[Role of Th1 cell in the pathogenesis of aplastic anemia].
OBJECTIVE
To detect the quantity, proportion and function of producing cytokines of Th1 and Th2 cells in aplastic anemia (AA) patients and their contribution to the hematopoietic failure.


METHODS
(1) Eleven patients with severe aplastic anemia (SAA) at diagnosis were observed by Marsh's method for the CFU-E, BFU-E and CFU-GM before and after depletion of CD(4)(+) T lymphocytes from bone marrow mononuclear cells (BMMNC); (2) Th1 (CD(4)(+) IFN-gamma(+)) and Th2 (CD(4)(+) IL-4(+)) cells in peripheral blood mononuclear cells (PBMNC) of 21 SAA patients and 17 normal controls were counted by FACS. (3) mRNA expression of IFN-gamma and IL-4 gene in unstimulated BMMNC from 16 SAA patients, 11 chronic aplastic anemia (CAA) patients, 26 other hematological diseases patients and 11 normal controls were measured by reverse transcriptase polymerase chain reaction (RT-PCR).


RESULTS
(1) CFU-E, CFU-GM and BFU-E increased significantly after depletion of CD(4)(+) T lymphocytes from BMMNC of SAA patients. (2) The percentage of IFN-gamma producing CD(4)(+) T cell (Th1) of SAA patients was significantly higher than that of controls, the percentages of IL-4 producing CD(4)(+) T cells (Th2) had no difference between SAA patients and normal controls. (3) IFN-gamma mRNA was detected in unstimulated BMMNC in 13 of 16 SAA patients, 6 of 11 CAA patients and one of 6 paroxysmal nocturnal hemoglobinuria (PNH) patients. The IFN-gamma mRNA was not detected in unstimulated BMMNC of 11 normal controls and other hematological diseases patients.


CONCLUSIONS
Disbalance of CD(4)(+) T lymphocytes subsets and increases in quantity and IFN-gamma producing function of Th1 cells might be important for the development of bone marrow failure in AA and in distinguishing AA from other kinds of pancytopenic diseases.
He
Hong
H
Institute of Hematology and Blood Diseases Hospital, CAMS and PUMC, Tianjin 300020, China.
Shao
Zonghong
Z
He
Guangsheng
G
Liu
Hong
H
Shi
Jun
J
Fu
Rong
R
Zhao
Mingfeng
M
Bai
Jie
J
Jia
Hairong
H
Sun
Juan
J
Cui
Zhenzhu
Z
Chu
Yulin
Y
Yang
Tianying
T
Yang
Chongli
C
D000293:Adolescent; D000328:Adult; D000741:Anemia, Aplastic / Q000097:blood* / Q000209:etiology; D003114:Colony-Forming Units Assay; D015672:Erythroid Precursor Cells / Q000166:cytology; D005260:Female; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics; D008264:Macrophages / Q000166:cytology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018417:Th1 Cells / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D018418:Th2 Cells / Q000166:cytology / Q000378:metabolism
D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma