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Graft Vs. Host Disease (graft + vs._host_disease)
Selected AbstractsQuantitative assessment of WT1 gene expression after allogeneic stem cell transplantation is a useful tool for monitoring minimal residual disease in acute myeloid leukemiaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2009Anna Candoni Abstract Introduction:,WT1 overexpression is described in several oncological diseases including acute myeloid leukemia (AML). Quantification of WT1 in bone marrow samples may be useful as a marker of minimal residual disease (MRD) and may predict the relapse of AML after allogeneic hematopoietic stem cell transplant (HSCT). Methods and results:, The quantitative expression of WT1 was measured in 38 AML patients (16 males and 22 females) at diagnosis, at the time of transplant and after the allogeneic HSCT (at precise time points). All cases showed high WT1 expression levels at diagnosis with a mean of 4189 (SD 3325) and a median of 3495 (range 454,13923) copies WT1/104Abl. At transplant, 25 patients (66%) were in complete cytologic remission (CcR) and 13 (34%) had refractory or relapsed AML. Bone marrow samples from patients transplanted in CcR showed significantly lower WT1 expression levels during HSCT compared with the samples from patients with a relapsed or refractory AML (P = 0.004). After HSCT, a rapid decline in WT1 expression levels was observed in all patients who attained or maintained a condition of CcR. Six of 38 patients (13%) relapsed after HSCT and all of them had an increase in WT1 expression at/or before relapse. Five of these six patients died of leukemia and one was successfully reinduced with donor lymphocyte infusion (DLI) + chemotherapy with a rapid reduction of WT1 levels. Besides, we found a complete concordance between WT1 expression levels and other disease markers (when available). Conclusions:, In our experience, there was a complete concordance between WT1 expression levels (measured by quantitative RT-PCR at precise time points) and status of AML before and after allogeneic HSCT. WT1 may be useful as a non-specific leukemia marker for monitoring MRD and as a predictor of AML clinical relapse. Based on these results, cases with increase of WT1 levels after HSCT and without graft vs. host disease may be candidate to discontinuation of immunosuppression and/or DLI therapy. [source] Parvovirus B19 infection as trigger of graft vs. host diseaseEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2008Gerhard Behre No abstract is available for this article. [source] Activated NKT cells increase dendritic cell migration and enhance CD8+ T cell responses in the skinEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2006Anton Abstract Activated NKT cells produce cytokines such as IL-4 and IFN-, that function locally to influence the strength and functional development of antigen-specific T cells. Here we identify an alternative mechanism by which NKT cells influence the strength of T cell responses: through modulation of peripheral dendritic cell (DC) trafficking. NKT cell activation with ,-galactosylceramide induced high systemic levels of TNF-, that mediated increased DC migration from skin to draining lymph nodes. This increased DC trafficking led to a threefold increase in effector T cell priming and in the immune response elicited to antigen challenge when ,-galactosylceramide was given at the time of immunization of the skin. These studies provide important implications for the use of NKT cell activation strategies to manipulate T cell-mediated responses including responses to cutaneous tumors and graft vs. host disease. [source] Lichenoid nail changes as sole external manifestation of graft vs. host diseaseINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2002Sara Isabel Palencia MD A 56-year-old-man who had refractory anemia with an excess of blasts underwent an allogeneic peripheral blood stem cell transplantation (PBSCT) from his brother after preparation with melphalan and fludarabin. He received GvHD (graft-vs.-host disease) prophylaxis with cyclosporine from day ,1 at a daily dose of 5 mg/kg of body weight. The daily dosage was tapered gradually from day +20. On post-PBSCT day 68 he developed acute cutaneous GvHD grade 3 and acute gastrointestinal GvHD grade 2,3, which was resolved with a daily dose of 1 mg/kg of body weight of prednisone. The patient was discharged in good clinical condition and without signs of GvHD, and he started tapering his immunosuppressive treatment. By day 160 he developed oral lichen planus-like changes, with several reticulate white lesions on the oral mucosa. A biopsy specimen was microscopically consistent with lichenoid GvHD (Fig. 1). By day 150 after PBSCT, when he was being treated with CsA 100 mg once daily and prednisone 10 mg once daily, his fingernails started to grow abnormally and gradually became dystrophic and painful. Two months later his toenails became similarly affected. Although affecting all finger and toe nails, the lesions were especially important in both thumbs. Physical examination revealed multiple findings on his nails (Fig. 2): thickening, fragility, onycholysis, longitudinal striations, and