Leukocytosis and ischemic vascular disease morbidity and mortality: is it time to intervene?

Macrophages in the pathogenesis of atherosclerosis

In atherosclerosis, the accumulation of apolipoprotein B-lipoproteins in the matrix beneath the endothelial cell layer of blood vessels leads to the recruitment of monocytes, the cells of the immune system that give rise to macrophages and dendritic cells. Macrophages derived from these recruited monocytes participate in a maladaptive, nonresolving inflammatory response that expands the subendothelial layer due to the accumulation of cells, lipid, and matrix. Some lesions subsequently form a necrotic core, triggering acute thrombotic vascular disease, including myocardial infarction, stroke, and sudden cardiac death. This Review discusses the central roles of macrophages in each of these stages of disease pathogenesis.

Granulocyte-CSF induced inflammation-associated cardiac thrombosis in iron loading mouse heart and can be attenuated by statin therapy

Background

Granulocyte colony-stimulating factor (G-CSF), a hematopoietic cytokine, was recently used to treat patients of acute myocardial infarction with beneficial effect. However, controversy exists as some patients developed re-stenosis and worsened condition post G-CSF delivery. This study presents a new disease model to study G-CSF induced cardiac thrombosis and delineate its possible mechanism. We used iron loading to mimic condition of chronic cardiac dysfunction and apply G-CSF to mice to test our hypothesis.

Methods and Results

Eleven out of fifteen iron and G-CSF treated mice (I+G) showed thrombi formation in the left ventricular chamber with impaired cardiac function. Histological analysis revealed endothelial fibrosis, increased macrophage infiltration and tissue factor expression in the I+G mice hearts. Simvastatin treatment to I+G mice attenuated their cardiac apoptosis, iron deposition, and abrogated thrombus formation by attenuating systemic inflammation and leukocytosis, which was likely due to the activation of pAKT activation. However, thrombosis in I+G mice could not be suppressed by platelet receptor inhibitor, tirofiban.

Conclusions

Our disease model demonstrated that G-CSF induces cardiac thrombosis through an inflammation-thrombosis interaction and this can be attenuated via statin therapy. Present study provides a mechanism and potential therapy for G-CSF induced cardiac thrombosis.

Genetic polymorphisms influence runners' responses to the dietary ingestion of antioxidant supplementation based on pequi oil (Caryocar brasiliense Camb.): a before-after study

Genes have been implicated in the levels of oxidative stress, lipids, CVD risk, immune reactivity, and performance. Pequi oil (Caryocar brasiliense) has shown anti-inflammatory and hypotensive effects, besides reducing exercise-induced DNA, tissue damages, and anisocytosis. Given that diet can interact with the human genome to influence health and disease, and because genetic variability can influence response to diet, we aim to investigate the influence of 12 gene polymorphisms on inflammatory markers, postprandial lipids, arterial pressure, and plasma lipid peroxidation of runners (N = 125), before and after 14 days of 400 mg pequi-oil supplementation, after races under closely comparable conditions. Arterial pressure was checked before races; blood samples were taken immediately after racing to perform leukogram and plateletgram, Tbars assay, lipid, and CRP dosages and genotyping. CAT, GST-M1/T1, CRP-G1059C, and MTHFR-C677T polymorphisms influenced post-pequi-oil responses in leukogram; Hp and MTHFR-C677T, in plateletgram; Hp, ACE, GSTT1, and MTHFR-A1298C, in lipid profile; MTHFR-A1298C, in C-reactive protein (CRP) levels; and Hp and MnSOD, in Tbars assay. Differences between ACE genotypes in leukogram and total cholesterol disappeared after pequi, and the same occurred for Hp and MnSOD in Tbars assay and for MTHFR-A1298C with CRP levels. Because genetic inheritance is one of the factors that drive atherosclerosis-related lipid abnormalities, results can contribute to a greater understanding of the influence of genetic polymorphisms in situations that push up free radicals. Knowledge is also expanded on how antioxidant supplementation affects an individual's genes and how athletic genetic makeup can affect the way a person responds to antioxidant supplements.

[Clinical relevance of leukocyte differential in patients with marked leukocytosis in the emergency room]

PURPOSE

We analyzed the characteristics of the leukocyte differential and the clinical outcome in patients admitted in an emergency department with marked leukocytosis greater than 20×10(9)G/L.

METHODS

We studied a case series of consecutive patients admitted in an emergency department. The medical records were retrospectively reviewed after patient discharge. Three groups were defined: patients with infectious disorders (group I), noninfectious disorders (group II), and trauma (group III). Admission in intensive care unit (ICU), consciousness impairment or death defined the subgroup S of high severity.

RESULTS

Groups I, II and III comprised, respectively, 150, 95 and 86 patients. The group I presented with higher temperature and neutrophilia (22,2±4.9 vs 20.9±4.0 and 21.1±3.9×10(9)G/L; P<0.001), and more profound eosinopenia (0.058±0.094 versus 0.098±0.170 and 0.092±0.104×10(9)G/L; P<0.001) and lymphopenia (1.16±0.98 vs 1.53±1.04 and 1.73±1.10×10(9)G/L; P<0.001) than the two other groups. Both neutrophilia and lymphopenia were independent predictors of infection by multivariate analysis. Frequencies of admission in ICU were, respectively, 8.7%, 40% and 43% (P<0.001). Leukocyte and neutrophil counts were significantly higher and basophil count significantly lower in subgroup S. Overall, 13.6% of the patients died and were characterized by basopenia.

CONCLUSION

Marked leukocytosis indicated severe illness. Lymphopenia, eosinopenia and temperature were significant predictors of infection. A more severe clinical course was correlated with higher neutrophilia and basopenia.

Longitudinal study on white blood cell count and the incidence of metabolic syndrome

OBJECTIVE

Many studies have revealed that white blood cell count (WBC) is related to insulin resistance which is a central mechanism of metabolic syndrome (MetS). However, few cohort studies have examined the role of WBC in the development of MetS. We hypothesized that WBC is associated with the future development of MetS, and investigated the longitudinal incidence of MetS in healthy workers.

