38 research outputs found
Identification of Rare High-Avidity, Tumor-Reactive CD8+ T Cells by Monomeric TCR-Ligand Off-Rates Measurements on Living Cells.
The avidity of the T-cell receptor (TCR) for antigenic peptides presented by the peptide-MHC (pMHC) on cells is a key parameter for cell-mediated immunity. Yet a fundamental feature of most tumor antigen-specific CD8(+) T cells is that this avidity is low. In this study, we addressed the need to identify and select tumor-specific CD8(+) T cells of highest avidity, which are of the greatest interest for adoptive cell therapy in patients with cancer. To identify these rare cells, we developed a peptide-MHC multimer technology, which uses reversible Ni(2+)-nitrilotriacetic acid histidine tags (NTAmers). NTAmers are highly stable but upon imidazole addition, they decay rapidly to pMHC monomers, allowing flow-cytometric-based measurements of monomeric TCR-pMHC dissociation rates of living CD8(+) T cells on a wide avidity spectrum. We documented strong correlations between NTAmer kinetic results and those obtained by surface plasmon resonance. Using NTAmers that were deficient for CD8 binding to pMHC, we found that CD8 itself stabilized the TCR-pMHC complex, prolonging the dissociation half-life several fold. Notably, our NTAmer technology accurately predicted the function of large panels of tumor-specific T cells that were isolated prospectively from patients with cancer. Overall, our results demonstrated that NTAmers are effective tools to isolate rare high-avidity cytotoxic T cells from patients for use in adoptive therapies for cancer treatment
HLA-B27 as a predictor of effectiveness of treatment with TNF inhibitors in axial spondyloarthritis: data from the Swiss Clinical Quality Management Registry
OBJECTIVE: To explore the impact of the human leucocyte antigen (HLA)-B27 on the effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (axSpA).
METHODS: A total of 1109 patients with available HLA-B27 status (831 B27+ patients and 278 B27- patients) fulfilling the Assessment of Spondyloarthritis international Society classification criteria for axSpA from the prospective Swiss Clinical Quality Management Registry initiating a first TNFi were included. Drug retention was investigated with multiple adjusted Cox proportional hazard models with imputation of missing values. Multiple-adjusted logistic regression analyses were used to assess the proportion of patients reaching 50% reduction in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50) at 1 year.
RESULTS: B27+ and B27- patients differed with regard to age, sex, BASDAI, C-reactive protein (CRP), body mass index, enthesitis, uveitis, and classification status. After adjustment for potential confounders for the relationship between HLA-B27 and drug effectiveness (sex and family history of spondyloarthritis), a higher risk of drug discontinuation was found in B27- patients (HR 1.53, 95% CI 1.27-1.83). This difference decreased after additional adjustment for parameters which may act as mediators (HR 1.30, 95% CI 1.30-1.55). Male sex and elevated C-reactive protein (CRP) levels were consistently associated with longer retention. Comparable results were obtained for BASDAI50 responses.
CONCLUSION: The HLA-B27 genotype is an important predictor of treatment effectiveness. Male sex and CRP seem, however, to better describe variability of response in individual patients. This data may help avoiding potential discrimination of B27- individuals with regard to TNFi initiation. Key Points • HLA-B27 is a predictor of effectiveness of TNF inhibitors in axial spondyloarthritis. • Variability of response in individual patients is better defined by sex and objective markers of disease activity, such as C-reactive protein
HLA-B27 as a predictor of effectiveness of treatment with TNF inhibitors in axial spondyloarthritis: data from the Swiss Clinical Quality Management Registry.
OBJECTIVE
To explore the impact of the human leucocyte antigen (HLA)-B27 on the effectiveness of tumor necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (axSpA).
METHODS
A total of 1109 patients with available HLA-B27 status (831 B27+ patients and 278 B27- patients) fulfilling the Assessment of Spondyloarthritis international Society classification criteria for axSpA from the prospective Swiss Clinical Quality Management Registry initiating a first TNFi were included. Drug retention was investigated with multiple adjusted Cox proportional hazard models with imputation of missing values. Multiple-adjusted logistic regression analyses were used to assess the proportion of patients reaching 50% reduction in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI50) at 1 year.
RESULTS
B27+ and B27- patients differed with regard to age, sex, BASDAI, C-reactive protein (CRP), body mass index, enthesitis, uveitis, and classification status. After adjustment for potential confounders for the relationship between HLA-B27 and drug effectiveness (sex and family history of spondyloarthritis), a higher risk of drug discontinuation was found in B27- patients (HR 1.53, 95% CI 1.27-1.83). This difference decreased after additional adjustment for parameters which may act as mediators (HR 1.30, 95% CI 1.30-1.55). Male sex and elevated C-reactive protein (CRP) levels were consistently associated with longer retention. Comparable results were obtained for BASDAI50 responses.
CONCLUSION
The HLA-B27 genotype is an important predictor of treatment effectiveness. Male sex and CRP seem, however, to better describe variability of response in individual patients. This data may help avoiding potential discrimination of B27- individuals with regard to TNFi initiation. Key Points • HLA-B27 is a predictor of effectiveness of TNF inhibitors in axial spondyloarthritis. • Variability of response in individual patients is better defined by sex and objective markers of disease activity, such as C-reactive protein
Tabletop imaging of structural evolutions in chemical reactions
The introduction of femto-chemistry has made it a primary goal to follow the
nuclear and electronic evolution of a molecule in time and space as it
undergoes a chemical reaction. Using Coulomb Explosion Imaging we have shot the
first high-resolution molecular movie of a to and fro isomerization process in
the acetylene cation. So far, this kind of phenomenon could only be observed
using VUV light from a Free Electron Laser [Phys. Rev. Lett. 105, 263002
(2010)]. Here we show that 266 nm ultrashort laser pulses are capable of
initiating rich dynamics through multiphoton ionization. With our generally
applicable tabletop approach that can be used for other small organic
molecules, we have investigated two basic chemical reactions simultaneously:
proton migration and C=C bond-breaking, triggered by multiphoton ionization.
The experimental results are in excellent agreement with the timescales and
relaxation pathways predicted by new and definitively quantitative ab initio
trajectory simulations
Impact of obesity on the response to tumor necrosis factor inhibitors in axial spondyloarthritis.
Few studies have investigated the impact of obesity on the response to tumor necrosis factor inhibitors (TNFi) in patients with axial spondyloarthritis (axSpA). The aim of our study was to investigate the impact of different body mass index (BMI) categories on TNFi response in a large cohort of patients with axSpA.
Patients with axSpA within the Swiss Clinical Quality Management (SCQM) program were included in the current study if they fulfilled the Assessment in Spondyloarthritis International Society (ASAS) criteria for axSpA, started a first TNFi after recruitment, and had available BMI data as well as a baseline and follow-up visit at 1 year (±6 months). Patients were categorized according to BMI: normal (BMI 18.5 to <25), overweight (BMI 25-30), and obese (BMI >30). We evaluated the proportion of patients achieving the 40% improvement in ASAS criteria (ASAS40), as well as Ankylosing Spondylitis Disease Activity Score (ASDAS) improvement and status scores at 1 year. Patients having discontinued the TNFi were considered nonresponders. We controlled for age, sex, HLA-B27, axSpA type, BASDAI, BASMI, elevated C-reactive protein (CRP), current smoking, enthesitis, physical exercise, and co-medication with disease-modifying antirheumatic drugs, as well as with nonsteroidal anti-inflammatory drugs in multiple adjusted logistic regression analyses.
A total of 624 axSpA patients starting a first TNFi were considered in the current study (332 patients of normal weight, 204 patients with overweight, and 88 obese patients). Obese individuals were older, had higher BASDAI levels, and had a more important impairment of physical function in comparison to patients of normal weight, while ASDAS and CRP levels were comparable between the three BMI groups. An ASAS40 response was reached by 44%, 34%, and 29% of patients of normal weight, overweight, and obesity, respectively (overall p = 0.02). Significantly lower odds ratios (ORs) for achieving ASAS40 response were found in adjusted analyses in obese patients versus patients with normal BMI (OR 0.27, 95% confidence interval (CI) 0.09-0.70). The respective adjusted ASAS40 OR in overweight versus normal weight patients was 0.62 (95% CI 0.24-1.14). Comparable results were found for the other outcomes assessed.
Obesity is associated with significantly lower response rates to TNFi in patients with axSpA
Early Switch from Intravenous to Oral Antibiotics in Skin- and Soft-tissue Infections: An Algorithm-based Prospective Multicentre Pilot Trial.
BACKGROUND: In hospitalized patients with skin and soft tissue infections (SSTIs), intravenous (IV) empiric antibiotic treatment is initiated. The best time point for switching from IV to oral treatment is unknown. We used an algorithm-based decision tree for the switch from IV to oral antibiotics within 48 hours and aimed to investigate the treatment outcome of this concept. METHODS: In a nonrandomized trial, we prospectively enrolled 128 patients hospitalized with SSTI from July 2019 to May 2021 at 3 institutions. Clinical and biochemical response data during the first week and at follow-up after 30 days were analyzed. Patients fulfilling criteria for the switch from IV to oral antibiotics were assigned to the intervention group. The primary outcome was a composite definition consisting of the proportion of patients with clinical failure or death of any cause. RESULTS: Ninety-seven (75.8%) patients were assigned to the intervention group. All of them showed signs of clinical improvement (ie, absence of fever or reduction of pain) within 48 hours of IV treatment, irrespective of erythema finding or biochemical response. The median total antibiotic treatment duration was 11 (interquartile range [IQR], 9–13) days in the invention group and 15 (IQR, 11–24) days in the nonintervention group (P < .001). The median duration of hospitalization was 5 (IQR, 4–6) days in the intervention group and 8 (IQR, 6–12) days in the nonintervention group (P < .001). There were 5 (5.2%) failures in the intervention group and 1 (3.2%) in the nonintervention group after a median follow-up of 37 days. CONCLUSIONS: In this pilot trial, the proposed decision algorithm for early switch from IV to oral antibiotics for SSTI treatment was successful in 95% of cases. Clinical Trials Registration. ISRCTN1524549
New Insights on the Management of Wildlife Diseases Using Multi-State Recapture Models: The Case of Classical Swine Fever in Wild Boar
The understanding of host-parasite systems in wildlife is of increasing interest in relation to the risk of emerging diseases in livestock and humans. In this respect, many efforts have been dedicated to controlling classical swine fever (CSF) in the European Wild Boar. But CSF eradication has not always been achieved even though vaccination has been implemented at a large-scale. Piglets have been assumed to be the main cause of CSF persistence in the wild since they appeared to be more often infected and less often immune than older animals. However, this assumption emerged from laboratory trials or cross-sectional surveys based on the hunting bags.In the present paper we conducted a capture-mark-recapture study in free-ranging wild boar piglets that experienced both CSF infection and vaccination under natural conditions. We used multi-state capture recapture models to estimate the immunization and infection rates, and their variations according to the periods with or without vaccination. According to the model prediction, 80% of the infected piglets did not survive more than two weeks, while the other 20% quickly recovered. The probability of becoming immune did not increase significantly during the summer vaccination sessions, and the proportion of immune piglets was not higher after the autumn vaccination.Given the high lethality of CSF in piglets highlighted in our study, we consider unlikely that piglets could maintain the chain of CSF virus transmission. Our study also revealed the low efficacy of vaccination in piglets in summer and autumn, possibly due to the low palatability of baits to that age class, but also to the competition between baits and alternative food sources. Based on this new information, we discuss the prospects for the improvement of CSF control and the interest of the capture-recapture approach for improving the understanding of wildlife diseases
Differences between men and women with nonradiographic axial spondyloarthritis: clinical characteristics and treatment effectiveness in a real-life prospective cohort
BACKGROUND
Sex differences with regard to clinical manifestations and response to tumor necrosis factor inhibitors (TNFi) have been delineated for the radiographic form of axial spondyloarthritis (axSpA). More limited evidence for a differential effectiveness of treatment in genders exists for the nonradiographic disease state (nr-axSpA). The aim of the study was to compare demographics, clinical parameters, and response to TNFi in women versus men with nr-axSpA.
METHODS
We compared disease characteristics of 264 women and 231 men with nr-axSpA at inclusion in the prospective Swiss Clinical Quality Management Cohort. Response to a first TNFi was assessed in 85 women and 78 men without diagnosed co-morbid fibromyalgia. The primary outcome was the proportion of patients achieving the 40% improvement in the Assessment of SpondyloArthritis international Society criteria (ASAS40) at 1 year. Additional response outcomes were evaluated as secondary outcomes. Patients having discontinued TNFi were considered non-responders. Logistic regression analyses were adjusted for baseline differences, which might potentially mediate the effect of sex on treatment response.
