title: [Preliminary study of "erythroblast island" in the bone marrow of hematocytopenic patients with positive BMMNC-Coombs test].
abstract: OBJECTIVE
  To explore the mechanism of 'erythroblast island (EI)' formation in the bone marrow of patients with immun-related hemocytopenia (IRP).
  
  
  METHODS
  The category of BM-auto antibody (au Ab) in 48 patients with IRP was detected with FCM. The BM-au Ab in the 'EI' of these cases were explored with immuonhistofluorescence (IF). Clinical and laboratory characteristics of these cases were also analyzed retrospectively.
  
  
  RESULTS
  IgG could be detected in the 'EI' on the BM smear of 14 cases (29.17%), BM-au Ab mainly deposited at the edge/membranes between macrophage and erythroblasts rather than cyto plasm. Positive reaction were seen in all the cases with GlycoAIgG. The red blood cell count [(1.8 ± 0.5) × 10(12)/L] and hemoglobin level [(59.6 ± 16.2)g/L] were significantly lower than that in the IF(-) group [(2.5 ± 0.9) × 10(12)/L and (83.4 ± 25.0) g/L] (P < 0.05). The percentage of reticulocyte [(2.0 ± 0.8)%], serum level of IBIL [(9.4 ± 4.7) µmol/L], percentage of erythroblats in sternum BM (0.441 ± 0.139) and response rate to therapy (85.7%) in IF(+) group were significantly higher than that in IF(-)group [(1.3 ± 1.0)%, (6.6 ± 6.7)µmol/L, 0.298 ± 0.082, 61.3%, respectively] (P < 0.05).
  
  
  CONCLUSIONS
  Macrophage was connected with erythroblasts through autologous IgG in the 'EI's of some patients with IRP. 'EI' were the places where macrophages devoured and destroyed erythroblasts rather than erythroid development and differentiation. The pathogenetic mechanism of IRP might be associated with macrophages phagocytosing and destroying BM hematopoietic cells.
authors.affiliation: Department of Hematology, General Hospital, Tianjin Medical University, TianJin 300052, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Fu
authors.forename: Yi-Hao
authors.initials: YH
authors.lastname: Wang
authors.forename: Shu-Wen
authors.initials: SW
authors.lastname: Dong
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Zou
authors.forename: Zong-Hong
authors.initials: ZH
authors.lastname: Shao
mesh_terms: D001772:Blood Cell Count; D001853:Bone Marrow; D001854:Bone Marrow Cells / Q000276:immunology; D003298:Coombs Test; D004900:Erythroblasts; D006801:Humans