27 research outputs found

    Hyperferritinemia and hypergammaglobulinemia predict the treatment response to standard therapy in autoimmune hepatitis.

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    Autoimmune hepatitis (AIH) is a chronic hepatitis with an increasing incidence. The majority of patients require life-long immunosuppression and incomplete treatment response is associated with a disease progression. An abnormal iron homeostasis or hyperferritinemia is associated with worse outcome in other chronic liver diseases and after liver transplantation. We assessed the capacity of baseline parameters including the iron status to predict the treatment response upon standard therapy in 109 patients with untreated AIH type 1 (AIH-1) in a retrospective single center study. Thereby, a hyperferritinemia (> 2.09 times upper limit of normal; Odds ratio (OR) = 8.82; 95% confidence interval (CI): 2.25-34.52) and lower immunoglobulins (<1.89 times upper limit of normal; OR = 6.78; CI: 1.87-24.59) at baseline were independently associated with the achievement of complete biochemical remission upon standard therapy. The predictive value increased when both variables were combined to a single treatment response score, when the cohort was randomly split into a training (area under the curve (AUC) = 0.749; CI 0.635-0.863) and internal validation cohort (AUC = 0.741; CI 0.558-0.924). Patients with a low treatment response score (<1) had significantly higher cumulative remission rates in the training (p<0.001) and the validation cohort (p = 0.024). The baseline hyperferritinemia was accompanied by a high serum iron, elevated transferrin saturations and mild hepatic iron depositions in the majority of patients. However, the abnormal iron status was quickly reversible under therapy. Mechanistically, the iron parameters were not stringently related to a hepatocellular damage. Ferritin rather seems deregulated from the master regulator hepcidin, which was down regulated, potentially mediated by the elevated hepatocyte growth factor. In conclusion, baseline levels of serum ferritin and immunoglobulins, which are part of the diagnostic work-up of AIH, can be used to predict the treatment response upon standard therapy in AIH-1, although confirmation from larger multicenter studies is pending

    Single-centre experience of allogeneic haemopoietic stem cell transplant in paediatric patients in Cape Town, South Africa

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    Background. Allogeneic haemopoietic stem cell transplant (Allo-HSCT) is a specialised and costly intervention, associated with significant morbidity and mortality. It is used to treat a broad range of paediatric conditions. South Africa (SA) is an upper middle-income country with limitations on healthcare spending. The role of paediatric Allo-HSCT in this setting is reviewed.Objectives. To review paediatric patients who underwent Allo-HSCT at the Groote Schuur Hospital/University of Cape Town Private Academic Hospital transplant unit in Cape Town, South Africa, and received post-transplant care at Red Cross War Memorial Children’s Hospital, over the period January 2006 - December 2014 in respect of indications for the transplant, donor sources, conditioning regimens, treatment-related morbidity and overall survival (OS).Methods. A retrospective analysis of patient records was performed and a database was created in Microsoft Access. Descriptive analyses of relevant demographic, clinical and laboratory data were performed. Summary statistics of demographic and clinical parameters were derived with Excel. OS was calculated from the date of transplant to the date of an event (death) or last follow-up using the Kaplan-Meier method in Statistica.Results. A total of 48 children received Allo-HSCT: 24 for haematological malignancies, 20 for non-oncological haematological conditions, 3 for immune disorders and 1 for adrenoleukodystrophy. There were 28 boys (median age 7.5 years) and 20 girls (8.5 years). There were 31 sibling matched peripheral-blood stem cell (PBSC) transplants and 1 maternal haploidentical PBSC transplant. Stem cells were mobilised from bone marrow into peripheral blood by administering granulocyte-colony stimulating factor to donors. PBSCs were harvested by apheresis. Eight patients received 10/10 HLA-matched grafts from unrelated donors. Six were PBSC grafts and 2 were bone marrow grafts. Three of the unrelated PBSC grafts were from SA donors. Eight transplants used umbilical cord blood from international registries. OS for patients with non-oncological disorders was 91.3% (median follow-up 3.9 years), while that for oncology patients was 56.8% (1.9 years). Two of the survivors developed chronic graft-versus-host disease.Conclusions. OS for non-oncological conditions was excellent, while outcomes for oncological disorders were on par with those in high-income settings. Transplantation offers many patients the opportunity for long-term survival and has been shown to be both feasible and rewarding in a less well-resourced environment servicing an economically diverse population

    Dual Function of the NK Cell Receptor 2B4 (CD244) in the Regulation of HCV-Specific CD8+ T Cells

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    The outcome of viral infections is dependent on the function of CD8+ T cells which are tightly regulated by costimulatory molecules. The NK cell receptor 2B4 (CD244) is a transmembrane protein belonging to the Ig superfamily which can also be expressed by CD8+ T cells. The aim of this study was to analyze the role of 2B4 as an additional costimulatory receptor regulating CD8+ T cell function and in particular to investigate its implication for exhaustion of hepatitis C virus (HCV)-specific CD8+ T cells during persistent infection. We demonstrate that (i) 2B4 is expressed on virus-specific CD8+ T cells during acute and chronic hepatitis C, (ii) that 2B4 cross-linking can lead to both inhibition and activation of HCV-specific CD8+ T cell function, depending on expression levels of 2B4 and the intracellular adaptor molecule SAP and (iii) that 2B4 stimulation may counteract enhanced proliferation of HCV-specific CD8+ T cells induced by PD1 blockade. We suggest that 2B4 is another important molecule within the network of costimulatory/inhibitory receptors regulating CD8+ T cell function in acute and chronic hepatitis C and that 2B4 expression levels could also be a marker of CD8+ T cell dysfunction. Understanding in more detail how 2B4 exerts its differential effects could have implications for the development of novel immunotherapies of HCV infection aiming to achieve immune control

    Combined immune checkpoint protein blockade and low dose whole body irradiation as immunotherapy for myeloma

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    BACKGROUND: Multiple myeloma is characterized by the presence of transformed neoplastic plasma cells in the bone marrow and is generally considered to be an incurable disease. Successful treatments will likely require multi-faceted approaches incorporating conventional drug therapies, immunotherapy and other novel treatments. Our lab previously showed that a combination of transient lymphodepletion (sublethal whole body irradiation) and PD-1/PD-L1 blockade generated anti-myeloma T cell reactivity capable of eliminating established disease. We hypothesized that blocking a combination of checkpoint receptors in the context of low-dose, lymphodepleting whole body radiation would boost anti-tumor immunity. METHODS: To test our central hypothesis, we utilized a 5T33 murine multiple myeloma model. Myeloma-bearing mice were treated with a low dose of whole body irradiation and combinations of blocking antibodies to PD-L1, LAG-3, TIM-3, CD48 (the ligand for 2B4) and CTLA4. RESULTS: Temporal phenotypic analysis of bone marrow from myeloma-bearing mice demonstrated that elevated percentages of PD-1, 2B4, LAG-3 and TIM-3 proteins were expressed on T cells. When PD-L1 blockade was combined with blocking antibodies to LAG-3, TIM-3 or CTLA4, synergistic or additive increases in survival were observed (survival rates improved from ~30% to >80%). The increased survival rates correlated with increased frequencies of tumor-reactive CD8 and CD4 T cells. When stimulated in vitro with myeloma cells, CD8 T cells from treated mice produced elevated levels proinflammatory cytokines. Cytokines were spontaneously released from CD4 T cells isolated from mice treated with PD-L1 plus CTLA4 blocking antibodies. CONCLUSIONS: These data indicate that blocking PD-1/PD-L1 interactions in conjunction with other immune checkpoint proteins provides synergistic anti-tumor efficacy following lymphodepletive doses of whole body irradiation. This strategy is a promising combination strategy for myeloma and other hematologic malignancies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40425-014-0043-z) contains supplementary material, which is available to authorized users

    Molecular signatures of T-cell inhibition in HIV-1 infection

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    The use of short tandem repeat polymorphisms for monitoring chimerism following bone marrow transplantation: A short report

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    Following immunohaematopoietic stem cell transplantation, it is of importance to determine whether the new blood forming system is of recipient or donor origin and such phenotypic characterisation is called chimerism analysis. This is a dynamic process, which may be complete, mixed or split between compartments and in this way, plays an increasingly important role in predicting outcome for engraftment, rejection or residual disease predicating the need for pre-emptive immunotherapy. Based on recent workshop recommendations, peripheral blood cells have been used in the short tandem repeat (STR) assay to serially characterise the haematologic course and so evaluate the usefulness of this system. Forty-six patients from a single centre were followed serially for periods ranging between 3 and 60 months. The analysis was initially performed using the Applied Biosystems Profiler Plus Kit; currently, the Promega Powerplex 16 system is used. The overlap between the two assays has allowed for continuous comparison. The initial analysis was performed at 14 days post-transplant and repeated monthly. Stored DNA from the patient and donor was used to establish the pre-transplant profile. All post-transplant analyses were performed using peripheral blood. The results obtained were expressed as a percentage of the donor profile. To illustrate the ability of this technology, three representative profiles are described. In the first, stable engraftment is confirmed at 20 months with only donor pattern present. The second is intermediate, and while the patient is clinically disease free, there exists stable mixed chimerism at about 75% of donor cells. The third patient initially engrafted but the reappearance of recipient alleles presaged a haematological relapse; the latter is an indication for salvage with donor lymphocyte infusion and here this assay will be used to show the effectiveness of the intervention. These preliminary results show this to be a useful additional tool in monitoring post-transplant engraftment. As a basis for pro-active therapy, a larger study integrating the results of haematological and cytogenetic markers is planned. © W. S. Maney & Son Ltd 2008.Articl

