Tracking the role of Aire in immune tolerance to the eye with a TCR transgenic mouse model.

Roughly one-half of mice with partial defects in two immune tolerance pathways (AireGW/+Lyn-/- mice) spontaneously develop severe damage to their retinas due to T cell reactivity to Aire-regulated interphotoreceptor retinoid-binding protein (IRBP). Single-cell T cell receptor (TCR) sequencing of CD4+ T cells specific for a predominate epitope of IRBP showed a remarkable diversity of autoantigen-specific TCRs with greater clonal expansions in mice with disease. TCR transgenic mice made with an expanded IRBP-specific TCR (P2.U2) of intermediate affinity exhibited strong but incomplete negative selection of thymocytes. This negative selection was absent in IRBP-/- mice and greatly defective in AireGW/+ mice. Most P2.U2+/- mice and all P2.U.2+/-AireGW/+ mice rapidly developed inflammation of the retina and adjacent uvea (uveitis). Aire-dependent IRBP expression in the thymus also promoted Treg differentiation, but the niche for this fate determination was small, suggesting differences in antigen presentation leading to negative selection vs. thymic Treg differentiation and a stronger role for negative selection in preventing autoimmune disease in the retina.

Thrombotic risk in patients with acute coronary syndromes discharged on prasugrel or clopidogrel: results from the PROMETHEUS study.

AIMS: Based on recent clinical data, the 2020 ESC guidelines on non-ST-elevation acute coronary syndrome (NSTE-ACS) suggest to tailor antithrombotic strategy on individual thrombotic risk. Nonetheless, prevalence and prognostic impact of the high thrombotic risk (HTR) criteria proposed are yet to be described. In this analysis from the PROMETHEUS registry, we assessed prevalence and prognostic impact of HTR, defined according to the 2020 ESC NSTE-ACS guidelines, and if the benefits associated with prasugrel vs. clopidogrel vary with thrombotic risk. METHODS AND RESULTS: PROMETHEUS was a multicentre prospective study comparing prasugrel vs. clopidogrel in ACS patients undergoing percutaneous coronary intervention (PCI). Patients were at HTR if presenting with one clinical plus one procedural risk feature. The primary endpoint was major adverse cardiac events (MACE), composite of death, myocardial infarction, stroke, or unplanned revascularization, at 1 year. Adjusted hazard ratio (adjHR) and 95% confidence intervals (CIs) were calculated with propensity score stratification and multivariable Cox regression. Among 16 065 patients, 4293 (26.7%) were at HTR and 11 772 (73.3%) at low-to-moderate thrombotic risk. The HTR conferred increased incidence of MACE (23.3 vs. 13.6%, HR 1.85, 95% CI 1.71-2.00, P < 0.001) and its single components. Prasugrel was prescribed in patients with less comorbidities and risk factors and was associated with reduced risk of MACE (HTR: adjHR 0.83, 95% CI 0.68-1.02; low-to-moderate risk: adjHR 0.75, 95% CI 0.64-0.88; pinteraction = 0.32). CONCLUSION: High thrombotic risk, as defined by the 2020 ESC NSTE-ACS guidelines, is highly prevalent among ACS patients undergoing PCI. The HTR definition had a strong prognostic impact, as it successfully identified patients at increased 1 year risk of ischaemic events.

Chewed Versus Swallowed Ticagrelor in P2Y12 Inhibitor-Naïve Patients Undergoing Percutaneous Coronary Intervention.