METHODS

WBC was measured in 5,073 workers (mean age 42.5 years) without MetS at baseline. The incidence of MetS was monitored over 7 years of follow-up, in relation to quartiles of WBC. During the follow-up, 925 participants were diagnosed as MetS.

RESULTS

Incidence of MetS was increased in participants with higher WBC: the rates of incidence of MetS were 22.6, 32.9, 42.9, and 57.5 per 1,000 person-years of follow-up in the 1st, 2nd, 3rd, and 4th quartiles of WBC, respectively. After adjustments for confounding factors, the adjusted hazards ratio (95% confidence interval) for MetS was 1.00 (reference), 1.22 (0.98 to 1.51), 1.52 (1.24 to 1.87), and 1.66 (1.35 to 2.04) through the quartiles of WBC, respectively, (p <0.001). This relationship was consistent among current smokers and never smokers, and among male and female genders, respectively.

CONCLUSION

WBC is useful in predicting the future development of MetS which leads to atherosclerotic diseases.

The paradox of the neutrophil's role in tissue injury

The neutrophil is an essential component of the innate immune system, and its function is vital to human life. Its production increases in response to virtually all forms of inflammation, and subsequently, it can accumulate in blood and tissue to varying degrees. Although its participation in the inflammatory response is often salutary by nature of its normal interaction with vascular endothelium and its capability to enter tissues and respond to chemotactic gradients and to phagocytize and kill microrganisms, it can contribute to processes that impair vascular integrity and blood flow. The mechanisms that the neutrophil uses to kill microorganisms also have the potential to injure normal tissue under special circumstances. Its paradoxical role in the pathophysiology of disease is particularly, but not exclusively, notable in seven circumstances: 1) diabetic retinopathy, 2) sickle cell disease, 3) TRALI, 4) ARDS, 5) renal microvasculopathy, 6) stroke, and 7) acute coronary artery syndrome. The activated neutrophil's capability to become adhesive to endothelium, to generate highly ROS, and to secrete proteases gives it the potential to induce local vascular and tissue injury. In this review, we summarize the evidence for its role as a mediator of tissue injury in these seven conditions, making it or its products potential therapeutic targets.

Platelet - leukocyte interactions: multiple links between inflammation, blood coagulation and vascular risk

The aim of this review is to summarize the contribution of platelets and leukocytes and their interactions in inflammation and blood coagulation and its possible relevance in the pathogenesis of thrombosis. There is some evidence of an association between infection/inflammation and thrombosis. This is likely a bidirectional relationship. The presence of a thrombus may serve as a nidus of infection. Vascular injury indeed promotes platelet and leukocyte activation and thrombus formation and the thrombus and its components facilitate adherence of bacteria to the vessel wall. Alternatively, an infection and the associated inflammation can trigger platelet and leukocyte activation and thrombus formation. In either case platelets and leukocytes co-localize and interact in the area of vascular injury, at sites of inflammation and/or at sites of thrombosis. Following vascular injury, the subendothelial tissue, a thrombogenic surface, becomes available for interaction with these blood cells. Tissue factor, found not only in media and adventitia of the vascular wall, but also on activated platelets and leukocytes, triggers blood coagulation. Vascular-blood cell interactions, mediated by the release of preformed components of the endothelium, is modulated by both cell adhesion and production of soluble stimulatory or inhibitory molecules that alter cell function: adhesion molecules regulate cell-cell contact and facilitate the modulation of biochemical pathways relevant to inflammatory and/or thrombotic processes.

White cells count in smokers affected by rheumatic diseases

Evidence shows that tobacco smoking interacts with development of rheumatic diseases. Increase in white cells count (leukocytosis) is frequently present, and in smokers, it is considered a biomarker of cardiovascular risk. Aim of the study is to evaluate this biomarker in smokers with rheumatic diagnosis. We carried out an observational study on 115 rheumatic outpatients (26 men and 89 women) divided into two groups according to their smoking habit: one composed of 56 smokers, the other of 59 not smokers. Diagnosis and common routinary clinical parameters were collected. In the total sample, smokers were 48.69%. Most common diagnosis was osteoarthritis (OA) (40.87% of the total); smokers in OA women were 36.11%, smokers in OA men were 54.55%. Second most common diagnosis was rheumatoid arthritis (RA) (23.48% of the total); smokers in RA women were 40.91%; smokers in RA men were 80%. OA smokers showed a significant increase (P < 0.05) in white cells count when compared with OA not smokers. Between RA smokers and not smokers, any clinical difference was found. RA subjects following regular pharmacological treatment in the last 2 months were 84.61%. OA patients treated with drugs in the last 2 months were only 22.2%. Results seem to confirm that smoking habit may influence the development as well as gender distribution of rheumatic diseases. They show also that in absence of pharmacological treatment in smokers affected by OA leukocytosis (biomarker of cardiovascular risk) is observed.

Smoking and atherosclerotic cardiovascular disease: part II: role of cigarette smoking in cardiovascular disease development

Potential mechanisms and biomarkers of atherosclerosis related to cigarette smoking - a modifiable risk factor for that disease - are discussed in this article. These include smoking-associated inflammatory markers, such as leukocytes, high-sensitivity C-reactive protein, serum amyloid A, ICAM-1 and IL-6. Other reviewed markers are indicative for smoking-related impairment of arterial endothelial function (transcapillary leakage of albumin, inhibition of endogenous nitric oxide synthase activity and reduced endothelium-dependent vasodilation) or point to oxidative stress caused by various chemicals (cholesterol oxidation, autoantibodies to oxidized low-density lipoprotein, plasma levels of malondialdehyde and F(2)-isoprostanes and reduced antioxidant capacity). Smoking enhances platelet aggregability, increases blood viscosity and shifts the pro- and antithrombotic balance towards increased coagulability (e.g., fibrinogen, von Willebrand factor, ICAM-1 and P-selectin). Insulin resistance is higher in smokers compared with nonsmokers, and hemoglobin A1c is dose-dependently elevated, as is homocysteine. Smoke exposure may influence the kinetics of markers with different response to transient or chronic changes in cigarette smoking behavior.

