Zimin Sun

Decrease of CD4+CD25+ regulatory T cells and TGF-β at early immune reconstitution is associated to the onset and severity of graft-versus-host disease following allogeneic haematogenesis stem cell transplantation

Graft-versus-host disease (GVHD) is a frequent and life threatening complication of allogeneic haematogenesis stem cell transplantation (aHSCT). The correlation of CD4(+)CD25(+) regulatory T cells (Tregs) in the patients after aHSCT to the occurrence and severity of acute and chronic GVHD (aGVHD and cGVHD) is not fully investigated. Here, we examined the levels of CD4(+)CD25(+) Tregs by assessment of CD4(+)CD25(high) and CD4(+)CD25(+)CD127(low) in peripheral blood, and the levels of serum TGF-beta and TNF-alpha in 56 patients at early immune reconstitution following aHSCT. Our data showed a significant reduction in the frequency of Tregs in patients with grades II-IV aGVHD and extensive cGVHD compared to healthy controls. Moreover, a decreased level of CD4(+)CD25(+) Tregs was correlated to increased severity of GVHD. The levels of CD4(+)CD25(+) Tregs in non-GVHD groups were however significantly higher than that in healthy controls. A significant decrease in the levels of TGF-beta and a significant increase the levels of TNF-alpha was also seen with increased severity of GVHD. This study suggested that measurement of CD4(+)CD25(+) Tregs along with serum TGF-beta and TNF-alpha at early immune reconstruction after aHSCT may indicate the onset and severity of both aGVHD and cGVHD.

Decreased cerebral blood flow velocity in apolipoprotein E ɛ4 allele carriers with mild cognitive impairment

The aim of this study was to investigate the changes in cerebral blood flow velocity (CBFV) and its relation to apolipoprotein E (apoE) ɛ4 allele in mild cognitive impairment (MCI). Thirty MCI and 30 controls were assessed using Mini‐Mental State Examination (MMSE) and Cambridge Cognitive Examination‐Chinese version (CAMCOG‐C), and then insonated in the anterior (ACA), middle (MCA) and basilar (BA) cerebral arteries using transcranial Doppler ultrasonography. Compared with controls, MCI showed significant decreases in the mean (Vm), systolic (Vs) and diastolic (Vd) CBFV, bilaterally in MCA and ACA (P < 0.05–0.001), but not in BA. Compared with 17 apoE ɛ4 allele non‐carriers, 13 carriers in MCI showed significant CBFV decreases, bilaterally in MCA (P < 0.05–0.001). Our findings, the decreased CBFV in apoE ɛ4 allele carriers with MCI, suggest that a large sample and longitudinal study in CBFV and cognitive changes may have the implications on early diagnosis of Alzheimers disease.

Correlation of the CD4+CD25high T-regulatory cells in recipients and their corresponding donors to acute GVHD.

Graft‐versus‐host disease continues to be a major life‐threatening complication after allogeneic hematopoietic stem cells transplantation (aHSCT). The relationship of acute GVHD (aGVHD) with the levels of peripheral CD4+CD25high T cells in patients after aHSCT and in their corresponding donors is not fully investigated. We examined the levels of CD4+CD25high T cells in patients after aHSCT and in their corresponding donors, and analyzed the relationship of CD4+CD25high T cells to the incidence and prognosis of aGVHD. The recipients with normal or high CD4+CD25high T cells (three of eight, 37.5%) had no or mild aGVHD (grade I), and all survived during the follow‐up period. In striking contrast, the recipients with lower or no CD4+CD25high T cells suffered from greater than grade II aGVHD (four of four, 100%), and all died within 1‐year post‐aHSCT. Moreover, the number of CD4+CD25high T cells in recipients correlated significantly with that of their corresponding donors. The CD4+CD25high T cells from the recipients and their corresponding donors expressed high levels of Foxp3, and effectively suppressed the proliferation of CD4+CD25− responder T cells. This study suggests that human Treg cells may play an important role in aGVHD, as has been seen in murine models. The levels of peripheral CD4+CD25high T cells in recipients and donors could be helpful for predicting of the onset and outcome of aGVHD.

Fibrinogen controls human platelet fibronectin internalization and cell-surface retention.

Summary.  Background: We recently demonstrated that platelet aggregation occurred in fibrinogen‐deficient mice. In these animals, platelet fibronectin (Fn) content was increased 3–5 fold, suggesting that Fn may also be involved in platelet aggregation. Methods and results:> We compared platelet Fn content from a severe hypofibrinogenemic patient (with approximately 0.5% of normal fibrinogen levels) with his parents (heterozygous) and healthy donors. A significant increase in the patient’s platelet Fn content was detected by immunoblot, flow cytometry, and immunoelectron microscopy (IEM). To examine the possible contribution of platelet Fn to platelet aggregation, we examined cell‐surface Fn expression after thrombin treatment. Unexpectedly, IEM detected only trace amounts of Fn retained on the patient’s platelet surface, and flow cytometry indicated that surface Fn was approximately 6‐fold lower than that of his parents and tenfold lower than that of healthy donors. An ELISA further confirmed that the patient’s platelet Fn was primarily released into the extracellular medium. To test whether retention of surface Fn was due to fibrin formation on the platelet surface, an antifibrin antibody (T2 G1) was employed. Fibrin was detected on platelets from healthy donors and from the father, but was negligible on the patient’s platelets. Consistent with these data, when gel‐filtered platelets of healthy donors were treated with thrombin receptor activation peptide (SFLLRN‐NH2; no conversion of fibrinogen to fibrin), little surface Fn was detected. Conclusion: Fibrinogen not only competitively inhibits human platelet Fn internalization but also controls platelet‐surface Fn retention via fibrin formation. The Fn–fibrin interaction is one possible mechanism to promote Fn interaction with platelets.

