The causal effect of adipose tissue on Hodgkin's lymphoma: two-sample Mendelian randomization study and validation.

Background: Extensive research has been conducted on the correlation between adipose tissue and the risk of malignant lymphoma. Despite numerous observational studies exploring this connection, uncertainty remains regarding a causal relationship between adipose tissue and malignant lymphoma. Methods: The increase or decrease in adipose tissue was represented by the height of BMI. The BMI and malignant lymphoma genome-wide association studies (GWAS) used a summary dataset from the OPEN GWAS website. Single-nucleotide polymorphisms (SNPs) that met the criteria of P <5e-8 and LD of r2 = 0.001 in the BMI GWAS were chosen as genetic instrumental variants (IVs). Proxy SNPs with LD of r2 > 0.8 were identified, while palindromic and outlier SNPs were excluded. Mendelian randomization (MR) analysis used five methods, including inverse-variance weighted (IVW) model, weighted median (WM), MR-Egger, simple mode, and weighted mode. Sensitivity assessments included Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis. Participants randomly selected by the National Center for Health Statistics (NHANSE) and newly diagnosed HL patients at Fujian Medical University Union Hospital were used for external validation. Results: The results of the MR analysis strongly supported the causal link between BMI and Hodgkin's lymphoma (HL). The research demonstrated that individuals with lower BMI face a significantly increased risk of developing HL, with a 91.65% higher risk (ORIVW = 0.0835, 95% CI 0.0147 - 0.4733, P = 0.005). No signs of horizontal or directional pleiotropy were observed in the MR studies. The validation results aligned with the results from the MR analysis (OR = 0.871, 95% CI 0.826 - 0.918, P< 0.001). And there was no causal relationship between BMI and non-Hodgkin's lymphoma (NHL). Conclusions: The MR analysis study demonstrated a direct correlation between lower BMI and HL. This suggested that a decrease in adipose tissue increases the risk of developing HL. Nevertheless, further research is essential to grasp the underlying mechanism of this causal association comprehensively.

The correlation of asparaginase enzyme activity levels after PEG-asparaginase administration with clinical characteristics and adverse effects in Chinese paediatric patients with acute lymphoblastic leukaemia.

Studies on asparaginase enzyme activity (AEA) monitoring in Chinese patients receiving PEG-asparaginase remain limited. We monitored AEA in paediatric patients diagnosed with acute lymphoblastic leukaemia (ALL) and treated according to the Chinese Children's Cancer Group study protocols, CCCG-ALL-2015/CCCG-ALL-2020 protocols. We measured the AEA at days 7 ± 1 and 14 ± 1 and analysed their association with patient characteristics and PEG-asparaginase-related adverse effects (AEs). We measured 2147 samples from 329 patients. Mean AEA levels (interquartile range) were 931 iu/L (654-1174 iu/L) at day 7 ± 1 and 664 iu/L (463-860 iu/L) at day 14 ± 1. The AEA levels were higher in younger children and increased with the cumulative dose numbers. PEG-asparaginase inactivation rate was 19.1%, and the silent inactivation (SI) rate was 12.5%. Nine patients were identified with allergic-like reactions. Hypofibrinogenaemia, hypertriglyceridaemia, pancreatitis and thrombosis were associated with older age, whereas hypoglycaemia was associated with younger age. The risk of hypertriglyceridaemia and hypoglycaemia increased with cumulative dose numbers of PEG-asparaginase. Except for hypofibrinogenaemia, elevated AEA levels did not increase the risk of PEG-asparaginase-related AEs. Drug monitoring can be utilized as guidance for treatment decision-making. Individualizing asparaginase doses do not reduce toxicities. The treatment target of PEG-asparaginase remains to achieve sustained and adequate activity.

Hematopoietic Stem Cell Transplantation Activity in China 2020-2021 During the SARS-CoV-2 Pandemic: A Report From the Chinese Blood and Marrow Transplantation Registry Group.

