Multiple sclerosis genomic map implicates peripheral immune cells and microglia in susceptibility

We analyzed genetic data of 47,429 multiple sclerosis (MS) and 68,374 control subjects and established a reference map of the genetic architecture of MS that includes 200 autosomal susceptibility variants outside the major histocompatibility complex (MHC), one chromosome X variant, and 32 variants within the extended MHC. We used an ensemble of methods to prioritize 551 putative susceptibility genes that implicate multiple innate and adaptive pathways distributed across the cellular components of the immune system. Using expression profiles from purified human microglia, we observed enrichment for MS genes in these brain-resident immune cells, suggesting that these may have a role in targeting an autoimmune process to the central nervous system, although MS is most likely initially triggered by perturbation of peripheral immune responses

ST-Segment Elevation Myocardial Infarction Following Transcatheter Aortic Valve Replacement

Background: Among patients with acute coronary syndrome following transcatheter aortic valve replacement (TAVR), those presenting with ST-segment elevation myocardial infarction (STEMI) are at highest risk. Objectives: The goal of this study was to determine the clinical characteristics, management, and outcomes of STEMI after TAVR. Methods: This was a multicenter study including 118 patients presenting with STEMI at a median of 255 days (interquartile range: 9 to 680 days) after TAVR. Procedural features of STEMI after TAVR managed with primary percutaneous coronary intervention (PCI) were compared with all-comer STEMI: 439 non-TAVR patients who had primary PCI within the 2 weeks before and after each post-TAVR STEMI case in 5 participating centers from different countries. Results: Median door-to-balloon time was higher in TAVR patients (40 min [interquartile range: 25 to 57 min] vs. 30 min [interquartile range: 25 to 35 min]; p = 0.003). Procedural time, fluoroscopy time, dose-area product, and contrast volume were also higher in TAVR patients (p < 0.01 for all). PCI failure occurred more frequently in patients with previous TAVR (16.5% vs. 3.9%; p < 0.001), including 5 patients in whom the culprit lesion was not revascularized owing to coronary ostia cannulation failure. In-hospital and late (median of 7 months [interquartile range: 1 to 21 months]) mortality rates were 25.4% and 42.4%, respectively (20.6% and 38.2% in primary PCI patients), and estimated glomerular filtration rate <60 ml/min (hazard ratio [HR]: 3.02; 95% confidence interval [CI]: 1.42 to 6.43; p = 0.004), Killip class 652 (HR: 2.74; 95% CI: 1.37 to 5.49; p = 0.004), and PCI failure (HR: 3.23; 95% CI: 1.42 to 7.31; p = 0.005) determined an increased risk. Conclusions: STEMI after TAVR was associated with very high in-hospital and mid-term mortality. Longer door-to-balloon times and a higher PCI failure rate were observed in TAVR patients, partially due to coronary access issues specific to the TAVR population, and this was associated with poorer outcomes

Class II HLA interactions modulate genetic risk for multiple sclerosis

Association studies have greatly refined the understanding of how variation within the human leukocyte antigen (HLA) genes influences risk of multiple sclerosis. However, the extent to which major effects are modulated by interactions is poorly characterized. We analyzed high-density SNP data on 17,465 cases and 30,385 controls from 11 cohorts of European ancestry, in combination with imputation of classical HLA alleles, to build a high-resolution map of HLA genetic risk and assess the evidence for interactions involving classical HLA alleles. Among new and previously identified class II risk alleles (HLA-DRB1*15:01, HLA-DRB1*13:03, HLA-DRB1*03:01, HLA-DRB1*08:01 and HLA-DQB1*03:02) and class I protective alleles (HLA-A*02:01, HLA-B*44:02, HLA-B*38:01 and HLA-B*55:01), we find evidence for two interactions involving pairs of class II alleles: HLA-DQA1*01:01-HLA-DRB1*15:01 and HLA-DQB1*03:01-HLA-DQB1*03:02. We find no evidence for interactions between classical HLA alleles and non-HLA risk-associated variants and estimate a minimal effect of polygenic epistasis in modulating major risk alleles.status: publishe

The Multiple Sclerosis Genomic Map: Role of peripheral immune cells and resident microglia in susceptibility

We assembled and analyzed genetic data of 47,351 multiple sclerosis (MS) subjects and 68,284 control subjects and establish a reference map of the genetic architecture of MS that includes 200 autosomal susceptibility variants outside the major histocompatibility complex (MHC), one chromosome X variant, and 32 independent associations within the extended MHC. We used an ensemble of methods to prioritize up to 551 potentially associated MS susceptibility genes, that implicate multiple innate and adaptive pathways distributed across the cellular components of the immune system. Using expression profiles from purified human microglia, we do find enrichment for MS genes in these brain - resident immune cells. Thus, while MS is most likely initially triggered by perturbation of peripheral immune responses the functional responses of microglia and other brain cells are also altered and may have a role in targeting an autoimmune process to the central nervous system. One Sentence Summary: We report a detailed genetic and genomic map of multiple sclerosis, and describe the role of putatively affected genes in the peripheral immune system and brain resident microglia