Publications by authors named "Lars P Ryder"

Pediatric hematopoietic stem cell transplantation (HSCT) is challenged by chronic graft-versus-host disease (cGvHD) significantly affecting survival and long-term morbidity, but underlying mechanisms including the impact of post-HSCT CMV infection are sparsely studied. We first investigated the impact of CMV infection for development of cGvHD in 322 children undergoing standard myeloablative HSCT between 2000 and 2018. Clinically significant CMV infection (n = 61) was an independent risk factor for chronic GvHD in a multivariable Cox regression analysis (HR = 2.

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Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by acute non-infectious toxicities, including sinusoidal obstruction syndrome (SOS), engraftment syndrome (ES) and capillary leak syndrome (CLS) among others. These complications are thought to be driven by a dysfunctional vascular endothelium, but the pathophysiological mechanisms remain incompletely understood, and the diagnoses are challenged by purely clinical diagnostic criteria that are partly overlapping, limiting the possibilities for progress in this field. There is, however, increasing evidence suggesting that these challenges may be met through the development of diagnostic biomarkers to improve diagnostic accuracy of pathogenetically homogenous entities, improved pre-transplant risk assessment and the early identification of patients with increased need for specific treatment.

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The effect of higher FOXP3 mRNA expression by recipient pre-transplant CD4+ T cells on leukaemia relapse was analysed in a series of 106 patients who received allogeneic haematopoietic stem cell transplantation after myeloablative conditioning with or without antithymocyte globulin (ATG) due to acute leukaemia in 1st or 2nd complete remission. FOXP3 mRNA was measured by qPCR in purified CD4+ T cells from blood obtained before conditioning. Higher FOXP3 mRNA expression was associated with an increased relapse risk when conditioning included ATG ( = 43, hazard ratio [HR] 11.

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Background: Thymic stromal lymphopoietin (TSLP) is an immunoregulatory, Th2-polarizing cytokine produced by epithelial cells. We hypothesized that TSLP affects immune reconstitution after hematopoietic stem cell transplantation (HSCT) leading to increased alloreactivity.

Methods: We measured plasma TSLP by ELISA in 38 patients and assessed the immune reconstitution by flow cytometry.

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Objectives: The aim of the study was to investigate whether high endogenous levels of insulin-like growth factor-1 (IGF-1) and its binding protein-3 (IGFBP-3) were related to a faster reconstitution of different blood cell populations in the early phase after allogeneic myeloablative haematopoietic stem cell transplantation (HSCT).

Methods: We measured IGF-1 and IGFBP-3 by chemiluminescence during the first three weeks after transplantation in 35 adult patients undergoing myeloablative HSCT and calculated area under the curve divided by time (AUC/t) for each patient.

Results: Circulating levels of IGF-1 and IGFBP-3 correlated with counts of reticulocytes (r = 0.

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Allogeneic hematopoietic stem cell transplantation (HSCT) is a potential cure for patients with hematological malignancies but substantial risks of recurrence of the malignant disease remain. TCR γδ and NK cells are perceived as potent innate effector cells in HSCT and have been associated with post-transplant protection from relapse in clinical studies. Immunocompetent cells from the donor are crucial for patient outcomes and peripheral blood stem cells (PBSC) are being increasingly applied as graft source.

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Objectives: The curative effect of allogeneic haematopoietic stem cell transplantation (HSCT) for acute leukaemia is due in part to the donor T cell-mediated graft-versus-leukaemia immune reaction (GvL). Several studies have suggested that donor CD25+CD4+Foxp3+regulator T cells (Tregs) may decrease graft-versus-host disease (GvHD) without abrogating GVL. This notion may need modification in acute lymphoblastic leukaemia (ALL).

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Mature immunocompetent cells from the stem cell graft as well as early robust immune reconstitution are essential for the graft-vs. -tumor (GVT) effect to eliminate residual malignant cells after allogeneic hematopoietic stem cell transplantation (HSCT). In this prospective study we characterized graft composition of T- and NK cell subsets in 88 recipients of peripheral blood stem cell grafts with multicolor flowcytometry.

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People living with HIV (PLHIV) are at increased risk for cardiovascular disease (CVD), and immunity against cytomegalovirus (CMV) may be a contributing factor. We hypothesized that enhanced T-cell responses against CMV and CMV-IgG antibody-levels are associated with higher arterial blood pressure in PLHIV. We assessed serum CMV-IgG, systolic- (SBP) and diastolic- (DBP) blood pressure, pulse pressure (PP), traditional risk factors, activated CD8+ T-cells (CD38+HLA-DR+), senescent CD8+ T-cells (CD28-CD57+) and interleukin-6 (IL-6) in 60 PLHIV and 31 HIV-uninfected controls matched on age, gender, education and comorbidity.

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T-cell receptor (TCR) γδ cells are perceived as innate-like effector cells with the possibility of mediating graft-vs. -tumor (GVT) without causing graft-vs.-host disease (GVHD) in the setting of hematopoietic allogeneic stem cell transplantation (HSCT).

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Background: An increasing number of HIV-positive individuals now start antiretroviral therapy (ART) with high CD4 cell counts. We investigated whether this makes restoration of CD4 and CD8 cell counts and the CD4:CD8 ratio during virologically suppressive ART to median levels seen in HIV-uninfected individuals more likely and whether restoration depends on gender, age, and other individual characteristics.

