Involvement of cytotoxic granules in the apoptosis of aplastic anaemia.

To study the involvement of cytotoxic granules in apoptosis of aplastic anaemia (AA), we analysed bone marrow clot sections of AA for apoptosis and perforin, granzyme B and T-cell intracellular antigen-1 (TIA-1) expression. Perforin, TIA-1 expression and apoptosis were significantly increased in AA patients compared with control subjects, but granzyme B was not. TIA-1 was significantly correlated with apoptotic cells of AA. No correlation was found between perforin and apoptotic cells of AA. These results suggest that perforin and TIA-1 play a role in the pathogenesis of AA. TIA-1 is implicated as an effector in the apoptosis of AA.