Increased apoptotic cells in bone marrow biopsies from patients with aplastic anaemia.

In order to investigate the involvement of apoptosis in the pathogenesis of aplastic anaemia (AA) we determined the proportion of apoptotic cells in paraffin-embedded bone marrow biopsies from patients with aplastic anaemia using an in situ TdT-catalysed DNA nick end labelling (TUNEL) staining method. A significant increase in the proportion of mononuclear apoptotic cells was demonstrated in biopsies from patients with aplastic anaemia (8.19 +/- 1.45%) when compared with controls (2.07 +/- 0.86%). These data support the view that apoptosis may play a role in the pathophysiology of bone marrow failure.