Endothelial Dysfunction and Pentraxin-3 in Clinically Stable Adult Asthma Patients.

BACKGROUND AND OBJECTIVE: Asthma is associated with low-grade systemic inflammation, prothrombotic state, and premature atherosclerosis. Objective: To evaluate the relationships between asthma, inflammatory biomarkers, and parameters of endothelial dysfunction. MATERIAL AND METHODS: We analyzed flow-mediated dilatation (FMD) of the brachial artery and intima-media thickness (IMT) of the common carotid artery using ultrasound in 92 clinically stable adult asthmatics and 62 well-matched controls. We also measured blood levels of selected inflammatory and asthma-specific biomarkers, including interleukin (IL) 4, IL-5, IL-6, IL-10, IL-12 (p70), IL-17A, IL-23, and interferon γ, as well as a disintegrin and metalloproteinase domain-containing protein 33 (ADAM-33). In addition, we assessed endothelial damage using 2 laboratory biomarkers: circulating von Willebrand factor (vWF) and pentraxin-3. We analyzed relationships between the study variables and asthma severity, lung function abnormalities, airway remodeling indices on computed tomography, and transthoracic echocardiography parameters. RESULTS: Asthmatics had higher IL-6, IL-10, and ADAM-33 levels. They were also characterized by 23% lower FMD% and 15% thicker IMT, as compared with controls (P<.001, both). In asthma, vWF was related to age (ß=0.28 [95%CI, 0.15-0.41]) and remained inversely associated with FEV1 (ß=-0.2 [95%CI, -0.05 to -0.35]). Surprisingly, a negative correlation was revealed between vWF and pentraxin-3 (ß=-0.17 [95%CI, -0.3 to -0.04]). Pentraxin-3 remained positively associated with airway remodeling indices. CONCLUSIONS: Asthma is characterized by endothelial dysfunction associated with airway obstruction. The biological role of pentraxin-3 is unknown, although our data suggest a protective role against endothelial damage and atherosclerosis.

Altered preoperative coagulation and fibrinolysis are associated with myocardial injury after non-cardiac surgery.

BACKGROUND: Myocardial injury after non-cardiac surgery (MINS), a complication with unclear pathogenesis, occurs within the first 30 days after surgery and worsens prognosis. Hypercoagulability induced by surgery might contribute to plaque rupture, with subsequent thrombosis and myocardial injury. This study assessed haemostatic markers before surgery and evaluated their association with MINS. METHODS: This is a substudy of VISION, a prospective cohort study of perioperative cardiovascular events. Of 475 consecutive vascular surgery patients, 47 (9.9%) developed MINS, defined as postoperative high-sensitivity troponin ≥50 ng litre -1 , with ≥20% elevation from the preoperative concentration. The control group consisted of 84 non-MINS patients matched for patient characteristics and co-morbidities. The following preoperative markers of hypercoagulability and fibrinolysis were measured: antithrombin, factor VIII activity, von Willebrand factor concentration and activity, fibrinogen, D-dimer, plasmin-antiplasmin complex, and tissue plasminogen activator. Moreover, C-reactive protein and CD40L concentrations were measured to assess inflammatory activity. RESULTS: Patients with MINS compared with the non-MINS group had a significantly higher concentration of factor VIII (186 vs 155%, P =0.006), von Willebrand factor activity (223 vs 160%, P <0.001), von Willebrand factor concentration (317 vs 237%, P =0.02), concentrations of fibrinogen (5.6 vs 4.2 g litre -1 , P =0.03), D-dimer (1680.0 vs 1090.0 ng ml -1 , P =0.04), plasmin-antiplasmin complex (747 vs 512 ng ml -1 , P =0.002) and C-reactive protein (10 vs 4.5 mg litre -1 , P =0.02) but not antithrombin (95 vs 94%, P =0.89), tissue plasminogen activator (11 vs 9.7 ng ml -1 , P =0.06) and CD40L (8790 vs 8580 pg ml -1 , P =0.73). CONCLUSIONS: Preoperative elevation of blood markers of hypercoagulability in patients undergoing vascular surgery is associated with a higher risk of MINS. CLINICAL TRIAL REGISTRATION: NCT00512109.

Asthma is associated with enhanced thrombin formation and impaired fibrinolysis.

