Umbilical Cord Blood-derived Mesenchymal Stem Cells Ameliorate Graft-Versus-Host Disease Following Allogeneic Hematopoietic Stem Cell Transplantation through Multiple Immunoregulations

Summary： Although mesenchymal stem cells （MSCs） are increasingly used to treat graft-versus-host disease （GVHD）, their immune regulatory mechanism in the process is elusive. The present study aimed to investigate the curative effect of third-party umbilical cord blood-derived human MSCs （UCB-hMSCs） on GVHD patients after allogeneic hematopoietic stem cell transplantation （allo-HSCT） and their immune regulatory mechanism. Twenty-four refractory GVHD patients after allo-HSCT were treated with UCB-hMSCs. Immune cells including T lymphocyte subsets, NK ceils, Treg cells and dendritic cells （DCs） and cytokines including interleukin-17 （IL-17） and tumor necrosis factor-alpha （TNF-α） were monitored before and after MSCs transfusion. The results showed that the symptoms of GVHD were alleviated significantly without increased relapse of primary disease and transplant-related complications after MSCs transfusion. The number of CD3^＋, CD3＋CD4^＋ and CD3＋CD8^＋ cells decreased significantly, and that of NK cells remained unchanged, whereas the number of CD4^＋ and CD8^＋ Tregs increased and reached a peak at 4 weeks; the number of mature DCs, and the levels of TNF-α and IL-17 decreased and reached a trough at 2 weeks. It was concluded that MSCs ameliorate GVHD and spare GVL effect via immunoregulations.

Advantageous tactics with certain probiotics for the treatment of graft-versus-host-disease after hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation(HSCT)becomes a standard form of cellular therapy for patients with malignant diseases.HSCT is the first-choice of immunotherapy,although HSCT can be associated with many complications such as graft-versus-host disease(GVHD)which is a major cause of morbidity and mortality after allogeneic HSCT.It has been shown that certain gut microbiota could exert protective and/or regenerative immunomodulatory effects by the production of short-chain fatty acids(SCFAs)such as butyrate in the experimental models of GVHD after allogeneic HSCT.Loss of gut commensal bacteria which can produce SCFAs may worsen dysbiosis,increasing the risk of GVHD.Expression of G-protein coupled receptors such as GPR41 seems to be upre-gulated in the presence of commensal bacteria,which might be associated with the biology of regulatory T cells(Tregs).Treg cells are a suppressive subset of CD4 positive T lymphocytes implicated in the prevention of GVHD after allogeneic HSCT.Here,we discuss the current findings of the relationship between the modification of gut microbiota and the GVHD-related immunity,which suggested that tactics with certain probiotics for the beneficial symbiosis in gut-immune axis might lead to the elevation of safety in the allogeneic HSCT.

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 transplanta-tion 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 recipi-ents in the absence of aGVHD or with gradeⅠaGVHD before and after the transplantation. The lev-els 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.

Gut microbiome in allogeneic hematopoietic stem cell transplantation and specific changes associated with acute graft vs host disease

Allogeneic hematopoietic stem cell transplantation(aHSCT)is a standard validated therapy for patients suffering from malignant and nonmalignant hematological diseases.However,aHSCT procedures are limited by potentially life-threatening complications,and one of the most serious complications is acute graft-versus-host disease(GVHD).During the last decades,DNA sequencing technologies were used to investigate relationship between composition or function of the gut microbiome and disease states.Even if it remains unclear whether these microbiome alterations are causative or secondary to the presence of the disease,they may be useful for diagnosis,prevention and therapy in aHSCT recipients.Here,we summarized the most recent findings of the association between human gut microbiome changes and acute GVHD in patients receiving aHSCT.

OMISSION OF DAY +11 METHOTREXATE DOES NOT APPEAR TO INFLUENCE INCIDENCE AND SEVERITY OF GRAFT-VERSUS- HOST DISEASE AFTER ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION

Objective: To explore the influence of omission of the day +11 dose of methotrexate (MIX) on the incidence and severity of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods: From April 1997 to October 2002, 80 leukemia patients (46 men and 34 women aged from 12 to 56 years with a median age of 35) underwent allo-HSCT at our BMT unit. Among them, 58 patients received grafts from HLA-identical siblings, 8 from HLA one major antigen mismatched siblings and 14 from HLA-matched unrelated donors. All patients received a modified cyclosporine and short-course MTX regimen for GVHD prophylaxis, which included MTX 15 mg on day +1, and 10 mg on days +3 and +6 (MTX day +11 dose omitted) and cyclosporine given daily. Results: The overall incidence of grade I~IV acute GVHD was 57.5% (46/80 patients), with grade II~IV acute GVHD in 28 patients (35%) and grade III~IV acute GVHD in 7 patients (8.8%). Among 58 patients receiving grafts from HLA-identical siblings, 24 patients developed grade I~IV acute GVHD (41.4%), with grade II~IV acute GVHD in 13 patients (22.4%) and grade III~IV acute GVHD in 4 patients (6.9%). 2l out of 22 patients receiving grafts from HLA one major antigen mismatched siblings and HLA-matched unrelated donors developed grade I~IV acute GVHD (95.5%), with grade II~IV acute GVHD in 14 patients (63.6%) and grade III~IV acute GVHD in 3 patients (13.6%). Chronic GVHD occurred in 38 out of 56 evaluable patients (67.9%), with extensive form in 15 patients (26.8%) and limited form in 23 patients (41.1%). With a median follow-up of 960 days (range 180~1980 days), the probability of leukemia-free survival at 3 years was 61.3% for all patients. Conclusion: Our results suggest that the day +11 MTX can be omitted without a major deleterious effect on the incidence and severity of graft-versus-host disease after HLA-identical sibling transplantation as well as HLA one major antigen mismatched sibling and HLA-matched unrelated donor transplantation.

Ruxolitinib add-on in corticosteroid-refractory graft-vs-host disease after allogeneic stem cell transplantation:Results from a retrospective study on 38 Chinese patients

BACKGROUND Graft-vs-host disease (GVHD) is a major cause of mortality after allogeneic hematopoietic stem cell transplantation.Some patients have steroid-refractory(SR) GVHD.AIM To evaluate the effect and safety of ruxolitinib add-on in the treatment of patients with SR acute (a) and chronic (c) GVHD.METHODS We retrospectively analyzed 38 patients administered ruxolitinib add-on to standard immunosuppressive therapy for SR-aGVHD or SR-cGVHD following allogeneic hematopoietic stem cell transplantation.Ruxolitinib was administered5-10 mg/d depending on disease severity,patient status,and the use of antifungal drugs.Overall response rate,time to best response,malignancy relapse rate,infection rate,and treatment-related adverse events were assessed.RESULTS The analysis included 10 patients with SR-aGVHD (gradeⅢ/Ⅳ,n=9) and 28patients with SR-cGVHD (moderate/severe,n=24).For the SR-aGVHD and SRcGVHD groups,respectively:Median number of previous GVHD therapies was 2(range:1-3) and 2 (1-4);median follow-up was 2.5 (1.5-4) and 5 (1.5-10) mo;median time to best response was 1 (0.5-2.5) and 3 (1-9.5) mo;and overall response rate was 100%(complete response:80%) and 82.1%(complete response:10.7%) with a response observed in all GVHD-affected organs.The malignancy relapse rates for the SR-aGVHD and SR-cGVHD groups were 10.0%and 10.7%,respectively.Reactivation rates for cytomegalovirus,Epstein-Barr virus,and varicella-zoster virus,respectively,were 30.0%,10.0%,and 0%for the SR-aGVHD group and 0%,14.3%,and 7.1%for the SR-cGVHD group.CONCLUSION Ruxolitinib add-on was effective and safe as salvage therapy for SR-GVHD.

