Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

Innovative Therapieansätze beim Ischämie-Reperfusionsschaden: Untersuchungen zu Poly-(ADP-Ribose)-Polymerase-Inhibitoren und einem anti-inflammatorischen Fibrinspaltprodukt im Klein- und Großtierexperiment

Der Ischämie/Reperfusionsschaden verstärkt durch Aktivierung inflammatorischer Prozesse das Ausmaß eines ischämischen Zellschadens. In der vorliegenden Arbeit werden zwei innovative Therapieansätze zur Reduktion des Ischämie/Reperfusionsschaden untersucht: Zum einen handelt es sich um einen Inhibitor der Poly-(ADP-Ribose)-Polymerase, ein in allen eukaryotischen Zellen vorkommendes bei Reperfusion aktiviertes Wächterenzyms, zum anderen um ein körpereigenes Fibrinopeptid (Bβ15-42). Beide Substanzen reduzierten direkt bzw. indirekt die Leukozyteneinwanderung in geschädigtem Gewebe

Toll-like receptor 4 deficiency or inhibition does not modulate survival and neurofunctional outcome in a murine model of cardiac arrest and resuscitation.

BackgroundPatients experiencing cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) often die or suffer from severe neurological impairment. Post resuscitation syndrome is characterized by a systemic inflammatory response. Toll-like receptor 4 (TLR4) is a major mediator of inflammation and TLR4 has been implicated in the pathogenesis of post-resuscitation encephalopathy. The aim of this study was to evaluate whether TLR4 deficiency or inhibition can modulate survival and neurofunctional outcome after CA/CPR.MethodsFollowing intubation and central venous cannulation, CA was induced in wild type (C57Bl/6J, n = 38), TLR4 deficient (TLR4-/-, n = 37) and TLR4 antibody treated mice (5mg/kg MTS510, n = 15) by high potassium. After 10min, CPR was performed using a modified sewing machine until return of spontaneous circulation (ROSC). Cytokines and cerebral TNFalpha levels were measured 8h after CA/CPR. Survival, early neurological recovery, locomotion, spatial learning and memory were assessed over a period of 28 days.ResultsFollowing CA/CPR, all mice exhibited ROSC and 31.5% of wild type mice survived until day 28. Compared to wild type mice, neither TLR4-/- nor MTS510 treated wild type mice had statistically significant altered survival following CA/CPR (51.3 and 26.7%, P = 0.104 and P = 0.423 vs. WT, respectively). Antibody-treated but not TLR4-/- mice had higher IL-1β and IL-6 levels and TLR4-/- mice had higher IL-10 and cerebral TNFalpha levels. No differences existed between mice of all groups in early neurological recovery, locomotion, spatial learning ability or remembrance.ConclusionTherapeutic strategies targeting TLR4 may not be suitable for the reduction of mortality or neurofunctional impairment after CA/CPR

In Reply

We appreciate the interest of Lagier et al. in our article.1 The authors highlighted in their letter the work of Montaigne et al.,2 who have recently published on the circadian rhythm in relation to ischemia reperfusion injury in a single-center retrospective propensity-matched cohort study addressing this subject on 596 (matched-pairs) patients undergoing aor-tic valve replacement with or without coronary artery bypass grafting, together with a single-center randomized study in 88 patients undergoing isolated aortic valve replacement, in which the perioperative myocardial injury has been assessed with the geometric mean of perioperative cardiac troponin T release

Effect of xenon anesthesia compared to sevoflurane and total intravenous anesthesia for coronary artery bypass graft surgery on postoperative cardiac troponin release. an international, multicenter, phase 3, single-blinded, randomized noninferiority trial

Abstract BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible

Genome-wide association study of myocardial infarction, atrial fibrillation, acute stroke, acute kidney injury and delirium after cardiac surgery – a sub-analysis of the RIPHeart-Study

Abstract Background The aim of our study was the identification of genetic variants associated with postoperative complications after cardiac surgery. Methods We conducted a prospective, double-blind, multicenter, randomized trial (RIPHeart). We performed a genome-wide association study (GWAS) in 1170 patients of both genders (871 males, 299 females) from the RIPHeart-Study cohort. Patients undergoing non-emergent cardiac surgery were included. Primary endpoint comprises a binary composite complication rate covering atrial fibrillation, delirium, non-fatal myocardial infarction, acute renal failure and/or any new stroke until hospital discharge with a maximum of fourteen days after surgery. Results A total of 547,644 genotyped markers were available for analysis. Following quality control and adjustment for clinical covariate, one SNP reached genome-wide significance (PHLPP2, rs78064607, p = 3.77 × 10− 8) and 139 (adjusted for all other outcomes) SNPs showed promising association with p < 1 × 10− 5 from the GWAS. Conclusions We identified several potential loci, in particular PHLPP2, BBS9, RyR2, DUSP4 and HSPA8, associated with new-onset of atrial fibrillation, delirium, myocardial infarction, acute kidney injury and stroke after cardiac surgery. Trial registration The study was registered with ClinicalTrials.gov NCT01067703, prospectively registered on 11 Feb 2010