[The role of B cell-activating factor secreted by peripheral blood monocyte-derived dendritic cell in chronic idiopathic thrombocytopenic purpura].
OBJECTIVE
To explore the characteristics of B cell-activating factor (BAFF) secreted by peripheral blood monocyte-derived dendritic cell (MoDC) in chronic idiopathic thrombocytopenic purpura (cITP) and the function of MoDC on B cell proliferation.


METHODS
Ten cITP patients were studied dynamically before and after treatment. The BAFF levels in serum and the supernatant of LPS stimulated MoDC were tested with ELISA. The BAFF gene expression in LPS stimulated MoDC was tested with RQ-PCR, the B cell proliferation co-cultured with the supernatant of LPS stimulated MoDC for 5 days was tested with flow cytometry for CFSE and (3)H thymidine incorporation.


RESULTS
The BAFF level in serum (serum BAFF) \[(2461 ± 483) ng/L\], and supernatant of LPS stimulated MoDC (supernatant BAFF) \[(1113 ± 113) ng/L\] and BAFF mRNA in LPS stimulated MoDC (BAFF mRNA) (1.70 ± 0.23) before treatment were higher than that after treatment \[(621 ± 53) ng/L, (490 ± 49) ng/L and 0.37 ± 0.12\] and normal group \[(742 ± 77) ng/L, (582 ± 63) ng/L and 0.52 ± 0.08\]. There was a positive correlation among serum BAFF, supernatant BAFF and BAFF mRNA, and a negative correlation among serum BAFF, supernatant BAFF and BAFF mRNA and blood platelet count (BPC) in all ITP patients. The supernatant of LPS-stimulated MoDC from untreated patients enhanced B cell proliferation as compared with the supernatant of LPS-stimulated MoDC from treated patients and normal group.


CONCLUSIONS
BAFF might contribute to disease development in cITP. MoDC may directly increase B cell proliferation by secreting BAFF without T cell help, playing an important role in the antibody production in cITP.
Department of Hematology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
Zhen-Hai
ZH
Zhou
Lan
L
Zhuang
Xiao-Yin
XY
Li
Juan
J
Li
Shao-Kai
SK
Luo
D001402:B-Lymphocytes / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D006801:Humans; D015847:Interleukin-4; D009000:Monocytes; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000276:immunology
D015847:Interleukin-4