RESULTS
Compared to men, women had a longer diagnostic delay, a higher level of perceived disease activity, and more enthesitis and were in a lower percentage HLA-B27 positive. An ASAS40 response was achieved by 17% of women and 38% of men (OR 0.34; 95% CI 0.12, 0.93; p = 0.02). A significantly lower response rate in women was confirmed in the adjusted analysis (OR 0.19; 95% CI 0.05, 0.62; p = 0.009) as well as for the other outcomes assessed.
CONCLUSION
Despite only few sex differences in patient characteristics in nr-axSpA, response rates to TNFi are significantly lower in women than in men
Chromium-51 (51Cr) Release Assay to Assess Human T Cells for Functional Avidity and Tumor Cell Recognition
Cytotoxic CD8+ T cells are able to specifically recognize and kill target cells through specific interaction between their T cell receptors (TCRs) and small immunogenic peptides (antigens) presented by major histocompatibility complex (MHC) molecules. The antigen recognition capacity and in vitro lytic activity of antigen-specific cytotoxic T cells can be assessed functionally in the so-called chromium 51 (51Cr) release assay, which was developed almost 50 years ago in our institution (Brunner et al., 1968). Radioactively-labelled cells deficient for endogenous antigen presentation [e.g., transporter for antigen presentation (TAP)-deficient T2 cells] and stably transfected with the MHC of interest (e.g., HLA-A2+) are typically used as targets during this 4h assay. Alternatively, 51Cr-labelled virus-infected or tumor cell lines presenting immunogenic antigens endogenously can serve as target cells (e.g., for the assessment of tumor recognition).In a peptide titration assay (section A), radioactively labelled target cells are pulsed with a serial dilution of the antigenic peptide and incubated at an effector (e.g., a CD8+ T cell clone) to target (51Cr -T2 cells) ratio (E:T) of 10:1 in a 96-well V-bottom plate for 4 h at 37 °C. In a tumor killing assay (section B), cytotoxic CD8+ effector cells are incubated at different ratios with the 51Cr-labelled target cell line (typically at E:T ratios of 30:1, 10:1, 3:1 and 1:1) in the presence or absence of the specific antigenic peptide (1 μM) and incubated for 4 h at 37 °C. At the end of the test, the amount of radioactivity release from the lysed target cells is determined in the supernatant using a liquid scintillation counter. The percentage of specific lysis, as well as the EC50 (i.e., 50% of maximal killing) and EMax values are then calculated, providing quantitative information about the antigen-specific functional avidity (i.e., the relative efficiency of T cell function based on antigen recognition via a defined TCR and maximal killing capacity of the analyzed T cells)
Comparison of drug survival on adalimumab, etanercept, golimumab and infliximab in patients with axial spondyloarthritis.
OBJECTIVES
To compare drug survival in patients with axial spondyloarthritis treated with different TNF inhibitors in standard dosage.
METHODS
Patients fulfilling the Assessment in SpondyloArthritis international Society classification criteria for axial spondyloarthritis in the Swiss Clinical Quality Management cohort were included in this study if a first TNF inhibitor on standard dosage was started after recruitment and if a baseline visit was available. Drug maintenance up to drug discontinuation or dose escalation was compared between TNF inhibitors with multiple adjusted Cox proportional hazards models and multiple imputation for missing baseline covariate data.
RESULTS
A total of 966 patients were included (adalimumab 344, etanercept 237, golimumab 214, infliximab 171). Patients on certolizumab (n = 18) were excluded. Patients starting golimumab had lower disease activity as well as better physical function and quality of life in comparison to patients starting another drug. A higher proportion of patients starting infliximab had a history of extra-articular manifestations. Drug dosage was more often escalated during follow-up in patients treated with infliximab than with subcutaneously administered agents. However, no significant differences in time up to drug discontinuation or dose escalation were observed in multiple adjusted analyses if treatment was initiated after 2009, when all 4 TNF inhibitors were available: hazard ratio for infliximab versus etanercept 1.16 (95% confidence interval 0.80; 1.67), p = 0.44, for golimumab versus etanercept 0.80 (0.58; 1.10), p = 0.17 and for adalimumab versus etanercept 0.93 (0.69; 1.26), p = 0.66.
CONCLUSION
In axial spondyloarthritis, drug survival with standard doses of different TNF inhibitors is comparable