THE VALUE OF IMMUNOHISTOCHEMISTRY
IN THE ASSESSMENT OF BONE MARROW DISORDERS

Attilio Orazi, M.D., FRCPath. and Dennis P. O'Malley, M.D.

P53 PROTEIN Several commercially available antibodies can be used to stain human p53 protein. The paraffin reactive antibodies (e.g. Pab1801, DO7) recognize both wild and mutant forms of p53 protein. Both reagents works well in formalin and B5 fixed tissues but requires heat-induced epitope retrieval. P53 overexpression is present in acute leukemias, particularly in those secondary to chronic myeloproliferative diseases and myelodysplastic syndromes, and in therapy-related cases. Reactivity can also be seen in high grade lymphomas, and in various metastatic carcinomas. References Brynes et al: Expression of p53, MDM2, p21waf1, bcl-2, and retinoblastoma gene proteins in myelodysplastic syndrome after autologous bone marrow transplantation for lymphoma. Mod Pathol. 1997 Nov;10(11):1120-7. Elghetany et al: Significance of p53 overexpression in bone marrow biopsies from patients with bone marrow failure: aplastic anemia, hypocellular refractory anemia, and hypercellular refractory anemia. Ann Hematol. 1998 Dec;77(6):261-4. Kanavaros et al: Immunohistochemical detection of p53, mdm2, waf1/p21, and Ki67 proteins in bone marrow biopsies in myelodysplastic syndroms, acute myelogenous leukaemias and chronic myeloproliferative disorders. Clin Exp Pathol. 1999;47:231-8. Magalhaes et al: p53 overexpression in refractory anemia. An immunohistochemical analysis of bone marrow biopsies. Haematologica. 1999; 84:377-8. Orazi A, Cattoretti G, Heerema NA, Sozzi G, John K, Neiman RS: Frequent p53 overexpression in therapy related myelodysplastic syndromes and acute myeloid leukemias: an immunohistochemical study of bone marrow biopsies. Mod Pathol 1993;6:521-525.