Mucus-degrading Bacteroides link carbapenems to aggravated graft-versus-host disease.

The intestinal microbiota is an important modulator of graft-versus-host disease (GVHD), which often complicates allogeneic hematopoietic stem cell transplantation (allo-HSCT). Broad-spectrum antibiotics such as carbapenems increase the risk for intestinal GVHD, but mechanisms are not well understood. In this study, we found that treatment with meropenem, a commonly used carbapenem, aggravates colonic GVHD in mice via the expansion of Bacteroides thetaiotaomicron (BT). BT has a broad ability to degrade dietary polysaccharides and host mucin glycans. BT in meropenem-treated allogeneic mice demonstrated upregulated expression of enzymes involved in the degradation of mucin glycans. These mice also had thinning of the colonic mucus layer and decreased levels of xylose in colonic luminal contents. Interestingly, oral xylose supplementation significantly prevented thinning of the colonic mucus layer in meropenem-treated mice. Specific nutritional supplementation strategies, including xylose supplementation, may combat antibiotic-mediated microbiome injury to reduce the risk for intestinal GVHD in allo-HSCT patients.

GVHD targets organoid-forming bile duct stem cells via a TGF-ß-dependent manner.

Graft-versus-host disease (GVHD) is a major life-threatening complication that occurs after allogeneic hematopoietic cell transplantation (HCT). While adult tissue stem cells have been identified as targets of GVHD in the skin and gut, their role in hepatic GVHD is yet to be clarified. In the current study, we explored the fate of bile duct stem cells (BDSCs), capable of generating liver organoids in vitro, during hepatic GVHD after allogeneic HCT. We observed a significant expansion of biliary epithelial cells (BECs) upon injury early after allogeneic HCT. Organoid-forming efficiency from the bile duct was also significantly increased early after allogeneic HCT. Subsequently, the organoid-forming efficiency from bile ducts was markedly decreased in association with the reduction of BECs and the elevation of plasma concentrations of bilirubin, suggesting that GVHD targets BDSCs and impairs the resilience of BECs. The growth of liver organoids in the presence of liver-infiltrating mononuclear cells from allogeneic recipients, but not from syngeneic recipients, significantly reduced in a TGF--dependent manner. Administration of SB-431542, an inhibitor of TGF-ß signaling, from day 14 to day 28 protected organoid-forming BDSCs against GVHD and mitigated biliary dysfunction after allogeneic HCT, suggesting that BDSCs are a promising therapeutic target for hepatic GVHD.

Engineering T cells to suppress acute GVHD and leukemia relapse after allogeneic hematopoietic stem cell transplantation.

Acute graft-versus-host disease (aGVHD) limits the therapeutic benefit of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and requires immunosuppressive prophylaxis that compromises antitumor and antipathogen immunity. OX40 is a costimulatory receptor upregulated on circulating T cells in aGVHD and plays a central role in driving the expansion of alloreactive T cells. Here, we show that OX40 is also upregulated on T cells infiltrating GVHD target organs in a rhesus macaque model, supporting the hypothesis that targeted ablation of OX40+ T cells will mitigate GVHD pathogenesis. We thus created an OX40-specific cytotoxic receptor that, when expressed on human T cells, enables selective elimination of OX40+ T cells. Because OX40 is primarily upregulated on CD4+ T cells upon activation, engineered OX40-specific T cells mediated potent cytotoxicity against activated CD4+ T cells and suppressed alloreactive T-cell expansion in a mixed lymphocyte reaction model. OX40 targeting did not inhibit antiviral activity of memory T cells specific to Epstein-Barr virus, cytomegalovirus, and adenoviral antigens. Systemic administration of OX40-targeting T cells fully protected mice from fatal xenogeneic GVHD mediated by human peripheral blood mononuclear cells. Furthermore, combining OX40 targeting with a leukemia-specific chimeric antigen receptor in a single T cell product provides simultaneous protection against leukemia and aGVHD in a mouse xenograft model of residual disease posttransplant. These results underscore the central role of OX40+ T cells in mediating aGVHD pathogenesis and support the feasibility of a bifunctional engineered T-cell product derived from the stem cell donor to suppress both disease relapse and aGVHD following allo-HSCT.

