Participation of B-cell-activating factor receptors in the pathogenesis of immune thrombocytopenia

ESSENTIALS: Dysfunctional B-cell-activating factor (BAFF) system is related to many autoimmune diseases. The regulatory functions of BAFF/BAFF receptors were investigated in an in vitro coculture system. Different regulatory roles of BAFF were investigated via different receptors in immune thrombocytopenia. The upregulated BAFF receptors on autoreactive lymphocytes lead to their hypersensitivity to BAFF.

SUMMARY

BACKGROUND

The pathogenesis of immune thrombocytopenia (ITP) remains enigmatic. B-cell-activating factor (BAFF) and its receptors (BAFF receptor [BAFF-R], transmembrane activator and calcium modulator and cyclophilin ligand interactor [TACI], and B-cell maturation antigen) play central roles in the integrated homeostatic regulation of lymphocytes.

OBJECTIVES

To investigate the pathologic roles of BAFF receptors in regulating the bioactivities of lymphocytes in ITP.

METHODS

An in vitro culture system was established by stimulating CD14(-) peripheral lymphocytes with platelet-preloaded dendritic cells in the presence of recombinant human BAFF (rhBAFF; 20 ng mL(-1)). The functions of BAFF receptors were specifically blocked with blocking antibodies.

RESULTS

BAFF-R, besides prolonging the survival of B cells in both patients and healthy controls, prominently promoted the survival of CD8(+) T cells and the proliferation of B cells in patients with ITP. TACI, as a positive regulator, not only promoted the proliferation of CD4(+) and CD8(+) T cells, but also significantly enhanced the secretion of interleukin-4 in patients with ITP, but not in controls. Besides revealing the pathologic roles of BAFF receptors, these results also indicate that lymphocytes of patients with ITP have enhanced antiapoptotic or proliferative capacity as compared with those from healthy controls when exposed under similar stimulation of rhBAFF. Further study demonstrated that activated autoreactive B cells and CD4(+) T cells from patients with ITP showed significantly higher expression of BAFF-R or TACI than those from healthy controls.

CONCLUSIONS

Both BAFF-R and TACI are pathogenic participants in ITP. Their dysregulated expression in patients with ITP may lead to hyperreactivity of activated autoreactive lymphocytes in response to rhBAFF, and thus is highly significant in the pathogenesis of ITP.

[Epidemiology of febrile neutropenia in patients with hematological disease-a prospective multicentre survey in China]

OBJECTIVE

To investigate the incidence, clinical and microbiological features of febrile, and risk factors during neutropenia periods in patients with hematological diseases.

METHODS

From October 20, 2014 to March 20, 2015, consecutive patients who had hematological diseases and developed neutropenia during hospitalization were enrolled in the prospective, multicenter and observational study.

RESULTS

A total of 784 episodes of febrile occurred in 1 139 neutropenic patients with hematological diseases. The cumulative incidence of febrile was 81.9% at 21 days after neutropenia. Multivariate analysis suggested that central venous catheterization (P<0.001, HR=3.407, 95% CI 2.276-4.496), gastrointestinal mucositis (P<0.001, HR=10.548, 95% CI 3.245-28.576), previous exposure to broad-spectrum antibiotics within 90 days (P<0.001, HR=3.582, 95% CI 2.387-5.770) and duration of neutropenia >7 days (P<0.001,HR=4.194, 95% CI 2.572-5.618) were correlated with higher incidence of febrile during neutropenia. With the increase of the risk factors, the incidence of febrile increased gradually (35.4%, 69.2%, 86.1%, 95.6%, P<0.001). Of 784 febrile cases, 253 (32.3%) were unknown origin, 429 (54.7% )of clinical documented infections and 102(13.0%) of microbiological documented infections. The most common sites of infection were pulmonary (49.5%), upper respiratory (16.0%), crissum (9.8%), blood stream (7.7%). The most common pathogens were gram-negative bacteria (44.54%), followed by gram-positive bacteria (37.99% ) and fungi (17.47% ). There was no significant difference in mortality rates between cases with febrile and cases without febrile (9.2% vs 4.8%, P=0.099). Multivariate analysis also suggested that >40 years old (P=0.047, HR=5.000, 95% CI 0.853-28.013), hemodynamic instability (P=0.001, HR=13.185, 95% CI 2.983-54.915), prior colonization or infection by resistant pathogens (P=0.005, HR=28.734, 95% CI 2.921-313.744), blood stream infection (P=0.038, HR=9.715, 95% CI 1.110-81.969) and pulmonary infection (P=0.031, HR=25.905, 95% CI 1.381-507.006) were correlated with higher mortality rate in cases with febrile.