Purpose: Dual antiplatelet therapy is standard for patients undergoing percutaneous coronary intervention (PCI) with stents. Traditionally, patients swallow the loading dose of a P2Y12 inhibitor before or during PCI. Time to achieve adequate platelet inhibition after swallowing the loading dose varies significantly. Chewed tablets may allow more rapid inhibition of platelet aggregation. However, data for this strategy in patients with stable ischemic heart disease or non-ST-elevation acute coronary syndrome (NSTE-ACS) are less robust. Methods: In this single-center prospective trial, 112 P2Y12-naïve patients with stable ischemic heart disease or NSTE-ACS on aspirin therapy and who received ticagrelor after coronary angiography but before PCI were randomized to chewing (n=55) or swallowing (n=57) the ticagrelor loading dose (180 mg). Baseline variables were compared using 2-sample t-test and chi-squared/Fisher's exact tests as appropriate, with alpha set at 0.05. P2Y12 reaction units (PRU) were compared at baseline, 1 hour, and 4 hours using Wilcoxon rank-sum test. Patients then received standard ticagrelor dosing. Results: After exclusions, P2Y12 PRU in the chewed and swallowed groups at baseline, 1 hour, and 4 hours after ticagrelor loading dose were 243 vs 256 (P=0.75), 143 vs 210 (P=0.09), and 28 vs 25 (P=0.89), respectively. No differences were found in major adverse cardiac events (MACE) or major bleeding at 30 days and 1 year. Conclusions: In patients with stable ischemic heart disease or NSTE-ACS, chewing rather than swallowing ticagrelor may lead to slightly faster inhibition of platelet aggregation at 1 hour with no increase in MACE or major bleeding.

Antithrombotic strategy variability in atrial fibrillation and obstructive coronary disease revascularised with percutaneous coronary intervention: primary results from the AVIATOR 2 international registry.

BACKGROUND: Managing percutaneous coronary intervention (PCI) patients with atrial fibrillation (AF) presents challenges given that there are several potential antithrombotic therapy (ATT) strategies. AIMS: We examined ATT patterns, agreement between subjective physician ratings and validated risk scores, physician-patient perceptions influencing ATT and 1-year outcomes. METHODS: The AVIATOR 2 prospective registry enrolled 514 non-valvular AF-PCI patients from 11 sites. Treating physicians selected ATT and completed smartphone surveys rating stroke and bleeding risks, compared against CHA2DS2-VASc and HAS-BLED scores. Patients completed surveys regarding treatment understanding. Primary outcomes were 1-year major adverse cardiac or cerebrovascular events (MACCE: composite of death, myocardial infarction, definite/probable stent thrombosis, stroke, target lesion revascularisation) and actionable bleeding (Bleeding Academic Research Consortium 2, 3 or 5). RESULTS: The mean patient age was 73.2±9.0 years, including 25.8% females. Triple therapy (TT: 1 anticoagulant and 2 antiplatelet agents) was prescribed in 66.5%, dual antiplatelet therapy (DAPT) in 20.7% and dual therapy (1 anticoagulant+1 antiplatelet agent) in 12.8% of patients. Physician ratings and validated risk scores showed poor agreement (stroke: kappa=0.03; bleeding: kappa=0.07). Physicians rated bleeding-related safety (93.8%) as the main factor affecting ATT choice. Patients worried about stroke over bleeding (50.6% vs 14.8%). No group differences by ATT strategy were observed in 1-year MACCE (TT 14.1% vs dual therapy 12.7% vs DAPT 18.5%; p=0.25), or actionable bleeding (14.7% vs 7.9% vs 15.1%, respectively; p=0.89). CONCLUSIONS: The AVIATOR 2 study is the first digital health study examining physician-patient perspectives on ATT choices after AF-PCI. TT was the most common strategy without differences in 1-year outcomes in ATT strategy. Physicians rated safety first when prescribing ATT; patients feared stroke over bleeding. CLINICALTRIALS: gov: NCT02362659.

Insights From Modern Imaging and Catheter Wire Measurements in Patients Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Prior studies have neither described methods for crossing a severely stenotic aortic valve (AV) in light of modern imaging modalities (echocardiography, computed tomography, fluoroscopy) nor characterized a successful crossing. This study aimed to fill that gap. METHODS: Time to cross the valve (TTCV) was measured prospectively in 35 consecutive patients undergoing transcatheter AV replacement and used to define two groups (≤60 seconds or >60 seconds). TTCV was analyzed as a function of 20 imaging variables. The AV was crossed systematically with a pigtail catheter parked in the non-coronary cusp, AL-1 catheter above the AV, and a straight wire for crossing, in 20° left anterior oblique view, as the operator adjusted catheter-to-catheter (CTC; AL-1 to pigtail) and catheter-to-wire (CTW; pigtail to wire) with each failed pass. RESULTS: Mean TTCV was 39.5 ± 59 seconds. Of all the imaging variables, only lower AV peak velocity (3.9 ± 0.69 m/s vs 4.28 ± 0.35 m/s; P<.05) and larger aortic annulus perimeter (77 ± 5.7 mm vs 65 ± 23 mm; P<.05) were significantly different in the <60 group (n = 29; TTCV, 21 ± 12 seconds) vs the >60 group (n = 6; TTCV, 157 ± 52 seconds). The successful pass was characterized by a CTC of 1.67 ± 0.78 cm and CTW of 0.2 ± 0.36 cm. These distances increased in horizontal hearts (CTC and CTW were 0.76 cm) to higher in normally oriented hearts (CTC, 1.63 cm; CTW, 0.5 cm) to even higher in vertical hearts (CTC, 2.9 cm; CTW, 0.56 cm). CONCLUSION: Although lower peak jet velocity was associated with rapid AV crossing, the major insight from these data is characterization of a successful pass, which can facilitate clinical practice.

