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42 result(s) for "Schaier, Matthias"
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Glucocorticoid maintenance therapy and severe infectious complications in ANCA-associated vasculitis: a retrospective analysis
To study the impact of glucocorticoid maintenance dose and treatment duration on outcomes in patients with AAV (ANCA-associated vasculitis) with emphasis on infectious complications. A total of 130 AAV patients from two German vasculitis centers diagnosed between August 2004 and January 2019 treated with cyclophosphamide and glucocorticoids for induction therapy and glucocorticoids for maintenance therapy were retrospectively enrolled. We investigated the influence of glucocorticoid maintenance therapy on patient survival, time to relapse, kidney function, infectious complications and irreversible physical damage. The patients were divided into the following groups: patients treated according to the predefined reduction scheme (< 7.5 mg) or patients treated with glucocorticoids ≥ 7.5 mg after 6 months. Compared to patients receiving < 7.5 mg glucocorticoids after 6 months, patients receiving ≥ 7.5 mg had an increased rate of infectious episodes per patient (1.7 vs. 0.6; p < 0.001), including urinary tract infection (p = 0.007), pneumonia (p = 0.003), opportunistic pneumonia (p = 0.022) and sepsis (p = 0.008). Especially pneumonia during the first 24 months after disease onset [hazard ratio, 3.0 (95% CI 1.5 − 6.1)] led to more deaths from infection (p = 0.034). Glucocorticoid maintenance therapy after 6 months had no impact on relapse rate or patient survival and decline in kidney function was comparable. Glucocorticoid maintenance therapy with ≥ 7.5 mg after 6 months is associated with more severe infectious complications leading to an increased frequency of deaths from infection. Glucocorticoid maintenance therapy has no effect on time to relapse or patient survival and should therefore be critically revised throughout the aftercare of AAV patients.
First-in-human Phase I studies of PRS-080#22, a hepcidin antagonist, in healthy volunteers and patients with chronic kidney disease undergoing hemodialysis
In chronic kidney disease both renal insufficiency and chronic inflammation trigger elevated hepcidin levels, which impairs iron uptake, availability. and erythropoiesis. Here we report the two first-in-human phase 1 trials of PRS-080#22, a novel, rationally engineered Anticalin protein that targets and antagonizes hepcidin. A single intravenous infusion of placebo or PRS-080#22 was administered to 48 healthy volunteers (phase 1a) and 24 patients with end stage chronic kidney disease (CKD) on hemodialysis (phase 1b) at different doses (0.08-16mg/kg for the phase 1a study and 2-8mg/kg for the phase 1b study) in successive dosing cohorts. The primary endpoint for both randomized, double-blind, phase 1 trials was safety and tolerability. Following treatment, all subjects were evaluable, with none experiencing dose limiting toxicities. Most adverse events were mild. One serious adverse event occurred in the phase 1b (CKD patient) study. There were no clinically significant changes in safety laboratory values or vital signs. PRS-080#22 showed dose-proportional pharmacokinetics (PK), with a terminal half-life of approximately three days in healthy volunteers and 10 to 12 days in CKD patients. Serum hepcidin levels were suppressed in a dose dependent manner and remained low for up to 48 hours after dosing. PRS-080#22 dose-dependently mobilized serum iron with increases in both serum iron concentration and transferrin saturation. No consistent changes were observed with regard to ferritin, reticulocytes, hemoglobin, and reticulocyte hemoglobin. Low titer anti-drug-antibodies were detected in five healthy volunteers but in none of the CKD patients. PRS-080#22, a novel Anticalin protein with picomolar affinity for hepcidin, was safe and well-tolerated when administered to healthy volunteers and CKD patients at all doses tested. The drug exhibited linear pharmacokinetics, longer half-life in CKD patients in comparison to healthy volunteers as well as expected pharmacodynamic effects which hold promise for further clinical studies.
