Linghui Xia

Prophylactic Effects of Interleukin-2 Receptor Antagonists against Graft-versus-Host Disease Following Unrelated Donor Peripheral Blood Stem Cell Transplantation

Basiliximab and daclizumab, two interleukin-2 receptor antagonists (IL-2RAs), prevent graft failure in renal transplantation, which also effectively treat steroid-refractory graft-versus-host disease (GVHD). However, only a few studies report that IL-2RAs prevent GVHD. Here we first retrospectively explored the prophylactic effects of basiliximab or daclizumab against GVHD in 82 patients with hematologic malignancies following unrelated donor-peripheral blood stem cell transplantation (URD-PBSCT). All recipients achieved engraftment. The rates of grade II-IV and III-IV acute GVHD (aGVHD) were 35.4% and 15.9%, respectively. Chronic GVHD (cGVHD) developed in 38.7% of evaluable patients. The transplantation-related mortality was 13.4%, while relapse rate was 8.5%. The 2-year overall survival (OS) reached 77.1% and disease-free survival (DFS) accumulated to 72.2%. The side effects of basiliximab and daclizumab were moderate and tolerable. There were no significant differences in aGVHD onset and survival between the daclizumab and basiliximab groups. However, basiliximab presented superior prophylactic effects on cGVHD than daclizumab. In conclusion, basiliximab or daclizumab prevents GVHD efficiently and feasibly following URD-PBSCT, and contributes to favorable outcome. Basiliximab has a similar effect on aGVHD but superior activity against cGVHD. Further prospective and randomized control studies are needed.

Elevated Fas/FasL system and endothelial cell microparticles are involved in endothelial damage in acute graft-versus-host disease: A clinical analysis

Acute graft-versus-host disease (aGVHD) is the major cause of early morbidity and mortality in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, but its mechanism remains not well understood. This study firstly compared dynamic change of Fas/Fas ligand (FasL) system in plasma and also in the surface of endothelial cell microparticles (EMPs) in aGVHD patients, pre-aGVHD patients (7, 14, 21 and 28 days after transplantation), non-aGVHD patients and normal controls. Plasma soluble FasL (sFasL) was detected by ELISA. Fas, FasL and EMPs were evaluated by Confocal microscopy and flow cytometric analysis respectively. Significantly higher levels of sFasL and EMPs were detected in the patients at the time of aGVHD attack. In addition, sFasL exhibited significant elevation but EMPs exhibited simultaneously decrease within the early phase (+21d) after allo-HSCT in pre-aGVHD group compared with non-aGVHD group. At +21d, there was a significant difference of sFasL and EMPs between pre-aGVHD group and non-aGVHD group. Moreover our present study firstly reported that EMPs expressed higher Fas antigen (Fas(+)-EMPs) in the patients with aGVHD. Therefore it can be inferred that EMPs may play protective roles through Fas in endothelial cell damage of aGVHD after allo-HSCT. This suggested monitoring EMPs and sFasL in the early phase after HSCT may be useful for the early diagnosis and forecast of aGVHD and it also provided new clues in understanding the pathogenesis of endothelial cell injury during aGVHD after allo-HSCT and meanwhile help identifying new drugs to circumvent it in clinic.

Endothelial microparticles carrying hedgehog-interacting protein induce continuous endothelial damage in the pathogenesis of acute graft-versus-host disease

Accumulating evidence suggests that endothelial microparticles (EMPs), a marker of endothelial damage, are elevated in acute graft-versus-host disease (aGVHD), and that endothelial damage is implicated in the pathogenesis of aGVHD, but the mechanisms remain elusive. In this study, we detected the plasma EMP levels and endothelial damage in patients and mice with aGVHD in vivo and then examined the effects of EMPs derived from injured endothelial cells (ECs) on endothelial damage and the role of hedgehog-interacting protein (HHIP) carried by EMPs in these effects in vitro. Our results showed that EMPs were persistently increased in the early posttransplantation phase in patients and mice with aGVHD. Meanwhile, endothelial damage was continuous in aGVHD mice, but was temporary in non-aGVHD mice after transplantation. In vitro, EMPs induced endothelial damage, including increased EC apoptosis, enhanced reactive oxygen species, decreased nitric oxide production and impaired angiogenic activity. Enhanced expression of HHIP, an antagonist for the Sonic hedgehog (SHH) signaling pathway, was observed in patients and mice with aGVHD and EMPs from injured ECs. The endothelial damage induced by EMPs was reversed when the HHIP incorporated into EMPs was silenced with an HHIP small interfering RNA or inhibited with the SHH pathway agonist, Smoothened agonist. This work supports a feasible vicious cycle in which EMPs generated during endothelial injury, in turn, aggravate endothelial damage by carrying HHIP into target ECs, contributing to the continuously deteriorating endothelial damage in the development of aGVHD. EMPs harboring HHIP would represent a potential therapeutic target for aGVHD.