ATP-binding cassette transporters and HDL suppress hematopoietic stem cell proliferation

Elevated leukocyte cell numbers (leukocytosis), and monocytes in particular, promote atherosclerosis; however, how they become increased is poorly understood. Mice deficient in the adenosine triphosphate-binding cassette (ABC) transporters ABCA1 and ABCG1, which promote cholesterol efflux from macrophages and suppress atherosclerosis in hypercholesterolemic mice, displayed leukocytosis, a transplantable myeloproliferative disorder, and a dramatic expansion of the stem and progenitor cell population containing Lin(-)Sca-1(+)Kit+ (LSK) in the bone marrow. Transplantation of Abca1(-/-) Abcg1(-/-) bone marrow into apolipoprotein A-1 transgenic mice with elevated levels of high-density lipoprotein (HDL) suppressed the LSK population, reduced leukocytosis, reversed the myeloproliferative disorder, and accelerated atherosclerosis. The findings indicate that ABCA1, ABCG1, and HDL inhibit the proliferation of hematopoietic stem and multipotential progenitor cells and connect expansion of these populations with leukocytosis and accelerated atherosclerosis.

Activated protein C-protein C inhibitor complex in peripheral arterial disease

BACKGROUND

Thrombin activation measured by the levels of the complex between activated protein C (APC) and the protein C inhibitor (PCI) is elevated in several atherosclerotic disorders. The aim of this study was to evaluate whether levels of the APC-PCI complex are related to the prognosis in peripheral arterial disease (PAD). Longitudinal study performed at the Vascular Centre, Malmö University Hospital, Sweden.

METHODS

APC-PCI complex levels were analyzed in 268 consecutive patients hospitalized for PAD and in 42 healthy controls (median age, 74 years). Patients (n = 35) with warfarin treatment less than 4 weeks before APC-PCI sampling were excluded from analysis. Data-based medical records of all 233 remaining patients (median age, 72 [64-79] years) were searched for vascular events such as hospitalization because of atherosclerotic disease, operative or endovascular recanalization of peripheral arteries, transtibial or transfemoral amputation because of PAD, acute coronary syndrome, stroke, or death.

RESULTS

Median duration of follow-up was 16 months (interquartile range, 12-23 months). APC-PCI complex levels were higher in PAD patients than in controls (0.240 [0.180-0.320] microg/L vs. 0.140 [0.190-0.220] microg/L; p < 0.0001) but not associated with an increased risk for death (p = 0.2054) or events during follow-up (p = 0.2850). Independent predictors of future events were low b-hemoglobin (p = 0.0084), high b-leukocytes (p = 0.0034), and history of a previous vascular event (p = 0.0032). Age (p = 0.0286), high p-creatinine (p = 0.0165), and history of a previous event (p = 0.0311) were independent predictors of death.

CONCLUSION

APC-PCI complex levels were higher in PAD patients than in controls, but did not predict the clinical outcome. The effect of a possible prethrombotic state, as reflected in increased APC-PCI levels, on prognosis and severity of atherosclerotic disease has to be further investigated.

Acute infection-inflammation and coronary stent thrombosis: an observational study

Coronary stent thrombosis (CST) is a major concern of interventional cardiology. Several risk factors for CST have been identified, but as a whole they do not explain the pathophysiology of CST. This study was designed to investigate whether acute infection-inflammation could facilitate the occurrence of CST. Forty-one patients, aged 66.6 +/- 11 years, consecutively admitted to our catheterization laboratory for acute, subacute or late CST, were retrospectively analysed. Transient acute infection-inflammation on admission for CST was diagnosed by predefined criteria. Prevalence of known risk factors for CST was also investigated. Twenty-one patients (51%) met predefined criteria for the occurrence of acute infection-inflammation. On admission, in these patients, levels of systemic humoral and cellular inflammatory markers were significantly higher than those of patients without recent or ongoing acute infection-inflammation (p < 0.05 for all). 62% of patients with acute infection-inflammation had less than two known risk factors for CST whereas only 37% patients without infection-inflammation showed less than two risk factors (p = 0.03) and showed more frequent interruption of antiplatelet treatment (17 vs. 2.4%, p = 0.02), mean longer stent length (20.5 +/- 4.8 vs. 16.5 +/- 5.1 mm, p = 0.02) and lower left ventricular ejection fraction before CST (42.9 +/- 14 vs. 47.3 +/- 11%, p = 0.02). In conclusion, acute infection-inflammation could play a role in facilitating the occurrence of CST in a subgroup with low risk profile for known risk factors. Our findings, if confirmed, could suggest new opportunities for prevention and treatment of CST.

Usefulness of neutrophil/lymphocyte ratio as predictor of new-onset atrial fibrillation after coronary artery bypass grafting

The neutrophil/lymphocyte (N/L) ratio integrates information on the inflammatory milieu and physiologic stress. It is an emerging marker of prognosis in patients with cardiovascular disease. We investigated the relation between the N/L ratio and postoperative atrial fibrillation (AF) in patients undergoing coronary artery bypass grafting. In a prospective cohort study, 275 patients undergoing nonemergency coronary artery bypass grafting were recruited. Patients with previous atrial arrhythmia or requiring concomitant valve surgery were excluded. The N/L ratio was determined preoperatively and on postoperative day 2. The study end point was AF lasting >30 seconds. Patients who developed AF (n = 107, 39%) had had a greater preoperative N/L ratio (median 3.0 vs 2.4, p = 0.001), but no differences were found in the other white blood cell parameters or C-reactive protein. The postoperative N/L ratio was greater in patients with AF (day 2, median 9.2 vs 7.2, p <0.001), and in multivariate models, a greater postoperative N/L ratio was independently associated with a greater incidence of AF (odds ratio 1.10 per unit increase, p = 0.003: odds ratio for N/L ratio >10.14 [optimal postoperative cutoff in our cohort], 2.83 per unit, p <0.001). Elevated pre- and postoperative N/L ratios were associated with an increased occurrence of AF after coronary artery bypass grafting. In conclusion, these results support an inflammatory etiology in postoperative AF but suggest that other factors are also important.