CONCLUSIONS

Febrile was the common complication during neutropenia periods in patients with hematological disease. There was different distribution of organisms in different sites of infection. Moreove, the duration of neutropenia >7 days, central venous catheterization, gastrointestinal mucositis and previous exposure to broad-spectrum antibiotics within 90 days were the risk factors for the higher incidence of febrile.

Elevated expression of CX3C chemokine receptor 1 mediates recruitment of T cells into bone marrow of patients with acquired aplastic anaemia

OBJECTIVE

Acquired aplastic anaemia (AA) is a T-cell-mediated, organ-specific autoimmune disease characterized by haematopoietic stem cell destruction in the bone marrow. The exact molecular mechanism of T-cell trafficking into the bone marrow is unclear in AA. Very late activation antigen-4 (VLA-4) and CX3C chemokine receptor 1 (CX3CR1) play active roles in many autoimmune diseases. Therefore, we investigated whether VLA-4 and CX3CR1 also contribute to T-cell migration into the bone marrow in acquired AA.

DESIGN, SETTING AND SUBJECTS

Expression levels of CX3CR1 and VLA-4 and their ligands [fractalkine (CX3CL1) and vascular cell adhesion molecule-1 (VCAM-1)] were examined in 63 patients with AA and 21 healthy control subjects. T-cell chemotaxis and adhesion were analysed in 17 patients with severe AA. We also prospectively evaluated the expression pattern of CX3CR1 during treatment with antithymocyte globulin plus cyclosporine in 11 patients with severe AA.

RESULTS

The proportion of peripheral and bone marrow CD4(+) and CD8(+) T cells expressing CX3CR1 and the level of CX3CL1 was increased in patients with AA. However, there was no significant difference in VLA-4 expression or VCAM-1 levels. Functional studies demonstrated that chemotaxis towards autologous bone marrow plasma or soluble CX3CL1 was significantly higher in T cells from AA patients and could be blocked by CX3CR1 inhibitors. CX3CR1-mediated T-cell adhesion was also upregulated in these patients. The expression of CX3CR1 was associated with the efficacy of immunosuppressive therapy.

CONCLUSION

The present findings demonstrate that CX3CR1 plays a pivotal role in recruitment of T cells into the bone marrow in acquired AA and is a potential therapeutic target for treatment of this disorder.

Expression analysis of a stress-related phosphoinositide-specific phospholipase C gene in wheat (Triticum aestivum L.)

Plant phosphoinositide-specific phospholipases C (PI-PLCs) function in several essential plant processes associated with either development or environmental stress. In this report, we examined the expression patterns of TaPLC1 under drought and high salinity stress at the transcriptional and post-transcriptional levels. TaPLC1 mRNA was expressed in all wheat organs examined. U73122 and edelfosine, the PLC inhibitor, impaired seedling growth and enhanced seedling sensitivity to drought and high salinity stress. Though TaPLC1 expression in wheat was lowest at the seedling stage, it was strongly induced under conditions of stress. When 6-day-old wheat seedlings were treated with 200 mM NaCl or 20% (w/v) PEG 6000 for 6 or 12 h, respectively, the TaPLC1 transcript level increased by 16-fold compared to the control. Western blotting showed that the TaPLC protein concentration was also maintained at a high level from 24 to 48 h during stress treatment. Together, our results indicate the possible biological functions of TaPLC1 in regulating seedling growth and the response to drought and salinity stress.

Association of autoantibody specificity and response to intravenous immunoglobulin G therapy in immune thrombocytopenia: a multicenter cohort study

BACKGROUND

Immune thrombocytopenia (ITP) is a common autoimmune bleeding disorder, in which platelet glycoprotein (GP)IIb-IIIa and GPIb-IX are the two most frequently targeted autoantigens. Our previous studies in animal models of ITP demonstrated that intravenous immunoglobulin G (IVIG) could protect against anti-GPIIb-IIIa autoantibody-mediated thrombocytopenia but failed to ameliorate ITP induced by most anti-GPIb-IX autoantibodies.

OBJECTIVES

The objective of this human study was to evaluate the association between the specificity of antiplatelet autoantibodies and response to IVIG treatment.

