Citations

Key Points Pembrolizumab was first shown to be clinically active in CLL patients with RT. PD-1 and PD-L1 expression in tumor microenvironment are promising biomarkers to select RT patients for PD-1 blockade.

Background Healthcare resources vary geographically, but associations between hospital‐based resources and acute stroke quality and outcomes remain unclear. Methods and Results Using Get With The Guidelines‐Stroke and Dartmouth Atlas of Health Care data, we examined associations between healthcare resource availability, stroke care, and outcomes. We categorized hospital referral regions with high‐, medium‐, or low‐resource levels based on the 2006 national per‐capita availability median of 6 relevant acute stroke care resources. Using multivariable logistic regression, we examined healthcare resource level and in‐hospital quality and outcomes. Of 1 480 308 admitted ischemic stroke patients (2006–2013), 28.8% were hospitalized in low‐, 44.4% in medium‐, and 26.9% in high‐resource hospital referral regions. Quality‐of‐care/timeliness metrics, adjusted length of stay, and in‐hospital mortality were similar across all resource levels. Conclusions Significant variation exists in regional availability of healthcare resources for acute ischemic stroke treatment, yet among Get With the Guidelines‐Stroke hospitals, quality of care and in‐hospital outcomes did not differ by regional resource availability.

AbstractObjectiveTo identify the molecular basis and elucidate the pathogenesis of a fatal congenital myasthenic syndrome.MethodsWe performed clinical electrophysiology studies, exome and Sanger sequencing, and analyzed functional consequences of the identified mutation.ResultsClinical electrophysiology studies of the patient revealed several‐fold potentiation of the evoked muscle action potential by high frequency nerve stimulation pointing to a presynaptic defect. Exome sequencing identified a homozygous c.340delA frameshift mutation in synaptobrevin 1 (SYB1), one of the three SNARE proteins essential for synaptic vesicle exocytosis. Analysis of both human spinal cord gray matter and normal human muscle revealed expression of the SYB1A and SYB1D isoforms, predicting expression of one or both isoforms in the motor nerve terminal. The identified mutation elongates the intravesicular C‐terminus of the A isoform from 5 to 71, and of the D isoform from 4 to 31 residues. Transfection of either mutant isoform into bovine chromaffin cells markedly reduces depolarization‐evoked exocytosis, and transfection of either mutant isoform into HEK cells significantly decreases expression of either mutant compared to wild type.InterpretationThe mutation is pathogenic because elongation of the intravesicular C‐terminus of the A and D isoforms increases the energy required to move their C‐terminus into the synaptic vesicle membrane, a key step for fusion of the synaptic vesicle with the presynaptic membrane, and because it is predicted to reduce expression of either isoform in the nerve terminal.

Key Points IMiDs inhibit TrxR-mediated intracellular decomposition of H2O2 and caused oxidative stress in MM cells. MM cells with lower antioxidative capacity were more vulnerable to lenalidomide-induced H2O2 accumulation and its associated cytotoxicity.

Abstract B7-H1 (aka PD-L1) blocking antibodies have been tested in the treatment of human cancers through blocking B7-H1 expressed by tumor cells; however, its impact on B7-H1 expressed by tumor-reactive CD8+ T cells is still unknown. Here, we report that tumor-reactive CD8+ T cells expressing B7-H1 were functional effector cells. An agonist antibody to PD-L1 deleted B7-H1+ PD-1+ tumor-reactive CD8+ T cells via activation of p38 MAPK, and failed to suppress tumor growth. As activation of p38 MAPK leads to CD8+ T cell apoptosis upon T cell activation, a PD-L1 antibody that activated p38 MAPK enhanced apoptosis of activated CD8+ T cells. An intracellular molecule, DNA-PKcs, was identified in association with B7-H1 and a DNA-PKcs inhibitor increased p38 MAPK activation in wild type but not in B7-H1 deficient CD8+ T cells. Our results suggest B7-H1 suppresses p38 MAPK activation via DNA-PKcs to prevent CD8+ T cell death. To maximize antitumor function, PD-L1 antibodies should be selected to avoid their collateral activation of p38 MAPK in tumor-reactive CD8+ T cells. Citation Format: Siyu Cao, Xin Liu, Xiaosheng Wu, Aaron Mansfield, Haidong Dong. B7-H1 identifies tumor-reactive effector CD8 T cells susceptible of deletion by agonist PD-L1 antibodies [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A131.

