Hiroyuki Ohigashi

Hepatitis B virus reactivation with a rituximab-containing regimen

Rituximab is currently used not only in the treatment of B-cell lymphoma but also for various other diseases, including autoimmune diseases, post-transplant graft vs host disease, and rejection following kidney transplants. Due to rituximabs widespread use, great progress has been made regarding research into complications that arise from its use, one of the most serious being the reactivation of hepatitis B virus (HBV), and efforts continue to establish guidelines for preventive treatment against this occurrence. This report discusses preventive measures against rituximab-induced HBV reactivation and future objectives.

R-Spondin1 expands Paneth cells and prevents dysbiosis induced by graft-versus-host disease

The intestinal microbial ecosystem is actively regulated by Paneth cell–derived antimicrobial peptides such as &agr;-defensins. Various disorders, including graft-versus-host disease (GVHD), disrupt Paneth cell functions, resulting in unfavorably altered intestinal microbiota (dysbiosis), which further accelerates the underlying diseases. Current strategies to restore the gut ecosystem are bacteriotherapy such as fecal microbiota transplantation and probiotics, and no physiological approach has been developed so far. In this study, we demonstrate a novel approach to restore gut microbial ecology by Wnt agonist R-Spondin1 (R-Spo1) or recombinant &agr;-defensin in mice. R-Spo1 stimulates intestinal stem cells to differentiate to Paneth cells and enhances luminal secretion of &agr;-defensins. Administration of R-Spo1 or recombinant &agr;-defensin prevents GVHD-mediated dysbiosis, thus representing a novel and physiological approach at modifying the gut ecosystem to restore intestinal homeostasis and host–microbiota cross talk toward therapeutic benefits.

5-Azacytidine partially restores CD20 expression in follicular lymphoma that lost CD20 expression after rituximab treatment: a case report

BackgroundThe loss of CD20 protein expression after a rituximab-containing regimen is one of the resistance mechanisms in non-Hodgkins lymphoma. Recently, it was reported that 5-azacitidine administration upregulates the expression of CD20 in CD20-negative B-cell acute lymphoblastic leukemia. Here we report a similar upregulation in a patient with follicular lymphoma who was treated with 5-azacitidine against secondary myelodysplastic syndrome.Case presentationA 69-year-old Japanese woman with follicular lymphoma with treatment-related myelodysplastic syndrome was negative for the CD20 antibody at the time of her relapse. After treatment of 5-azacytidine for her myelodysplastic syndrome, CD20 expression was upregulated in the follicular lymphoma cells in her peripheral blood. We also observed follicular lymphoma cell stimulation in her peripheral blood due to 5-azacytidine.ConclusionsAlthough partial, CD20 expression was upregulated after treatment with 5-azacitidine. However, CD20 expression was not re-upregulated after a second administration of 5-azacitidine and we also observed the risk of lymphoma cell stimulation due to 5-azacitidine.

Sustained CD4 and CD8 lymphopenia after rituximab maintenance therapy following bendamustine and rituximab combination therapy for lymphoma.

Bendamustine (B), which was initially synthesized around 50 years ago in the former East Germany, has become an important drug in combination with rituximab (R) (BR therapy) in the treatment of B-cell lymphoma [1]. One major side effect of B is CD4 lymphopenia. R is another key drug for the treatment of B-cell lymphoma. Since a recent study suggested that B-cell depletion by R also impairs the survival of memory T cells [2], R therapy might further enhance CD4 lymphopenia mediated by B. In this study, we investigated the effects of R maintenance therapy on CD4 and CD8 lymphopenia following BR therapy in patients with relapsed or refractory indolent B-cell lymphoma or mantle cell lymphoma. This study is a retrospective analysis of data from patients with relapsed/refractory indolent lymphoma or mantle cell lymphoma who were treated with BR from January 2011 to March 2013. It was approved by the Hakodate Municipal Hospital Institutional Review Board. All patients gave written informed consent according to the Declaration of Helsinki. Patients were treated with R (375 mg/m2 on day 1) and B (90 mg/m2 on days 2 and 3) every 28 days for 4–6 courses. The treatment response was determined 1 month after the last BR course. R maintenance therapy (375 mg/m2) was administered every 2–3 months. The CD4 and CD8 counts were analyzed after each cycle of chemotherapy and once every 1–3 months thereafter. The therapeutic effect was evaluated based on the Revised International Workshop Criteria [3]. Progression-free survival (PFS) was calculated from the date of initiation of treatment to the date of disease progression or last follow-up. The overall survival (OS) rate was calculated from the date of initiation of treatment to the date of death for any reason or the last date of evaluation. These were estimated using the Kaplan–Meier method, and the survival curves were compared by log-rank test. We analyzed the corrected independent data by means of the Mann–Whitney U-test with StatMate V (ATMS Co., Ltd., Tokyo, Japan). Thirty patients were enrolled for this analysis. Diseases were follicular lymphoma in 19 patients, mantle cell lymphoma in four patients, mucosa associated lymphoid tissue (MALT) lymphoma in three patients, small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) in two patients, plasmablastic lymphoma in one patient and macrogloblinemia in one patient. All patients had a history of prior treatments mostly with R-CHOP (R, cyclophosphamide, doxorubicin, vincristine, prednisone) or R-CHOP like chemotherapies. All 30 patients were treated with BR therapy, followed by R maintenance therapy. Twenty-two patients remained on R maintenance therapy for a median of 24 months, while the remaining eight were off R after a median 7 months of maintenance. Varicella zoster virus infection developed in seven patients, hepatitis B virus (HBV) reactivation developed in two patients and infection complications developed in 12. One patient developed fatal sepsis, and another developed fatal Fournier gangrene during R maintenance; three patients died due to disease progression. The OS rate was 77.7% at 45 months, and PFS was 59% at 45 months in this analysis. Figure 1(a) shows the course of the CD4 counts. Day 0 was 1 month after the completion of BR therapy in patients on R maintenance and 1 month after the completion of R maintenance in those off R maintenance. There were no significant differences in CD4 counts at the onset of treatment (p  0.45). CD4 lymphopenia was sustained, and the CD4 levels were lower in patients on R maintenance therapy than in those off maintenance treatment, although the difference was not statistically significant. CD8 cell counts also tended to be lower in the on-maintenance group than in off-maintenance treatment, although again the difference was not statistically significant [Figure 1(b)]. The reduction of CD4 cell counts is one adverse effect of B [4,5]. Our study also demonstrated CD4 lymphopenia after BR therapy, which reached its lowest level 6 months after

