Hypoplastic anemia in B cell chronic lymphocytic leukemia: evolution of T
cell-mediated suppression of erythropoiesis in early-stage and late- stage
disease
KF Mangan and L D'Alessandro
To define further the role of marrow T suppressor lymphocytes in the
pathogenesis of the hypoproliferative anemia in all Rai clinical stages of
B cell chronic lymphocytic leukemia (CLL), marrow erythroid progenitor cell
(CFU-E and BFU-E) frequency, marrow T gamma lymphocyte frequency per 1,000
nucleated marrow cells, and T cell-erythroid progenitor cell interactions
were examined in 30 CLL patients and normal control subjects. As compared
with control subjects, decreased numbers of CFU-E and BFU-E were found in
patient marrow depleted of neoplastic B cells in all Rai stages of the
disease. As a group, Rai stage III through IV patients with or without
aplasia (CLL-aplasia) had significantly fewer CFU-E and BFU-E than did Rai
O through II stage patients. The numbers of T gamma cells infiltrating CLL
marrows were increased 3, 9, and 20 times normal in Rai O through II, Rai
III through IV, and CLL-aplasia groups, respectively. Removal of T cells
from marrow increased growth of CFU-E and BFU-E in all Rai O through IV
patients, but the increase was significant in the CLL-aplasia group only (P
less than .05). However, autologous coculture of marrow T cells or T gamma
cells but not B cells with marrow B + T-depleted null cells at ratios of
0.2:1 to 1:1 suppressed CFU-E and BFU-E growth in all three patient groups.
We conclude that the hypoproliferative anemia occurring in the course of B
cell CLL is due to gradual accumulation in the marrow of T gamma
lymphocytes which suppress erythroid progenitor cell growth. T gamma cell
suppression of erythropoiesis and marrow T gamma cell expansion is
detectable in the earliest Rai stages of the disease.
Volume 66,
Issue 3,
pp. 533-541,
09/01/1985
Copyright © 1985 by The American Society of Hematology