Reactive granulopoiesis depends on T-cell production of IL-17A and neutropenia-associated alteration of gut microbiota.

Granulopoiesis in the bone marrow adjusts cellular output as demand for neutrophils changes. Reactive granulopoiesis is induced by profound neutropenia, but its mechanism remains to be clarified. We herein explored its mechanisms using mouse models of syngeneic hematopoietic stem cell transplantation (SCT) and 5-fluorouracil-induced neutropenia. After SCT, T cell production of IL-17A was up-regulated. Neutrophil recovery was significantly delayed in IL-17A-deficient or T cell-deficient RAG1-/- mice, and adoptive transfer of wild-type (WT) T cells facilitated neutrophil engraftment. Gut decontamination with oral antibiotics suppressed T cell production of IL-17A and impaired neutrophil recovery. Transplantation of fecal microbiota collected from neutropenic, not naive, mice promoted neutrophil recovery in these mice, suggesting that neutropenia-associated microbiota had a potential to stimulate reactive granulopoiesis. Our study uncovered a cross talk between gut microbiota and neutropenia after SCT and chemotherapy.

[Emergence of mutation in the colony-stimulating factor 3 receptor gene during follow-up of unclassifiable myeloproliferative neoplasm].

A 25-year-old male with a medical history of stress polycythemia was admitted to a previous hospital for leukocytosis, anemia, and thrombocytopenia. Bone marrow examination revealed left-shifted myeloid hyperplasia without increased blasts and normal male karyotype. No mutations of JAK2, V617F, and colony-stimulating factor 3 receptor gene (CSF3R) were detected. Fluorescence in-situ hybridization for BCR-ABL1 and FIP1L1-PDGFRA were negative. Based on these findings, a diagnosis of an unclassifiable myeloproliferative neoplasm was made, and he was started on hydroxyurea treatment. He was referred to our hospital in April 2016 for transfusion dependence. Bone marrow examination performed at our hospital revealed granulocytic dysplasia and CSF3R T618I was detected. After induction therapy, CSF3R T618I became undetectable, and he went on to undergo allogeneic stem cell transplantation in October 2016. He has been in remission for >4 years posttransplantation. CSF3R T618I is one of the genes responsible for chronic neutrophilic leukemia and atypical chronic myeloid leukemia, suggesting its involvement in the pathogenesis of this case.

Vitamin A-coupled liposomes containing siRNA against HSP47 ameliorate skin fibrosis in chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (SCT) is characterized by multiorgan fibrosis and profoundly affects the quality of life of transplant survivors. Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, plays a critical role in collagen synthesis in myofibroblasts. We explored the role of HSP47 in the fibrotic process of cutaneous chronic GVHD in mice. Immunohistochemical analysis showed massive fibrosis with elevated amounts of collagen deposits and accumulation of F4/80+ macrophages, as well as myofibroblasts expressing HSP47 and retinol-binding protein 1 in the skin after allogeneic SCT. Repeated injection of anti-colony-stimulating factor (CSF-1) receptor-blocking antibodies significantly reduced HSP47+ myofibroblasts in the skin, indicating a macrophage-dependent accumulation of myofibroblasts. Vitamin A-coupled liposomes carrying HSP47 small interfering RNA (siRNA) (VA-lip HSP47) delivered HSP47 siRNA to cells expressing vitamin A receptors and knocked down their HSP47 in vitro. Intravenously injected VA-lip HSP47 were specifically distributed to skin fibrotic lesions and did not affect collagen synthesis in healthy skin. VA-lip HSP47 knocked down HSP47 expression in myofibroblasts and significantly reduced collagen deposition without inducing systemic immunosuppression. It also abrogated fibrosis in the salivary glands. These results highlight a cascade of fibrosis in chronic GVHD; macrophage production of transforming growth factor ß mediates fibroblast differentiation to HSP47+ myofibroblasts that produce collagen. VA-lip HSP47 represent a novel strategy to modulate fibrosis in chronic GVHD by targeting HSP47+ myofibroblasts without inducing immunosuppression.