Pre-engraftment syndrome after unrelated donor umbilical cord blood transplantation in patients with hematologic malignancies.

Pre‐engraftment syndrome (PES) after umbilical cord blood transplantation (CBT) remains poorly characterized, and the prognosis and appropriate management are unclear. Therefore, we retrospectively analyzed the incidence, risk factors, manifestations, and clinical outcomes of PES in CBT recipients, who had been treated for hematologic malignancies at our transplantation center. PES was defined as unexplained fever higher than 38.3°C that is not associated with documented infection and unresponsive to antimicrobial manipulations and/or unexplained erythematous skin rash occurring prior to neutrophil engraftment. A total of 81 patients (median 18 yr, range 3–48) received either myeloablative (n = 72) or non‐myeloablative (n = 9) conditioning. Neutrophil engraftment was achieved in 69 of the 81 cases [86.2%, 95% confidence interval (CI) = 78.9–94.1%], and the median time to more than 0.5 × 109/L ANC was 19 d (range, 12–39). Fifty‐one patients (63.0%) developed PES at a median of 7 d (range 3–15) post‐transplant: 46 patients had both rash and unexplained fever; one patient had unexplained fever alone; and four patients had rash only. Forty‐seven patients (92.2%) received IV methylprednisolone (MP) at a median dose of 1 mg/kg (range 0.4–3). All patients treated with MP responded as evidenced by fever resolution combined with resolution of rash. All patients with PES had high serum levels of C‐reactive protein (CRP), which were significantly reduced after effective steroid treatment. Univariate analysis identified myeloablative conditioning and younger age as significant risk factors for developing PES. Cumulative incidence of grade II–IV acute graft‐versus‐host disease (aGVHD) in the PES+ and PES− groups was 51.5% (95% CI = 38.0–70.0%) and 17.0% (95% CI = 6.9–41.7%), respectively. In a multivariate analysis, we found significantly increased risk of grade II–IV aGVHD among PES patients (P = 0.041). However, PES was not associated with sustained donor engraftment, the day to neutrophil recovery, chronic graft‐versus‐host disease, transplant‐related mortality at day 180, and overall survival. Despite of the inherent limitations of this small retrospective study, PES seemed to be common after CBT and associated with high incidence of aGVHD.

Comparison of Conditioning Regimens with or without Antithymocyte Globulin for Unrelated Cord Blood Transplantation in Children with High-Risk or Advanced Hematological Malignancies

The role and potential efficacy of antithymocyte globulin (ATG) in patients receiving cord blood transplantation (CBT) remain controversial. We retrospectively evaluated the effect of ATG on patient outcomes in 207 children with high-risk or advanced hematological malignancies at 8 child blood disease centers in China. The cumulative incidence of platelet recovery on day 100 was significantly lower in the ATG cohort compared with the non-ATG cohort (77.3% versus 89.8%) (P = .046). There was no significant difference in the incidence of grade II to IV acute and chronic graft-versus-host disease (GVHD), and transplantation-related mortality (TRM) between the 2 groups (P = .76, P = .57, and P = .46, respectively). The incidence of CMV infection was significantly higher among the ATG group compared with that among the non-ATG group (P = .003). The 5-year cumulative incidence of relapse was significantly higher in the ATG cohort (30.7% versus 15.4%) (P = .009). Overall survival in the non-ATG group was slightly higher than that of the ATG cohort (64.1% versus 52.1%, P = .093) and leukemia-free survival in the non-ATG cohort was significantly higher than in the ATG cohort (56.6% versus 37.7%, P = .015). Our study demonstrated that, for high-risk or advanced childhood hematological malignancies receiving unrelated CBT, patients who received conditioning that omitted ATG had a faster platelet recovery, a comparable GVHD and TRM, a significantly lower relapse risk, and an improved long-term survival compared with those patients who received ATG in the conditioning.