Aldosterone abrogates nuclear factor kappaB-mediated tumor necrosis factor alpha production in human neutrophils via the mineralocorticoid receptor

Mineralocorticoid receptor (MR) activation by aldosterone controls salt homeostasis and inflammation in several tissues and cell types. Whether or not a functional MR exists in polymorphonuclear neutrophils is unknown. We investigated the hypothesis that aldosterone modulates inflammatory neutrophil responses via the MR. By flow cytometry, Western blot analysis, and microscopy, we found that neutrophils possess MR. Preincubation with aldosterone (10(-11) to 10(-6) M) dose-dependently inhibited nuclear factor kappaB activation in interleukin (IL)-8- and granulocyte/macrophage colony-stimulating factor-treated neutrophils on fibronectin by IkappaBalpha Western blotting, electrophoretic mobility shift assay, and RT-PCR for IkappaBalpha mRNA. Aldosterone had no effect on tumor necrosis factor alpha- and lipopolysaccharide-mediated nuclear factor kappaB activation or on IL-8- and granulocyte/macrophage colony-stimulating factor-induced extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, or phosphatidylinositol 3-kinase/Akt activation. Spironolactone prevented nuclear factor kappaB inhibition, indicating an MR-specific aldosterone effect. By RT-PCR, we found that neutrophils have 11beta-hydroxysteroid dehydrogenase. Tumor necrosis factor alpha, which is controlled by nuclear factor kappaB, increased in the cell supernatant with IL-8 treatment. Aldosterone completely prevented this effect. RT-PCR showed a strong tumor necrosis factor alpha mRNA increase with IL-8 that was blocked by aldosterone, excluding the possibility that the tumor necrosis factor alpha increase was merely a consequence of secretion. Finally, conditioned medium from IL-8-treated neutrophils increased intercellular adhesion molecule-1 expression on endothelial cells and subsequently the adhesion of IL-8-treated neutrophils to endothelial cells. These effects were reduced when conditioned medium from aldosterone-pretreated neutrophils was used, and spironolactone blocked the aldosterone effect. Our data indicate that a functional MR exists in neutrophils mediating antiinflammatory effects that are at work when neutrophils interact with endothelial cells. These data could be relevant to MR-blockade treatment protocols.

Novel markers of peripheral arterial disease

Peripheral arterial disease (PAD), a relatively common manifestation of atherosclerotic vascular disease, is associated with significant morbidity and mortality. Although conventional risk factors contribute to the onset and progression of PAD, the role of 'novel' biomarkers in pathways of inflammation, thrombosis, lipoprotein metabolism, and oxidative stress in determining susceptibility to PAD is being increasingly recognized. Validation of novel risk factors for PAD may allow earlier detection, an improved understanding of disease etiology and progression, and the development of new therapies. In this review, we discuss available evidence for associations between novel circulating markers and several aspects of PAD including disease susceptibility, progression, functional limitation, and adverse outcomes.

Role of polymorphonuclear neutrophils in atherosclerosis: current state and future perspectives

Contrary to the long-standing and widely accepted belief that polymorphonuclear neutrophils (PMN) are of marginal relevance in atherosclerosis, evidence revealing a previously unappreciated role of PMN in the process of atherosclerosis is being accumulating. Systemic inflammation involving activated PMN is clearly associated with unstable conditions of coronary artery disease and an increased number of circulating neutrophils is a well-known risk indicator of future cardiovascular outcomes. Furthermore, PMN are activated in a number of clinical conditions associated with high risk of developing atherosclerosis and are detectable into culprit lesions of patients with coronary artery disease. At present, pharmacological interventions aimed at blocking neutrophil emigration from the blood into the arterial wall and/or inhibiting neutrophil-mediated inflammatory functions are not an option for treating atherosclerosis. Nevertheless, several lines of evidence suggest that part of the atheroprotective effects of statins as well as HDL and HDL apolipoproteins may be related to their ability to modulate neutrophilic inflammation in the arterial wall. These hypotheses are not definitely established and warrant for further study. This Review describes the evidence suggesting that PMN may have a causative role in atherogenesis and atheroprogression and discusses the potential importance of modulating neutrophilic inflammation as part of a novel, improved strategy for preventing and treating atherosclerosis.

Combined 3D-QSAR modeling and molecular docking study on quinoline derivatives as inhibitors of P-selectin

P-selectin is a promising target for developing novel atherosclerosis drugs. To understand the structure-activity correlation of quinolines-based P-selectin inhibitors, we have carried out a combined molecular docking and three-dimensional quantitative structure-activity relationship (3D-QSAR) modeling study. The study has resulted in two types of satisfactory 3D-QSAR models, including the CoMFA model (r(2), 0.863; q(2), 0.589) and CoMSIA model (r(2), 0.866; q(2), 0.636), to predict the biological activity of new compounds. The detailed microscopic structures of P-selectin binding with inhibitors have been studied by molecular docking. We have also developed docking based 3D-QSAR models (CoMFA with r(2), 0.934; q(2), 0.591; CoMSIA with r(2), 0.896; q(2), 0.573). The contour maps obtained from the 3D-QSAR models in combination with the docked binding structures help to better interpret the structure-activity relationship. All of the structural insights obtained from both the 3D-QSAR contour maps and molecular docking are consistent with the available experimental activity data. The satisfactory results strongly suggest that the developed 3D-QSAR models and the obtained P-selectin-inhibitor binding structures are reasonable for the prediction of the activity of new inhibitors and in future drug design.

White blood cell count predicts all-cause mortality in patients with suspected peripheral arterial disease

OBJECTIVE

We investigated whether markers of inflammation-white blood cell (WBC) count, C-reactive protein (CRP), and lipoprotein-associated phospholipase A2-are associated with mortality in patients referred for noninvasive lower-extremity arterial evaluation.

METHODS

Participants (n = 242, mean age 68 years, 54% men) were followed for a median of 71 months. Ankle-brachial index (ABI), WBC count, plasma CRP, and lipoprotein-associated phospholipase A2 were measured at the start of the study. Factors associated with all-cause mortality were identified using Cox proportional hazards.