Prasugrel use and clinical outcomes by age among patients undergoing PCI for acute coronary syndrome: from the PROMETHEUS study.

BACKGROUND: Prasugrel is a potent thienopyridine that may be preferentially used in younger patients with lower bleeding risk. OBJECTIVE: We compared prasugrel use and outcomes by age from the PROMETHEUS study. We also assessed age-related trends in treatment effects with prasugrel versus clopidogrel. METHODS: PROMETHEUS was a multicenter acute coronary syndrome (ACS) percutaneous coronary intervention (PCI) registry. We compared patients in age tertiles (T1 < 60 years, T2 60-70 years, T3 > 70 years). Major adverse cardiac events (MACE) were a composite of death, myocardial infarction, stroke or unplanned revascularization. Data were adjusted using multivariable Cox regression for age-related risks and propensity score stratification for thienopyridine effects. RESULTS: The study included 19,914 patients: 7045 (35.0%) in T1, 6489 (33.0%) in T2 and 6380 (32.0%) in T3. Prasugrel use decreased from T1 to T3 (29.2% vs. 23.5% vs. 7.5%, p < 0.001). Crude 1-year MACE rates were highest in T3 (17.4% vs. 16.8% vs. 22.7%, p < 0.001), but adjusted risk was similar between the groups (p-trend 0.52). Conversely, crude incidence (2.8% vs. 3.8% vs. 6.9%, p < 0.001) and adjusted bleeding risk were highest in T3 (HR 1.24, 95% CI 0.99-1.55 in T2; HR 1.83, 95% CI 1.46-2.30 in T3; p-trend < 0.001; reference = T1). Treatment effects with prasugrel versus clopidogrel did not demonstrate age-related trends for MACE (p-trend = 0.91) or bleeding (p-trend = 0.28). CONCLUSIONS: Age is a strong determinant of clinical risk as well as prasugrel prescription in ACS PCI with much lower use among older patients. Prasugrel did not have a differential treatment effect by age for MACE or bleeding. Frequency of prasugrel use and age-related temporal risks of all-cause death and bleeding after ACS PCI.

Incidence, predictors and impact of stroke on mortality among patients with acute coronary syndromes following percutaneous coronary intervention-Results from the PROMETHEUS registry.

BACKGROUND: Stroke represents a potentially calamitous complication among patients with acute coronary syndrome (ACS) undergoing percutaneous intervention (PCI). Data on the distribution of stroke occurrence post-PCI and its impact on mortality are scarce. OBJECTIVES: We sought to determine the incidence, predictors and impact of stroke on mortality in ACS patients undergoing PCI. METHODS: A total of 19,914 ACS patients underwent PCI in the PROMETHEUS multicenter observational study. We calculated the cumulative stroke incidence at 30 days and 1 year using the Kaplan Meier method. We also compared the distribution of stroke, myocardial infarction (MI), and bleeding across time and evaluated their overlap. Predictors of stroke were identified through multivariable Cox-regression. Stroke, MI, and bleeding were assessed as time-updated covariates to estimate how each impacts subsequent mortality. RESULTS: We found that 244 patients had a stroke within 1 year, a cumulative incidence of 1.5%. Previous cerebrovascular disease was the strongest predictor for post-PCI stroke, followed by ST-elevation MI presentation, hypertension, non-ST-elevation MI presentation, smoking, female sex, and age. Mortality risk was significantly higher among those who had a stroke versus those who did not (adjusted HR 4.84, p < .0001). However, the association attenuated over time with a much larger effect in the first 30 days of its occurrence (adjusted HR 17.7; 95% CI: 12.3-25.4, p < .0001) versus beyond 30 days (adjusted HR 1.22; 95% CI: 0.6-2.46, p = .58). CONCLUSIONS: Stroke occurrence within 1 year was not uncommon for ACS patients undergoing PCI. When compared with MI and bleeding, stroke had a substantial impact on mortality that attenuated rapidly over time.

Antigen Complexed with a TLR9 Agonist Bolsters c-Myc and mTORC1 Activity in Germinal Center B Lymphocytes.

The germinal center (GC) is the anatomical site where humoral immunity evolves. B cells undergo cycles of proliferation and selection to produce high-affinity Abs against Ag. Direct linkage of a TLR9 agonist (CpG) to a T-dependent Ag increases the number of GC B cells. We used a T-dependent Ag complexed with CpG and a genetic model for ablating the TLR9 signaling adaptor molecule MyD88 specifically in B cells (B-MyD88- mice) together with transcriptomics to determine how this innate pathway positively regulates the GC. GC B cells from complex Ag-immunized B-MyD88- mice were defective in inducing gene expression signatures downstream of c-Myc and mTORC1. In agreement with the latter gene signature, ribosomal protein S6 phosphorylation was increased in GC B cells from wild-type mice compared with B-MyD88- mice. However, GC B cell expression of a c-Myc protein reporter was enhanced by CpG attached to Ag in both wild-type and B-MyD88- mice, indicating a B cell-extrinsic effect on c-Myc protein expression combined with a B cell-intrinsic enhancement of gene expression downstream of c-Myc. Both mTORC1 activity and c-Myc are directly induced by T cell help, indicating that TLR9 signaling in GC B cells either enhances their access to T cell help or directly influences these pathways to further enhance the effect of T cell help. Taken together, these findings indicate that TLR9 signaling in the GC could provide a surrogate prosurvival stimulus, "TLR help," thus lowering the threshold for selection and increasing the magnitude of the GC response.

Associations between use of prasugrel vs clopidogrel and outcomes by type of acute coronary syndrome: an analysis from the PROMETHEUS registry.

We sought to investigate the utilization of prasugrel and its association with outcomes relative to clopidogrel in three typical subgroups of ACS in a real-world setting. Prasugrel is superior to clopidogrel for reducing risk of ischemic events in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), but is associated with an increased risk of bleeding complications. PROMETHEUS was a retrospective multicenter observational study of 19,913 ACS patients undergoing PCI from 8 centers in the United States between 2010 and 2013. Major adverse cardiovascular events (MACE) were defined as a composite of all-cause mortality, myocardial infarction, stroke or unplanned revascularization. The study cohort included 3285 (16.5%) patients with ST-segment elevation myocardial infarction (STEMI), 5412 (27.2%) patients with NSTEMI and 11,216 (56.3%) patients with unstable angina (UA). The frequency of prasugrel use at discharge was highest in STEMI and lowest in UA patients, 27.3% versus 22.2% versus 18.9% (p < 0.001). Use of prasugrel vs clopidogrel was associated with a lower rate of MACE in STEMI, NSTEMI, or UA at 1 year, but the differences were attenuated for all groups except for patients with UA (adjusted HR 0.81, 95% CI 0.69-0.94, p = 0.006) after propensity adjusted analysis. After adjustment, there was no difference in bleeding risk between prasugrel and clopidogrel for all groups at 1 year. STEMI patients were more likely to receive prasugrel compared to NSTEMI and UA patients. Prasugrel was associated with reduced adverse outcomes compared with clopidogrel in unadjusted analyses, findings that were largely attenuated upon adjustment and suggest preferential use of prasugrel in low vs high risk patients.

Use of prasugrel and clinical outcomes in African-American patients treated with percutaneous coronary intervention for acute coronary syndromes.

OBJECTIVE: To investigate the use of prasugrel after percutaneous coronary intervention (PCI) in African American (AA) patients presenting with acute coronary syndrome (ACS). BACKGROUND: AA patients are at higher risk for adverse cardiovascular outcomes after PCI and may derive greater benefit from the use of potent antiplatelet therapy. METHODS: Using the multicenter PROMETHEUS observational registry of ACS patients treated with PCI, we grouped patients by self-reported AA or other races. Clinical outcomes at 90-day and 1-year included non-fatal myocardial infarction (MI), major adverse cardiac events (composite of death, MI, stroke, or unplanned revascularization) and major bleeding. RESULTS: The study population included 2,125 (11%) AA and 17,707 (89%) non-AA patients. AA patients were younger, more often female (46% vs. 30%) with a higher prevalence of diabetes mellitus, chronic kidney disease, and prior coronary intervention than non-AA patients. Although AA patients more often presented with troponin (+) ACS, prasugrel use was much less common in AA vs. non-AA (11.9% vs. 21.4%, respectively, P = 0.001). In addition, the use of prasugrel increased with the severity of presentation in non-AA but not in AA patients. Multivariable logistic regression showed AA race was an independent predictor of reduced use of prasugrel (0.42 [0.37-0.49], P < 0.0001). AA race was independently associated with a significantly higher risk of MI at 90-days and 1 year after PCI. CONCLUSIONS: Despite higher risk clinical presentation and worse 1-year ischemic outcomes, AA race was an independent predictor of lower prasugrel prescription in a contemporary population of ACS patients undergoing PCI.

Use of prasugrel vs clopidogrel and outcomes in patients with and without diabetes mellitus presenting with acute coronary syndrome undergoing percutaneous coronary intervention.

BACKGROUND: Clinical trial data studies suggest superiority of prasugrel over clopidogrel in patients with diabetes. However, the use, safety and efficacy profile of prasugrel in unselected diabetic patients presenting with acute coronary syndromes (ACS) remain unclear. METHODS: PROMETHEUS was a prospective multicenter observational study of 19,919 ACS PCI patients enrolled between 2010 and 2013. The primary endpoint was 90-day major adverse cardiovascular events (MACE), comprising all-cause death, myocardial infarction, stroke or unplanned revascularization. The safety endpoint was bleeding requiring hospitalization. RESULTS: We identified 7580 (38%) subjects with and 12,329 (62%) without diabetes. Diabetic patients were older and had significantly higher rates of cardiovascular risk factors. However, they were less likely to receive prasugrel (18.2% vs. 21.7%). Use of prasugrel did not increase with the severity of clinical presentation in diabetics, whereas, among non-diabetics, prescription of prasugrel was higher in NSTEMI and STEMI compared to unstable angina. The 90-day and 1-year adjusted risk of MACE was greater in diabetics (at 1 year: 22.7% vs. 16.5%; HR 1.22 [1.14-1.33], p < 0.001). At 1 year, the risk of bleeding was also higher in diabetics (4.9% vs. 4.1%, HR 1.19 [1.01-1.39], p = 0.035). After multivariable adjustment, use of prasugrel was associated with a lower risk of death in diabetic patients both at 90 days and 1 year. CONCLUSIONS: Use of prasugrel in diabetic patients with PCI-treated ACS was lower than in non-diabetics despite their high-risk profile and the severity of their clinical presentation. In diabetics, prasugrel was associated with a lower adjusted risk of 90-day death compared with clopidogrel.

The prevalence, predictors and outcomes of guideline-directed medical therapy in patients with acute myocardial infarction undergoing PCI, an analysis from the PROMETHEUS registry.

OBJECTIVES: To investigate the prevalence, predictors and associations between guideline-directed medical therapy (GDMT) and clinical outcomes in acute myocardial infarction (AMI) patients undergoing percutaneous coronary intervention (PCI) from eight academic centers in the United States. BACKGROUND: Evidence for GDMT in patients with AMI comes from randomized controlled trials. The use of GDMT in clinical practice is unknown in this setting. METHODS: PROMETHEUS is a multicenter observational registry comprising 19,914 patients with acute coronary syndrome (ACS) undergoing PCI. Patients with AMI were divided into two groups based on the prescription of GDMT or not (non-GDMT) at discharge. GDMT was defined according to American College of Cardiology/American Heart Association (ACC/AHA) class I recommendations, specifically, dual antiplatelet therapy, statin and beta-blocker for all AMI patients, and additional ACEI/ARB in patients with left ventricular ejection fraction (LVEF) less than 40%, hypertension, diabetes mellitus (DM) or chronic kidney disease (CKD). The primary endpoint was major adverse cardiovascular events (MACE) defined as a composite of all-cause death, MI, stroke or unplanned target vessel revascularization (TVR) at 1 year. RESULTS: Out of 4,834 patients with AMI, 3,356 (69.4%) patients were discharged on GDMT. Patients receiving GDMT were more often younger and male. Compared with non-GDMT patients, GDMT patients had a significantly lower frequency of comorbidities. Predictors of greater GDMT prescription at discharge were ST-segment elevation myocardial infarction (STEMI), and increased body mass index (BMI), whereas hypertension, prior PCI, anemia and CKD were associated with less GDMT prescription. At 1 year, the use of GDMT was associated with a significantly lower incidence of MACE (13.7% vs. 22.5%; adjusted HR 0.68; 95%CI 0.58-0.80; P < 0.001), death (3.7% vs. 9.4%; adjusted HR 0.61; 95%CI 0.46-0.80; P < 0.001), and unplanned TVR (8.4% vs. 11.3%; adjusted HR 0.76; 95%CI 0.61-0.96; P = 0.020). However, there were no significant differences in the incidence of MI (4.3% vs. 7.0%; adjusted HR 0.75; 95%CI 0.56-1.01; P = 0.056), stroke (1.5% vs. 2.0%; adjusted HR 0.79; 95%CI 0.47-1.34; P = 0.384) between the two groups. CONCLUSION: In a contemporary practice setting in the United States, GDMT was utilized in just over two-thirds of AMI patients undergoing PCI. Predictors of GDMT prescription at discharge included STEMI, BMI and absence of hypertension, CKD, anemia or prior PCI. Use of GDMT was associated with significantly lower risk of 1-year MACE and mortality.

Understanding the Musical Dance of the Engaged Coronary Catheter: Insights From Advanced Myocardial Mechanics.

A case of a 56-year-old woman with normal coronaries displays the side-to-side motion of the unengaged catheter followed by the rhythmic up-and-down, piston-like movements of the catheter tip after engagement.

Multilayer Control of B Cell Activation by the B Cell Antigen Receptor: Following Themes Initiated With Bill Paul.

This article describes the work I did in Bill Paul's lab as a postdoctoral fellow between 1979 and 1983, and to a lesser extent puts that work in the context of other work on B cell activation and antibody responses that was going on in Bill's lab at that time and shortly beforehand, including the discovery of interleukin 4. In addition, this work describes the subsequent and continuing work in my own lab following-up on themes I began during my time working directly with Bill. A particular emphasis was on understanding the biochemical mechanisms of signaling by the B cell antigen receptor (BCR) to the interior of the B cell. Some of the studies from my lab related to the regulation of BCR signaling by Lyn are described in relationship to the lymphocyte tuning hypothesis put forth by Grossman and Paul in 1992 and subsequently.

Associations Between Complex PCI and Prasugrel or Clopidogrel Use in Patients With Acute Coronary Syndrome Who Undergo PCI: From the PROMETHEUS Study.

BACKGROUND: Potent P2Y12 inhibitors might offer enhanced benefit against thrombotic events in complex percutaneous coronary intervention (PCI). We examined prasugrel use and outcomes according to PCI complexity, as well as analyzing treatment effects according to thienopyridine type. METHODS: PROMETHEUS was a multicentre observational study that compared clopidogrel vs prasugrel in acute coronary syndrome patients who underwent PCI (n = 19,914). Complex PCI was defined as PCI of the left main, bifurcation lesion, moderate-severely calcified lesion, or total stent length ≥ 30 mm. Major adverse cardiac events (MACE) were a composite of death, myocardial infarction, stroke, or unplanned revascularization. Outcomes were adjusted using multivariable Cox regression for effect of PCI complexity and propensity-stratified analysis for effect of thienopyridine type. RESULTS: The study cohort included 48.9% (n = 9735) complex and 51.1% (n = 10,179) noncomplex patients. Second generation drug-eluting stents were used in 70.1% complex and 66.2% noncomplex PCI patients (P < 0.0001). Complex PCI was associated with greater adjusted risk of 1-year MACE (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.20-1.39; P < 0.001). Prasugrel was prescribed in 20.7% of complex and 20.1% of noncomplex PCI patients (P = 0.30). Compared with clopidogrel, prasugrel significantly decreased adjusted risk for 1-year MACE in complex PCI (HR, 0.79; 95% CI, 0.68-0.92) but not noncomplex PCI (HR, 0.91; 95% CI, 0.77-1.08), albeit there was no evidence of interaction (P interaction = 0.281). CONCLUSIONS: Despite the use of contemporary techniques, acute coronary syndrome patients who undergo complex PCI had significantly higher rates of 1-year MACE. Adjusted magnitude of treatment effects with prasugrel vs clopidogrel were consistent in complex and noncomplex PCI without evidence of interaction.

B Cell-Intrinsic MyD88 Signaling Promotes Initial Cell Proliferation and Differentiation To Enhance the Germinal Center Response to a Virus-like Particle.

Although TLR signaling in B cells has been implicated in the germinal center (GC) responses during viral infections and autoimmune diseases, the underlying mechanism is unclear. Bacterial phage Qß-derived virus-like particle (Qß-VLP) contains TLR ligands, which can enhance Qß-VLP-induced Ab response, including GC response, through TLR/MyD88 signaling in B cells. In this study, by examining Ag-specific B cell response to Qß-VLP, we found that lack of B cell MyD88 from the beginning of the immune response led to a more severe defect in the GC scale than abolishing MyD88 at later time points of the immune response. Consistently, B cell-intrinsic MyD88 signaling significantly enhanced the initial proliferation of Ag-specific B cells, which was accompanied with a dramatic increase of plasma cell generation and induction of Bcl-6+ GC B cell precursors. In addition, B cell-intrinsic MyD88 signaling promoted strong T-bet expression independent of IFN-γ and led to the preferential isotype switching to IgG2a/c. Thus, by promoting the initial Ag-specific B cell proliferation and differentiation, B cell-intrinsic MyD88 signaling enhanced both T-independent and T-dependent Ab responses elicited by Qß-VLP. This finding will provide additional insight into the role of TLR signaling in antiviral immunity, autoimmune diseases, and vaccine design.

Associations Between Chronic Kidney Disease and Outcomes With Use of Prasugrel Versus Clopidogrel in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Report From the PROMETHEUS Study.

OBJECTIVES: This study sought to compare clinical outcomes in a contemporary acute coronary syndrome (ACS) percutaneous coronary intervention (PCI) cohort stratified by chronic kidney disease (CKD) status. BACKGROUND: Patients with CKD exhibit high risks for both thrombotic and bleeding events, thus complicating decision making regarding antiplatelet therapy in the setting of ACS. METHODS: The PROMETHEUS study was a multicenter observational study comparing outcomes with prasugrel versus clopidogrel in ACS PCI patients. Major adverse cardiac events (MACE) at 90 days and at 1 year were defined as a composite of death, myocardial infarction, stroke, or unplanned revascularization. Clinically significant bleeding was defined as bleeding requiring transfusion or hospitalization. Cox regression multivariable analysis was performed for adjusted associations between CKD status and clinical outcomes. Hazard ratios for prasugrel versus clopidogrel treatment were generated using propensity score stratification. RESULTS: The total cohort included 19,832 patients, 28.3% with and 71.7% without CKD. CKD patients were older with greater comorbidities including diabetes and multivessel disease. Prasugrel was less often prescribed to CKD versus non-CKD patients (11.0% vs. 24.0%, respectively; p < 0.001). At 1 year, CKD was associated with higher adjusted risk of MACE (1.27; 95% confidence interval: 1.18 to 1.37) and bleeding (1.46; 95% confidence interval: 1.24 to 1.73). Although unadjusted rates of 1-year MACE were lower with prasugrel versus clopidogrel in both CKD (18.3% vs. 26.5%; p < 0.001) and non-CKD (10.9% vs. 17.9%; p < 0.001) patients, associations were attenuated after propensity stratification. Similarly, unadjusted differences in 1-year bleeding with prasugrel versus clopidogrel (6.0% vs. 7.4%; p = 0.18 in CKD patients; 2.6% vs. 3.5%; p = 0.008 in non-CKD patients) were not significant after propensity score adjustment. CONCLUSIONS: Although risks for 1-year MACE were significantly higher in ACS PCI patients with versus without CKD, prasugrel use was 50% lower in patients with renal impairment. Irrespective of CKD status, outcomes associated with prasugrel use were not significant after propensity adjustment. These data highlight the need for randomized studies evaluating the optimal antiplatelet therapy in CKD patients with ACS.

Role of MyD88 signaling in the imiquimod-induced mouse model of psoriasis: focus on innate myeloid cells.

Psoriasis is a chronic skin disease associated with deregulated activation of immune cells and keratinocytes. In this study, we used the imiquimod (IMQ)-induced mouse model of psoriasis to dissect better the contribution of hematopoietic and skin-resident stromal cells to psoriasis development. The comparison of disease development in mice carrying the hematopoietic cell-specific deletion of MyD88 (Myd88fl/flVav-cre+ mice) with mice carrying the total MyD88 deficiency (Myd88-/- mice), we show that the progression of skin and systemic inflammation, as well as of epidermal thickening, was completely dependent on MyD88 expression in hematopoietic cells. However, both Myd88-/- mouse strains developed some degree of epidermal thickening during the initial stages of IMQ-induced psoriasis, even in the absence of hematopoietic cell activation and infiltration into the skin, suggesting a contribution of MyD88-independent mechanisms in skin-resident stromal cells. With the use of conditional knockout mouse strains lacking MyD88 in distinct lineages of myeloid cells (Myd88fl/flLysM-cre+ and Myd88fl/flMRP8-cre+ mice), we report that MyD88 signaling in monocytes and Mϕ, but not in neutrophils, plays an important role in disease propagation and exacerbation by modulating their ability to sustain γδ T cell effector functions via IL-1ß and IL-23 production. Overall, these findings add new insights into the specific contribution of skin-resident stromal vs. hematopoietic cells to disease initiation and progression in the IMQ-induced mouse model of psoriasis and uncover a potential novel pathogenic role for monocytes/Mϕ to psoriasis development.

Use of prasugrel vs clopidogrel and outcomes in patients with acute coronary syndrome undergoing percutaneous coronary intervention in contemporary clinical practice: Results from the PROMETHEUS study.

BACKGROUND AND OBJECTIVES: We sought to determine the frequency of use and association between prasugrel and outcomes in acute coronary syndrome patients undergoing percutaneous coronary intervention (PCI) in clinical practice. METHODS: PROMETHEUS was a multicenter observational registry of acute coronary syndrome patients undergoing PCI from 8 centers in the United States that maintained a prospective PCI registry for patient outcomes. The primary end points were major adverse cardiovascular events at 90days, a composite of all-cause death, nonfatal myocardial infarction, stroke, or unplanned revascularization. Major bleeding was defined as any bleeding requiring hospitalization or blood transfusion. Hazard ratios (HRs) were generated using multivariable Cox regression and stratified by the propensity to treat with prasugrel. RESULTS: Of 19,914 patients (mean age 64.4years, 32% female), 4,058 received prasugrel (20%) and 15,856 received clopidogrel (80%). Prasugrel-treated patients were younger with fewer comorbid risk factors compared with their counterparts receiving clopidogrel. At 90days, there was a significant association between prasugrel use and lower major adverse cardiovascular event (5.7% vs 9.6%, HR 0.58, 95% CI 0.50-0.67, P<.0001) and bleeding (1.9% vs 2.9%, HR 0.65, 95% CI 0.51-0.83, P<.001). After propensity stratification, associations were attenuated and no longer significant for either outcome. Results remained consistent using different approaches to adjusting for potential confounders. CONCLUSIONS: In contemporary clinical practice, patients receiving prasugrel tend to have a lower-risk profile compared with those receiving clopidogrel. The lower ischemic and bleeding events associated with prasugrel use were no longer evident after accounting for these baseline differences.