[Study on quantity and function of bone marrow macrophages in patients with BMMNC-Coombs Test(+) pancytopenia].
OBJECTIVE
To explore the quantity and function of bone marrow (BM) macrophages in patients with BMMNC-Coombs Test(+) pancytopenia (BCTP).


METHODS
Sixty-one patients with BCTP, 10 with severe aplastic anemia (SAA) and 13 normal controls were enrolled in this study. The quantity of BM macrophages was measured by FACS and their function was evaluated by phagocytosis test.


RESULTS
The number of macrophages, phagocytosis ratio and index of cock's red blood cells (CRBC) in BCTP patients were (0.57 +/- 0.30)%, (37.56 +/- 15.20)%, and 0.75 +/- 0.34, respectively, being significantly higher than those in SAA group \[0.46 +/- 0.08)%, (28.26 +/- 10.46)%, and in 0.59 +/- 0.39\] and in normal control \[0.44 +/- 0.69)% (25.63 +/- 14.75)%, and 0.55 +/- 0.16\] (P < 0.05). The BCTP patients were classified into two subgroups according to the quantity of macrophages: Group A (M(Phi) > or = 0.5%, 34 cases) and Group B (M(Phi) < 0.5%, 27 cases). There were 32 cases (94.12%) with BMMNC-IgG(+) in Group A and only 2 cases (7.41%) in Group B. There were significant differences in phagocytosis ratio and index of macrophages between Group A \[46.62 +/- 13.38)% and 0.91 +/- 0.36\] and Group B \[(28.67 +/- 12.59)% and 0.61 +/- 0.30\] (P < 0.05), while no statistical differences between group B and other two control groups (P > 0.05). Thirty-four BMMNC-IgG(+) patients were further divided into two subgroups: High level (HL) group \[> or = 0.75%, 9 cases (26.47%)\] and Low level (LL) group \[< 0.75%, 25 cases (73.53%)\]. Only one lineage of BMMNC-IgG could be detected in LL group. Among 9 patients in HL group, 8(23.53%) had two lineages of BMMNC-IgG and 1(2.94%) had three lineages. Phagocytosis ratio and index of macrophages were significantly higher in HL group \[(60.22 +/- 12.51)% and 1.23 +/- 0.23\] than in LL group \[(43.32 +/- 9.24)% and 0.84 +/- 0.24\] (P < 0.05). The level of peripheral blood(PB) RBC, HGB and PLT in HL group were significantly lower than in LL group (P < 0.05), while the percentage of Ret, the level of TBIL and the ratio of erythroid of sternal BM in HL group were significantly higher than in LL group (P < 0.05).


CONCLUSIONS
More quantity and stronger function of macrophages are observed in BCTP patients with BMMNC-IgG(+). One of the mechanism of hematocytopenia might be that macrophages activated by IgG autoantibodies phagocytose hematopoietic cells in BM. Macrophages do not involve in damage process of BM in BCTP with IgM or cold autoantibodies.
Wang
Yi-hao
YH
Department of Hematology, General Hospital, Tianjin Medical University, Tianjin 300052, China.
Fu
Rong
R
Shao
Zong-hong
ZH
Wang
Hua-quan
HQ
Xing
Li-min
LM
Liu
Hong
H
Wu
Yu-hong
YH
Li
Li-juan
LJ
Liu
Hui
H
Wang
Jun
J
Chen
Jin
J
Wang
Hong-lei
HL
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology; D001854:Bone Marrow Cells / Q000276:immunology* / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D003298:Coombs Test; D005260:Female; D006801:Humans; D008264:Macrophages / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010198:Pancytopenia / Q000276:immunology* / Q000473:pathology; D055815:Young Adult
D001323:Autoantibodies