THE VALUE OF IMMUNOHISTOCHEMISTRY IN THE ASSESSMENT OF BONE MARROW DISORDERS
Attilio Orazi, M.D., FRCPath. and Dennis P. O'Malley, M.D.
APOPTOSIS BY IN-SITU END LABELING
The rate of cell death due to apoptosis can be evaluated by a nonisotopic in situ end-labeling (ISEL)
technique applied to paraffin sections. With this technique, residues of digoxigenin-nucleotides
(digoxigenin-dUTP) are catalytically added to the fragmented (apoptotic) DNA by adding the enzyme TdT to the
slides. The added residues are then immunostained by using an anti-digoxigenin peroxidase-conjugated
antibody (Orazi et al, Mod Pathol, 1996). The peroxidase activity is then revealed by routine DAB staining.
Apoptosis assessment may be of interest in evaluating bone marrow biopsies in patients with myelodysplastic
syndromes and after cytokine treatment
Orazi et al: p53 overexpression in myeloid leukemic disorders is associated with increased apoptosis of
hematopoietic marrow cells and ineffective hematopoiesis. Mod Pathol. 1996 9:48-52.
Mangili et al: Staining apoptosis in paraffin sections. Advantages and limits. Anal Quant Cytol
Histol. 1999; 21:273-6.
Raza et al: Apoptosis in bone marrow biopsy samples involving stromal and hematopoietic cells in 50
patients with myelodysplastic syndromes. Blood. 1995; 86:268-76.