A comparative study of outcomes of idarubicin- and etoposide-intensified conditioning regimens for allogeneic peripheral blood stem cell transplantation in patients with high-risk acute leukemia

AbstractAim:To analyze the results of idarubicin (IDA)- versus etoposide (VP16)-intensified myeloablative conditioning regimen in allogeneic hematopoietic stem cell transplantation (allo-SCT) for high-risk acute leukemia.Methods:From January 2005 to June 2008, 48 consecutive patients (male: n=29; median age: 30 years, range 14–51 years) with high-risk acute leukemia underwent allo-SCT following an IDA- or VP16-intensified conditioning regimen. The conditioning regimens were modified BUCY2 (busulfan+cyclophosphamide) consisting of IDA (15 mg/m2 per day, days -12 to -10) or VP16 (25 mg/kg per day, days -3 to -2) and CY/TBI (cyclophosphamide/total body irradiation) intensified with IDA (15 mg/m2 per day, days -6 to -5) or VP16 (25 mg/kg per day, days -3 to -2) for acute myeloid leukemia and acute lymphoblastic leukemia, respectively.Results:Between the two groups, no significant differences in terms of baseline characteristics, incidence of acute or chronic graft-versus-host disease (GVHD) or transplant-related mortality (TRM) (P=0.50) were observed. However, the IDA group demonstrated higher incidences of mucositis and Aspergillus pneumonia (P<0.01 and P=0.03, respectively). For the IDA and VP16 groups, relapse rates were 28% and 50%, respectively (P=0.13). For the same groups, the 2-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 72% versus 51% (P=0.04) and 74% versus 53% (P=0.04), respectively.Conclusion:This retrospective analysis suggests that conditioning regimens intensified with IDA can achieve better outcomes than conditioning regimens with VP16 in patients preparing to undergo allo-SCT for high-risk acute leukemia.

Comparison of outcomes of idarubicin intensified TBI–CY and traditional TBI–CY conditioning regimen for high-risk acute lymphoblastic leukemia undergoing allogeneic hematopoietic stem cell transplantation: A single center experience

High-risk acute lymphoblastic leukemia (ALL) carries a very poor prognosis, even after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Exploring novel conditioning regimen to more effectively eliminate leukemic clone while not alter transplant-related mortality (TRM) has become focus of attention. We retrospectively evaluated outcomes of 87 high-risk ALL patients undergoing allo-HSCT: 47 patients received idarubicin (IDA) intensified TBI-CY and 40 patients received traditional TBI-CY regimen. In IDA intensified group, patients received TBI (8Gy) on day-8, IDA of 15mg/m2/d from day-6 to -5, followed by CY (60mg/kg/d) on day-3 to -2. The cumulative incidence of relapse was significantly lower in IDA intensified group compared with TBI-CY group (P=0.018). Oropharyngeal mucositis was observed more frequent in IDA intensified group (P=0.013), while not followed by increased TRM. Very high-risk ALL patients benefit from IDA intensified regimen with only two of eight patients in no remission (NR) pre-transplantation and two of twelve ph+ALL patients relapsed after transplantation. After a median follow-up for all survivors of 21 months (range, 12-53 months), 2-year estimated OS and DFS was 66.2% vs 45.3% (P=0.031) and 62.5% vs 43.5% (P=0.044), respectively. In conclusion, IDA intensified TBI-CY regimen may reduce relapse while not increasing TRM, providing better survival for high-risk ALL patients undergoing allo-HSCT.