PATIENTS/METHODS

In this retrospective study, a cohort of 156 previously untreated adults with severe ITP who underwent IVIG therapy (0.4 g kg(-1)  day(-1) for 5 days) was analyzed. The primary outcome was response defined as platelet counts of ≥ 30 × 10(9)  L(-1) and a doubling of baseline counts within 7 days of dosing, and an absence of bleeding.

RESULTS AND CONCLUSIONS

Among the 66 patients with anti-GPIb-IX autoantibodies, only 24 (36.4%) achieved a response, as compared with 72 of 90 patients (80.0%) who were negative for anti-GPIb-IX autoantibodies (relative risk 2.2; 95% confidence interval 1.6-3.1). This study found no difference in response between patients with anti-GPIIb-IIIa autoantibodies (61.7%) and those without anti-GPIIb-IIIa autoantibodies (61.3%). Logistic regressions, including main effects and the interaction between these two autoantibodies, showed no influence of anti-GPIIb-IIIa autoantibodies on the effects of anti-GPIb-IX autoantibodies with regard to their association with IVIG response. Thus, in adults with ITP, the presence of anti-GPIb-IX autoantibodies is a predictive factor for poor response to IVIG treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01666795.

[A randomized clinical trial of preoperative neoadjuvant chemotherapy followed by surgery in the treatment of stage III non-small cell lung cancer]

BACKGROUND

To explore the feasibility and toxicity of preoperative neoadjuvant chemotherapy followed by surgery in the treatment of stage III NSCLC and to evaluate its effects on tumor response, resection rate, tumor downstaging, and survival rate.

METHODS

From Jan. 1990 to Jan. 2001, 624 patients were randomly devided into group A ( preoperative neoadjuvant chemotherapy group) and group B ( control group, without neoadjuvant chemotherapy) . Group A had 314 patients and group B had 310 cases. The patients in group A were give 2 cycles of neoadjuvant chemotherapy, and operations were performed in 4 weeks after finishing the last chemotherapy. Twenty-one patients were given bronchial artery intervensional chemotherapy. The other 293 cases were given intravenous chemotherapy. The regimens included MVP in 68 cases, CAP in 36 cases, EP in 67 cases, VIP in 20 cases, Gem+ DDP in 30 cases, NVB+ DDP in 32 cases, Taxol+ NVB in 30 cases, and Taxol+ DDP in 10 cases. The patients in group B were firstly operated. Thoracic radiation therapy of 50-55 Gy was g iven in the patients with N1 and N2 disease both in group A and group B.

RESULTS

The tumor response to induction chemotherapy was 73. 57%( 231/ 314) in group A. The tumor downstaging was 43. 63%( 137/ 314) . The histological complete response was 15. 92%( 50/ 314) . The resection rate was 97. 69% in group A, and 91. 94% in group B. No significant differences of blood loss, operative complications and mortality were observed between the group A and group B. The 1-, 3-, 5- and 10-year survival rates were 89. 35%, 67. 46% , 34. 39% and 29. 34% in group A, and 87. 53%, 51. 54%, 24. 19% and 21. 64% in group B respectively. The long-term survival rate in group A was remarkably higher than that in group B ( P < 0. 01) .

CONCLUSIONS

The results demonstrate that the preoperative neoadjuvant chemotherapy is safe and effective. It is helpful to decrease the tumor staging , to increase the resection rate of the tumor, and to improve the long-term survival rate and life qualities of patients with stage III NSCLC.

Spatiotemporal image correlation-derived volumetric Doppler impedance indices from spherical samples of the placenta: intraobserver reliability and correlation with conventional umbilical artery Doppler indices

OBJECTIVE

Volumetric impedance indices derived from spatiotemporal image correlation (STIC) power Doppler ultrasound (PDU) might overcome the influence of machine settings and attenuation. We examined the feasibility of obtaining these indices from spherical samples of anterior placentas in healthy pregnancies, and assessed intraobserver reliability and correlation with conventional umbilical artery (UA) impedance indices.

METHODS

Uncomplicated singleton pregnancies with anterior placenta were included in the study. A single observer evaluated UA pulsatility index (PI), resistance index (RI) and systolic/diastolic ratio (S/D) and acquired three STIC-PDU datasets from the placenta just above the placental cord insertion. Another observer analyzed the STIC-PDU datasets using Virtual Organ Computer-aided AnaLysis (VOCAL) spherical samples from every frame to determine the vascularization index (VI) and vascularization flow index (VFI); maximum, minimum and average values were used to determine the three volumetric impedance indices (vPI, vRI, vS/D). Intraobserver reliability was examined by intraclass correlation coefficients (ICC) and association between volumetric indices from placenta, and UA Doppler indices were assessed by Pearson's correlation coefficient.