Methods: We determined median and quartile reference values for CD4 and CD8 cell counts and their ratio using cross-sectional data from 2309 HIV-negative individuals.

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Acute infectious spondylodiscitis (AIS) is a serious infection of the spine with rising incidence and a mortality of 3-6%. The role of the immune system in AIS is largely unknown. We performed extensive B and T-lymphocyte phenotyping in patients with AIS at diagnosis and after treatment cessation.

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Background: Mechanisms leading to neurocognitive impairment (NCI) in people living with HIV (PLWHIV) on stable combination antiretroviral therapy (cART) remain unknown. We investigated the association between immunity against cytomegalovirus (CMV), HIV-specific variables, and NCI in PLWHIV on stable cART and with low comorbidity.

Methods: Fifty-two PLWHIV on stable cART and 31 HIV-uninfected controls matched on age, sex, education, and comorbidity were tested with a neurocognitive test battery, and CMV-immunoglobulin G (CMV-IgG) levels were measured.

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In people living with HIV (PLWHIV), coinfection with cytomegalovirus (CMV) has been associated with inflammation, immunological ageing, and increased risk of severe non-AIDS related comorbidity. The effect of CMV-specific immune responses on systemic inflammation, immune activation and T-cell senescence was evaluated in 53 PLWHIV treated with combination antiretroviral therapy (cART). Activated-, terminally differentiated-, naïve-, and senescent T-cells were assessed by flow cytometry, and plasma levels of CMV IgG, interleukin-6, tumor necrosis factor-α, high-sensitivity C-reactive protein and soluble-CD14 were measured.

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The efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) is challenged by acute and chronic graft-versus-host disease (aGVHD and cGVHD) and viral infections due to long-lasting immunodeficiency. Interleukin-7 (IL-7) is a cytokine essential for T cell generation in thymus and peripheral T cell homeostasis. In this study, we investigated the impact of the single nucleotide polymorphism in the IL-7 receptor α-chain (IL-7Rα) which has previously been associated with several autoimmune diseases.

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Successful reconstitution of T lymphocytes after allogeneic haematopoietic stem cell transplantation (HSCT) is needed to establish the graft-versus-leukaemia effect and an effective anti-microbial defense, but the ratio between functionally different T-cell subsets needs to be balanced to avoid graft-versus-host disease (GVHD). IL-7 is essential for T-cell generation in the thymus and peripheral T-cell homeostasis. High IL-7 levels have been associated with impaired T-cell reconstitution, increased risk of acute GVHD and treatment-related mortality, but the underlying cellular mechanisms behind these associations have not been investigated previously.

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Interleukin-7 is a cytokine essential for T cell homeostasis. IL-7 binds to cellular IL-7 receptors in competition with a soluble form of the receptor (sIL-7Rα). We hypothesized that altered sIL-7Rα levels may cause adverse outcomes in patients undergoing HSCT.

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Optimal CD4+ T cell recovery after initiating combination antiretroviral treatment (cART) in HIV infection reduces risk of morbidity and mortality. T-allele homozygosity ('TT') in the single nucleotide polymorphism, rs6897932(C/T), in the IL-7 receptor α (IL-7RA) is associated with faster CD4+ T cell recovery after cART initiation compared to C-allele homozygosity in rs6897932 ('CC'). However, underlying mechanisms are unknown.

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Early immune reconstitution plays a critical role in clinical outcome after allogeneic hematopoietic stem cell transplantation (HSCT). Natural killer (NK) cells are the first lymphocytes to recover after transplantation and are considered powerful effector cells in HSCT. We aimed to evaluate the clinical impact of early NK cell recovery in T cell-replete transplant recipients.

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Objective: Inflammation may contribute to an increased risk of cardiovascular disease (CVD) in HIV-1 infection. MicroRNAs (miRNAs) are involved in the regulation of inflammation. In treated HIV-1-infected individuals, we aimed to identify differentially expressed miRNAs with known roles in inflammation and CVD risk and to investigate associations between these and systemic inflammation.

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Recent studies suggest that exposure to perfluorinated alkylate substances (PFASs) may induce immunosuppression in humans and animal models. In this exploratory study, 12 healthy adult volunteers were recruited. With each subject, serum-PFAS concentrations were measured and their antibody responses prospectively followed for 30 days after a booster vaccination with diphtheria and tetanus.

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Background: Recurrent invasive pneumococcal disease (rIPD) occurs mostly in children with an underlying disease, but some cases remain unexplained. Immunodeficiency has been described in children with rIPD, but the prevalence is unknown. We used a nationwide registry of all laboratory-confirmed cases of rIPD to identify cases of unexplained rIPD and examine them for immunodeficiency.

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Objectives: To examine trajectories of CD8(+) T-cell counts before and after combination antiretroviral therapy (cART) in human immunodeficiency virus (HIV)-infected individuals and associations with mortality.

Methods: CD8(+) T-cell counts were measured in 3882 HIV-infected individuals who received care in Copenhagen during 1995-2012. Reference values were obtained from 1230 persons from the background population.

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