Between 2020 and 2021, 31,525 hematopoietic stem cell transplantations (HSCTs) were reported to the Chinese Blood and Marrow Transplantation Registry Group throughout mainland China. In this report, we describe the activity and current trends for HSCT in China during the SARS-CoV-2 pandemic. In 2020, a total of 13,415 cases of HSCT were reported from 166 transplantation teams, and 75% (10,042 cases) were allogeneic HSCTs. In 2021, a total of 18,110 cases of HSCT were reported from 174 transplantation teams, and 70% (12,744 cases) were allogeneic HSCTs. Haploidentical donor (HID) transplantation accounted for 63% (7977 cases) of allogeneic HSCTs in 2021. The most common indications for allogeneic HSCT for malignant disease were acute myeloid leukemia (37%) and acute lymphoblastic leukemia (23%), and the largest proportion of nonmalignant disease comprised aplastic anemia (13%). The peripheral blood stem cell source accounted for 41% of HIDs and 75% of matched sibling donors. The BuCy-based regimen (57%) was the most popular conditioning regimen for allogeneic HSCT, followed by the BuFlu-based regimen (28%) and total body irradiation-based regimen (11%). This survey provides comprehensive information about the current activities and might benefit clinical physicians' decision planning for HSCT.

Successful treatment with HLA-matched peripheral hematopoietic stem cell transplantation for very severe hepatitis-associated aplastic anemia complicated with multidrug-resistant bacterial and fungal infections: A case report.

Hepatitis-associated aplastic anemia (HAAA) is a life-threatening hematologic disorder characterized by bone marrow failure. Allogeneic hematopoietic stem cell transplantation (HSCT) is the first-line treatment for HAAA. Severe infection and complications in patients with very severe aplastic anemia are the challenges to the efficacy of HSCT. We report a rare case of successful transplantation with HLA-matched peripheral hematopoietic stem cells for a 15-year-old girl suffering from HAAA with multidrug-resistant bacterial and fungal infections. Through effectively controlling infection and optimal timing of transplantation by adjusting the conditioning regimen, the allo-HSCT was successfully performed for the patient. Updated data of following-up 26 months after transplantation showed that the patient was still in complete remission with a good quality of life. This case provided a reference for treating severely infected patients with HAAA before HSCT.

High Efficacy of Stem Cell Mobilization With Etoposide+Cytarabine Plus G-CSF in Patients With Multiple Myeloma.

BACKGROUND: Efficient mobilization of CD34+ hematopoietic stem cells plays a vital role in successful autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM), especially in cases with high-risk cytogenetic recommended for tandem ASCT. However, the optimal mobilization strategy remains a matter of debate in the era of lenalidomide. The combination of etoposide with Cytarabine plus G-CSF as a novel mobilization regimen in MM has not been reported previously. METHODS: This research retrospectively studied mobilization efficacy and safety using etoposide combined with Cytarabine (etoposide 50-100 mg/m2, qd d1-3; AraC 0.5 g/m2, q12h d1~3) plus G-CSF (5 µg/kg/day, from d5 until the day of apheresis) in 128 patients with MM. 70(54.7%) patients received lenalidomide-based induction regimens treatment. RESULTS: A median of 27.75×106 CD34+ cells/kg was collected in the first apheresis, and 28.23×106 CD34+ cells/kg were collected overall. Of the 128 patients, all achieved adequate collection (≥2×106 CD34+ cells/kg), 121(94.5%) achieved optimal collection for single ASCT (≥5×106 CD34+ cells/kg), and 114(89.1%) harvested optimal collection for tandem ASCT (≥10×106 CD34+ cells/kg). In particular, the target yield of optimal collection for tandem ASCT was reached in 82.8% (106/128) by a single apheresis procedure. 14 patients obtained deeper response post mobilization. In multivariate analysis, cycles of prior chemotherapy independently affected the optimal achievement of CD34+ cells (p=0.004, OR 0.695, 95% CI 0.544~0.888). Previous lenalidomide exposure did not significantly impair CD34+ cells collection. Although 68% episodes of antibiotic usage were observed, no severe infection or treatment-related mortality occurred. CONCLUSION: Stem cell mobilization with Etoposide + Cytarabine plus G-CSF was highly efficient and safe in patients with MM, which could be considered in high-risk MM patients who were referred for tandem ASCT.