RESULTS

A total of 25 pregnant women were evaluated but five were excluded because of artifacts observed during analysis. The reliability of measurement of volumetric indices of both VI and VFI from three STIC-PDU datasets was similar, with all ICCs ≥ 0.78. Pearson's r values showed a weak and non-significant correlation between UA pulsed-wave Doppler indices and their respective volumetric indices from spherical samples of placenta (all r ≥ 0.23). VOCAL indices from specific phases of the cardiac cycle showed good repeatability (ICC ≥ 0.92).

CONCLUSION

Volumetric impedance indices determined from spherical samples of placenta are sufficiently reliable but do not correlate with UA Doppler indices in healthy pregnancies.

Investigation of space-time clusters and geospatial hot spots for the occurrence of tuberculosis in Beijing

OBJECTIVE

To characterise the geographic and spatiotemporal distribution of confirmed tuberculosis (TB) cases in Beijing between 2005 and 2009.

DESIGN

The yearly notification rate maps were used to describe the distribution of confirmed adult TB patients. Spatial autocorrelation (Moran's I) and hot-spot analysis were adopted to detect the clusters and hot spots of TB.

RESULTS

The TB incidence rate (cases per 100,000 population) in Beijing increased from 29.8 in 2005 to 35.0 in 2009. The incidence rate was significantly higher in the Urban Development New District and the Ecologic Reservation Development District (>30/100,000) than in the other districts. There was a significant spatial autocorrelation throughout the city (u = 2.58, P = 0.01). Evident clusters were observed in the Capital Functional Core District and the Urban Function Extension District (G(i)* > 1).

CONCLUSION

Spatial autocorrelation and hot-spot analysis may serve as efficient tools to detect space-time clusters and geospatial hot spots of TB incidence. Between 2005 and 2009, TB incidence in Beijing showed population density and mobility-dependent and eco-social status-dependent space-time clusters and geospatial hot spots.

Deficiency in TLR2 but not in TLR4 impairs dendritic cells derived IL-10 responses to schistosome antigens

The purpose of this study was to observe the diverse functions of Toll-like receptors (TLRs) in responses to specific schistosome antigens. Bone marrow-derived dendritic cells (BMDCs) from TLR2-deficient (TLR2(-/-)) or TLR4-deficient (TLR4(-/-)) mice were activated with soluble schistosomule antigen (SSA) or soluble egg antigen (SEA). TLR2 mRNA expression was significantly increased in B6 BMDCs following SEA stimulation. TLR2-deficient BMDCs showed enhanced MHCII expression following SSA and SEA stimulation. TLR2-deficient but not TLR4-deficient BMDC failed to produce IL-12p70 and IL-10 in response to schistosome antigens. TLR2-deficient BMDCs induced a stronger CD4(+) T cell proliferative response. IL-4 and IL-10 expression was inhibited in CD4(+) T cells primed with TLR2-deficient BMDCs, while enhanced in TLR4-deficient BMDCs-primed CD4(+) T cells. These results suggest that TLR2 is essential for the establishment of the DC production of IL-12p70 and IL-10.

Ontogenesis of Ap-2γ expression in rat testes

Searching for useful markers of spermatogonial stem cells and their differentiation, we used rat testes from ages representing different stages of testicular maturation to investigate the expression profile of transcription factor activation protein-2γ (Ap-2γ). The immunohistochemical and immunocytochemical evaluation using Ap-2γ and promyelocytic leukemia zinc finger in combination with sorting of CD9 and CD90 positive cells (undifferentiated spermatogonia) by fluorescence-activated cell sorting was performed. Our experiments revealed that Ap-2γ is detectable in testes of late fetal age and up to 60 days postnatally and is expressed in gonocytes and spermatogonia from late fetal age throughout all maturational stages. Restricted nuclear expression of Ap-2γ to undifferentiated male germ cells was verified by coexpression of Ap-2γ with promyelocytic leukemia zinc finger in sections of paraffin-embedded testes as well as in cells sorted positive for CD9 and CD90 expression. Our study demonstrated clearly that nuclear expression of Ap-2γ is a useful marker for identifying undifferentiated male germ cells, although its functional role is yet to be fully explored.