Exhaustion of CD8pos central memory regulatory T cell differentiation is involved in renal allograft rejection
BackgroundThe role of regulatory CD8pos T cells (CD8pos Tregs) and cytotoxic CD8pos responder T cells (CD8pos Tresps) in maintaining stable graft function in kidney transplant recipients (KTR) remains largely unclear. The pathogenesis of graft deterioration in case of rejection involves the exhaustive differentiation of both CD8pos T cell subsets, but the causal mechanisms have not yet been identified.MethodsIn this study, we separately investigated the differentiation of CD8posTregs/Tresps in 134 stable KTR with no evidence of renal graft rejection, in 41 KTR diagnosed with biopsy-confirmed rejection at enrolment and in 5 patients who were unremarkable at enrolment, but developed rejection within three years of enrolment. We were investigating whether changed differentiation of CCR7posCD45RAposCD31pos recent thymic emigrant (RTE) cells via CD45RAnegCD31pos memory (CD31pos memory) cells (pathway 1), via direct proliferation (pathway 2), or via CCR7posCD45RA+CD31neg resting mature naïve (MN) cells (pathway 3) into CD45RAnegCD31neg memory (CD31neg memory) cells affects the CD8pos Treg/Tresp ratio or identifies a CD8pos Treg/Tresp subset that predicts or confirms renal allograft rejection.ResultsWe found that RTE Treg differentiation via pathway 1 was age-independently increased in KTR, who developed graft rejection during the follow-up period, leading to abundant MN Treg and central memory Treg (CM Treg) production and favoring a strongly increased CD8pos Treg/Tresp ratio. In KTR with biopsy-confirmed rejection at the time of enrolment, an increased differentiation of RTE Tregs into CCR7negCD45RAposCD31neg terminally differentiated effector memory (CD31neg TEMRA Tregs) and CD31pos memory Tregs was observed. CD31neg memory Treg production was maintained by alternative differentiation of resting MN Tregs, resulting in increased effector memory Treg (EM Treg) production, while the CD8pos Treg/Treg ratio was unaffected. An altered differentiation of CD8pos Tresps was not observed, shifting the Treg/Tresp ratio in favor of Tregs.ConclusionsOur results show that exhaustive CD8pos Treg differentiation into CM Tregs may lead to future rejection, with a shift towards EM Treg production and an accumulation of CD31neg TEMRA Tregs in KTR with current rejection.
Exhaustion of CD8+ central memory responder T cell differentiation provokes non-melanoma skin cancer in elderly kidney transplant recipients
Immunosuppressive therapy prevents graft rejection but increases the risk of non-melanoma skin cancer (NMSC), especially in elderly kidney transplant recipients (KTR). In this study, we separately investigated the differentiation of CD8 regulatory T cells (Tregs) and responder T cells (Tresps) between healthy KTR without NMSC, KTR developing NMSC within two years after the enrolment, and KTR with NMSC at the time of enrolment. Antigen-unexperienced CCR7 CD45RA CD31 recent thymic emigrant (RTE) cells differentiate CD45RA CD31 memory (CD31 memory) cells, resting mature naïve (MN) cells or direct proliferation into CD45RA CD31 memory (CD31 memory) cells, consisting of both CCR7 CD45RA central memory (CM) and CCR7 CD45RA effector memory (EM) cells. We found that both RTE Treg and Tresp differentiation CD31 memory Tregs/Tresps was age-independently increased in KTR, who developed NMSC during the follow-up period, causing abundant CM Treg/Tresp production, which may be crucial for cancer immunity. These changes favored a strongly increased CD8 Treg/Tresp ratio, suggesting this ratio as a reliable marker for NMSC development in KTR. However, with age, this differentiation was replaced by increased conversion of resting MN Tregs/Tresps into CM Tregs/Tresps, which exhausted for Tresps but not for Tregs. In KTR with already existing NMSC at enrolment, differentiation was maintained conversion and proliferation of resting MN Tregs/Tresps, which however increasingly exhausted with age, especially for Tresps. This resulted in a strong accumulation of terminally differentiated effector memory (TEMRA) Tresps in elderly individuals. Patients with NMSC recurrence showed increased proliferation of resting MN Tregs/Tresps into EM Tregs/Tresps, which tended to exhaust more rapidly, particularly for Tresps, than in patients without NMSC recurrence. In conclusion, we provide evidence that immunosuppressive therapy inhibits differentiation of CD8 Tregs more than that of CD8 Tresps, resulting in an exhausted Tresp profile, thus providing a possible therapeutic approach to improve poor cancer immunity in elderly KTR.