Sequential Transplantation of Haploidentical Stem Cell and Unrelated Cord Blood With Using ATG/PTCY Increases Survival of Relapsed/Refractory Hematologic Malignancies.

Allogeneic haploidentical HSCT (haplo-HSCT) and unrelated umbilical cord blood transplantation(UCBT)are used in patients lacking HLA-identical sibling or unrelated donors. With myeloablative condition and GVHD prophylaxis of using low-dose ATG and post-transplantation cyclophosphamide (PTCY), we conducted a prospective clinical trial. Of eligible 122 patients from February 2015 to December 2019 in the study, 113 patients were involved. Forty-eight patients were in the group of sequential haplo-cord transplantation (haplo-cord HSCT), and 65 patients were in the group of single UCBT. The primary endpoint of 2-year disease-free survival (DFS) was no statistical difference between groups (64.1 vs. 56.5%), p>0.05. The analysis of subgroup patients with relapsed/refractory showed haplo-cord HSCT was associated with better OS (HR 0.348, 95% CI, 0.175-0.691; p=0.0025), DFS (HR 0.402, 95% CI, 0.208-0.779; p=0.0069), and GRFS (HR 0.235, 95% CI, 0.120-0.457, p<0.0001) compared to the single cord group. The 2-year's probability in OS, DFS, and GRFS was 64.9 vs. 31.6%, 64.5 vs. 31.6%, and 60.8 vs. 15.0% in the haplo-cord group and single cord group, respectively. III-IV acute GVHD 8.3 vs. 6.2%, chronic GVHD 25.8 vs. 13.7%, and extensive chronic GVHD 5.3 vs. 1.8% were shown in corresponding group, p>0.05. The patients engrafted persistently with UCB showed better survival outcomes. Our sequential Haplo-cord HSCT with ATG/PTCY improved the survival of patients and might be an alternative transplantation approach for patients with relapsed/refractory hematologic malignancies.

A multicenter retrospective study on the real-world outcomes of autologous vs. allogeneic hematopoietic stem cell transplantation for peripheral T-cell lymphoma in China.

BACKGROUND: There were few studies on real-world data about autologous hematopoietic stem cell transplantation (auto-HSCT) or allogeneic HSCT (allo-HSCT) in peripheral T-cell lymphoma (PTCL). This study aimed to investigate the clinical outcomes of patients who received auto-HSCT or allo-HSCT in China. METHODS: From July 2007 to June 2017, a total of 128 patients who received auto-HSCT (n  = 72) or allo-HSCT (n  = 56) at eight medical centers across China were included in this study. We retrospectively collected their demographic and clinical data and compared the clinical outcomes between groups. RESULTS: Patients receiving allo-HSCT were more likely to be diagnosed with stage III or IV disease (95% vs. 82%, P = 0.027), bone marrow involvement (42% vs. 15%, P = 0.001), chemotherapy-resistant disease (41% vs. 8%, P = 0.001), and progression disease (32% vs. 4%, P < 0.001) at transplantation than those receiving auto-HSCT. With a median follow-up of 30 (2-143) months, 3-year overall survival (OS) and progression-free survival (PFS) in the auto-HSCT group were 70%(48/63) and 59%(42/63), respectively. Three-year OS and PFS for allo-HSCT recipients were 46%(27/54) and 44%(29/54), respectively. There was no difference in relapse rate (34%[17/63] in auto-HSCT vs. 29%[15/54] in allo-HSCT, P = 0.840). Three-year non-relapse mortality rate in auto-HSCT recipients was 6%(4/63) compared with 27%(14/54) for allo-HSCT recipients (P = 0.004). Subanalyses showed that patients with lower prognostic index scores for PTCL (PIT) who received auto-HSCT in an upfront setting had a better outcome than patients with higher PIT scores (3-year OS: 85% vs. 40%, P = 0.003). Patients with complete remission (CR) undergoing auto-HSCT had better survival (3-year OS: 88% vs. 48% in allo-HSCT, P = 0.008). For patients beyond CR, the outcome of patients who received allo-HSCT was similar to that in the atuo-HSCT group (3-year OS: 51% vs. 46%, P = 0.300). CONCLUSIONS: Our study provided real-world data about auto-HSCT and allo-HSCT in China. Auto-HSCT seemed to be associated with better survival for patients in good condition (lower PIT score and/or better disease control). For patients possessing unfavorable characteristics, the survival of patients receiving allo-HSCT group was similar to that in the auto-HSCT group.

Emergency Combination of Four Drugs for Bloodstream Infection Caused by Carbapenem-Resistant Enterobacteriaceae in Severe Agranulocytosis Patients with Hematologic Malignancies after Hematopoietic Stem Cell Transplantation.

Bloodstream infection (BSI) caused by multidrug-resistant (MDR) bacteria or extensively drug-resistant (XDR) bacteria is a global threat. However, an effective treatment regimen is still controversial and inadequate due to the rapid deterioration caused by the bacteria. In immunocompromised and neutropenic patients, MDR-BSI is an emergency, which causes treatment-related mortality. In this study, four agranulocytosis patients with hematologic malignancies after HSCT receiving treatment for carbapenem-resistant Enterobacteriaceae- (CRE-) BSI were included. Conventional treatment using two to three combined antibiotics was administered in the first and second patients. Combination treatment using four drugs, polymyxin B, high-dose tigecycline, fosfomycin, and double-dose carbapenem, was administered in the third and fourth patients. None of the patients receiving conventional treatment survived. Both patients receiving combination treatment using four drugs survived. Therefore, four-drug combination therapy may be needed in CRE-BSI patients who experienced severe agranulocytosis after HSCT. The efficacy of the four-drug combination treatment for CRE-BSI patients as well as the adverse effects need to be further studied.

Overall prevalence of human parvovirus B19 among blood donors in mainland China: A PRISMA-compliant meta-analysis.

BACKGROUND: Human parvovirus B19 (B19V) infection exhibits a broad range of clinical outcomes. Blood transfusion is a common route of B19V transmission. However, information about the overall prevalence of B19V infection and B19V genotypes among blood donors in mainland China is lacking. METHODS: This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search for studies reporting the B19V prevalence among blood donors in mainland China from 2000 to 2018 was performed. The prevalence of B19V was estimated through a meta-analysis of the relevant literature. A comprehensive meta-analysis program was used for data processing and statistical analysis. RESULTS: Twenty-one eligible articles were included, involving 48,923 participants assessed for B19V-DNA, 12,948 participants assessed for anti-B19V immunoglobulin M (IgM), and 8244 participants assessed for anti-B19V immunoglobulin G (IgG). The analysis revealed the pooled estimates of the prevalence rates of B19V-DNA, anti-B19V IgM, and anti-B19V IgG among blood donors to be 0.7% (95% confidence interval [CI] 0.2-2.4%), 2.7% (95% CI 1.7-4.3%), and 33.6% (95% CI 28.2-39.4%), respectively. Moreover, phylogenetic analyses indicated that 142 of 169 (84.0%) B19V isolates belonged to Genotype 1. CONCLUSIONS: The overall prevalence of B19V among blood donors is not high in mainland China, and most isolates belong to Genotype 1.

Unrelated cord blood transplantation versus haploidentical transplantation in adult and pediatric patients with hematological malignancies-A meta-analysis and systematic review.

Several clinical trials have compared the safety and efficacy of umbilical cord blood transplantation (UCBT) with haploidentical transplantation (HIT) in patients with hematological malignancies. To obtain more reliable evidence, we performed a systematic review and meta-analysis. Seven studies were included and there was a combined total of 102 children and 1311 adults undergoing UCBT, along with 94 children and 915 adults undergoing HIT. Pooled comparisons of studies of UCBT and HIT in children found that the incidence of chronic graft-versus-host disease (GVHD) and disease-free survival (DFS) at 2 years (RR 0.34, 95% CI (0.03, 4.53), P=0.41; HR 0.51, 95% CI (0.23, 1.09), P=0.08) were not statistically different. For adults, although the incidence of grade II-IV acute GVHD differ (RR 1.17, 95% CI (1.02, 1.34), P=0.02), but it indicates a very small difference between the groups as the RR is barely above 1. On the other hand, although the incidence of grade III-IV acute GVHD did not differ (RR 1.51, 95% CI (0.78, 2.92), P=0.22), but there is a tendency of higher risk for the UCBT. And the incidence of chronic GVHD did not differ (RR 1.05, 95% CI (0.82, 1.34), P=0.71). There was no difference in relapse, non-relapse mortality (NRM) and DFS at 2 years (HR 0.92, 95% CI (0.74, 1.13), P=0.42; HR 0.87, 95% CI (0.49, 1.52) P=0.62 and HR 0.74 95% CI (0.39, 1.43), P=0.37). In conclusion, UCBT and HIT could be considered as equally effective option for adult patients without HLA-matched donors.

Retrospective cohort study comparing the outcomes of intravenous busulfan vs. total-body irradiation after single cord blood transplantation.

Limited to inadequate stem-cell doses, cord blood transplantation (UCBT) is accompanied by increased graft failure and delayed haematopoietic recovery. The conditioning regimen is critically important for engraftment, and numerous trials have been undertaken comparing the outcomes of IV Bu and TBI, but there are no comparative data for UCBT. We conducted a retrospective multicentre study to analyse the outcomes of IV Bu and TBI in UCBT patients with haematologic malignancies. Between 1 May, 2008 and 31 Mar, 31 2018, a total of 331 patients from the China Umbilical Cord Blood Transplantation Corporation (IV Bu, n = 131; TBI, n = 200) were evaluated. The cumulative incidence of neutrophil engraftment was 91.6% in the IV Bu/Cy cohort and 98.0% in the Cy/TBI cohort (P < 0.001). The median times to neutrophil engraftment were 16 and 19 days (P < 0.001), respectively. Multivariate analysis showed no statistical difference for nonrelapse mortality (hazard ratio [HR], 1.11; 95% confidence interval [CI], 0.66 to 1.86; P = 0.695), relapse (HR, 0.90; 95% CI, 0.50 to 1.60; P = 0.713) and overall survival (HR, 0.94; 95% CI, 0.61 to 1.44; P = 0.763) between the two conditioning regimens. Our results show that both IV Bu and TBI are valid myeloablative conditioning regimens for haematologic malignancy patients treated with UCBT.

A Case of Acute Lymphocytic Leukaemia with t(3;13) and Central Nervous System Leukemia after Allogenic Cord Blood Transplantation.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is a neoplastic cancer characterized by clonal expansion of leukemic cells in lymph organs and bone marrow. Lots of kinds of different chromosomal translocations can be found in those leukemic cells. However, the role of abnormal chromosomes and genes in leukemogenesis is not yet fully understood. Identifying new chromosomal translocations can facilitate a better understanding of pathogenesis of this disease. CASE PRESENTATION: We report a rare case of acute lymphocytic leukaemia with t(3;13)(q29, q21). The patient was diagnosed pre-B-ALL with no abnormal chromosomal or gene fusion and achieved complete remission (CR) after induction chemotherapy; 10 months later, she relapsed in the consolidation, with cytogenetics tests showing 46, XX, t(3;13)(q29, q21). Given no CR after two chemotherapy regimens, the patient received salvage cord blood transplantation. Regular intrathecal methotrexate was applied to prevent central nervous system leukemia. Good graft versus leukemia was induced by daily injection of a low dose of IL-2 2 months post-transplantation. Minimal residual disease negativity was maintained until central nervous system (CNS) leukemia was found 8 months after transplantation. A whole exome sequencing was performed. Nine driver mutation genes and seven tumor genes were found. CONCLUSIONS: We highly suspect that the relapse in the CNS after transplantation is associated with a rare chromosomal translocation.