RESULTS

During the follow-up period, 56 patients (25%) died. Factors associated with higher mortality were greater age, history of coronary artery disease/cerebrovascular disease, lower ABI, higher serum creatinine, and higher WBC count/plasma CRP. In stepwise multivariable regression analysis, ABI, serum creatinine, WBC count, and CRP were associated significantly with mortality. Patients in the top tertile of WBC count and CRP level had a relative risk of mortality of 3.37 (confidence interval [CI], 1.56-7.27) and 2.12 (CI, 0.97-4.62), respectively. However, only the WBC count contributed incrementally to prediction of mortality. Inferences were similar when analyses were limited to patients with peripheral arterial disease (ABI<0.9, n = 114).

CONCLUSION

WBC count, but not plasma CRP level, provides incremental information about the risk of death in patients referred for lower-extremity arterial evaluation and in the subset of these patients with peripheral arterial disease.

Neutrophilia predicts death and heart failure after myocardial infarction: a community-based study

BACKGROUND

The relationship between neutrophils and outcomes post-myocardial infarction (MI) is not completely characterized. We examined the associations of neutrophil count with mortality and post-MI heart failure (HF) and their incremental value for risk discrimination in the community.

METHODS AND RESULTS

MI was diagnosed with cardiac pain, biomarkers, and Minnesota coding of the ECG. Neutrophil count at presentation, reported as counts x10(9)/L, was categorized by tertiles (lower tertile, <5.7; middle tertile, 5.7 to 8.5; upper tertile, >8.5). From 1979 to 2002, 2047 incident MIs occurred in Olmsted County, Minn (mean age, 68+/-14 years; 44% women). Median (25th to 75th percentile) neutrophil count was 7.0 (5.1 to 9.5). Within 3 years post-MI, 577 patients died, and 770 developed HF. Overall survival and survival free of HF decreased with increased neutrophil tertile (P<0.001). Compared with the lower tertile, the age and sex adjusted hazard ratio for death was 1.44 (95% CI, 1.14 to 1.81) for the middle tertile and 2.60 (95% CI, 2.10 to 3.22) for the upper tertile (P<0.001). Similarly, for HF, the hazard ratio was 1.32 (95% CI, 1.09 to 1.59) for the middle and 2.12 (95% CI, 1.77 to 2.53) for the upper tertile (P<0.001). These associations persisted after adjustment for risk factors, comorbidities, Killip class, revascularization, and ejection fraction. Neutrophil count improved risk discrimination as indicated by increases in the area under the receiver operating characteristic curves (all P<0.05) and by the integrated discrimination improvement analysis (all P<0.001).

CONCLUSIONS

In the community, the neutrophil count was strongly and independently associated with death and HF post-MI and improved risk discrimination over traditional predictors.

Vascular complications after splenectomy for hematologic disorders

The most widely recognized long-term risk of splenectomy is overwhelming bacterial infection. More recently, thrombosis has become appreciated as another potential complication of the procedure. Because of these long-term risks, the indications for and timing of splenectomy are debated in the medical community. Accordingly, the adverse effects and benefits of splenectomy for hematologic disorders and other conditions demand further study. This comprehensive review summarizes the existing literature pertaining to vascular complications after splenectomy for hematologic conditions and attempts to define the potential pathophysiologic mechanisms involved. This complex topic encompasses diverse underlying conditions for which splenectomy is performed, diverse thrombotic complications, and multiple pathophysiologic mechanisms.

Vitamin C attenuates hypochlorite-mediated loss of paraoxonase-1 activity from human plasma

Paraoxonase 1 (PON1) is a cardioprotective enzyme associated with high-density lipoprotein (HDL). We tested the hypothesis that vitamin C protects HDL and PON1 from deleterious effects of hypochlorous acid, a proinflammatory oxidant. In our experiments, HDL (from human plasma) or diluted human plasma was incubated with hypochlorite in either the absence (control) or presence of vitamin C before measuring chemical modification and PON1 activities. Vitamin C minimized chemical modification of HDL, as assessed by lysine modification and accumulation of chloramines. In the absence of vitamin C, chloramines accumulated to 114 +/- 4 micromol/L in HDL incubated with a 200-fold molar excess of hypochlorite; but addition of vitamin C (200 micromol/L) limited formation to 36 +/- 6 micromol/L (P < .001). In plasma exposed to hypochlorite, IC(50) values of 1.2 +/- 0.1, 9.5 +/- 1.0, and 5.0 +/- 0.6 mmol/L were determined for PON1's phosphotriesterase, arylesterase, and (physiologic) lactonase activities, respectively. Vitamin C lessened this inhibitory effect of hypochlorite on PON1 activities. In plasma supplemented with vitamin C (400 micromol/L), PON1 phosphotriesterase activity was 72% +/- 17% of normal after incubation with hypochlorite (2 mmol/L), compared with 42% +/- 6% for unsupplemented plasma (P < .05). Similar effects were seen for other PON1 activities. In some experiments, vitamin C also appeared to reverse hypochlorite-mediated loss of PON1 phosphotriesterase activity; but this effect was not observed for the other PON1 activities. In conclusion, vitamin C attenuated hypochlorite-mediated loss of PON1 activity in vitro and may, therefore, preserve cardioprotective properties of HDL during inflammation.

Association of neutrophil count with microembolization in patients with symptomatic carotid artery stenosis

BACKGROUND AND PURPOSE

Inflammation plays an important role in the initiation and progression of atherosclerosis but the contribution of neutrophils to this process is unclear. Asymptomatic cerebral microembolization can be detected by transcranial Doppler (TCD) and has been associated with increased risk of early stroke recurrence in patients with recently symptomatic carotid stenosis. In the present study, we sought to determine whether spontaneous microembolization was associated with neutrophil count in patients with recently symptomatic carotid stenosis.

METHODS

We continuously monitored Transcranial Doppler (TCD) spectra of middle cerebral artery blood flow ipsilateral to recently symptomatic carotid artery stenosis in 60 consecutive patients. Microembolic signals (MES) were diagnosed by experienced observers blinded to leukocyte count and high-sensitive C-reactive protein (hs-CRP) level measurement.

RESULTS

We found MES in 20 (33.3%) patients. Microembolization was associated with higher neutrophil counts (p=0.003). Differences in monocyte count and lymphocyte count between patients with MES and patients without MES were not statistically significant. Microembolization remained strongly associated with neutrophil count in multivariable analysis (p=0.003) whereas the association with hs-CRP was not significant.