Endoscopic diagnosis of cytomegalovirus gastritis after allogeneic hematopoietic stem cell transplantation

AIM:To clarify the endoscopic and clinical findings of cytomegalovirus(CMV) gastritis after allogeneic hematopoietic stem cell transplantation(allo-SCT).METHODS:Between 1999 and 2005,523 patients underwent allo-SCT at our hospital,and 115 of these patients with gastrointestinal symptoms underwent esophagogastroduodenoscopy.RESULTS:CMV gastritis was diagnosed pathologically in seven patients(1.3%) with the other 108 patients serving as controls.Six of the seven patients developed positive CMV antigenemia,and five complained of abdominal pain.Development of abdominal pain preceded CMV antigenemia in four of the f ive patients.Endoscopic examination showed oozing(n=2),erosion(n=6),and redness(n=5) in the seven patients with CMV gastritis,while the control patients showed oozing(n=3),erosion(n=24),and redness(n=100).Erosion and oozing were more frequently documented in patients with CMV gastritis compared with the controls,and the differences were statistically significant(P=0.0012 and 0.029,respectively).CMV inclusion bodies were documented in 12 of 14 biopsy specimens obtained from erosive lesions,while they were identif ied in 4 of 15 biopsy specimens obtained from lesions other than erosions(P=0.0025).CONCLUSION:This study suggests that erosion and oozing,as well as abdominal pain,are useful indicators in the diagnosis of CMV gastritis following allo-SCT.

Clinical approach to diarrheal disorders in allogeneic hematopoietic stem cell transplant recipients

Diarrhea is a common complication of allogeneic hematopoietic stem cell transplant(HSCT), with an average incidence of approximately 40%-50%. A wide variety of etiologies can contribute to diarrhea in HSCT patients, including medication-induced mucosal inflammation, infections, graft-vs-host disease and cord colitis syndrome in umbilical cord blood transplant. Clinical manifestations can vary from isolated diarrheal episodes, to other organ involvement including pneumonia or myocarditis, and rarely multiorgan failure. The approach for diagnosis of diarrheal disorders in HSCT patients depends on the most likely cause. Given the risk of life-threatening conditions, the development of clinically significant diarrhea requires prompt evaluation, supportive care and specific therapy, as indicated. Serious metabolic and nutritional disturbances can happen in HSCT patients, and may even lead to mortality. In this review, we aim to provide a practical approach to diagnosis and management of diarrhea in the post-transplant period.

Profiles of interferon-gamma and interleukin-2 in patients after allogeneic hematopoietic stem cell transplantation

BACKGROUND Allogeneic hematopoietic stem cell transplantation(allo-HSCT)may be related to the occurrence of complications,including graft-versus-host disease(GvHD)and infections.The pathogenesis of acute GvHD is connected with T lymphocytes,which identify alloantigens on host's antigen-presenting cells,activate production of interferon-gamma(IFN-gamma)and interleukin-2(IL-2),and act on the immune effector cells and damage tissues and organs.AIM The aim of the study was to investigate and distinguish serum concentration profiles of IFN-gamma and IL-2 within a 30-d period after allo-HSCT.METHODS We enrolled 62 patients,i.e.,30(48%)male and 32(52%)female subjects[median age 49.5(19-68)years],after allo-HSCT from siblings(n=12)or unrelated donors(n=50)due to acute myeloid leukemia with myeloablative conditioning(n=26;42%)and with non-myeloablative conditioning(n=36;58%).All patients were given standard immunosuppressive therapy with cyclosporin-A and methotrexate and pre-transplant antithymocyte globulin in the unrelated setting.Blood samples were collected pre-transplant before and after(on day-1)the conditioning therapy and on days+2,+4,+6,+10,+20,and+30 after allo-HSCT.Serum levels of IL-2 and IFNgamma were determined using ELISA.RESULTS Patients were divided into four groups depending on the presence of acute GvHD and clinical manifestations of infection.Group I included patients with neither acute GvHD nor infections[n=15(24%)],group II consisted of patients with infections without acute GvHD[n=17(27%)],group III was comprised of patients with acute GvHD without infections[n=9(15%)],and group IV included patients with both acute GvHD and infections[n=21(34%)].IFN-gamma concentrations were higher in Group II than in other groups on days+20(P=0.014)and+30(P=0.008).Post-hoc tests showed lower concentrations of IFN-gamma on day+30 in groups I(P=0.039)and IV(P=0.017)compared to group II.The levels of IL-2 were mostly undetectable.CONCLUSION Serum levels of IFN-gamma following allo-HSCT progressively escalate.High serum levels of IFN-gamma are related to infectious complications rather than acute GvHD.Serum concentrations of IL-2 in most patients are undetectable.

TLR4 inactivation protects from graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Graft-versus-host disease （GVHD） is the most common complication after hematopoietic stem cell transplantation. To clarify the role of Toll-like receptor 4 （TLR4）, which is a major receptor for bacterial lipopolysaccharides （LPS）, in the development of acute GVHD, we used a TLR4-knockout （TLR4-/-） mouse GVHD model and analyzed the underlying immunological mechanisms. When TLR4-/- mice were used as bone marrow and splenocyte cell graft donors or recipients, GVHD symptom occurrence and mortality were delayed compared to wild-type （TLR4＋/＋） mice. In addition, histopathological analyses revealed that in TLR4-/-→BALB/c chimeras, liver and small intestine tissue damage was reduced with minimal lymphocytic infiltration. In contrast to TLR4＋/＋, TLR4-/- mice dendritic cells did not express CD80, CD86, CD40, MHC-II or IL-12 during LPS induction and remained in an immature state. Furthermore, the ability of TLR4-/- mice spleen dendritic cells to promote allogeneic T-cell proliferation and, in particular, T-helper cell 1 （Th 1） development was obviously attenuated compared with TLR4＋/＋ mice dendritic cells, and the levels of interferon-T （IFN-γ） and IL-IO, Th2-cell specific cytokines, were significantly higher in the serum of TLR4-/-→BALB/c than in TLR4＋/＋→BALB/c chimeric mice. Overall, our data revealed that TLR4 may play a role in the pathogenesis of GVHD and that targeted TLR4 gene therapy might provide a new treatment approach to reduce the risk of GVHD.

Ex vivo expansion of regulatory T cells for clinical applications against graft-versus-host disease in allogeneic hematopoietic stem cell transplantation

Objective To review the characteristics of regulatory T cells （Tregs） and ex vivo expansion of Tregs for treatment of graftversus-host disease （GVHD）.Data sources The data used in this review were retrieved from PubMed （1970-2013）.The terms ＂ex vivo expansion＂,＂regulatory T cell＂,and ＂graft-versus-host disease＂ were used for literature search.Study selection The publications about the characteristics of Tregs,ex vivo expansion of Tregs and clinical applications of Tregs against GVHD were identified,retrieved and reviewed.Results Tregs can be classified as natural Tregs （nTregs） and induced Tregs （iTregs）.Both subsets share most Treg features.Given their immunosuppressive property,Tregs have been tested for their capability of preventing GVHD.The bottleneck of Treg therapy is the limited numbers of naturally existing Tregs.To solve this problem,ex vivo expansion of nTregs or iTregs has been executed.The initial data indicate Treg therapy is effective in reducing GVHD without compromising graft-versus-leukemia （GVL）.Conclusion Ex vivo expansion of Tregs is a reliable way to prepare sufficient number of Tregs for management of GVHD.

Chinese Medicine Treatment on Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Graft-versus-host disease(GVHD)is the most common complication after allogeneic hematopoietic stem cell transplantation,and also an important factor affecting the survival and quality of life in patients after transplantation.Currently,immunosuppressive therapy is commonly used for GVHD,but the curative effect is not ideal.How to effectively prevent and treat GVHD is one of the difficulties to be solved urgently in the field of transplantation.In this paper,we summarize the latest progress in pathogenesis,prevention and treatment of GVHD with Chinese medicine(CM).We hope it will provide ideas and methods for exploring the mechanism and establishing a new comprehensive therapy for GVHD with CM.

Endoscopic diagnosis of gastrointestinal graft-versus-host disease

AIM:To evaluate the diagnostic value of endoscopy in patients with gastrointestinal graft-versus-host disease (GI GVHD). METHODS:We identified 8 patients with GI GVHD following allogeneic hematopoietic stem cell trans-plantation (HSCT). GVHD was defined histologically as the presence of gland apoptosis, not explained by other inflammatory or infectious etiologies. RESULTS:The symptoms of GI GVHD included anorexia, nausea, vomiting, watery diarrhea, abdominal pain, GI bleeding, etc. Upper endoscopic appearance varied from subtle mucosal edema, hyperemia, erythema to obvious erosion. Colonoscopic examination showed diffuse edema, hyperemia, patchy erosion, scattered ulcer, sloughing and active bleeding. Histological changes in GI GVHD included apoptosis of crypt epithelial cells, dropout of crypts, and lymphocytic infiltration in epithelium and lamina propria. The involvement of stomach and rectocolon varied from diffuse to focal. CONCLUSION:Endoscopy may play a significant role in early diagnosis of GI GVHD patients following allogeneic HSCT, and histologic examination of gastrointestinal biopsies is needed to confirm the final diagnosis.

Hemorrhagic cystitis following hematopoietic stem cell transplantation:incidence,risk factors and association with CMV reactivation and graft-versus-host disease

Background The definite pathogenesis of hemorrhagic cystitis （HC） after allogenic hematopoietic stem cell transplantation （allo-HSCT） has not been well elucidated. The role of cytomegalovirus （CMV） reactivation and graft-versus-host disease （GVHD） in the development of HC remains obscure. This study determined the incidence and risk factors for HC after alIo-HSCT and analyzed its association with CMV reactivation and GVHD. Methods We retrospectively studied 250 patients at high risk for CMV disease who underwent alIo-HSCT all based on busulfan/cyclophosphamide （BU/CY） myloablative regimens. The incidence, etiology, risk factors and clinical management of HC were investigated. Results HC developed within 180 days of transplant in 72 patients, with an overall incidence of 28.8% and an incidence of 12.6% in patients with HLA-matched related donors （MRD）, 34.38% in those with HLA-matched unrelated donors （MUD）, 49.45% in those with mismatched related donors （MMRD）. CMV-viremia significantly increased the incidence of later onset HC （LOHC）; however, only 9 out of 15 patients with CMV viruria actually developed LOHC. Multiple regression analysis identified grade II-IV acute GVHD （RR=2.75; 95% CI 1.63-4.66; P〈0.01） and grafts from MUD or MMRD （RR=2.60; 95% CI 1.52-5.20; P〈0.01） as independent risk factors for HC. Event sequence analysis indicated a majority of HC episodes began around GVHD initiation. Conclusions CMV-viremia is a high risk factor for LOHC. Our data also showed a correlation between acute GVHD and HC, which suggested that alloimmunity may be involved in the pathogenesis of HC.

Single-cell immune landscape of measurable residual disease in acute myeloid leukemia

Measurable residual disease(MRD)is a powerful prognostic factor of relapse in acute myeloid leukemia(AML).We applied the single-cell RNA sequencing to bone marrow(BM)samples from patients with(n=20)and without(n=12)MRD after allogeneic hematopoietic stem cell transplantation.A comprehensive immune landscape with 184,231 cells was created.Compared with CD8+T cells enriched in the MRDnegative group(MRD‒_CD8),those enriched in the MRD-positive group(MRD+_CD8)showed lower expression levels of cytotoxicity-related genes.Three monocyte clusters(i.e.,MRD+_M)and three B-cell clusters(i.e.,MRD+_B)were enriched in the MRD-positive group.Conversion from an MRD-positive state to an MRD-negative state was accompanied by an increase in MRD‒_CD8 clusters and vice versa.MRDenriched cell clusters employed the macrophage migration inhibitory factor pathway to regulate MRD‒_CD8 clusters.These findings revealed the characteristics of the immune cell landscape in MRD positivity,which will allow for a better understanding of the immune mechanisms for MRD conversion.

Current assessment and management of measurable residual disease in patients with acute lymphoblastic leukemia in the setting of CAR-T-cell therapy

Chimeric antigen receptor(CAR)-modified T-cell therapy has achieved remarkable success in the treatment of acute lymphoblastic leukemia(ALL).Measurable/minimal residual disease(MRD)monitoring plays a significant role in the prognostication and management of patients undergoing CAR-T-cell therapy.Common MRD detection methods include flow cytometry(FCM),polymerase chain reaction(PCR),and next-generation sequencing(NGS),and each method has advantages and limitations.It has been well documented that MRD positivity predicts a poor prognosis and even disease relapse.Thus,how to perform prognostic evaluations,stratify risk based on MRD status,and apply MRD monitoring to guide individual therapeutic decisions have important implications in clinical practice.This review assesses the common and novel MRD assessment methods.In addition,we emphasize the critical role of MRD as a prognostic biomarker and summarize the latest studies regarding MRD-directed combination therapy with CAR-T-cell therapy and allogeneic hematopoietic stem cell transplantation(allo-HSCT),as well as other therapeutic strategies to improve treatment effect.Furthermore,this review discusses current challenges and strategies for MRD detection in the setting of disease relapse after targeted therapy.