BACKGROUND: There is evidence that altered blood coagulation and fibrinolysis are involved in the pathogenesis of asthma. Increased thromboembolic risk has been reported in asthmatics. OBJECTIVE: To investigate whether enhanced thrombin generation and impaired fibrinolysis occur in asthmatics. METHODS: Plasma thrombin generation profile together with a computational assessment of thrombin dynamics and fibrinolytic capacity expressed as clot lysis time (CLT) were determined in 164 consecutive patients with stable asthma and 72 controls matched for age, gender, weight and smoking. RESULTS: Asthma patients had 20.2% increased endogenous thrombin potential (ETP), 41.4% higher peak thrombin concentration, 61% higher maximal prothrombin conversion rate, 15.5% faster rate of thrombin formation (all, P < 0.0001) and 10% lower thrombin decay capacity (P = 0.0004) compared with controls. Asthmatics had also 14.4% longer CLT (P = 0.001) associated with 21.3% higher plasminogen activator inhibitor-1 (PAI-1) (P < 0.0001), and 13% higher plasma α2 -macroglobulin (P = 0.0002). Using ETP and CLT above 75th percentile of the control values as the cut-off levels, we found increased risks of enhanced thrombin generation and hypofibrinolysis in asthmatics, also after correction for potential confounders. ETP and CLT were associated inversely with forced expiratory volume in 1 s/vital capacity (FEV1 /VC) index, after adjustment for age and body mass index. Non-allergic asthma (n = 70, 42.6%) was characterized by 17.5% longer CLT (P = 0.02), which positively associated with PAI-1. Thrombin generation profile was not affected by allergy. CONCLUSION AND CLINICAL RELEVANCE: Asthma is associated with enhanced thrombin generation and impaired fibrinolysis, which might contribute to thromboembolic events in this disease.

Signs of impaired immunoregulation and enhanced effector T-cell responses in the primary antiphospholipid syndrome.

INTRODUCTION: We investigated whether primary antiphospholipid syndrome (PAPS) is characterized by a deficiency in immunoregulatory pathways, a phenomenon recently implicated in the pathogenesis of autoimmune diseases. METHODS: Serum levels of immunoregulatory (e.g., IL-10 and TGF-ß1) and proinflammatory (e.g., IL-17A) cytokines were measured in PAPS, systemic lupus erythematosus (SLE) with secondary APS (SAPS), or without APS, and in healthy controls (n = 40 in each group). In a subgroup of PAPS patients we also compared phenotype and function (flow cytometry) of regulatory T-cells (Treg) and cytokine production by effector T-cells. RESULTS: Our major finding was decreased levels of TGF-ß1 in PAPS and SAPS as compared to SLE without APS and controls. TGF-ß1 was the lowest in PAPS patients showing high levels of aPL IgG with significant negative correlation with the titer. SLE patients were characterized by lower serum levels of IL-2 and increased IL-17A, as compared to the other groups. The numbers of circulating Treg cells and their phenotype (e.g., FoxP3 isoforms) were not disturbed in PAPS. However, surface expression of latency associated peptide (binds TGF-ß) in activated FoxP3 + cells and in vitro production of TGF-ß1 were decreased in PAPS patients with high titers of aPL IgG. Moreover, frequencies of cytokine producing effector T-helper cells (including Th17) were significantly elevated in this group. CONCLUSIONS: PAPS patients with high titers of aPL IgG antibodies were characterized by decreased systemic levels of TGF-ß1 and its impaired production in vitro, suggesting impaired immunoregulation and enhanced adaptive autoimmune responses leading to the production of aPL antibodies.

A comment on powder averaging in wide line NMR.

Computer calculations of wide line NMR spectra of powders usually involve numerical evaluation of double integrals over two Euler angles. Practice confirms intuition-based expectations that the integration results should be independent from the choice of the crystal-fixed (or molecule-fixed) coordinate system used in the calculations. However, a closer inspection of the relevant integration formulas may make one wonder why this is so. The present paper provides a rigorous mathematical proof of the validity of these intuitive predictions, by formulating the problem in terms of surface integrals on a sphere, which has presumably no precedence in the NMR literature.

Avidity of anti-ß2-glycoprotein I antibodies in patients with antiphospholipid syndrome.

Antibodies against ß(2)-glycoprotein I (anti-ß(2)GPI) are one of the hallmarks of the antiphospholipid syndrome (APS). However, they are heterogenic regarding their epitope specificity, pathogenic mechanisms and their avidity. In the current study we present some outstanding issues about avidity of anti-ß(2)GPI antibodies. Our results confirmed that high avidity anti-ß(2)GPI are associated with thrombosis and APS, while in low avidity anti-ß(2)GPI group non-APS (predominantly systemic lupus erythematosus) patients prevailed.

Revised classification criteria for antiphospholipid syndrome and the thrombotic risk in patients with autoimmune diseases.

