Page 29 - Haematologica-5

TCR repertoire of effector memory T cells in AA
showed Vβ skewing in 1-5 Vβ subgroups, and frequencies of the immunodominant clones ranged from 2.1% to 66.5% (mean: 9.9%).
Progression-free survival (PFS) analysis was performed on all SAA patients, divided according to pre-treatment frequencies of effector memory CD8+ T cells (cut-off value 13.3%) (Figure 2B). No patients with low CD8+CD57+ cell
frequency (n=7) experienced relapse (median survival not reached; median follow-up time: 13.6 months), while 7 of the 17 SAA subjects with expanded effector memory T cells relapsed or died (median survival 13.2 months; medi- an follow up: 10.4 months). However, statistical signifi- cance between the two curves was not reached (P=0.089). Vβ usage was analyzed in CD4+ and CD8+ T-cell subsets
A
B
**
Figure 1. Immunophenotyping and flow cytometry analysis of Vβ usage in severe aplastic anemia (SAA) patients and healthy subjects. (A) Percentages of CD28+ and CD57+ cells were calculated in both CD4+ and CD8+ compartments for healthy controls and SAA patients. Data are shown as mean±Standard Deviation (SD). Unpaired t-test was performed. *P<0.05; **P<0.01. (B) Vβ usage was studied in T-cell compartments (by row), and percentages of each Vβ family were reported as total CD4+ or CD8+ cell percentage. For Vβ usage in healthy subjects, data are shown as mean+SD, combining the results from all 34 healthy donors. For SAA patients, 2 representative cases are shown.
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