymphocytes in patients with trisomy 8 myelodysplastic syndrome

2005; Elsevier BV; Volume: 106; Issue: 3 Linguagem: Inglês

10.1182/blood-2004-05-2017

1528-0020

Elaine M. Sloand, Lori Mainwaring, Monika Führer, Shakti Ramkissoon, Antonio M. Risitano, Keyvan Keyvanafar, Jun Lu, Atanu Basu, A. John Barrett, Neal S. Young,

Fungal Infections and Studies

Abstract Clinical observations and experimental evidence link bone marrow failure in myelodysplastic syndrome (MDS) with a T cell–dominated autoimmune process. Immunosuppressive therapy is effective in improving cytopenias in selected patients. Trisomy 8 is a frequent cytogenetic abnormality in bone marrow cells in patients with MDS, and its presence has been associated anecdotally with good response to immunotherapy. We studied 34 patients with trisomy 8 in bone marrow cells, some of whom were undergoing treatment with antithymocyte globulin (ATG). All had significant CD8+ T-cell expansions of one or more T-cell receptor (TCR) Vβ subfamilies, as measured by flow cytometry; expanded subfamilies showed CDR3 skewing by spectratyping. Sorted T cells of the expanded Vβ subfamilies, but not of the remaining subfamilies, inhibited trisomy 8 cell growth in short-term hematopoietic culture. The negative effects of Vβ-expanded T cells were inhibited by major histocompatibility complex (MHC) class 1 monoclonal antibody (mAb) and Fas antagonist and required direct cell-to-cell contact. Sixty-seven percent of patients who had de novo MDS with trisomy 8 as the sole karyotypic abnormality responded to ATG with durable reversal of cytopenias and restoration of transfusion independence, with stable increase in the proportion of trisomy 8 bone marrow cells and normalization of the T-cell repertoire. An increased number of T cells with apparent specificity for trisomy 8 cells is consistent with an autoimmune pathophysiology in trisomy 8 MDS.