Search results for "immunosuppressive agent"
showing 10 items of 282 documents
SARS-CoV-2-specific Cell-mediated Immunity in Kidney Transplant Recipients Recovered From COVID-19.
2021
BACKGROUND: The magnitude and kinetics of severe acute respiratory syndrome coronavirus 2-specific cell-mediated immunity (SARS-CoV-2-CMI) in kidney transplant (KT) recipients remain largely unknown. METHODS: We enumerated SARS-CoV-2-specific interferon-I³-producing CD69+ CD4+ and CD8+ T cells at months 4 and 6 from the diagnosis of coronavirus disease 2019 (COVID-19) in 21 KT recipients by intracellular cytokine staining. Overlapping peptides encompassing the SARS-CoV-2 spike (S) glycoprotein N-terminal 1- to 643-amino acid sequence and the membrane protein were used as stimulus. SARS-CoV-2 IgG antibodies targeting the S1 protein were assessed by ELISA at month 6. RESULTS: Detectable (≥0.1…
Dimethyl fumarate treatment restrains the antioxidative capacity of T cells to control autoimmunity
2021
Abstract Dimethyl fumarate, an approved treatment for relapsing-remitting multiple sclerosis, exerts pleiotropic effects on immune cells as well as CNS resident cells. Here, we show that dimethyl fumarate exerts a profound alteration of the metabolic profile of human CD4+ as well as CD8+ T cells and restricts their antioxidative capacities by decreasing intracellular levels of the reactive oxygen species scavenger glutathione. This causes an increase in mitochondrial reactive oxygen species levels accompanied by an enhanced mitochondrial stress response, ultimately leading to impaired mitochondrial function. Enhanced mitochondrial reactive oxygen species levels not only result in enhanced T…
CD28-dependent Rac1 activation is the molecular target of azathioprine in primary human CD4+ T lymphocytes
2003
Azathioprine and its metabolite 6-mercaptopurine (6-MP) are immunosuppressive drugs that are used in organ transplantation and autoimmune and chronic inflammatory diseases such as Crohn disease. However, their molecular mechanism of action is unknown. In the present study, we have identified a unique and unexpected role for azathioprine and its metabolites in the control of T cell apoptosis by modulation of Rac1 activation upon CD28 costimulation. We found that azathioprine and its metabolites induced apoptosis of T cells from patients with Crohn disease and control patients. Apoptosis induction required costimulation with CD28 and was mediated by specific block- ade of Rac1 activation thro…
Azathioprine suppresses ezrin-radixin-moesin-dependent T cell-APC conjugation through inhibition of Vav guanosine exchange activity on rac proteins
2006
Abstract We have shown recently that the azathioprine metabolite 6-Thio-GTP causes immunosuppression by blockade of GTPase activation in T lymphocytes. In the present study, we describe a new molecular mechanism by which 6-Thio-GTP blocks GTPase activation. Although 6-Thio-GTP could bind to various small GTPases, it specifically blocked activation of Rac1 and Rac2 but not of closely related Rho family members such as Cdc42 and RhoA in primary T cells upon stimulation with αCD28 or fibronectin. Binding of 6-Thio-GTP to Rac1 did not suppress Rac effector coupling directly but blocked Vav1 exchange activity upon 6-Thio-GTP hydrolysis, suggesting that 6-Thio-GTP loading leads to accumulation of…
Pregnancy in primary sclerosing cholangitis
2011
Background There is a paucity of data on fertility or pregnancy in patients with primary sclerosing cholangitis (PSC). Objective To assess fertility in PSC by comparing the number of children in a large cohort of PSC patients to healthy controls and to investigate the outcome of pregnancy, as well as the influence of pregnancy on the disease course. Design Case series. Setting Germany. Participants 229 PSC patients and 569 healthy controls were evaluated for the number of children. 17 patients with PSC and at least one pregnancy, or who received a diagnosis of PSC within 6 months after delivery, were included in the more detailed analysis. Main outcome measures Number of children per patien…
Effects of immunosuppressive drugs on the cognitive functioning of renal transplant recipients: A pilot study
2011
Some renal transplant patients show cognitive, emotional, and behavioral changes as part of possible neurotoxic effects associated with immunosuppressive medication, especially tacrolimus. This study evaluated effects of immunosuppressive drugs on some cognitive tasks. Patients treated with sirolimus and cyclosporine reported some of the noncognitive side effects related to immunosuppressive treatment. We observed attention and working memory impairment in patients treated with sirolimus or tacrolimus. Performance of cyclosporine-treated subjects was similar to that of healthy volunteer controls. Since the mood, anxiety, and sleep patterns measured were unaffected, it could be concluded tha…
Development of cytochrome P450 2D6-specific LKM-autoantibodies following liver transplantation for Wilson's disease -- possible association with a st…
1999
Abstract Background/Aims: Antibodies to cytochrome P450 2D6, also knownas LKM1-autoantibodies, are characteristic for a subgroup of patients with autoimmune hepatitis, but can also occasionally be found in hepatitis C. We observed the occurrence of LKM1-autoantibodies 4 months after liver transplantation for Wilson's disease, in close association with a steroid-resistant rejection episode, in the absence of evidence for autoimmune hepatitis or hepatitis C. Methods: Sera from several time points prior to and following transplantation were tested for LKM-reactivity by immunofluorescence, ELISA and Western blotting. Antigen specificity was confirmed by Western blotting analysis on different cy…
Livebirth after uterus transplantation.
2015
Uterus transplantation is the first available treatment for absolute uterine infertility, which is caused by absence of the uterus or the presence of a non-functional uterus. Eleven human uterus transplantation attempts have been done worldwide but no livebirth has yet been reported.In 2013, a 35-year-old woman with congenital absence of the uterus (Rokitansky syndrome) underwent transplantation of the uterus in Sahlgrenska University Hospital, Gothenburg, Sweden. The uterus was donated from a living, 61-year-old, two-parous woman. In-vitro fertilisation treatment of the recipient and her partner had been done before transplantation, from which 11 embryos were cryopreserved.The recipient an…
Unusual high dose of tacrolimus in liver transplant patient, a case report.
2012
Case We describe the case of a liver transplant patient who had great difficulty in reaching the desired trough blood levels despite the use of high dose tacrolimus. The patient was homozygous for the CYP3A5*3 allele. However, the respective donor carried the wild-type CYP3A5*1/*1 genotype. Regarding ABCB1 SNPs at exon 21 and 26, the patient showed the 2677GT and 3435CC genotypes. For the corresponding donor we observed the 2677GG and 3435CC wild-type genotypes. One, two and three weeks after transplantation the patient received daily 0.219, 0.287 and 0.273 mg/kg of tacrolimus, respectively. However, the corresponding tacrolimus trough blood levels were of 4.6, 5.6 and 6.1 ng/mL. The tacrol…
Association of SNPs with the efficacy and safety of immunosuppressant therapy after heart transplantation.
2015
Aim: Studying the possible influence of SNPs on efficacy and safety of calcineurin inhibitors upon heart transplantation. Materials & methods: In 60 heart transplant patients treated with tacrolimus or cyclosporine, we studied a panel of 36 SNPs correlated with a series of clinical parameters during the first post-transplantation year. Results: The presence of serious infections was correlated to ABCB1 rs1128503 (p = 0.012), CC genotype reduced the probability of infections being also associated with lower blood cyclosporine concentrations. Lower renal function levels were found in patients with rs9282564 AG (p = 0.003), related to higher blood cyclosporine blood levels. A tendency tow…