CONCLUSIONS

Neutrophil count was associated with microembolization in patients with recently symptomatic carotid artery stenosis. Our findings suggest that neutrophils may play a role in the pathogenesis of stroke related to carotid atherosclerosis.

Perspectives on thrombosis in essential thrombocythemia and polycythemia vera: is leukocytosis a causative factor?

Leukocyte (WBC) count has been recently identified as an independent predictor of major thrombosis in both essential thrombocythemia (ET) and polycythemia vera (PV). However, whether leukocytosis should be simply considered a marker for vascular disease or whether elevated WBC levels actually contribute directly to causing such disorders is presently matter of many studies. By adopting epidemiologic criteria for causation, we have examined the characteristics to support this association such as (1) strength, (2) consistency, (3) specificity, (4) temporality, (5) biologic gradient, (6) plausibility, (7) experimental evidence, and (8) analogy. Our conclusion supports the notion that baseline leukocytosis in ET and PV patients adds prognostic significance to existing risk factors and that may be considered causative of vascular events. These developments could induce clinicians to incorporate WBC count into standard clinical practice. However, we need prospective clinical studies with stratification of patients according to their baseline leukocyte counts. Until such evidence is available, the decision on how to manage these patients should continue to follow conventional criteria.

Heterotypic interactions enabled by polarized neutrophil microdomains mediate thromboinflammatory injury

Selectins and their ligands mediate leukocyte rolling, allowing interactions with chemokines that lead to integrin activation and arrest. Here we show that E-selectin is crucial for generating a secondary wave of activating signals, transduced specifically by E-selectin ligand-1, that induces polarized, activated alpha(M)beta(2) integrin clusters at the leading edge of crawling neutrophils, allowing capture of circulating erythrocytes or platelets. In a humanized mouse model of sickle cell disease, the capture of erythrocytes by alpha(M)beta(2) microdomains leads to acute lethal vascular occlusions. In a model of transfusion-related acute lung injury, polarized neutrophils capture circulating platelets, resulting in the generation of oxidative species that produce vascular damage and lung injury. Inactivation of E-selectin or alpha(M)beta(2) prevents tissue injury in both inflammatory models, suggesting broad implications of this paradigm in thromboinflammatory diseases. These results indicate that endothelial selectins can influence neutrophil behavior beyond its canonical rolling step through delayed, organ-damaging, polarized activation.

Is thrombin a key player in the 'coagulation-atherogenesis' maze?

In addition to its established roles in the haemostatic system, thrombin is an intriguing coagulation protease demonstrating an array of effects on endothelial cells, vascular smooth muscle cells (VSMC), monocytes, and platelets, all of which are involved in the pathophysiology of atherosclerosis. There is mounting evidence that thrombin acts as a powerful modulator of many processes like regulation of vascular tone, permeability, migration and proliferation of VSMC, recruitment of monocytes into the atherosclerotic lesions, induction of diverse pro-inflammatory markers, and all of these are related to the progression of cardiovascular disease. Recent studies in transgenic mice models indicate that the deletion of the natural thrombin inhibitor heparin cofactor II promotes an accelerated atherogenic state. Moreover, the reduction of thrombin activity levels in apolipoprotein E-deficient mice, because of the administration of the direct thrombin inhibitor melagatran, attenuates plaque progression and promotes stability in advanced atherosclerotic lesions. The combined evidence points to thrombin as a pivotal contributor to vascular pathophysiology. Considering the clinical development of selective anticoagulants including direct thrombin inhibitors, it is a relevant moment to review the different thrombin-induced mechanisms that contribute to the initiation, formation, progression, and destabilization of atherosclerotic plaques.

Leukocyte count is associated with increased platelet reactivity and diminished response to aspirin in healthy individuals with a family history of coronary artery disease

BACKGROUND

Markers of systemic inflammation, including blood leukocyte count, are associated with increased cardiovascular risk, but the mechanisms underlying this association are unclear. Leukocytes may promote platelet reactivity and thrombus formation, providing a basis for increased risk, but a relation between leukocyte count and platelet function has not been studied.

METHODS

We evaluated the relation of blood leukocyte count, C-reactive protein (CRP), and interleukin-6 (IL-6) to platelet aggregation to collagen, ADP and arachidonic acid, and to urinary excretion of 11-dehydro thromboxane B2. Studies were conducted in 1600 individuals (45.0+/-12.9 years, 42.7% male) at risk for coronary artery disease (CAD) before and after low dose aspirin.

RESULTS

At baseline, platelet reactivity increased with increasing quartile of leukocyte count (median counts for each quartile were normal) for all measures of platelet function (P<0.0001). These relations were unchanged by aspirin. The relation between leukocyte count and each measure of platelet reactivity remained significant (P<0.05) after multivariable adjustment for CRP, IL-6, cardiac risk factors, hematologic variables, and platelet thromboxane production. CRP and IL-6 were independently associated with few measures of platelet reactivity.

CONCLUSIONS

Increasing quartile of leukocyte count, even within the normal range, is associated with increasing platelet reactivity in individuals at risk for CAD. This relationship is not altered by aspirin and is independent of inflammatory markers and platelet thromboxane production. Additional studies are needed to determine the mechanism(s) for this association and therapies to reduce cardiovascular risk in patients with elevated leukocyte counts.

Cardiovascular biomarkers in groups of established smokers after a decade of smoking

To investigate tools for evaluation of smoking-associated disease initiation and progression, we examined basic clinical parameters and biomarkers of cardiovascular disease risk, in a group of healthy volunteers with an average 10-year smoking history. A small cross-sectional study of never-smokers, moderate smokers and smokers was performed. Caucasians were recruited to match pre-defined cigarette tar yields and cigarettes smoked per day. For haematological parameters, significant differences between never-smokers and all female smokers combined were seen for haemoglobin concentration, haematocrit, total leucocyte count, neutrophil count and lymphocyte count. For all male smokers combined, only total leucocyte count was statistically different. Analysis of exhaled CO and other smoke exposure biomarker (nicotine and its metabolites) data showed a statistically significant increase in all groups of smokers with a trend related to the number of cigarettes smoked per day. Thromboxane urinary metabolites 11-dehydro-thromboxane B(2) and 2,3-dinor-thromboxane B(2) were statistically significantly elevated in smokers. Significant statistical differences between smokers with approximately 10 years of smoking history and non-smokers in white cells count, hemoglobin and thromboxane turnover were seen, although they did not reach levels associated with overt diseases. These data could provide insight into early biomarkers predictive of risk for coronary and vascular disease.

Hemoglobin, leukocytosis and clinical outcomes of ST-elevation myocardial infarction treated with primary angioplasty: ANIN Myocardial Infarction Registry

BACKGROUND

Hemoglobin (Hb) levels may interact with inflammatory activation, but it is unknown whether the interaction has any impact on clinical outcomes in acute coronary syndromes. The aim of this study was to assess the relationship between admission Hb levels, leukocytosis and clinical outcomes of ST-elevation myocardial infarction (STEMI) treated with primary angioplasty. Methods and Results The study group comprised 1,904 (1,380 men) patients with STEMI treated with primary percutaneous coronary intervention, enrolled in a prospective registry. The primary endpoint of in-hospital death occurred in 90 (4.7%) patients. According to univariate analysis, extreme values of Hb (for 1(st) and 5(th) vs mid quintiles respectively: hazard ratio (HR) =7.1, P<0.001 and HR =3.2, P=0.024) and leukocytosis above median (HR =2.09, P=0.001) significantly correlated with in-hospital death. After dividing patients into high and low white blood cell (WBC) count groups, a U-shaped relationship of Hb levels and mortality was observed for patients with higher leukocytosis (1(st) and 5(th) vs mid quintiles respectively: HR =8.1, P=0.001 and HR =4.4, P=0.022), whereas in patients with lower WBC count higher mortality was related solely to the lowest Hb quintile (HR =6.9, P=0.010 vs mid quintile). Conclusion Higher mortality associated with higher Hb levels in STEMI patients treated with primary angioplasty is limited to patients with increased leukocytosis.

Increased inflammatory gene expression in ABC transporter-deficient macrophages: free cholesterol accumulation, increased signaling via toll-like receptors, and neutrophil infiltration of atherosclerotic lesions

BACKGROUND

Two macrophage ABC transporters, ABCA1 and ABCG1, have a major role in promoting cholesterol efflux from macrophages. Peritoneal macrophages deficient in ABCA1, ABCG1, or both show enhanced expression of inflammatory and chemokine genes. This study was undertaken to elucidate the mechanisms and consequences of enhanced inflammatory gene expression in ABC transporter-deficient macrophages.

METHODS AND RESULTS

Basal and lipopolysaccharide-stimulated thioglycollate-elicited peritoneal macrophages showed increased inflammatory gene expression in the order Abca1(-/-)Abcg1(-/-)>Abcg1(-/-)>Abca1(-/-)>wild-type. The increased inflammatory gene expression was abolished in macrophages deficient in Toll-like receptor 4 (TLR4) or MyD88/TRIF. TLR4 cell surface concentration was increased in Abca1(-/-)Abcg1(-/-)>Abcg1(-/-)> Abca1(-/-)> wild-type macrophages. Treatment of transporter-deficient cells with cyclodextrin reduced and cholesterol-cyclodextrin loading increased inflammatory gene expression. Abca1(-/-)Abcg1(-) bone marrow-derived macrophages showed enhanced inflammatory gene responses to TLR2, TLR3, and TLR4 ligands. To assess in vivo relevance, we injected intraperitoneally thioglycollate in Abcg1(-/-) bone marrow-transplanted, Western diet-fed, Ldlr-deficient mice. This resulted in a profound inflammatory infiltrate in the adventitia and necrotic core region of atherosclerotic lesions, consisting primarily of neutrophils.

CONCLUSIONS

The results suggest that high-density lipoprotein and apolipoprotein A-1 exert anti-inflammatory effects by promoting cholesterol efflux via ABCG1 and ABCA1 with consequent attenuation of signaling via Toll-like receptors. In response to a peripheral inflammatory stimulus, atherosclerotic lesions containing Abcg1(-/-) macrophages experience an inflammatory "echo," suggesting a possible mechanism of plaque destabilization in subjects with low high-density lipoprotein levels.

Human neutrophil peptides: a novel potential mediator of inflammatory cardiovascular diseases

The traditional view of atherosclerosis has recently been expanded from a predominantly lipid retentive disease to a coupling of inflammatory mechanisms and dyslipidemia. Studies have suggested a novel role for polymorphonuclear neutrophil (PMN)-dominant inflammation in the development of atherosclerosis. Human neutrophil peptides (HNPs), also known as alpha-defensins, are secreted and released from PMN granules upon activation and are conventionally involved in microbial killing. Current evidence suggests an important immunomodulative role for these peptides. HNP levels are markedly increased in inflammatory diseases including sepsis and acute coronary syndromes. They have been found within the intima of human atherosclerotic arteries, and their deposition in the skin correlates with the severity of coronary artery diseases. HNPs form complexes with LDL in solution and increase LDL binding to the endothelial surface. HNPs have also been shown to contribute to endothelial dysfunction, lipid metabolism disorder, and the inhibition of fibrinolysis. Given the emerging relationship between PMN-dominant inflammation and atherosclerosis, HNPs may serve as a link between them and as a biological marker and potential therapeutic target in cardiovascular diseases including coronary artery diseases and acute coronary syndromes.