Ruxolitinib protects skin stem cells and maintains skin homeostasis in murine graft-versus-host disease.

Graft-versus-host disease (GVHD) is the major complication after allogeneic stem cell transplantation (SCT). Emerging evidence indicates that GVHD leads to injury of intestinal stem cells. However, it remains to be investigated whether skin stem cells could be targeted in skin GVHD. Lgr5+ hair follicle stem cells (HFSCs) contribute to folliculogenesis and have a multipotent capacity to regenerate all epithelial cells in repair. We studied the fate of Lgr5+ HFSCs after SCT and explored the novel treatment to protect Lgr5+ HFSCs against GVHD using murine models of SCT. We found that GVHD reduced Lgr5+ HFSCs in association with impaired hair regeneration and wound healing in the skin after SCT. Topical corticosteroids, a standard of care for a wide range of skin disorders including GVHD, damaged HFSCs and failed to improve skin homeostasis, despite of their anti-inflammatory effects. In contrast, JAK1/2 inhibitor ruxolitinib significantly ameliorated skin GVHD, protected Lgr5+ HFSCs, and restored hair regeneration and wound healing after SCT. We, for the first time, found that GVHD targets Lgr5+ HFSCs and that topical ruxolitinib represents a novel strategy to protect skin stem cells and maintain skin homeostasis in GVHD.

Myeloid differentiation factor 88 signaling in donor T cells accelerates graft-versus-host disease.

Myeloid differentiation factor 88 (MyD88) signaling has a crucial role in activation of both innate and adoptive immunity. MyD88 transduces signals via Toll-like receptor and interleukin-1 receptor superfamily to the NFκB pathway and inflammasome by forming a molecular complex with interleukin-1 receptor-associated kinase 4. The MyD88/interleukin-1 receptor-associated kinase 4 pathway plays an important role, not only in innate immunity, but also T-cell immunity; however, its role in donor T cells on the pathophysiology of graft-versus-host disease (GvHD) remains to be elucidated. We addressed this issue by using MyD88-deficient T cells in a mouse model of allogeneic hematopoietic stem cell transplantation (allo-SCT). While MyD88-deficient and wild-type T cells proliferated equivalently after transplantation, MyD88-deficient T cells demonstrated impaired survival and differentiation toward Th1, Tc1, and Th17, and induced less severe GvHD compared to wild-type T cells. Administration of interleukin-1 receptor-associated kinase 4 inhibitor PF-06650833 significantly ameliorated GvHD after allo-SCT. These results thus demonstrate that donor T-cell MyD88/interleukin-1 receptor-associated kinase 4 pathway is a novel therapeutic target against GvHD after allo-SCT.

Histological and magnified endoscopic evaluation of villous atrophy in gastrointestinal graft-versus-host disease.

AIM:  To measure histological villous atrophy and to clarify the diagnostic accuracy of endoscopic villous atrophy in gastrointestinal graft-versus-host disease. METHODS:  Data for patients who underwent upper and/or lower endoscopic examinations after hematopoietic stem cell transplantation were retrospectively collected. In study 1, group A included 56 patients in whom GI-GVHD was histologically confirmed and group B included 60 patients in whom GI-GVHD was not histologically confirmed. Group C included 59 patients before HSCT. The lengths of villi and crypts in the duodenum and terminal ileum were histologically measured. In study 2, the diagnostic accuracies of villous atrophy of the duodenum and of the terminal ileum using magnifying endoscopy were evaluated. RESULTS:  In study 1, the lengths of villi and the villi/crypt (V/C) ratios of the duodenum and terminal ileum in group A were significantly smaller than those in the other groups (p < 0.05). V/C ratio was moderately correlated with clinical severity, histological grades, and endoscopic grades in the terminal ileum. In study 2, the diagnostic accuracies of magnified images for villous atrophy were 83.8% in the duodenum and 94.9% in the terminal ileum. CONCLUSION:  Magnifying endoscopy enables evaluation of villous atrophy and is useful for optical biopsy of GVHD.

Feasibility and efficacy of low-dose pegfilgrastim for CD34+ cell mobilization in lymphoma.