Angiogenic factors are associated with development of acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

SummaryAcute graft-versus-host disease (aGVHD) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the mechanisms of aGVHD are not well understood. We aim to investigate the roles of the three angiogenic factors: angiopoietin-1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) in the development of aGVHD. Twenty-one patients who underwent allo-HSCT were included in our study. The dynamic changes of Ang-1, Ang-2 and VEGF were monitored in patients before and after allo-HSCT. In vitro, endothelial cells (ECs) were treated with TNF-β in the presence or absence of Ang-1, and then the Ang-2 level in the cell culture medium and the tubule formation by ECs were evaluated. After allo-HSCT, Ang-1, Ang-2 and VEGF all exhibited significant variation, suggesting these factors might be involved in the endothelial damage in transplantation. Patients with aGVHD had lower Ang-1 level at day 7 but higher Ang-2 level at day 21 than those without aGVHD, implying that Ang-1 may play a protective role in early phase yet Ang-2 is a promotion factor to aGVHD. In vitro, TNF-β promoted the release of Ang-2 by ECs and impaired tubule formation of ECs, which were both weakened by Ang-1, suggesting that Ang-1 may play a protective role in aGVHD by influencing the secretion of Ang-2, consistent with our in vivo tests. It is concluded that monitoring changes of these factors following allo-HSCT might help to identify patients at a high risk for aGVHD.Acute graft-versus-host disease (aGVHD) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the mechanisms of aGVHD are not well understood. We aim to investigate the roles of the three angiogenic factors: angiopoietin-1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) in the development of aGVHD. Twenty-one patients who underwent allo-HSCT were included in our study. The dynamic changes of Ang-1, Ang-2 and VEGF were monitored in patients before and after allo-HSCT. In vitro, endothelial cells (ECs) were treated with TNF-β in the presence or absence of Ang-1, and then the Ang-2 level in the cell culture medium and the tubule formation by ECs were evaluated. After allo-HSCT, Ang-1, Ang-2 and VEGF all exhibited significant variation, suggesting these factors might be involved in the endothelial damage in transplantation. Patients with aGVHD had lower Ang-1 level at day 7 but higher Ang-2 level at day 21 than those without aGVHD, implying that Ang-1 may play a protective role in early phase yet Ang-2 is a promotion factor to aGVHD. In vitro, TNF-β promoted the release of Ang-2 by ECs and impaired tubule formation of ECs, which were both weakened by Ang-1, suggesting that Ang-1 may play a protective role in aGVHD by influencing the secretion of Ang-2, consistent with our in vivo tests. It is concluded that monitoring changes of these factors following allo-HSCT might help to identify patients at a high risk for aGVHD.

Simvastatin Ameliorates Graft-vs-Host Disease by Regulating Angiopoietin-1 and Angiopoietin-2 in a Murine Model

Angiopoietins play an important role in vascular endothelial function. Endothelial damage is an important pathogenesis relating with acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), protecting endothelial cells (ECs) from damage may be a potent prophylaxis and therapeutic strategy of acute GVHD (aGVHD). In this study, we explored changes in Angiopoietin-1 (Ang-1) and Ang-2 expression in a aGVHD mouse model and determined whether simvastatin prevents GVHD through regulating Ang-1 and Ang-2 expression. In vitro simvastatin administration increased Ang-1 production and release but conversely inhibited Ang-2 release from EA.hy926 ECs. Simvastatin improved the survival of aGVHD mice, attenuated the histopathological GVHD grades and plasma levels of Ang-2, and elevated the plasma levels of Ang-1 as well as the aortic endothelial levels of Ang-1 and Ang-2. In summary, simvastatin represents a novel approach to combat GVHD by increasing Ang-1 production while suppressing Ang-2 release to stabilize endothelial cells.

Idarubicin-intensified BUCY2 conditioning regimen improved survival in high-risk acute myeloid, but not lymphocytic leukemia patients undergoing allogeneic hematopoietic stem cell transplantation: A retrospective comparative study

The intensity of conditioning regimen is highly correlated with outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT). We have previously reported that idarubicin (IDA) intensified BUCY2 regimen could reduce relapse and improve survival for high-risk hematological malignancies undergoing allo-HSCT. However, there is no published study comparing the efficacy of IDA-BUCY2 regimen for high-risk acute myeloid leukemia (AML) versus acute lymphocytic leukemia (ALL). We further retrospectively compared therapeutic outcomes of intensified conditioning regimen on 140 high-risk AML and ALL patients in the data analyses. IDA 15mg/m(2)/d was administered by continuous infusion from day -11 to -9, followed by intravenous injection of busulfan (BU) (3.2mg/kg/d) from day -6 to -4, and intravenous injection of cyclophosphamide (CY) (1.8g/m(2)/d) from day -3 to -2 in IDA-BUCY2 regimen. For high-risk AML, cumulative probabilities of 3-year relapse rates in IDA-BUCY2 and traditional BUCY2 regimens were 16.9%, 43.3% (P=0.016). Cumulative probabilities of 3-year overall survival (OS) and disease-free survival (DFS) were 69.2% vs 44.0% (P=0.024), and 66.9% vs 38.2% (P=0.01). However, two regimens showed no significant differences for high-risk ALL. Multivariate analysis also indicated that IDA intensified BUCY2 conditioning was the favorable variable to reduce relapse and elevate survival for high-risk AML patients. In conclusion, IDA-BUCY2 regimen reduces relapse and improves survival for high-risk AML undergoing allo-HSCT, but not presenting uniform therapeutic effects for high-risk ALL.

