Effects of cytotoxin-associated gene A [CagA] positive Helicobacter pylori infection on anti-platelet glycoprotein antibody producing B cells in patients with primary idiopathic thrombocytopenic purpura [ITP]

To explore the effects of cytotoxin-associated gene A [CagA] positive Helicobacter pylori [H. pylori or HP] infection on circulating B cells producing specific platelet glycoprotein antibodies and the association between therapeutic outcomes in primary idiopathic thrombocytopenic purpura [ITP] patients. A total of 76 newly diagnosed primary ITP patients were included in the study which was conducted at the first affiliated hospital of Shantou University Medical college, in Shantou city China, between January 2013 and January 2014. These patients were tested for H. pylori infection by 13C urea breath test and for anti-CagA antibody in H. pylori positive cases by enzyme-linked immunosorbent assay [ELISA] method. Anti-GPIb and anti-GPIIb/IIIa antibody-producing B cells were measured using an enzyme-linked immunospot [ELISPOT] assay in all ITP patients and 30 controls. Anti-nuclear antibody [ANA] was also detected in ITP patients. The numbers of anti-GPIIb/IIIa antibody-producing B cells in HP+CagA+ patients were higher than in HP+CagA- or HP- patients. However, anti-GPIb antibody-producing B cells were found higher in HP- patients. Analysis of treatment outcomes showed that a therapeutic response was more likely in patients presenting anti-GPIIb/IIIa B cells, but the poor response was found to be associated with anti-GPIb B cells and ANA presences. CagA antigen of H. pylori may induce anti-GPIIb/IIIa antibodies production by a molecular mimicry mechanism. Anti-GPIIb/IIIa and anti-GPIb antibody producing B Cells detection is useful for predicting treatment effects of primary ITP

The role of B cell-activating factor secreted by peripheral blood monocyte-derived dendritic cell in chronic idiopathic thrombocytopenic purpura / 中华血液学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Clinical feature of acquired pure amegakaryocytic thrombocytopenic purpura / 中国基层医药

Objective To explore the clinical feature of acquired pure amegakdryocytic thrombocytopenic purpura(AATP).Methods 18 patients were analyzed retrospectively.And 112 patients with ITP in the same term were to be control group.Each group's megakaryocytic (MK),platelet (PLT) count,mean platelet volume (MPV) and platelet associated immunoglobulin G(PAIgG) were rested.Results The MK total number of AATP group was obvious decreased or even absent,while the ITP group was increased[(0.8?1.5) vs (195.0?47.3),P0.05).About the PAIgG posi- tive rate,AATP group was 55.6 % while ITP group was 83% (P

Expression, purification and characterization of the recombinant anthrax protective antigen / 生物工程学报

An expression plasmid carrying anthrax protective antigen (PA) gene was constructed, which has an OmpA signal sequence attached to the 5' end of PA gene. The plasmid was transformed into E. coli and induced to express recombinant PA (rPA) . The recombinant protein, about 10% of the total bacterial protein in volume, was secreted to the periplasmic space of the cell. After a purification procedure including ion-exchange, hydrophobic interaction chromatography, and gel filtration, about 15 mg of 95 % pure rPA was obtained from 1-liter culture. The bioactivity of rPA was proved by in vitro cytotoxicity assay. The polyclonal antiserum from rabbits immunized with rPA could inhibit the action of anthrax lethal toxin in vitro, which suggests that antibodies against rPA can provide high passive protection against anthrax. The results reported here may be helpful to develop a safe and efficacious recombinant PA vaccine against anthrax.