BACKGROUND: The classification criteria for antiphospholipid syndrome (APS) were updated in 2006. OBJECTIVE: The aim of the study was to analyze associations between clinical complications and laboratory test abnormalities typical for APS in a group of patients with autoimmune diseases, based on the recently updated criteria. PATIENTS/METHODS: Three hundred and thirty-six patients were enrolled into the study, with the majority (n = 235) suffering from systemic lupus erythematosus. Laboratory determinations included: lupus anticoagulant (LA), anticardiolipin (aCL) and anti-beta(2)-glycoprotein I (anti-beta(2)GPI) antibodies (ABs) [of both immunoglobulin G (IgG) and IgM class]. RESULTS: A significant association was found between laboratory and clinical features of APS; odds ratios (ORs) for thrombosis associated with the presence of LA, aCL, and anti-beta(2)GPI Abs were 4.04 [95% CI: 2.44-6.68], 3.71 (95% CI 2.32-5.92) and 2.57 (95% CI 1.60-4.1), respectively. Detailed analysis showed marked differences between the risk of clinical complications associated with the presence of an antibody in the IgG class (OR 4.15, 95% CI 2.42-7.12, and OR 4.77, 95% CI 2.37-9.61 for aCL and anti-beta(2)GPI, respectively) and in the IgM class (OR 2.2, 95% CI 1.31-3.70, and OR 1.9, 95% CI 1.15-3.14 for aCL and anti-beta(2)GPI, respectively). The postulated inclusion of anti-beta(2)GPI antibody positivity into the previous laboratory criteria changed only slightly the number of patients diagnosed with APS (from 112 to 117). CONCLUSIONS: The updated APS classification criteria clearly represent a step forward. However, our results argue against the use of overall positivity for aCL or anti-beta(2)GPI, and favor a clear distinction between the IgG and IgM classes of antiphospholipid ABs. Patients with both LA and anti-beta(2)GPI IgG or LA and aCL IgG positivity may represent the subgroups at the highest risk of thrombotic complications.

Immunoreactivity and avidity of IgG anti-ß2-glycoprotein I antibodies from patients with autoimmune diseases to different peptide clusters of ß2-glycoprotein I.

The pathogenicity of antibodies against ß2-glycoprotein I (anti-ß2GPI) depends on multiple factors such as subclass type, epitope binding and avidity. Due to their large heterogeneity, their impact on antiphospholipid syndrome (APS) onset is still not fully clarified. We studied the binding characteristics of IgG anti-ß2GPI with known avidity from sera of 201 autoimmune patients (87 with APS, 67 with APS associated with systemic lupus erythematosus (SLE), 47 with only SLE) to six ß2GPI peptides corresponding to amino acid clusters on domains I-II, II, III and III-IV by indirect ELISA and evaluated their association with clinical features of APS. Peptides A (LKTPRV; domain I-II), B (KDKATF; domain IV) and C (TLRVYK; domain III) were derived from a hexapeptide phage display library previously shown to react with pathogenic monoclonal anti-ß2GPI. Peptides D (NGPANSK; domain III), E (YNPLWFV; domain II) and F (KMDGNHP; domain III-IV) represent surface amino acid clusters on ß2GPI. The percentage of patients positive for peptides were observed as follows: 30.3% for peptide D, 28.90% for B, 25.9% for C, 24.9% for E, 24.4% for F and 10.0% for A. The anti-peptide antibodies in studied serum samples were predominantly of heterogeneous avidity, followed by law avidity anti-peptide antibodies, whereas only a few were of high avidity. Positive and negative correlations were found between several anti-peptide antibodies and the rate of thrombosis. Our results indicated diverse reactivity of IgG anti-ß2GPI to different epitopes on ß2GPI. Classification of IgG anti-ß2GPI into subgroups regarding epitope specificity and avidity could represent an additional tool in understanding their pathogenicity in APS.

Altered fibrin clot structure/function in patients with antiphospholipid syndrome: association with thrombotic manifestation.

