Overgrowth of a leukemic culture by a minor CD34+ population.
Leuk Res
; 22(6): 549-56, 1998 Jun.
Article
in En
| MEDLINE
| ID: mdl-9678721
ABSTRACT
We have investigated the differentiation potential of blast cells in a case of acute myeloid leukemia which comprised a majority CD34- population and a minor (2%) CD34+ fraction. Blasts were cultured for 2 weeks in a combination of cytokines--c-Kit ligand, interleukin 3 and granulocyte macrophage colony-stimulating factor (SIGm mix)--together with all-trans retinoic acid or 1alpha ,25-dihydroxy vitamin D3. Maturation of blasts was assessed by morphology on Romanowsky-stained slides, changes in surface CD markers and clonogenic culture. After 7 days of culture of unseparated blasts in SIGm, most maturation was monocytic, but with retinoic acid 63% of blasts had matured into granulocytes. Vitamin D3 enhanced monocytic differentiation, with 60% of cells becoming monocytic. The percentage of CD14 and CD15 positive cells decreased over 7 days in SIGm (from 62% to 17% and from 76% to 39% for CD14 and CD15, respectively). CD14+ cell numbers were maintained, or recovered, in cultures supplemented with vitamin D3 (59% at day 7), and CD15+ cell numbers, too, remained unchanged in the presence of retinoic acid (67%) or vitamin D3 (66%). Aberrant markers CD7 and CD56 declined under any conditions. When separated, both the CD34- and CD34+ fractions showed similar changes in morphology and surface maturation markers, suggesting that these two populations may be closely related. However, only a few CD34+ cells expressed the aberrant markers present on the majority blast population. The CD34- population declined in culture while the CD34+ fraction rapidly expanded. This probably reflects the difference in progenitor content; high numbers of colony-forming cells were concentrated in the CD34+ subpopulation. We conclude that both CD34- and CD34+ populations can differentiate but only the CD34+ fraction proliferates. Primitive clonogenic CD34+ cells from this patient may generate occasional aberrant CD34+ blasts which could then differentiate into the accumulating aberrant CD34- blast population.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Leukocytes, Mononuclear
/
Leukemia, Myeloid
/
Antigens, CD34
Limits:
Aged
/
Humans
Language:
En
Journal:
Leuk Res
Year:
1998
Document type:
Article
Affiliation country: