Significance of p53 overexpression in bone marrow biopsies from patients with bone marrow failure: aplastic anemia, hypocellular refractory anemia, and hypercellular refractory anemia

 Among patients with bone marrow failure, differentiating acquired aplastic anemia (AA) from hypocellular refractory anemia (hypo RA) can be a difficult and challenging task. Morphological, cytochemical, immunocytochemical, and cytogenetic studies may provide tools for discriminating between both entities. In addition, differences in the pattern of proliferation and apoptosis of bone marrow cells in AA and in the myelodysplastic syndrome have been reported. Because of the correlation between p53 and apoptosis, we examined the overexpression of p53 on bone marrow biopsies in RA and AA. Our study included 14 patients with hypo RA, 14 patients with hypercellular (hyper) RA, ten patients with classic acquired AA, and 37 hematologically normal individuals. p53 was overexpressed in eight (57%) hypo RA patients and 11 (79%) hyper RA patients. All normal individuals and patients with AA showed no overexpression of p53 in their marrow. These results were statistically significant:p<0.01 (AA vs hypo RA),p<0.001 (AA vs hyper RA), while the difference between hypo RA and hyper RA was not statistically significant. We conclude that p53 overexpression in bone marrow biopsies is a valuable tool for studying bone marrow failure and may provide additional information to help differentiate hypo RA from acquired AA.