Anti-platelet antibodies in patients with systemic lupus erythematosus and the primary antiphospholipid antibody syndrome: their relationship with the observed thrombocytopenia

The role of antiphospholipid antibodies in the pathogenesis of the thrombocytopenia observed during primary antiphospholipid antibody syndrome (APAS) and systemic lupus erythematosus (SLE) remains controversial. We have used the MAIPA test to examine the frequency and specificity of anti-platelet antibodies directed against the major platelet membrane glycoproteins (GP IIb–IIIa, GP Ib–IX, GP Ia–IIa and GP IV) in patients where SLE and APAS were associated or not with thrombocytopenia. Results were compared with a series of 26 ITP patients, 46% of whom were shown to possess anti-platelet antibodies directed against one or more of the platelet surface glycoproteins. When APAS was associated with thrombocytopenia, 7/10 patients possessed antibodies against GP IIb–IIIa and/or GP Ib–IX. For SLE patients with thrombocytopenia, 6/10 patients were shown to have antiplatelet antibodies against GP IIb–IIIa, GP Ib–IX or GP IV. In contrast, for APAS ( n =11) and SLE patients ( n =11) without thrombocytopenia, only one patient had an antibody directed against GP IIb–IIIa and one patient had an antibody to GP IV. Our results suggest that antibodies directed against major platelet membrane glycoproteins may play a role in the thrombocytopenia that is seen during SLE and APAS.     

Enhanced atherogenesis is not an obligatory response to systemic herpesvirus infection in the apoE-deficient mouse: comparison of murine gamma-herpesvirus-68 and herpes simplex virus-1

Viral and bacterial infectious agents have been implicated in the etiology of atherosclerosis. We have previously shown that a gamma-herpesvirus can accelerate atherosclerosis in the apolipoprotein E-deficient (apoE-/-) mouse. To address whether a virally induced systemic immune response is sufficient to trigger enhanced atheroma formation, we infected apoE-/- mice with murine gamma-herpesvirus-68 (MHV-68) or herpes simplex virus-1 (HSV-1). In this study, we show that both viruses were able to induce a cell-mediated and humoral immune response in the apoE-/- mouse, which was sustained over a period of 24 weeks. Although intranasal or intraperitoneal infection with MHV-68 induced similar levels of virus-specific IgG1 and IgG2a antibodies in the serum of apoE-/- mice, those infected with HSV-1 showed higher anti-HSV-1 IgG2a compared with IgG1 antibody levels. In addition, viral message was not detected in the aortas of HSV-1-infected animals, whereas we have shown previously that MHV-68 mRNA can be detected in the aortas of infected mice as early as 5 days after infection. Compared with control mice, apoE-/- mice infected with MHV-68 showed accelerated atherosclerosis, whereas mice infected with HSV-1 did not. These data indicate that a systemic immune response to any particular infectious agent is insufficient to induce enhanced atherosclerosis in the apoE-/- mouse and point to specific infections or immune mechanisms that might be essential for virally enhanced atherogenesis.     

Novel approach to discriminate left bundle branch block from nonspecific intraventricular conduction delay using pacing-induced functional left bundle branch block

Purpose

Left bundle branch block (LBBB) has a predictive value for response to cardiac resynchronization therapy as reported by Zareba et al. (Circulation 123(10):1061–1072, 2011). However, based on ECG criteria, the discrimination between complete LBBB and nonspecific intraventricular conduction delay is challenging. We tested the hypothesis that discrimination can be performed using standard electrophysiological catheters and a simple stimulation protocol.

Methods

Fifty-nine patients were analyzed retrospectively. Patients were divided into groups of narrow QRS (n?=?20), wide QRS of right bundle branch block (RBBB) morphology (n?=?14), and wide QRS of LBBB morphology (n?=?25). Using a diagnostic catheter placed in the coronary sinus, left ventricular activation was assessed during intrinsic conduction as well as during right ventricular (RV) stimulation.

Results

In patients with narrow QRS and RBBB, the Q-LV/QRS ratio was 0.43?±?0.013 (n?=?20) and 0.41?±?0.026 (n?=?14), respectively. In patients with LBBB morphology, the Q-LV/QRS split up into a group of patients with normal (0.43?±?0.022, n?=?7) and a group with delayed left ventricular activation (0.75?±?0.016, n?=?18). By direct comparison of the Q-LV/QRS ratio during intrinsic conduction with the Q-LV/QRS ratio during RV pacing leading to a functional LBBB, a clear distinction between a group of “true LBBB” and another group of “apparent LBBB”/nonspecific intraventricular conduction delay (NICD) could be generated.