even pterygium. The micological cultures were negative. A biopsy specimen showed an sparse papillary dermis lymphoid infiltrate with focal exocytosis and presence of isolated multiple necrotic keratinocytes (Fig. 3). These findings were interpreted as a lichenoid GvHD with oral and nail involvement. The patient did not have other associated cutaneous lesions. He did not develop signs or symptoms consistent with hepatic GvHD. In May 2000 thalidomide was added to the immunosuppressive therapy, at a daily dose from 100 to 300 mg according to tolerance (constipation, sedation, ,). The lesions on the oral mucous showed a substantial improvement, but the nail changes remained more or less stable. Thalidomide was discontinued after 7 months because the patient displayed numbness and tingling in the hands and feet consistent with a peripheral neuropathy. Twenty days later he stopped taking thalidomide and the oral lichenoid lesions worsened, resulting in difficulty in eating. He also developed periungueal erythema, swelling and intense pain after minimal trauma. The daily dose of prednisone increased to 20,30 mg with moderate improvement. However, the dose could not be increased because of the secondary immunosuppressive effects. Twenty-three months post-PBSCT the patient remains with intense oral and nail lichenoid lesions. Figure Figure 1 . Oral mucosa with a lichenoid hiperplasia and a band-like lymphoid infiltrate. Note the basal lymphocytosis with isolated necrotic keratinocytes Figure 2. Lichenoid graft-vs.-host disease showing marked nail involvement with a ridge in the midline Figure 3. Panoramic view of the nail epithelium. Dermal lymphocytes with basal exocytosis and apoptotic keratinocytes (arrow) are evident [source] Population pharmacokinetics of mycophenolic acid in children and young people undergoing blood or marrow and solid organ transplantationBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 4 2010Lihua Zeng WHAT IS ALREADY KNOWN ABOUT THIS PROJECT? , Mycophenolate mofetil (MMF) is an immunosuppressant drug used for the treatment and prevention of graft vs. host disease in blood or marrow transplantation and acute graft rejection in solid organ transplantation. , Mycophenolic acid (MPA) pharmacokinetics have not been thoroughly studied in paediatric blood or marrow transplant recipients and guidance for optimal dosing of mycophenolic acid in children is lacking. , Mycophenolic acid exhibits considerable inter- and intra-patient pharmacokinetic variability in adults and paediatric transplant recipients. , The AUC of mycophenolic acid over a 12 h dose interval at steady-state is generally agreed to be the most reliable metric associated with the risk of acute rejection. , Population pharmacokinetic analysis can utilize concentration information from both intensive sampling and sparse sampling to provide pharmacokinetic parameter estimates, estimates of inter- individual and intra-individual variability in these parameters and allows patient characteristics explaining inter-individual variability to be quantified. WHAT THIS STUDY ADDS , This study is one of the first investigations in which a population pharmacokinetic modelling approach was applied to assess the pharmacokinetics of both intravenous and oral MMF in children and young people undergoing blood or marrow and solid organ transplantation. , Bodyweight and concomitant ciclosporin were found to influence MPA pharmacokinetics. , This study evaluated current dosing strategies and found that they may be suboptimal for children weighing less than 10 kg. AIMS To characterize the population pharmacokinetics of mycophenolic acid (MPA) and evaluate dose regimens using a simulation approach and accepted therapeutic drug monitoring targets in children and young people undergoing blood or marrow, kidney and liver transplantation. METHODS MPA concentration,time data were collected using an age specific sampling protocol over 12 h. Some patients provided randomly timed but accurately recorded blood samples. Total and unbound MPA were measured by HPLC. NONMEM was employed to analyze MPA pharmacokinetic data. Simulations (n= 1000) were conducted to assess the suitability of the MPA dose regimens to maintain total MPA AUC(0,12 h) within the range 30 and 60 mg l,1 h associated with optimal outcome. RESULTS A two-compartment pharmacokinetic model with first-order elimination best described MPA concentration,time data. Population mean estimates of MPA clearance, inter-compartmental clearance, volumes of distribution in the central and peripheral compartments, absorption rate constant and bioavailability were 6.42 l h,1, 3.74 l h,1, 7.24 l, 16.8 l, 0.39 h,1 and 0.48, respectively. Inclusion of bodyweight and concomitant ciclosporin reduced the inter-individual variability in CL from 54.3% to 31.6%. Children with a bodyweight of 10 kg receiving standard MPA dose regimens achieve an MPA AUC below the target range suggesting they may be at a greater risk of acute rejection. CONCLUSIONS The population pharmacokinetic model for MPA can be used to explore dosing guidelines for safe and effective immunotherapy in children and young people undergoing transplantation. [source] | ||||||||||