Chronic Kidney Failure Provokes the Enrichment of Terminally Differentiated CD8+ T Cells, Impairing Cytotoxic Mechanisms After Kidney Transplantation
Chronic kidney failure (KF) provokes the development of immune senescent CD8 + cytotoxic T cells, affecting the occurrence of graft rejection, viral infections, and malignancies after kidney transplantation. In this study, we analyzed the impact of KF, subsequent dialysis treatment, and kidney transplantation on the differentiation of CD8 + CD31 + CD45RA + CCR7 + recent thymic emigrant (CCR7 + RTE) Tregs/Tresps into CD8 + CD31 - CD45RA - memory (CD31 - memory) Tregs/Tresps and its effect on the release of cytokines, Fas receptor, Fas ligand as well as cytotoxic mediators by naïve, central memory (CM), effector memory (EM), and terminally differentiated effector memory (TEMRA) Tresps. We found that normal age-dependent differentiation of CD8 + Tregs/Tresps generally differs in the way that TEMRA cells only arise in Tresps. Compared to healthy controls, KF patients revealed an age-independently decreased frequency of CCR7 + RTE Tregs/Tresps, but increased frequencies of CCR7 + MN Tregs/Tresps and CD31 - memory Tregs/Tresps, suggesting an increased differentiation via CD31 + CD45RA - memory (CD31 + memory) Tregs/Tresps into CD31 - memory Tregs/Tresps. Intensified differentiation via CD31 + memory Tresps increased the emergence of apoptosis-resistant CM Tresps with strong Fas ligand-mediated cytotoxicity. CCR7 + RTE Tresp proliferation generated TEMRA Tresps, secreting high levels of cytotoxic mediators. In dialysis and transplant patients, CD31 + TEMRA Tregs/Tresps accumulated, proposing an impaired CCR7 + RTE Treg/Tresp differentiation via CD31 + memory Tregs/Tresps into CD31 - memory Tregs/Tresps. Increased percentages of CD31 - TEMRA Tresps, but not of CD31 - TEMRA Tregs, were observed in all patient groups, indicating impaired proliferation of CCR7 + RTE Tresps, but not of CCR7 + RTE Tregs, into CD31 - memory Tregs/Tresps. In transplant patients, CCR7 + RTE Tregs accumulated, while frequencies of CCR7 + RTE Tresps were decreased, suggesting that the immunosuppressive therapy only prevented excessive CCR7 + RTE Treg differentiation but not that of CCR7 + RTE Tresps. Presumably, this caused the accumulation of TEMRA Tresps with decreased release of cytotoxic mediators, such as perforin. In conclusion, we propose that chronic KF affects both the differentiation of CD8 + Tregs and CD8 + Tresps. However, the immunosuppressive therapy after transplantation may successfully prevent excessive Treg differentiation, but not as suffciently that of Tresps. Therefore, the risk for graft rejection may be reduced, while the susceptibility for infections and malignancies may be increased in these patients.