    Screening for HCV-specific T cell responses: the use of peptide pools impair the proliferation of antigen specific CD8 T- cells

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    Proliferation of antigen-specific CD4/CD8 T-cells, in response to stimulation using peptide pools, has been routinely used in epitope discovery and vaccine development research. However, neither the optimal concentration of peptides nor the number of peptides per pool has been defined. Thus, the main objective of this study was to examine whether the number of peptides per pool or different peptide concentrations influence different effector functions of T-cell responses against defined CD8 T-cell epitopes. For this purpose, PBMCs isolated from HLA-A2-positive individuals responding to either to the influenza matrix peptide (GILGFVFTL), the CMV peptide pp65 (NLVPMVATV) or the HCV peptide NS3-1073 (CINGVCWTV) were studied. PBMC were cultured with these peptides and varying concentrations of different unrelated overlapping peptide pools specific for the hepatitis D and E viruses. Proliferation of peptide-specific CD8 T-cells was studied by staining with multimeric peptide-MHC complexes as well as by CFSE. Furthermore, cytokine secretion (IFN-gamma and TNF-alpha) was investigated by ELIspot and intra-cellular cytokine staining (ICS). Importantly, both HEV and HDV peptide pools inhibited the proliferation of Flu, CMV and HCV-specific CD8 T-cells in a dose dependent manner. In addition, the number of peptides per pool also influenced T cell responses as the number of proliferating Flu-, CMV and HCV-specific CD8 T cells was significantly lower when PBMCs were stimulated with pools containing 25 peptides when compared with 10 peptides. Cell death was excluded as an explanation for this phenomenon. The inhibition of proliferation was independent from the addition of IL-2. In contrast, neither IFN-gamma production nor TNF-alpha production of peptide-specific CD8 T-cells was affected by unrelated peptide pools. These results show that the total number of peptides in a pool and that the peptide concentration may largely influence CD8 T cell proliferation and warrants caution while using T cell proliferation in epitope discovery studies

    Single-centre experience of allogeneic haemopoietic stem cell transplant in paediatric patients in Cape Town, South Africa

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    Background. Allogeneic haemopoietic stem cell transplant (Allo-HSCT) is a specialised and costly intervention, associated with significant morbidity and mortality. It is used to treat a broad range of paediatric conditions. South Africa (SA) is an upper middle-income country with limitations on healthcare spending. The role of paediatric Allo-HSCT in this setting is reviewed. Objectives. To review paediatric patients who underwent Allo-HSCT at the Groote Schuur Hospital/University of Cape Town Private Academic Hospital transplant unit in Cape Town, South Africa, and received post-transplant care at Red Cross War Memorial Children’s Hospital, over the period January 2006 - December 2014 in respect of indications for the transplant, donor sources, conditioning regimens, treatment-related morbidity and overall survival (OS). Methods. A retrospective analysis of patient records was performed and a database was created in Microsoft Access. Descriptive analyses of relevant demographic, clinical and laboratory data were performed. Summary statistics of demographic and clinical parameters were derived with Excel. OS was calculated from the date of transplant to the date of an event (death) or last follow-up using the Kaplan-Meier method in Statistica. Results. A total of 48 children received Allo-HSCT: 24 for haematological malignancies, 20 for non-oncological haematological conditions, 3 for immune disorders and 1 for adrenoleukodystrophy. There were 28 boys (median age 7.5 years) and 20 girls (8.5 years). There were 31 sibling matched peripheral-blood stem cell (PBSC) transplants and 1 maternal haploidentical PBSC transplant. Stem cells were mobilised from bone marrow into peripheral blood by administering granulocyte-colony stimulating factor to donors. PBSCs were harvested by apheresis. Eight patients received 10/10 HLA-matched grafts from unrelated donors. Six were PBSC grafts and 2 were bone marrow grafts. Three of the unrelated PBSC grafts were from SA donors. Eight transplants used umbilical cord blood from international registries. OS for patients with non-oncological disorders was 91.3% (median follow-up 3.9 years), while that for oncology patients was 56.8% (1.9 years). Two of the survivors developed chronic graft-versus-host disease. Conclusions. OS for non-oncological conditions was excellent, while outcomes for oncological disorders were on par with those in high-income settings. Transplantation offers many patients the opportunity for long-term survival and has been shown to be both feasible and rewarding in a less well-resourced environment servicing an economically diverse population
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