BACKGROUND: The lipoprotein scavenger receptor BI ( SCARB1 ) rs10846744 noncoding variant is significantly associated with atherosclerotic disease independently of traditional cardiovascular risk factors. We identified a potentially novel connection between rs10846744, the immune checkpoint inhibitor lymphocyte activation gene 3 ( LAG3 ), and atherosclerosis. METHODS: In vitro approaches included flow cytometry, lipid raft isolation, phosphosignaling, cytokine measurements, and overexpressing and silencing LAG3 protein. Fasting plasma LAG3 protein was measured in hyperalphalipoproteinemic (HALP) and Multi-Ethnic Study of Atherosclerosis (MESA) participants. RESULTS: In comparison with rs10846744 reference (GG homozygous) cells, LAG3 protein levels by flow cytometry ( P < 0.001), in lipid rafts stimulated and unstimulated ( P = 0.03), and phosphosignaling downstream of B cell receptor engagement of CD79A ( P = 0.04), CD19 ( P = 0.04), and LYN ( P = 0.001) were lower in rs10846744 risk (CC homozygous) cells. Overexpressing LAG3 protein in risk cells and silencing LAG3 in reference cells confirmed its importance in phosphosignaling. Secretion of TNF-α was higher ( P = 0.04) and IL-10 was lower ( P = 0.04) in risk cells. Plasma LAG3 levels were lower in HALP carriers of the CC allele ( P < 0.0001) and by race ( P = 0.004). In MESA, race ( P = 0.0005), age ( P = 0.003), lipid medications ( P = 0.03), smoking history ( P < 0.0001), and rs10846744 genotype ( P = 0.002) were independent predictors of plasma LAG3. In multivariable regression models, plasma LAG3 was significantly associated with HDL-cholesterol (HDL-C) ( P = 0.007), plasma IL-10 ( P < 0.0001), and provided additional predictive value above the Framingham risk score ( P = 0.04). In MESA, when stratified by high HDL-C, plasma LAG3 was associated with coronary heart disease (CHD) (odds ratio 1.45, P = 0.004). CONCLUSION: Plasma LAG3 is a potentially novel independent predictor of HDL-C levels and CHD risk. FUNDING: This work was supported by an NIH RO1 grant (HL075646), the endowed Linda and David Roth Chair for Cardiovascular Research, and the Harold S. Geneen Charitable Trust Coronary Heart Disease Research award to Annabelle Rodriguez. MESA is conducted and supported by the National Heart, Lung, and Blood Institute (NHLBI) in collaboration with MESA investigators. Support for MESA is provided by contracts HHSN268201500003I, N01-HC-95159, N01-HC-95160, N01-HC-95161, N01-HC-95162, N01-HC-95163, N01-HC-95164, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168, N01-HC-95169, UL1-TR-001079, UL1-TR-000040, and DK063491. Cardiometabochip genotyping data for the MESA samples was supported in part by grants and contracts R01HL98077, N02-HL-64278, HL071205, UL1TR000124, DK063491, RD831697, and P50 ES015915.

Background— Lead-related or valve-related endocarditis can complicate cardiovascular implantable electronic device (CIED) infection in patients with both CIED and prosthetic valves. The objective of this study was to determine the outcomes of transvenous lead extraction for CIED infection in patients with prosthetic valves. Methods and Results— We retrospectively screened 794 transvenous lead extraction procedures, between September 1, 2001 and August 31, 2012, at Mayo Clinic to identify patients with prosthetic valves who underwent lead extraction for infection. Demographic, clinical, and follow-up characteristics were analyzed. In total, 51 patients (6%) met the study inclusion criteria, of whom 20 had pocket infection and 31 had lead-related or valve-related, or both, endocarditis or bloodstream infection (mean age, 67 [18] years). Staphylococcal species were the most common pathogens, including Staphylococcus aureus in 20 cases (39%) and coagulase-negative staphylococci in 19 cases (37%). Overall, 127 transvenous leads (median lead age, 52 months) were extracted. Of these leads, 123 (97%) were removed completely. The in-hospital mortality rate was 9.8%; no deaths were attributable to the extraction procedure. Ninety-five percent of patients who survived had no evidence of recurrent device-related or valve-related infection. Conclusions— Transvenous lead extraction seems safe and curative in patients with CIED infection and prosthetic valves. Cure of infection can be achieved in the majority of patients with complete CIED removal and antimicrobial therapy and without valve surgery.