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.

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 β 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.

Late onset toxic epidermal necrolysis induced by mogamulizumab, an anti-CC chemokine receptor 4 antibody for the treatment of adult T-cell leukaemia/lymphoma.

To the Editor Adult T-cell leukaemia/lymphoma (ATLL) is a rare type of highly aggressive peripheral T-cell malignancy induced by infection with human T-cell leukaemia virus type 1 (HTLV-1) [1]. Acute and lymphoma types of ATLL particularly display an aggressive clinical course with a poor outcome because of the resistance to conventional combination chemotherapies [2]. Mogamulizumab (MOG), a defucosylated humanized monoclonal antibody targeting CC chemokine receptor 4 (CCR4), has recently been launched for treatment of ATLL; almost all ATLL cells express CCR4 [3]. On the other hand, skin rashes have been reported as significant adverse effects of MOG [3]. It is often difficult to distinguish between a skin lesion caused by MOG and an ATLL lesion, and the detail characteristics, clinical course and treatment are still unclear, particularly in severe events including Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Here, we report a case of TEN induced by MOG for the treatment of ATLL, which developed at a very late phase after the last infusion of MOG. A 77-year-old man was introduced to our hospital for general fatigue, palpitation and abnormal lymphocytes in peripheral blood. He was diagnosed as having acute type of ATLL by flow cytometry analysis and detection of HTLV-1 antibody. He received low-dose etoposide as an initial treatment; however, lung infiltration of ATLL cells was demonstrated by bronchoalveolar lavage and transbronchial lung biopsy 7months after diagnosis. Because combination chemotherapies were considered to be a high risk for his general condition, MOG monotherapy was started for 8months. Detail clinical course of the patient following the treatment of MOG was shown in Figure 1. At the initial infusion of MOG, an infusion reaction was diagnosed for the rapid development of respiratory failure, hyperthermia and systemic skin rash. Three courses of MOG monotherapy were given in combination with a steroid, and MOG was then discontinued owing to a grade 4 adverse effect of thrombocytopenia. He achieved complete remission in both peripheral blood and lung lesions after the therapy. Serum soluble interleukin-2 receptor levels were also significantly decreased from 6290 to 1190U/ml.

Intestinal Lymphatic Endothelial Cells Produce R-Spondin3

The R-Spondin (R-Spo) family regulates WNT signaling and stimulates the proliferation and differentiation of intestinal stem cells (ISCs). R-Spo plays a critical role in maintaining intestinal homeostasis, but endogenous producers of R-Spo in the intestine remain to be investigated. We found that R-Spo3 was the major R-Spo family member produced in the intestine and it was predominantly produced by CD45−CD90+CD31+ lymphatic endothelial cells (LECs) in the lamina propria of the intestinal mucosa. Transcriptome analysis demonstrated that LECs highly expressed R-Spo receptor, Lgr5, suggesting an autocrine stimulatory loop in LECs. LECs were significantly reduced in number, and their R-Spo3 production was impaired in intestinal graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. The impaired production of R-Spo3 in the intestine may be a novel mechanism of delayed tissue repair and defective mucosal defense in intestinal GVHD. We demonstrate a novel role of intestinal LECs in producing R-Spondin3 to maintain intestinal homeostasis.