Heterologous ChAdOx1 nCoV-19/BNT162b2 Prime-Boost Vaccination Induces Strong Humoral Responses among Health Care Workers
Despite limited data on safety and immunogenicity, heterologous prime-boost vaccination is currently recommended for individuals with ChAdOx1 nCoV-19 prime immunization in certain age groups. In this prospective, single-center study we included 166 health care workers from Heidelberg University Hospital who received either heterologous ChAdOx1 nCoV-19/BNT162b2, homologous BNT162b2 or homologous ChAdOx1 nCoV-19 vaccination between December 2020 and May 2021. We measured anti-S1 IgG, SARS-CoV-2 specific neutralizing antibodies, and antibodies against different SARS-CoV-2 fragments 0–3 days before and 19–21 days after boost vaccination. Before boost, 55/70 (79%) ChAdOx1 nCoV-19-primed compared with 44/45 (98%) BNT162b2-primed individuals showed positive anti-S1 IgG with a median (IQR) anti-S1 IgG index of 1.95 (1.05–2.99) compared to 9.38 (6.26–17.12). SARS-CoV-2 neutralizing antibodies exceeded the threshold in 24/70 (34%) of ChAdOx1 nCoV-19-primed and 43/45 (96%) of BNT162b2-primed individuals. After boosting dose, median (IQR) anti-S1 IgG index in heterologous ChAdOx1 nCoV-19/BNT162b2 vaccinees was 116.2 (61.84–170), compared to 13.09 (7.03–29.02) in homologous ChAdOx1 nCoV-19 and 145.5 (100–291.1) in homologous BNT162b2 vaccinees. All boosted vaccinees exceeded the threshold for neutralization, irrespective of their vaccination scheme. Vaccination was well-tolerated overall. We show that heterologous ChAdOx1 nCoV-19/BNT162b2 vaccination is safe and induces a strong and broad humoral response in healthy individuals.
Longitudinal Humoral Responses after COVID-19 Vaccination in Peritoneal and Hemodialysis Patients over Twelve Weeks
It has been demonstrated that patients on hemo- or peritoneal dialysis are particularly susceptible to SARS-CoV-2 infection and impaired seroconversion compared to healthy controls. Follow-up data on vaccination response in dialysis patients is limited but is greatly needed to individualize and guide (booster) vaccination strategies. In this prospective, multicenter study we measured anti-spike S1 and neutralizing antibodies in 124 hemodialysis patients, 41 peritoneal dialysis patients, and 20 age- and sex-matched healthy controls over 12 weeks after homologous BNT162b2 vaccination. Compared to healthy controls, both hemodialysis and peritoneal dialysis patients had lower anti-S1 IgG antibodies (median (IQR) 7.0 (2.8–24.3) and 21.8 (5.8–103.9) versus 134.9 (23.8–283.6), respectively; p < 0.001 and p < 0.05) and a reduced SARS-CoV-2 spike protein–ACE2 binding inhibition caused by vaccine-induced antibodies (median (IQR) 56% (40–81) and 77% (52–89) versus 96% (90–98), respectively; p < 0.001 and p < 0.01) three weeks after the second vaccination. Twelve weeks after the second vaccination, the spike protein–ACE2 binding inhibition significantly decreased to a median (IQR) of 45% (31–60) in hemodialysis patients and 55% (36–78) in peritoneal dialysis patients, respectively (p < 0.001 and p < 0.05). Peritoneal dialysis patients mounted higher antibody levels compared with hemodialysis patients at all time points during the 12-week follow-up. Individual booster vaccinations in high-risk individuals without seroconversion or rapidly waning neutralizing antibody levels are required and further data on the neutralization of emerging variants of concern in these patients are urgently needed.
Impact of deceased-donor characteristics on early graft function: outcome of kidney donor pairs accepted for transplantation
The impact of deceased donor characteristics on kidney transplant outcomes is controversial. Correspondingly, the predictive performance of deceased donor scores remains moderate, and many transplant centers lack validated criteria for graft acceptance decisions. To better dissect donor-related risk from recipient and periprocedural variables, we analyzed outcomes of kidney donor pairs transplanted in different individuals. This study explored (a)symmetry of early outcomes of 328 cadaveric kidney transplant recipients from 164 donor pairs transplanted at three Eurotransplant centers. The primary discriminatory factor was (a)symmetry of partner graft function, defined as early graft loss or impaired graft function [estimated glomerular filtration rate (eGFR) <30 mL/min] 3 months after transplantation. We reasoned that a relevant impact of donor factors would result in a high concordance rate of limited graft function or failure. The observed number of symmetric graft failure after transplantation was less than statistically expected (3 months: 1 versus 2, p = 0.89; and 12 months: 3 versus 5, p = 0.26). However, we found a trend toward an impaired 5-year graft survival of grafts with good function 3 months after transplantation but a failed or impaired partner graft compared to symmetrically well-functioning grafts (p = 0.09). Subsequently, we explored the impact of individual donor and recipient variables on early transplant outcomes. Generalized estimating equations after feature selection with LassoGEE bootstrap selected donor age, donor body mass index, and donor eGFR as the relevant risk factors. Our findings indicate that donor factors impact early outcomes in kidney transplantation but may have a limited role in long-term graft survival, once a graft has been accepted for transplantation. Utilizing donor-based clinical scores has the potential to aid clinicians in acceptance decisions, giving them an estimate of individual posttransplant outcomes. However, the ultimate decision for acceptance should rest with clinicians, who must consider the complex interplay of donor factors, as well as recipient and periprocedural characteristics.