Effect and mechanism of acute graft versus host disease on early diffuse murine lung injury following allogeneic stem cell transplantation

To explore the effect and pathogenssis of acute graft-versus-host disease (aGVHD) on early diffuse lung injury in allogeneic hematopoietic stem cell transplantation (allo-HSCT), we established an aGVHD model of C57BL/6→BALB/c mice. Chest computed tomography (CT) scans, histopathology and the levels of cytokines including tumor necrosis factor α (TNFα) and Interferon (IFNγ) in lungs were dynamically detected in recipient mice after transplantation. The incidence of aGVHD was respectively 0%, 0% and 100% in simple irradiation group (A), syngeneic transplant group(B) and allogeneic transplant group (C). Chest CT scans of recipient mice were normal in 3 groups on days +3 and +7 after transplantation. CT showed that two of ten mice had bilateral lung diffuse infiltrate on day +12 (on the brink of death) in group A and 6 of 10 mice had bilateral lung diffuse infiltrate on day +14 (3 d after aGVHD occurring) in group C, and were normal on days +12 and +14 in group B after transplantation. Histopathology of lungs in the 3 groups was similar, consisting of minor interstitial pneumonitis on day +3. Group A showed edema, hyperplasia of epithelial cells and widened alveolar interval on day +7, and epithelial cell necrosis, lymphocyte infiltration, hemorrhage, protein leakage, and local consolidation on day +12. The histopathology of group B showed slight edema of epithelial cells on +7 day, which were slighter than that on day +3, and virtually normal on day +14. The histopathology in group C was characterized by the significant expansion and congestion of capillaries, and lymphocyte infiltration on day +7, the acute pneumonitis was present involving tissue edema, lymphocyte and macrophage infiltration, protein leakage and perivascular inflammation on day +14. In group A, the levels of TNFα were lower on day +7 than on day +3. In group B, the levels of TNFα attained a peak on day +3, which decreased on days +7 and +14. In group C, the levels of TNFα were highest on day +7 and there was a significant difference between those on days +7 and +14 (P=0.816). In group A, the levels of IFNγ on day +7 were higher than on day +3. In group B, the levels of IFNγ increased progressively, but the comparison of IFNγ levels in different times had no statistical significance (P=0.521, 0.118, 0.340). In group C, the levels of IFNγ attained a peak by day +7 and decreased on day +14. aGVHD is the main cause of early non-infectious lung injury. T lymphocytes and TNFα are possibly implicated in the pathogenesis of acute GVHD-induced lung injury. The decreased levels of IFNγ in lung tissues following transplantation might be associated with pulmonary fibrosis in late non-infectious pulmonary complications.

Clinical and serological characterization of autoimmune hemolytic anemia after allogeneic hematopoietic stem cell transplantation

Background Autoimmune hemolytic anemia （AIHA） is an uncommon complication of allogeneic hematopoietic stem cell transplantation （allo-HSCT） which has only been reported in a few cases.We here aimed to explore its mechanism.Methods We retrospectively analyzed 296 patients who underwent allo-HSCT in our center from July 2010 to July 2012.Clinical manifestations were carefully reviewed and the response to currently available treatment approaches were evaluated.The survival and risk factors of AIHA patients after allo-HSCT were further analyzed.Results Twelve patients were diagnosed with AIHA at a median time of 100 days （15-720 days） after allo-HSCT.The incidence of AIHA after allo-HSCT was 4.1％.IgG antibody were detected in ten patients and IgM antibody in two patients.The two cold antibody AIHA patients had a better response to steroid corticoid only treatment and the ten warm antibody AIHA patients responded to corticosteroid treatment and adjustment of immunosuppressant therapy.Rituximab was shown to be effective for AIHA patients who failed conventional therapy.Survival analysis showed that the combination of AIHA in allo-HSCT patients hinted at poor survival.Cytomegalovirus （CMV） infection,graft-versus-host disease （GVHD） and histocompatibility leukocyte antigen （HLA） mismatch seemed to increase the risk of developing AIHA.Conclusions Patients who develop AIHA after allo-HSCT have poor survival compared to non-AIHA patients.Possible risk factors of AIHA are CMV infection,GVHD,and HLA mismatch.Rituximab is likely to be the effective treatment choice for the refractory patients.