We tested the hypothesis that plasma fibrin clot structure/function is unfavourably altered in patients with antiphospholipid syndrome (APS). Ex vivo plasma clot permeability, turbidity and susceptibility to lysis were determined in 126 consecutive patients with APS enrolled five months or more since thrombotic event vs 105 controls. Patients with both primary and secondary APS were characterised by 11% lower clot permeability (p<0.001), 4.8% shorter lag phase (p<0.001), 10% longer clot lysis time (p<0.001), and 4.7% higher maximum level of D-dimer released from clots (p=0.02) as compared to the controls. Scanning electron microscopy images confirmed denser fibrin networks composed of thinner fibres in APS. Clots from patients with "triple-antibody positivity" were formed after shorter lag phase (p=0.019) and were lysed at a slower rate (p=0.004) than in the remainder. Clots from APS patients who experienced stroke and/or myocardial infarction were 8% less permeable (p=0.01) and susceptible to lysis (10.4% longer clot lysis time [p=0.006] and 4.5% slower release of D-dimer from clots [p=0.01]) compared with those following venous thromboembolism alone. Multivariate analysis adjusted for potential confounders showed that in APS patients, lupus anticoagulant and "triple-positivity" were the independent predictors of clot permeability, while "triple-positivity" predicted lysis time. We conclude that APS is associated with prothrombotic plasma fibrin clot phenotype, with more pronounced abnormalities in arterial thrombosis. Molecular background for this novel prothrombotic mechanism in APS remains to be established.

Lupus anticoagulant: performance of the tests as recommended by the latest ISTH guidelines.

OBJECTIVES: Lupus anticoagulant (LA) is clinically the most relevant among all antiphospholipid antibody tests. Recently, new guidelines for LA detection were published. The objective of this retrospective cohort study was to compare tests recommended under these guidelines with other methods used for LA detection. METHODS: The study group consisted of 336 subjects suffering from various autoimmune diseases. We used activated partial thromboplastin time (aPTT), diluted Russell viper venom time (dRVVT) and diluted prothrombin time (dPT) tests for LA detection together with a ratio between sensitive and insensitive aPTT reagent. We also tested if LA was dependent on ß(2) glycoprotein I (ß(2) GPI) using one of the recently described methods. RESULTS: All LA tests performed were associated with a history of thrombosis. The highest odds ratio (OR) for thrombosis was found for ß(2) GPI-dependent LA but sensitivity was low (OR = 8.4; specificity/sensitivity = 98%/15%). All LA tests showed a much stronger association with thrombosis than with pregnancy failure. CONCLUSIONS: LA tested by aPTT and/or dRVVT (at least one out of two tests positive), as recommended by the guidelines, was associated less strongly with a history of thrombosis (OR = 4.1) than either of these tests separately (OR = 5.0 and 4.3, respectively). With both tests positive ('double LA positivity') the association with thrombosis was stronger (OR = 6.5) compared with only one positive test. In fact, 'double LA positivity', detected by combinations of any of the tests studied, was markedly associated with a history of thrombosis.

Valine/Leucine247 polymorphism of beta2-glycoprotein I in patients with antiphospholipid syndrome: lack of association with anti-beta2-glycoprotein I antibodies.

In antiphospholipid syndrome (APS) the presence of anti-beta2-glycoprotein I (beta2GPI) antibodies is strongly associated with thromboembolic complications. It has been suggested that the common beta2GPI Valine/Leucine247 (Val/Leu247) polymorphism could be found more commonly in APS and might influence the generation of anti-beta2GPI antibodies. Therefore we studied beta2GPI Val/Leu247 single-nucleotide polymorphism (SNP) by PCR in 338 patients with various autoimmune diseases (46 with secondary and 84 with primary APS) and 147 sex and age-matched healthy controls. In all patients lupus anticoagulant, anticardiolipin and anti-beta2GPI antibodies (both IgG and IgM) were also determined. All patients and controls were Caucasians. Frequencies of the SNP genotypes in patients did not depart from genetic equilibrum and did not differ from those found in controls. There was also no association between the presence of beta2GPI Val/Leu247genotypes and the presence or absence of lupus anticoagulant, anticardiolipin antibodies, anti-beta2GPI antibodies or clinical APS symptoms in all patients studied. In conclusion, among the exclusively Caucasian, Polish population of autoimmune patients beta2GPI Val/Leu247SNP has the same distribution as in healthy subjects and does not influence the production of anti-beta2GPI antibodies.

[Diagnostic difficulties in cases with spurious thrombocytopenia]. / Trudnosci diagnostyczne w przypadkach maloplytkowosci rzekomej.

Pseudothrombocytopenia (PTP) is a rare laboratory phenomenon of falsely low platelet count in the presence of anticoagulant, most often EDTA. It may be confused with true thrombocytopenia, leading to the refusal of further invasive procedures and inappropriate diagnosis and treatment. PTP is due to presence of antiplatelet antibodies--agglutinins--usually temperature dependent. Here we present two cases of such spurious thrombocytopenia and discuss the differential diagnosis.