Conclusions

We present a novel and practical method that might facilitate discrimination between patients with apparent LBBB and true LBBB by comparing Q-LV/QRS ratios during intrinsic activation and during RV stimulation. Although this method can already be directly applied, validation by 3D electrical mapping and prospective correlation to cardiac resynchronization therapy (CRT) response will be required for further translation into clinical practice.

     

Plaque composition in the left main stem mimics the distal but not the proximal tract of the left coronary artery: influence of clinical presentation, length of the left main trunk, lipid profile, and systemic levels of C-reactive protein.

OBJECTIVES: We sought to investigate whether plaques located in the left main stem (LMS) differ in terms of necrotic core content from those sited in the proximal tract of the left coronary artery. BACKGROUND: Plaque composition, favoring propensity to vulnerability, might be nonuniformly distributed along the vessel, which might explain the greater likelihood for plaque erosion or rupture to occur in the proximal but not in the distal tracts of the coronary artery or in LMS. METHODS: A total of 72 patients were included prospectively; 48 (32 men; mean age 57 +/- 11 years; 25 with stable angina and 23 affected by acute coronary syndromes) underwent a satisfactory nonculprit vessel investigation through spectral analysis of intravascular ultrasound radiofrequency data (IVUS-Virtual Histology, Volcano Corp., Rancho Cordova, California). The region of interest was subsequently divided into LMS and LMS carina, followed by 6 consecutive nonoverlapping 6-mm segments in left anterior descending artery in 34 patients or in circumflex artery in 14 patients. RESULTS: Necrotic core content (%): 1) was minimal in LMS (median [interquartile range]: 4.6 [2 to 7]), peaked in the first 6-mm coronary segment (11.8 [8 to 16]; p < 0.01), and then progressively decreased distally; 2) was overall greater in patients with acute coronary syndromes (11.4 [5.5 to 19.8]) than stable angina (7.3 [3.2 to 12.9]; p < 0.001); 3) was largely independent from plaque size; and 4) did not correlate to systemic levels of C-reactive protein or lipid profile. CONCLUSIONS: Plaques located in the LMS carry minimal necrotic content. Thus, they mimic the distal but not the proximal tract of the left coronary artery, where plaque rupture or vessel occlusion occurs more frequently.     

Undetectable viral load is associated with sexual risk taking in HIV serodiscordant gay couples in Sydney

OBJECTIVE: To determine whether reporting that the HIV-positive partner's viral load is undetectable rather than detectable is associated with unprotected anal intercourse (UAI) in HIV serodiscordant gay couples. METHOD: A cross-sectional study nested within two cohort studies, the Health in Men (HIM) cohort of HIV-negative men, from July 2001 to December 2003 and the Positive Health (PH) cohort of HIV-positive men, from February 2002 to August 2003. The study participants were 119 men in an HIV serodiscordant regular relationship of at least 6 months duration (45 HIV-negative men from HIM, 74 HIV-positive men from PH). The main outcome measure was the occurrence of UAI within the relationship in the previous 6 months. RESULTS: Eighty-two men reported no UAI and 37 reported some UAI. Of couples in which the HIV-positive partner's viral load was reported to be undetectable, 39.4% reported UAI compared with 20.8% of those where viral load was reported to be detectable (P = 0.04). In multivariate analysis, significant predictors of UAI were younger age [odds ratio (OR), 0.94; 95% confidence interval (CI), 0.87-1.00; P = 0.05], greater HIV optimism (OR, 4.98; 95% CI, 1.25-19.8; P = 0.02) and reported undetectable viral load (OR, 2.88; 95% CI, 1.13-7.37; P = 0.03). CONCLUSIONS: Most serodiscordant gay couples do not engage in any UAI. UAI within such relationships is significantly more likely to occur where the HIV-positive partner is reported to have undetectable viral load. UAI in HIV serodiscordant relationships is problematic even if viral load is undetectable because of unknown risk parameters, viral load variability and the possibility of drug-resistant strains of HIV.     

Fluvastatin reduces the 4-year cardiac risk in patients with multivessel disease

BACKGROUND: To evaluate the impact of the extent of coronary disease (single- or multivessel) and of fluvastatin treatment on the incidence of long-term cardiac atherosclerotic complications in the Lescol Intervention Prevention Study (LIPS). METHODS: A total of 1063 patients with single-vessel disease and 614 patients with multivessel disease were randomized to receive fluvastatin (40 mg bid) or placebo for at least 3 years following a first successful percutaneous coronary intervention. The incidence of cardiac atherosclerotic events (cardiac death, non-fatal myocardial infarction, and coronary re-interventions not related to restenosis) was evaluated. RESULTS: Patients with multivessel disease tended to be older and presented a higher prevalence of associated risk factors and cardiovascular antecedents. The presence of multivessel disease markedly increased the risk of cardiac atherosclerotic events compared with single-vessel disease among patients allocated to placebo (RR 1.67 [95% CI: 1.24-2.25]; p<0.001). In patients treated with fluvastatin, however, no significant differences in long-term outcomes were observed between patients with multivessel disease and patients single-vessel disease (RR 1.28 [95% CI: 0.90-1.81]; p=0.2). CONCLUSIONS: Multivessel coronary disease impaired the 4-year outcomes after percutaneous intervention. However, the hazardous effect of multivessel disease was significantly reduced by long-term fluvastatin treatment.     