Endothelial microparticles delivering microRNA-155 into T lymphocytes are involved in the initiation of acute graft-versus-host disease following allogeneic hematopoietic stem cell transplantation

Endothelial microparticles (EMPs) upregulation has been observed in acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the role of EMPs remains unclear. We found that EMPs derived from TNF-α-stimulated human umbilical vein endothelial cells (EA.hy926) concentrated more microRNA-155 (miR-155) compared with maternal cells. The miR-155 levels in MPs from peripheral blood of aGVHD patients and mice were remarkably elevated and significantly higher than the levels in plasma. Moreover, the rising peak of miR-155 in MPs occurred significantly prior to the peak in T lymphocytes. Additionally, we observed fluorescently-labeled miR-155 in EMPs actively transported into recipient T lymphocytes. Inhibition of miR-155 in EMPs by antagomir-155 did not influence the proliferation and apoptosis of T lymphocytes, but induced defective differentiation toward Th1, Th9 and Th17 cells and skewed differentiation toward Th2 and Treg cells. Furthermore, intravenous injection of miR-155-deficient-EMPs into aGVHD mice significantly attenuated the exacerbation of aGVHD manifestations and abnormal T lymphocytes differentiation induced by high concentration EMPs. Taken together, these data provide a mechanistic framework in which miR-155 delivered by EMPs is involved in aGVHD pathogenesis by activating specific T lymphocytes functions. The results may provide new therapeutic approaches for aGVHD while preserving graft-versus-leukemia (GVL) effect.

Expressions of tissue factor and tissue factor pathway inhibitor in patients with acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

This study examined the expressions of human serum tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their clinical significance. The serum TF and TFPI levels were detected by ELISA in 28 allo-HSCT recipients before and after the transplantation and the changes of TF and TFPI levels were dynamically monitored at different phases of the disease. No significant differences in the serum TF and TFPI levels were found in allo-HSCT recipients in the absence of aGVHD or with grade I aGVHD before and after the transplantation. The levels of serum TF and TFPI were substantially increased in the patients with gradeII aGVHD at the peak of aGVHD (P<0.05) and they were even higher in the patients with grade III–IV aGVHD (P<0.01). When the conditions became stable after treatment with immunosuppressive agents, the serum TFPI level was decreased to the baseline level (P>0.05) and the TF level was lowered but still higher than the baseline level (P<0.05). It was concluded that the levels of serum TF and TFPI were increased significantly in the patients with grade II–IV aGVHD after allo-HSCT and decreased markedly after the treatment. Monitoring the levels of serum TF and TFPI in the patients with allo-HSCT is important to predict the occurrence, outcome and prognosis of aGVHD.SummaryThis study examined the expressions of human serum tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their clinical significance. The serum TF and TFPI levels were detected by ELISA in 28 allo-HSCT recipients before and after the transplantation and the changes of TF and TFPI levels were dynamically monitored at different phases of the disease. No significant differences in the serum TF and TFPI levels were found in allo-HSCT recipients in the absence of aGVHD or with grade I aGVHD before and after the transplantation. The levels of serum TF and TFPI were substantially increased in the patients with gradeII aGVHD at the peak of aGVHD (P<0.05) and they were even higher in the patients with grade III–IV aGVHD (P<0.01). When the conditions became stable after treatment with immunosuppressive agents, the serum TFPI level was decreased to the baseline level (P>0.05) and the TF level was lowered but still higher than the baseline level (P<0.05). It was concluded that the levels of serum TF and TFPI were increased significantly in the patients with grade II–IV aGVHD after allo-HSCT and decreased markedly after the treatment. Monitoring the levels of serum TF and TFPI in the patients with allo-HSCT is important to predict the occurrence, outcome and prognosis of aGVHD.