BACKGROUND: Pegfilgrastim has equivalent efficacy to daily granulocyte colony-stimulating factor (G-CSF) in enhancing neutrophil recovery after chemotherapy, but data on its use for peripheral blood stem cell (PBSC) mobilization are limited. We evaluated the safety and efficacy of CD34+ PBSC mobilization by low-dose (3.6 mg) pegfilgrastim after chemotherapy in patients with malignant lymphoma. STUDY DESIGN AND METHODS: Twenty patients with malignant lymphoma were enrolled in this study. Cytotoxic chemotherapy was started on day 1, and 3.6 mg of pegfilgrastim was subcutaneously administered on day 7. CD34+ cells were counted in the peripheral blood daily from days 11 to 14 using a flow cytometric analysis. RESULTS: In 19 of the 20 patients (95%), the CD34+ cell counts in the peripheral blood exceeded 10 × 106/L, with a mean value of 20.3 on day 11, 38.0 on day 12, 40.3 on day 13, and 40.1 on day 14. Older age was associated with lower maximum CD34+ cell mobilization. The most frequent adverse events associated with pegfilgrastim were back pain, nausea, appetite loss, and lactate dehydrogenase elevation. CONCLUSION: Our data indicated that a single dose of 3.6 mg pegfilgrastim on day 7 after chemotherapy safely and effectively mobilized CD34+ cells.

Novel Ultrasonographic Scoring System of Sinusoidal Obstruction Syndrome after Hematopoietic Stem Cell Transplantation.

Sinusoidal obstruction syndrome (SOS)/hepatic veno-occlusive disease (VOD) is a well-documented complication after hematopoietic stem cell transplantation (HSCT). Transabdominal ultrasonography (US) enables the visualization of blood flow abnormalities and is therefore useful for the diagnosis of SOS/VOD. We herein prospectively evaluated accuracy of a novel US diagnostic scoring system of SOS/VOD based on US findings. We carried out US in 106 patients on day 14 and when SOS/VOD was suspected after allogeneic HSCT. Among 106 patients, 10 patients (9.4%) were diagnosed as SOS/VOD by Baltimore or Seattle criteria. According to univariate analysis of 17 US findings (US-17 screening), we established a novel scoring system (HokUS-10) consisting of 10 parameters, such as gallbladder wall thickening, ascites, and blood flow signal in the paraumbilical vein. The sensitivity and specificity were 100% and 95.8%, respectively. Diagnostic performance of the HokUS-10 was significantly better than US-17 screening. In 4 of 10 patients US detection of SOS/VOD preceded to clinical diagnosis. The HokUS-10 scoring system is useful in the diagnosis of SOS/VOD; however, our results should be validated in other cohorts.

Hematogones Predict Better Outcome in Allogeneic Hematopoietic Stem Cell Transplantation Irrespective of Graft Sources.

Benign precursors of B lymphocytes, termed hematogones, are observed in the regenerative state of hematopoiesis following chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT). Previous studies have demonstrated that expansion of hematogones correlates with better clinical outcomes after allo-HSCT. We retrospectively analyzed the association between hematogones and clinical outcomes in 309 consecutive patients who underwent allo-HSCT, which is the largest population-based cohort reported so far. The incidence of hematogones was significantly higher in complete remission (CR) patients at the time of transplantation than in non-CR patients, after myeloablative conditioning than after reduced-intensity conditioning, with tacrolimus-based graft-versus-host disease (GVHD) prophylaxis than with cyclosporine-based prophylaxis, and with disease other than malignant lymphoma (all P < .05). Patients with hematogones developed less acute GVHD and infections than did those without them (P < .05). Emergence of hematogones was associated with superior GVHD-free relapse-free survival and lower nonrelapse mortality, and was an independent prognostic factor for overall survival, irrespective of donor sources.