Risk factors for bronchiolitis obliterans syndrome in allogeneic hematopoietic stem cell transplantation

Background The occurrence of bronchiolitis obliterans syndrome （BOS） after allogeneic hematopoietic stem cell transplantation （alIo-HSCT） is rare but severe. We examine the role of pre-HSCT chemotherapeutic exposure, pre-HSCT comorbidities, and transplant-related complications in the development of BOS after alIo-HSCT. Methods A nested case-control study was designed. Cases with BOS and controls matched for the year of alIo-HSCT and length of the follow-up were identified from a cohort of 1646 patients who underwent alIo-HSCT for treatment of hematologic malignancies between 2006 and 2011. Antithymocyte globulin was used in the partial matched related and unrelated matched donor HSCT, or patients with severe aplastic anemia. Results Thirty-six patients suffered from BOS; the mean age at the time of presentation was （32.7±2.4） years, and the mean time to presentation was （474±350） days post-HSCT. A pre-HSCT cyclophosphamide dose of 〉3.2 g/m2 （OR=8.74, P=0.025）, chronic graft-versus-host disease （moderate to severe） （OR=12.02, P=0.000）, and conditioning regimens without antithymocyte globulin （OR=2.79, P=0.031） were independently associated with BOS. Conclusions We found that higher pre-HSCT cyclophosphamide exposure, a conditioning regimen without antithymocyte globulin, and moderate to severe chronic graft-versus-host disease are significantly and independently associated with BOS. Based on these results, we can identify patients who are at a higher risk of developing BOS after alIo-HSCT, select a more appropriate therapeutic strategy, and improve the outcome of HSCT recipients.

人类白细胞抗原相合同胞新鲜脐血移植治疗儿童β重型地中海贫血

背景:异基因造血干细胞移植是目前根治重型地中海贫血最有效的方法,然而仅有不到一半的患者能找到相合的骨髓或外周血干细胞。同胞来源脐血干细胞与骨髓和外周血干细胞具有不同的特征,是重型地中海贫血患者移植治疗的一种潜在造血干细胞替代来源。目的:探讨应用人类白细胞抗原相合同胞新鲜脐血移植治疗儿童β重型地中海贫血的疗效。方法:选择2010年6月至2020年6月南方医科大学南方医院收治的β重型地中海贫血患儿48例,男28例,女20例,中位年龄4岁,均接受人类白细胞抗原相合同胞新鲜脐血移植治疗,脐血移植前均采用清髓性不含抗胸腺细胞球蛋白的预处理方案,脐血移植后均采用环孢素A+吗替麦考酚酯+/-短程甲氨蝶呤预防移植物抗宿主病。结果与结论:(1)48例患儿输注的总有核细胞中位数为8.17×10^(7)/kg,输注的CD34^(+)细胞中位数为2.40×10^(5)/kg,脐血移植后中位随访时间98个月,44例植入成功,粒细胞和血小板植入中位时间分别为28 d和31 d,其中37例移植后植入证据检测为供者型完全嵌合,7例移植后早期检测为供受者稳定混合嵌合;(2)44例植入成功患儿中,4例发生急性移植物抗宿主病,分别为Ⅰ级(n=2)和Ⅱ级(n=2),受累器官均为皮肤,均未发生慢性移植物抗宿主病;(3)脐血移植后,48例患儿中5例发生巨细胞病毒感染及激活,12例发生败血症,3例发生侵袭性真菌病,21例发生口腔炎,8例发生出血性膀胱炎,1例发生肝静脉闭塞;(4)48例患儿中,47例存活,1例在移植后28 d因重症肺炎合并急性心力衰竭死亡,43例无病存活,3例发生原发性植入失败,1例发生移植后全血细胞减少,5年总生存率和无病生存率分别为98%和89%,1年时移植相关死亡的累计发病率为2.1%;(5)结果显示,人类白细胞抗原相合同胞新鲜脐血移植治疗儿童β重型地中海贫血的效果良好,移植物抗宿主病的发生风险低。