Efficacy and Safety of Eltrombopag for Aplastic Anemia: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: Eltrombopag seems to be effective in treating patients with aplastic anemia in several clinical trials. This paper aims to perform the first meta-analysis analyzing the efficacy and safety of eltrombopag for aplastic anemia. METHODS: Literatures were retrieved from PubMed, EMBASE, OVID, Web of Science, Cochrane, Wanfang, http://clinicaltrials.gov and World Health Organization International Clinical Trials Registry Platform search portal from establishment to July 2018. Using Stata statistical software version 12.0, subgroup analyses and sensitivity analyses were conducted. RESULTS: The overall hematologic response rate is 88% (95% CI 83-94%) for patients treated with eltrombopag plus immunosuppressive therapy, and 47% (95% CI 38-56%) for patients with refractory aplastic anemia using eltrombopag alone. Karyotype abnormality rates include an overall rate of 10% (95% CI 7-14%), a subtotal rate of 8% (95% CI 3-13%) for patients who are treated with eltrombopag plus immunosuppressive therapy without using antithymocyte globulin before, and a subtotal rate of 17% (95% CI 10-24%) for patients with refractory aplastic anemia treated with eltrombopag alone. CONCLUSIONS: With different treatments and in different conditions eltrombopag showed a distinctive effect for aplastic anemia. However, clone evolution and adverse events were associated with treatment.

Plerixafor and granulocyte-colony-stimulating factor for mobilization of hematopoietic stem cells for autologous transplantation in Chinese patients with non-Hodgkin's lymphoma: a randomized Phase 3 study.

BACKGROUND: This Phase 3 randomized, double-blind study evaluated the efficacy and safety of plerixafor plus granulocyte-colony-stimulating factor for the mobilization of hematopoietic stem cells in Chinese patients with non-Hodgkin's lymphoma. STUDY DESIGN AND METHODS: Adults (ages 18-75 years) with non-Hodgkin's lymphoma in first or second complete or partial remission, without previous hematopoietic stem cell mobilization or autologous transplant, were included. Patients received granulocyte-colony-stimulating factor 10 µg/kg/day from Days 1 through 4 before they were randomized (1:1) to receive either plerixafor 0.24 mg/kg/day or placebo subcutaneously on Days 4 through 7 plus continued granulocyte-colony-stimulating factor on Days 5 through 8. Apheresis began on Day 5 and continued for no more than 4 days. The primary endpoint was collection of 5 × 106 CD34+ cells/kg or greater over no more than 4 days of apheresis. Other endpoints included the collection of 2 × 106 CD34+ cells/kg or greater and safety. RESULTS: Overall, 101 patients were enrolled, and 50 were randomized to each group. More patients in the plerixafor group achieved 5 × 106 CD34+ cells/kg or greater (62 vs. 20%; p < 0.0001) or 2 × 106 CD34+ cells/kg or greater (88 vs. 66%) and underwent transplantation (88 vs. 68%) compared with those in the placebo group. The most common plerixafor-related adverse events were nausea (7.8%) and diarrhea (3.9%). CONCLUSION: Plerixafor plus granulocyte-colony-stimulating factor is superior to placebo plus granulocyte-colony-stimulating factor for the mobilization of CD34+ cells for autologous transplantation and is generally well tolerated in Chinese patients with non-Hodgkin's lymphoma.

Population pharmacokinetics analysis of intravenous busulfan in Chinese patients undergoing hematopoietic stem cell transplantation.