Cecum ulcer is a reliable endoscopic finding in cytomegalovirus colitis concomitant with graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Although graft-versus-host disease (GVHD) is the major complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT), cytomegalovirus (CMV) reactivation also occurs in patients after allo-HSCT and these conditions often clinically overlap. The aim of this study was to determine reliable endoscopic findings of CMV colitis in patients with gastrointestinal graft-versus-host-disease (GI-GVHD). Patients after allo-HSCT who were histologically confirmed to have GI-GVHD with or without CMV colitis and patients with an immunosuppressive condition were retrospectively analyzed. We divided the patients into three groups: GI-GVHD with CMV colitis (group A), GI-GVHD without CMV colitis (group B), and CMV colitis without undergoing allo-HSCT (group C). From medical records, the involved colorectal areas and endoscopic findings according to the groups were compared. A total of 70 patients were divided into three groups (group A: n = 19, group B: n = 28, group C: n = 23). Mucosal injuries in groups A and C frequently occurred in the cecum including ileocecal valves. On the other hand, there were no abnormal lesions on ileocecal valves in group B. Furthermore, ulcer lesions were more frequently observed in groups A and C than in group B (p < 0.001). The sensitivity and specificity of mucosal injuries in the cecum for prediction of CMV colitis were 89.5 and 76.5%, respectively, and mucosal injuries in the cecum were more reliable findings than CMV antigenemia. Ulcer lesions in the cecum are reliable endoscopic findings for CMV colitis in patients with GI-GVHD after allo-HSCT.

The association between the incidence of intestinal graft-vs-host disease and antibiotic use after allogeneic hematopoietic stem cell transplantation.

Intestinal microbiota plays an important role in the regulation of allogeneic immune reaction after allogeneic hematopoietic stem cell transplantation (allo-SCT). Intestinal graft-vs-host disease (GVHD) is one of the major causes of mortality after allo-SCT and often complicated with intestinal dysbiosis. Recent studies suggest that antibiotic-induced dysbiosis is a risk factor for intestinal GVHD. We retrospectively evaluated the impacts of antibiotic use on the incidence of intestinal GVHD occurring before day 100 after allo-SCT. Among 213 patients who underwent allo-SCT, 200 patients achieving engraftment were analyzed. Antibiotics were classified into carbapenem, quinolone, penicillin, cephem, and glycopeptide. Among 128 patients who developed acute GVHD, intestinal GVHD developed in 36 patients. Patients with intestinal GVHD received significantly longer administration of carbapenem and glycopeptide compared to those without it in periengraftment period. In multivariate analysis, use of carbapenem for greater than 7 days was associated with an increased risk of intestinal GVHD. However, use of antibiotics for greater than 7 days was not associated with poor overall survival and high nonrelapse mortality. Long use of carbapenem in periengraftment period may be a risk for intestinal GVHD. Prospective studies are required to validate our findings.

α-Mannan induces Th17-mediated pulmonary graft-versus-host disease in mice.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative therapy for various hematopoietic disorders. Graft-versus-host disease (GVHD) and infections are the major obstacles of HSCT, and their close relationship has been suggested. Although roles of bacterial and viral infections in the pathophysiology of GVHD are well described, impacts of fungal infection on GVHD remain to be elucidated. In mouse models of GVHD, injection of α-mannan (Mn), a major component of fungal cell wall, or heat-killed Candida albicans exacerbated GVHD, particularly in the lung. Mn-induced donor T-cell polarization toward Th17 and lung-specific chemokine environment in GVHD led to accumulation of Th17 cells in the lung. The detrimental effects of Mn on GVHD depended on donor IL-17A production and host C-type lectin receptor Dectin-2. These results suggest a previously unrecognized link between pulmonary GVHD and fungal infection after allogeneic HSCT.

[Disruption of gut immune system caused by damage of intestinal stem cells and their niche in graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.]

Allogeneic hematopoietic stem cell transplantation(allo-SCT)is curative therapy for various hematological diseases. Graft-versus-host disease(GVHD)and infection remain the main problems in allo-SCT. Gastrointestinal tract is targeted by GVHD. In intestinal GVHD, intestinal stem cells and Paneth cells reside at the base of crypts are damaged by donor T cells. These damage leads to disruption of intestinal mucosal barrier and intestinal dysbiosis, resulting in more exaggerated GVHD. Recently, we and others have reported that R-Spondin1 and interleukin-22 as factors regenerated intestinal tissue homeostasis in murine model of bone marrow transplantation. It is important to understand biology of various cells targeted by intestinal GVHD and develop novel methods to protect them from GVHD damage.