The consensus on indications, conditioning regimen, and donor selection of allogeneic hematopoietic cell transplantation for hematological diseases in China—recommendations from the Chinese Society of Hematology

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is widely used to treat malignant hematological neoplasms and non-malignant hematological disorders. Approximately, 5000 allo-HSCT procedures are performed in China annually. Substantial progress has been made in haploidentical HSCT (HID-HSCT), pre-transplantation risk stratification, and donor selection in allo-HSCT, especially after the establishment of the “Beijing Protocol” HID-HSCT system. Transplant indications for selected subgroups in low-risk leukemia or severe aplastic anemia (SAA) differ from those in the Western world. These unique systems developed by Chinese doctors may inspire the refining of global clinical practice. We reviewed the efficacy of allo-HSCT practice from available Chinese studies on behalf of the HSCT workgroup of the Chinese Society of Hematology, Chinese Medical Association and compared these studies to the consensus or guideline outside China. We summarized the consensus on routine practices of all-HSCT in China and focused on the recommendations of indications, conditioning regimen, and donor selection.

Quantitative Analysis of Global Proteome and Lysine Acetylome Reveal the Differential Impacts of VPA and SAHA on HL60 Cells

Valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) are both HDAC inhibitors (HDACi). Previous studies indicated that both inhibitors show therapeutic effects on acute myeloid leukaemia (AML), while the differential impacts of the two different HDACi on AML treatment still remains elusive. In this study, using 3-plex SILAC based quantitative proteomics technique, anti-acetyllysine antibody based affinity enrichment, high resolution LC-MS/MS and intensive bioinformatic analysis, the quantitative proteome and acetylome in SAHA and VPA treated AML HL60 cells were extensively studied. In total, 5,775 proteins and 1,124 lysine acetylation sites were successfully obtained in response to VAP and SAHA treatment. It is found that VPA and SAHA treatment differently induced proteome and acetylome profiling in AML HL60 cells. This study revealed the differential impacts of VPA and SAHA on proteome/acetylome in AML cells, deepening our understanding of HDAC inhibitor mediated AML therapeutics.

Comparison of outcomes after umbilical cord blood and unmanipulated haploidentical hematopoietic stem cell transplantation in children with high-risk acute lymphoblastic leukemia.

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective therapy for children with high‐risk acute lymphoblastic leukemia (ALL). Human leukocyte antigen (HLA)‐haploidentical HSCT (haplo‐HSCT) or umbilical cord blood transplantation (UCBT) are both important alternative sources of stem cells for those without an HLA‐identical sibling donor or unrelated matched donor. We aimed to compare the therapeutic effects of single UCBT and unmanipulated haplo‐HSCT in high‐risk ALL children (n = 129). Hematopoietic recovery was significantly faster in haplo‐HSCT recipients than in UCBT recipients. The 2‐year cumulative incidences of relapse in the haplo‐HSCT and UCBT groups were 16.1% and 24.1%, respectively (p = 0.169). The 2‐year cumulative incidences of non‐relapse mortality in the haplo‐HSCT and UCBT groups were 12.8% and 18.8%, respectively (p = 0.277). The 2‐year probabilities of overall survival in the haplo‐HSCT and UCBT groups were 82.0% and 69.6%, respectively (p = 0.071), and the 2‐year probability of disease‐free survival in the haplo‐HSCT group was higher than in the UCBT group (71.0% vs. 57.2%, p = 0.040). However, several variables (such as leukocyte count and cytogenetics at diagnosis) were different between the groups, and a possible center effect should also be considered. In addition, only mild and moderate chronic graft‐versus‐host disease (GVHD) was associated with significantly improved survival compared to those without chronic GVHD in multivariate analysis. Thus, our results show that both unmanipulated haplo‐HSCT and UCBT are valid for high‐risk ALL children lacking a HLA matched donor, and both strategies expand the donor pool for children in need.

CD123 redirected multiple virus-specific T cells for acute myeloid leukemia

Hematopoietic stem cell transplantation (HSCT) has been increasingly used as a curative treatment for acute myeloid leukemia (AML). However, relapse rates after HSCT in complete remission (CR) are reported between 30% and 70%. In addition, numerous studies suggested that secondary viral infection from a variety of viruses including Epstein-Barr virus (EBV), adenovirus (Adv), and cytomegalovirus (CMV) are among the most common causes of death post-HSCT. Currently, chimeric antigen receptor (CAR)-based T cells have been developed to treat AML in clinical studies, while virus-specific cytotoxic T cells (VST) have been proven to be able to effectively prevent or treat viral infection after HSCT. Thus it would be desirable to develop T cells with the ability of simultaneously targeting AML relapse and viral infection. In this article, we now describe the generation of VST cells that are engineered to express CAR for a specific AML cell-surface antigen CD123 (CD123-CAR-VST). Using Dendritic cells (DCs) pulsed with EBV, Adv, and CMV peptides as sources of viral antigens, we generated VST from A2 donor peripheral mononuclear cells (PBMC). VST were then transduced with retroviral vector encoding CD123-CAR to generate CD123-CAR-VST. We demonstrated that CD123-CAR-VST recognized EBV, Adv, and CMV epitopes and had HLA-restricted virus-specific cytotoxic effector function against EBV target. In addition, CD123-CAR-VST retained the specificity against CD123-positive AML cell lines such as MOLM13 and THP-1 in vitro. Thus our results suggested that CD123-CAR-VST might be a valuable candidate to simultaneously prevent or treat relapse and viral infection in AML HSCT recipients.