T-cell nonmalignant clonal proliferation in ataxia telangiectasia: a cytological, immunological, and molecular characterization

• Published in: Blood 1989-04, Vol.73 (5), p.1285-1290
• Main Authors: Stern, MH, Theodorou, I, Aurias, A, Maier-Redelsperger, M, Debre, M, Debre, P, Griscelli, C
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V73.5.1285.bloodjournal7351285

Cytogenetically abnormal T-cell nonmalignant clones are a characteristic feature of ataxia telangiectasia (AT). Here, we study a t(14;14) clone from a patient with AT, and provide a cytological, immunological, and molecular characterization. This cellular population is clonal at the molecular level, but is phenotypically heterogeneous, with CD4+CD8+ and CD4-CD8+ cells. Although these cells do not divide in the peripheral blood, a majority of them are found in G1 phase and express the membrane antigen 4F2, a very early marker of activation. Many similarities are found between this nonmalignant AT clone and T- cell prolymphocytic leukemia at the morphologic, cytogenetic, and immunologic levels, despite the different clinical courses associated with these proliferations. We hypothesize that the t(14;14) translocation is linked to the abnormal morphology and immunophenotype of the AT clone cells, but that this translocation confers only a preactivated state to the cells. A complete malignant transformation would then be due to secondary events.