Mammalian target of rapamycin inhibitors permit regulatory T cell reconstitution and inhibit experimental chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) remains a major late complication of allogeneic bone marrow transplantation (BMT). In a previous study, impaired thymic negative selection of the recipients permitted the emergence of pathogenic T cells that cause chronic GVHD using MHC class II-deficient (H2-Ab1 KO) B6 into C3H model and CD4(+) T cells isolated from chronic GVHD mice caused chronic GVHD when administered into the secondary recipients. In this study, we evaluated the kinetics of regulatory T cell (Treg) reconstitution in wild type B6 into C3H model. After myeloablative conditioning, host Tregs disappeared rapidly, followed by expansion of Tregs derived from the donor splenic T cell inoculum. However, the donor splenic T cell-derived Treg pool contracted gradually and was almost completely replaced by newly generated donor bone marrow (BM)-derived Tregs in the late post-transplantation period. Next, we compared the effects of cyclosporine (CSA) and mammalian target of rapamycin (mTOR) inhibitors on Treg reconstitution. Administration of CSA significantly impaired Treg reconstitution in the spleen and thymus. In contrast, BM-derived Treg reconstitution was not impaired in mTOR inhibitor-treated mice. Histopathological examination indicated that mice treated with CSA, but not mTOR inhibitors, showed pathogenic features of chronic GVHD on day 120. Mice treated with CSA until day 60, but not mTOR inhibitors, developed severe chronic GVHD followed by adoptive transfer of the pathogenic CD4(+) T cells isolated from H2-Ab1 KO into C3H model. These findings indicated that long-term use of CSA impairs reconstitution of BM-derived Tregs and increases the liability to chronic GVHD. The choice of immunosuppression, such as calcineurin inhibitor-free GVHD prophylaxis with mTOR inhibitor, may have important implications for the control of chronic GVHD after BMT.

Synthetic retinoid Am80 ameliorates chronic graft-versus-host disease by down-regulating Th1 and Th17.

Chronic GVHD (cGVHD) is a main cause of late death and morbidity after allogeneic hematopoietic cell transplantation, but its pathogenesis remains unclear. We investigated the roles of Th subsets in cGVHD with the use of a well-defined mouse model of cGVHD. In this model, development of cGVHD was associated with up-regulated Th1, Th2, and Th17 responses. Th1 and Th2 responses were up-regulated early after BM transplantation, followed by a subsequent up-regulation of Th17 cells. Significantly greater numbers of Th17 cells were infiltrated in the lung and liver from allogeneic recipients than those from syngeneic recipients. We then evaluated the roles of Th1 and Th17 in cGVHD with the use of IFN-γ-deficient and IL-17-deficient mice as donors. Infusion of IFN-γ(-/-) or IL-17(-/-) T cells attenuated cGVHD in the skin and salivary glands. Am80, a potent synthetic retinoid, regulated both Th1 and Th17 responses as well as TGF-ß expression in the skin, resulting in an attenuation of cutaneous cGVHD. These results suggest that Th1 and Th17 contribute to the development of cGVHD and that targeting Th1 and Th17 may therefore represent a promising therapeutic strategy for preventing and treating cGVHD.

The effect of adding rituximab to CHOP-based therapy on clinical outcomes for Japanese patients with diffuse large B-cell lymphoma: a propensity score matching analysis.

We conducted a retrospective analysis to evaluate the impact on clinical outcomes of adding rituximab to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) treatment for diffuse large B-cell lymphoma (DLBCL) patients in Japan. A propensity score method was used to compensate for the non-randomized study design. From January 2000 to December 2004, 378 patients who were newly diagnosed with DLBCL at 13 institutes were enrolled: 123 in the rituximab plus CHOP-based chemotherapy (R+) group, and 255 in the CHOP-based chemotherapy only (R-) group. The complete response rate was significantly higher in the R+ group than in the R- group (77.7 vs. 69.4%, P < 0.001). The progression-free survival (PFS) at 2 years was 62.4% in the R+ group and 57.0% in the R- group. The 2-year overall survival (OS) was 76.9% for the R+ group and 70.5% for the R- group. A multivariate analysis revealed that the addition of rituximab was a strong independent prognostic factor for PFS (hazard ratio 0.64, 95% CI 0.43-0.96, P = 0.031). A subgroup analysis revealed that R+ particularly benefited younger patients (hazard ratio 0.25, 95% CI 0.08-0.75, P = 0.013). IPI also showed significant impact for PFS (hazard ratio 1.82, 95% CI 1.55-2.14 for one score increase, P < 0.001) as well as OS (hazard ratio 2.10, 95% CI 1.71-2.57, P < 0.001). In summary, the addition of rituximab to CHOP-based chemotherapy results in better outcomes for Japanese DLBCL patients, particularly younger patients.

Febrile neutropenia and periodontitis: lessons from a case periodontal treatment in the intervals between chemotherapy cycles for leukemia reduced febrile neutropenia.

GOALS OF WORK: Oral and systemic infections arising from the oral cavity are significant problems in clinical management of patients undergoing leukemia treatment. However, there is significant disparity in the reported incidences of development of periodontal infections. Evidence is limited to those showing the systemic influence of periodontal infection in neutropenic patients. This study indicated an association between febrile neutropenia (FN) and periodontitis in a case in which periodontal treatment in the intervals between chemotherapy cycles reduced FN in subsequent courses of chemotherapy and hematopoietic transplantation (HCT). MATERIALS AND METHODS: Periodontal treatment was performed in a 61-year-old man with advanced periodontitis, who received HCT following three cycles of chemotherapy. After recovery from neutropenia induced by initial chemotherapy, periodontal treatment was performed in each chemotherapy interval period. Following extraction of teeth with severe advanced periodontitis, all teeth were subjected to periodontal pocket curettage and root planning, which are common periodontal treatments to reduce periodontal pockets harboring anaerobic periodontal bacteria, before HCT. MAIN RESULTS: Periodontal treatment successfully reduced periodontal pockets from 4.1 +/- 1.5 mm to 3.0 +/- 0.6 mm, which was almost within the healthy range (<3.0 mm), before HCT. The frequency of FN decreased significantly with increasing cycles of chemotherapy, and decreases in FN corresponded to progress of periodontal treatment. Blood cultures obtained a total of 12 times throughout leukemia treatment were all negative. CONCLUSIONS: The observations reported here indicate the importance of periodontal treatment in clinical management of patients undergoing leukemia treatment to prevent FN, although all blood cultures were negative.

Adult T-cell leukemia in a liver transplant recipient that did not progress after onset of graft rejection.

A liver allograft recipient developed acute-type adult T-cell leukemia (ATL) during tacrolimus treatment, 2 years after undergoing transplantation for subacute fulminant hepatitis. Both donor and recipient were asymptomatic carriers of human T-cell lymphotropic virus type I (HTLV-I), but the ATL cells originated from the recipient. Tacrolimus treatment was discontinued, and combination chemotherapy was administered. The patient achieved complete remission, but the transplanted liver was acutely and chronically rejected. The patient did not respond to rescue therapy with tacrolimus, prednisolone, and mycophenolate mofetil and died of hepatic failure. Liver biopsies showed CD4+ ATL cell infiltration at the onset of ATL but not at the terminal stage. Moreover, Southern blotting revealed clonal integration of HTLV-I into the host genome of lymphoma cells at onset but not at the terminal stage. ATL after liver transplantation has not been previously described. The clinical course of the posttransplantational ATL was atypical, because it did not progress after the onset of rejection.