Analysis of leukocyte differentiation antigens in blood and bone marrow
from preleukemia (refractory anemia) patients using monoclonal antibodies
P Hokland, G Kerndrup, JD Griffin and J Ellegaard
Peripheral blood and bone marrow mononuclear cells from patients with
refractory anemia (RA) or RA with sideroblasts (defined according to the
revised French-American-British classification with less than 5% blast
cells in the bone marrow) were analyzed using a panel of monoclonal
antibodies directed against leukocyte antigens on B lymphocytes, T
lymphocytes, monocytes, and myeloid cells. In the peripheral blood an
increased proportion of T lymphocytes (and correspondingly a decreased
proportion of B cells) could be demonstrated. However, when expressed in
terms of absolute numbers, the T cell component was depressed because of
severely decreased numbers of T4+ helper cells. In contrast, the absolute
numbers of T8+ suppressor cells were either normal or increased in the
majority of the patients. This resulted in markedly decreased ratios of
T4+/T8+ cells, which were closely correlated to the number of transfusions
given to the patients because of their refractory anemia. Finally, nearly
all of the patients exhibited decreased numbers of cells reactive with the
N901 natural killer (NK) antibody, thus explaining our earlier finding of
decreased NK activity in these patients. In the bone marrow increased
proportions of myeloid cells reactive with monoclonal antibodies present on
immature myeloid cells (My7 and My9) were found, suggesting the presence of
malignant clones. Indeed, when the numbers of My7+ cells and the
morphologic evaluations of bone marrow smears at the time of diagnosis were
compared to the progression of the disease, a group of patients with high
numbers of My7+ cells and normal morphology could be identified that had a
high probability of progression to refractory anemia with an excess of
blasts or to overt acute myeloid leukemia. Thus, the use of antibodies
defining leukocyte differentiation antigens might be of significant value
in the diagnosis and prognostication of the myelodysplastic syndromes.
These findings are discussed in relation to the pathogenesis of this
potentially premalignant condition with special emphasis on possible
defects in the immunologic defense mechanisms against early neoplasias.
Volume 67,
Issue 4,
pp. 898-902,
04/01/1986
Copyright © 1986 by The American Society of Hematology