Polymorphisms in the CD14 gene associated with pulmonary function in farmers

RATIONALE AND OBJECTIVES: Farmers experience airway obstruction, which may be attributable in part to endotoxin inhalation. CD14 is a receptor for endotoxin. MATERIALS AND METHODS: Based on our findings of increased circulating CD14 associated with the CD14/-159 T allele, we hypothesized that carriers of this allele would have decreased lung function among endotoxin-exposed individuals. CD14/-159TT farmers (n = 19) had significantly lower lung function as measured by FEV1 (p = 0.028) and mean forced expiratory flow during the middle half of the FVC (FEF25-75) (p = 0.05) compared with farmers with the C allele (n = 78). Also, farmers with the CD14/-1619GG genotype (n =11) were associated with lower lung function (FEV1, p = 0.008; FEF25-75, p = 0.009) compared with farmers with the A allele (n = 86). RESULTS: No association between CD14/-550 and lung function was observed (FEV1, p = 0.32; FEF25-75, p = 0.11). Increased prevalence of wheezing was reported in farmers homozygous for CD14/-159T (p = 0.013) or CD14/-1619G (p = 0.019) compared with farmers with the CC or AA genotype, respectively. No association was found between TLR4/Asp299Gly and lung function or wheeze. CONCLUSION: We conclude that the CD14/-159 or CD14/-1619 loci may play a role in modulating lung function and wheeze among agricultural workers.     

Spontaneous bacterial peritonitis in asymptomatic outpatients with cirrhotic ascites

The prevalence and natural history of spontaneous bacterial peritonitis in asymptomatic patients with ascites secondary to cirrhosis is unknown. From a prospectively recorded database, we reviewed the clinical and laboratory features of all outpatients with cirrhotic ascites undergoing paracentesis between July 1994 and December 2000. The prevalence of spontaneous bacterial peritonitis in the population of 427 cirrhotic outpatients as defined by neutrocytic ascites (absolute neutrophil count >or=250 cells/mm(3)) was 3.5%. Of the 15 patients with neutrocytic ascites, 6 were culture positive (1.4%) and 9 culture negative (2.1%). Eight other patients (1.9%) had bacterascites. The organisms cultured from ascitic fluid in these asymptomatic patients with culture positive neutrocytic ascites and bacterascites were predominantly gram positive. No patient developed hepatorenal syndrome, and 1-year survival of 67% was better than historical data from hospitalized patients with spontaneous bacterial peritonitis. Moreover, patients who did not receive antibiotics for neutrocytic ascites fared no worse than patients who did receive antibiotics. In conclusion, spontaneous bacterial peritonitis in outpatients with cirrhotic ascites is less frequent, occurs in patients with less advanced liver disease, and may have a better outcome than its counterpart in hospitalized patients. In addition, the organisms cultured from ascitic fluid in outpatients are predominantly gram positive. A reassessment of diagnostic criteria for spontaneous bacterial peritonitis in outpatients may be required.     

Right Ventricular Flow Dynamics in Dilated Right Ventricles: Energy Loss Estimation Based on Blood Speckle Tracking Echocardiography—A Pilot Study in Children

Using blood speckle tracking (BST) based on high-frame-rate echocardiography (HFRE), we compared right ventricle (RV) flow dynamics in children with atrial septal defects (ASDs) and repaired tetralogy of Fallot (rTOF). Fifty-seven children with rTOF with severe pulmonary insufficiency (PI) (n = 21), large ASDs (n = 11) and healthy controls (CTL, n = 25) were included. Using a flow phantom, we studied the effects of imaging plane and smoothing parameters on 2-D energy loss (EL). RV diastolic EL was similar in ASD and rTOF, but both were greater than in CTL. Locations of high EL were similar in all groups in systole, occurring in the RV outflow tract and around the tricuspid valve leaflets in early diastole. An additional apical early diastolic area of EL was noted in rTOF, corresponding to colliding tricuspid inflow and PI. The flow phantom revealed that EL varied with imaging plane and smoothing settings but that the EL trend was preserved if kept consistent.