Neutralizing Antibody Activity Against the B.1.617.2 (delta) Variant Before and After a Third BNT162b2 Vaccine Dose in Hemodialysis Patients
Hemodialysis patients are at high risk for severe COVID-19, and impaired seroconversion rates have been demonstrated after COVID-19 vaccination. Humoral immunity wanes over time and variants of concern with immune escape are posing an increasing threat. Little is known about protection against the B.1.617.2 (delta) variant of concern in hemodialysis patients before and after third vaccination. We determined anti-S1 IgG, surrogate neutralizing, and IgG antibodies against different SARS-CoV-2 epitopes in 84 hemodialysis patients directly before and three weeks after a third vaccine dose with BNT162b2. Third vaccination was performed after a median (IQR) of 119 (109–165) days after second vaccination. In addition, neutralizing activity against the B.1.617.2 (delta) variant was assessed in 31 seroconverted hemodialysis patients before and after third vaccination. Triple seropositivity for anti-S1 IgG, surrogate neutralizing, and anti-RBD antibodies increased from 31/84 (37%) dialysis patients after second to 80/84 (95%) after third vaccination. Neutralizing activity against the B.1.617.2 (delta) variant was significantly higher after third vaccination with a median (IQR) ID 50 of 1:320 (1:160–1:1280) compared with 1:20 (0–1:40) before a third vaccine dose ( P <0.001). The anti-S1 IgG index showed the strongest correlation with the ID 50 against the B.1.617.2 (delta) variant determined by live virus neutralization (r=0.91). We demonstrate low neutralizing activity against the B.1.617.2 (delta) variant in dialysis patients four months after standard two-dose vaccination but a substantial increase after a third vaccine dose. Booster vaccination(s) should be considered earlier than 6 months after the second vaccine dose in immunocompromised individuals.
Adjusted Donor Age: A Clinical Score to Support Organ Acceptance Decisions in Deceased-Donor Kidney Transplantation
As transplant programmes have evolved to allow a wider donor pool, organ acceptance decisions have become increasingly complex and lack transparency and equality. Clinical scoring tools exist but there is limited consensus on their use. From a prospective observation of consecutive deceased-donor kidney offers in a large urban transplant centre, a simple score was developed based on donor age and other risk characteristics, excluding ischemia time and graft histology. The score was validated in subsequent cohorts of consecutive offers in the United Kingdom and Germany. In the development cohort of 389 kidney offers, 110 (28%) were transplanted and 175 (45%) declined. Nine risk factors were incorporated into a score based on age, but adjusted for the number of risk factors present, making an “adjusted donor age,” with offers separated into equal quintiles by decade. The score was validated in a UK cohort of 380 subsequent offers, and a German cohort of 431 offers. In both cohorts adjusted donor age discriminated between favourable and poor post-transplant outcomes (C-statistic 0.77 in the United Kingdom, 95% CI 0.65–0.88, and 0.71 in Germany, 95% CI 0.64–0.77). Adjusted donor age is a simple score quantifying deceased donor kidney quality, which is consistent with current practice and predicts post-transplant outcome.