There are several reports describing population pharmacokinetic (popPK) models of busulfan (BU). However, limited information is available in Chinese hematopoietic stem cell transplantation (HSCT) patients. The present study aimed to establish a popPK model of intravenous BU in Chinese HSCT patients for individualized drug therapy. The popPK model of BU was developed from a total of 284 concentration-time points from 53 patients. The effects of demographic and biochemical covariates were investigated by nonlinear mixed effect model (NONMEM) software. Plots, visual predictive check (VPC), bootstrap and normalized prediction distribution error (NPDE) were performed to determine the stability and the reliability of the final model. A one-compartment model with first-order elimination process was confirmed as the final structural model for BU. For a typical patient whose body surface area (BSA) is 1.7 m2 , the population typical values of CL and Vd were 11.86 L/h, and 48.2 L, respectively. The result suggested BSA showed significant influence on CL and Vd (P<.001). Plots revealed the final model was performing a goodness fit. The steady rate verified by bootstrap was 100%, relative deviation was less than 4.00%, estimated value of final model was in the 95% confidence interval (CI). The VPC results showed the observed values were almost all positioned within the 5th and 95th CIs. The mean and variance of the NPDE were 0.0363 (Wilcoxon signed-rank test, 0.298) and 0.877 (Fisher variance test, 0.134; SW test of normality, 0.108), respectively. The global adjusted P value was 0.305, which indicated that the prediction of the BU popPK model was adequate. A physician-friendly Microsoft Excel-base tool was implemented using the final popPK model for designing individualized dosing regimens.

Chemosensitivity enhancement toward arsenic trioxide by inhibition of histone deacetylase in NB4 cell line.

OBJECTIVE: To investigate the cytotoxic effects of suberanilohydroxamic acid (vorinostat) in combination with arsenic trioxide (ATO) on the human NB4 cell line in vitro. METHODS: The rates of cell proliferation following treatment with vorinostat with or without ATO were measured. Flow cytometry of Annexin-V/propidium iodide double-stained cells was used to measure apoptosis. Acridine Orange and ethidium bromide staining was used to observe morphological changes characteristic of apoptosis. Western blot analysis was used to measure protein levels. RESULTS: Vorinostat and ATO, alone and in combination, inhibited the proliferation of NB4 cells in a time- and dose-dependent manner and the effect was additive. NB4 cells treated with vorinostat + ATO demonstrated greater levels of apoptosis compared with cells treated with either drug alone. Both vorinostat and ATO alone and in combination resulted in lower levels of promyelocytic leukaemia/retinoic acid receptor alpha fusion protein and increased levels of acetyl-histone H3 and acetyl-histone H4 proteins compared with controls. Vorinostat + ATO resulted in lower levels of Akt protein compared with either drug alone. CONCLUSION: The combination of vorinostat and ATO inhibited cell proliferation, induced apoptosis, and enhanced the chemosensitivity of NB4 cells. The mechanism might be associated with increasing histone acetylation levels as well as downregulation of the Akt signalling pathway.

MHC-mismatched mixed chimerism augments thymic regulatory T-cell production and prevents relapse of EAE in mice.

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system with demyelination, axon damage, and paralysis. Induction of mixed chimerism with allogeneic donors has been shown to not cause graft-versus-host disease (GVHD) in animal models and humans. We have reported that induction of MHC-mismatched mixed chimerism can cure autoimmunity in autoimmune NOD mice, but this approach has not yet been tested in animal models of MS, such as experimental autoimmune encephalomyelitis (EAE). Here, we report that MHC-mismatched mixed chimerism with C57BL/6 (H-2(b)) donor in SJL/J (H-2(s)) EAE recipients eliminates clinical symptoms and prevents relapse. This cure is demonstrated by not only disappearance of clinical signs but also reversal of autoimmunity; elimination of infiltrating T, B, and macrophage cells in the spinal cord; and regeneration of myelin sheath. The reversal of autoimmunity is associated with a marked reduction of autoreactivity of CD4(+) T cells and significant increase in the percentage of Foxp3(+) Treg among host-type CD4(+) T cells in the spleen and lymph nodes. The latter is associated with a marked reduction of the percentage of host-type CD4(+)CD8(+) thymocytes and an increase of Treg percentage among the CD4(+)CD8(+) and CD4(+)CD8(-) thymocytes. Thymectomy leads to loss of prevention of EAE relapse by induction of mixed chimerism, although there is a dramatic expansion of host-type Treg cells in the lymph nodes. These results indicate that induction of MHC-mismatched mixed chimerism can restore thymic negative selection of autoreactive CD4(+) T cells, augment production of Foxp3(+) Treg, and cure EAE.