Primary Bone Lymphoma: A Clinical Analysis of 17 Patients in a Single Institution.

Primary bone lymphoma (PBL) comprises less than 1% of all malignant lymphomas. Because few studies of PBL have been conducted in Japan, the characteristics of Japanese patients with PBL have not been fully elucidated. We retrospectively analyzed 17 patients diagnosed with PBL at our institution between 2001 and 2011. Median patient age was 60 years. Eleven patients had diffuse large B-cell lymphoma and 2 patients had T-cell lymphoma histology. The spine was the most frequently involved site at the time of presentation. There were 11 patients with stage IV disease and 11 patients with high or high-intermediate risk according to the International Prognostic Index (IPI). Thirteen patients achieved complete response (CR) after initial treatment. At a median follow-up of 31 months, the 3-year overall survival (OS) and progression free survival were 63.5 and 49.9%, respectively. Localized disease, low or low-intermediate IPI, and CR after initial treatment were associated with a good outcome in patients with PBL and significantly associated with a better OS. Spine involvement and T/NK-cell phenotype are more frequent in Japanese than in Caucasian patients with PBL.

[Posterior reversible encephalopathy syndrome following paralytic ileus caused by vincristine in a patient with T cell lymphoblastic lymphoma].

A 22-year-old woman presented with high fever, chest tightness and cough in January 20XX. Since CT scans revealed an anterior mediastinal mass, percutaneous needle biopsies of the mass were performed and she was diagnosed with T-cell lymphoblastic lymphoma (T-LBL). After the immunophenotype of lymphocytes in her pleural effusion had been identified, she received CHOP therapy because her dyspnea worsened, and induction therapy for acute lymphoblastic leukemia was subsequently performed after confirmation of her diagnosis as T-LBL. During this induction therapy, she developed paralytic ileus. One week thereafter, she suddenly exhibited visual disturbance, headache and nausea. Her cerebrospinal fluid was normal. Magnetic resonance imaging showed symmetrical high signal intensities on T2-weighted and fluid-attenuated inversion recovery images, and low signal intensities on T1-weighted images in the cortical and subcortical white matter of the posterior parietal and occipital lobes. Based on these findings, she was diagnosed as having posterior reversible encephalopathy syndrome (PRES). During chemotherapy for hematologic malignancies, some patients with PRES reportedly develop paralytic ileus or tumor lysis syndrome. PRES should be considered in patients with neurological abnormalities following such complications during chemotherapy.

R-Spondin1 protects gastric stem cells and mitigates gastric GVHD in allogeneic hematopoietic stem cell transplantation.

ABSTRACT: Graft-versus-host disease (GVHD) is the major obstacle to performing allogeneic hematopoietic cell transplantation (allo-HCT). We and others have shown that intestinal stem cells are targeted in lower gastrointestinal GVHD. A leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5)-expressing gastric stem cells (GSCs) reside at the base of the gastric glands in mice. After experimental allo-HCT, Lgr5+ GSCs significantly decreased. Parietal cells, which underwent continuous renewal by GSCs, were injured in gastric GVHD, leading to failure of gastric acidification and aerobic bacterial overgrowth in the duodenum. Fate-mapping analysis demonstrated that administration of R-Spondin1 (R-Spo1) that binds to Lgr5 for 6 days in naïve mice significantly increased proliferating epithelial cells derived from Lgr5+ GSCs. R-Spo1 administered on days -3 to -1 and from days +1 to +3 of allo-HCT protected GSCs, leading to amelioration of gastric GVHD and restoration of gastric acidification, and suppression of aerobic bacterial overgrowth in the duodenum. In conclusion, Lgr5+ GSCs were targeted by gastric GVHD, resulting in disruption of the gastric homeostasis, whereas R-Spo1 protected Lgr5+ GSCs from GVHD and maintained homeostasis in the stomach.