title: Significance of fetal hemoglobin-containing erythroblasts (F blasts) and the F blast/F cell ratio in myelodysplastic syndromes.
abstract: To investigate the relationship between the fetal hemoglobin-containing erythroblasts (F blasts) and apoptosis in myelodysplastic syndromes (MDS), we immunohistochemically assessed F blasts, F cells, and apoptosis in 137 patients with MDS. A marked increase in the number of F blasts in the bone marrow was identified in 116 of 137 patients (84.7%), and the number of F cells was elevated in 54 patients (39.4%). Among the erythroblasts stained by anti-glycophorin C antibody, the mean percentage of F blasts was 14.63 +/- 9.17% in MDS, which was significantly higher than that in non-MDS patients with stress erythropoiesis (4.82 +/- 3.35%, P < 0.01), although there were no significant differences in the number of F cells between these groups. In particular, 62 of the 137 MDS patients (45.3%) had an apparent increase in F blasts but no elevation of F cells. The apoptotic rate was significantly higher in the patients with a F blast/F cell (Fb/Fc) ratio >or=5.0 than in those with a Fb/Fc ratio <1.0 (P < 0.01). The results indicate that F cell precursors are incapable of maturing into functioning end-stage F cells, presumably owing to apoptotic cell death. The measurement of F blasts in the bone marrow is needed for the precise evaluation of fetal-type erythropoiesis in MDS.
authors.affiliation: Department of Pathology, Nagoya University Hospital, Nagoya, Japan.
authors.forename: J W
authors.initials: JW
authors.lastname: Choi
authors.forename: Y
authors.initials: Y
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Fujino
authors.forename: M
authors.initials: M
authors.lastname: Ito
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D001854:Bone Marrow Cells / Q000473:pathology; D002452:Cell Count; D004900:Erythroblasts / Q000737:chemistry / Q000473:pathology; D015672:Erythroid Precursor Cells / Q000737:chemistry* / Q000473:pathology; D005260:Female; D005319:Fetal Hemoglobin / Q000032:analysis*; D006021:Glycophorins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000473:pathology*
chemical_list: D006021:Glycophorins; D005319:Fetal Hemoglobin