Exploring the usefulness of inflammation-sensitive biomarkers to reveal potential sex differences in relation to low-grade inflammation in individuals with the metabolic syndrome

Sex differences exist in the expression of different inflammation-sensitive biomarkers in relation to the metabolic syndrome (MetS). We have presently explored these differences in relation to commonly used inflammation-sensitive biomarkers including the high-sensitivity C-reactive protein (hs-CRP), quantitative fibrinogen, erythrocyte sedimentation rate (ESR), white blood cell count (WBCC), and absolute number of polymorphonuclear leukocytes. This is a cross-sectional analysis of a group of apparently healthy men (n = 5560) and women (n = 3049) in whom the results of the above-mentioned inflammation-sensitive biomarkers were analyzed in relation to the different components of MetS. The concentration of hs-CRP increased pari passu with the number of components of the MetS, the differences between the sexes being significant for any number of components of the MetS. Regarding fibrinogen, the influence of sex turned significant for waist only, similarly to the results of the ESR. None of these interactions were found to be significant for both the WBCC and the absolute number of polymorphonuclear leukocytes. Quantitative fibrinogen, ESR, WBCC, as well as the absolute number of polymorphonuclear leukocytes are not sensitive enough to reveal the potential sex differences in relation to the various components of the MetS and the expression of the low-grade inflammation. High-sensitivity CRP does have the capability to reveal these differences.

Harms and benefits of lymphocyte subpopulations in patients with acute stroke

Lymphocytes are major players in the development of innate and adaptive immune responses but their behavior in patients with acute stroke has received little attention.

EXPERIMENTAL PROCEDURES

Using flow cytometry we identified total lymphocytes, T cells, helper T (Th) cells, cytotoxic T lymphocytes (CTL), natural killer (NK) cells, B cells, and regulatory T (Treg) cells in 46 consecutive patients with acute stroke within a median of 180 min of clinical onset, and at days 2, 7, and 90. Daily neurological score (National Institutes of Health Stroke Scale), diffusion-weighted imaging on brain magnetic resonance imaging, functional impairment, and stroke-associated infection (SAI) at day 7 were assessed. Apoptosis in lymphocyte subsets, tumor necrosis factor (TNF) -alpha/interleukin (IL) -4 production in stimulated Th and CTL, cluster of differentiation 86 (CD86) (B7-2) expression in B cells, cortisol and metanephrine in serum were measured. Multivariate analyses were used to evaluate SAI, and stroke outcome.

RESULTS

Increased apoptosis and a fall of T, Th, CTL, B, and Treg cells were observed after stroke. Severer stroke on admission and SAI disclosed a greater decline of T, Th, and CTL cells. Increased cortisol and metanephrine was associated with severe stroke and SAI, and inversely correlated with T, and CTL. T cells, and CTL were correlated with infarct growth. Stroke but not SAI resulted in lower TNF-alpha production in Th cells. SAI showed the greatest fall of lymphocytes, T, Th, and CTL, but not B cells, or Treg. Poor outcome was associated with reduced levels of B cells, and increased expression of CD86 in B cells, but not with SAI.

CONCLUSION

Lymphopenia and increased apoptosis of T, Th, CTL, Treg and B cells are early signatures after human stroke. A decreased cellular response after stroke is a marker of ongoing brain damage, the stress response, and a higher risk of infection. A lower humoral response is predictor of poorer long-term outcome.

Leukocytosis and risk stratification assessment in essential thrombocythemia

PURPOSE

Established risk factors for thrombosis in essential thrombocythemia (ET) include age and previous vascular events. We aimed to refine this risk stratification by adding baseline leukocytosis.

PATIENTS AND METHODS

We enrolled 657 patients with ET followed for a median of 4.5 years who developed 72 major thrombosis. Cox proportional hazard model was performed to analyze the thrombotic risk and to discriminate ET patients with or without thrombosis, multivariable C statistic index was used. We searched for leukocytes cutoff with the best sensitivity and specificity by a receiver operating characteristic curve.

RESULTS

Results confirmed that age and prior events are independent risk factors for thrombosis and showed a gradient between baseline leukocytosis and thrombosis. On the contrary, no significant association was found either for JAK2(V617F) allele burden and for other laboratory parameters, including platelet number. In the model with conventional risk factors alone, C statistic ratio for total thrombosis was 0.63 and when leukocytosis was added, the change was small (C = 0.67). In contrast, in younger and asymptomatic patients (low-risk category), C statistic value indicated an high risk for thrombosis in patients with leukocytosis, similar to that calculated in conventionally defined high-risk group (C = 0.65). The best leukocyte cutoff values for predicting the events was found to be 9.4 (x 10(9)/L).

CONCLUSION

We suggest to include baseline leukocytosis in the risk stratification of ET patients enrolled in clinical trials.

Predictive value of white blood cell subtypes for long-term outcome following myocardial infarction

INTRODUCTION

Elevation of total white blood cells (WBC) count is associated with higher mortality in patients with acute coronary syndromes. However, it is unknown which specific subset of leukocytes best correlates with increased risk of adverse outcome.

METHODS AND RESULTS

We prospectively studied the predictive value of WBC subtypes for long-term outcome in 1037 patients with acute myocardial infarction (AMI). Total WBC, neutrophil, monocyte and lymphocyte counts, and high-sensitivity C-reactive protein (CRP) were obtained in each patient. The median duration of follow up was 23 months (range, 6-42 months). Analyzed separately, baseline total WBC (HR 2.2, 95% CI 1.5-3.3; P<0.0001), neutrophil (HR 2.7, 95% CI 1.8-4.1; P<0.0001) and monocyte (HR 1.9, 95% CI 1.3-2.8; P=0.001) counts in the upper quartile, and lymphocyte count in the lower quartile (HR 1.5, 95% CI 1.1-2.3; P=0.03), were all independent predictors of mortality. Comparing nested models, adding other WBC data failed to improve model based on neutrophil count. In contrast, adding neutrophil count to the models based on total WBC (P=0.01), on monocyte count (P<0.0001) or on lymphocyte count (P<0.0001) improved the prediction of the models. Neutrophil count in the upper quartile (>or=9800 microL(-1)) remained a strong independent predictor of mortality after adjustment for left ventricular systolic function and for CRP (HR 2.2, 95% CI 1.6-3.0; P<0.0001).

CONCLUSION

Of all WBC subtypes, elevated neutrophil count best correlates with mortality in patients with AMI. Neutrophil count provides additive prognostic information when combined with CRP.

Influence of polymorphonuclear leukocytes on the plasma clot formation as evaluated by thromboelastometry (ROTEM®)

OBJECTIVE

It has been emphasized that polymorphonuclear leukocytes (PMN) participate in the regulation of coagulation. However, the mechanisms of action are not clear. Besides a procoagulant activity, anticoagulant or fibrinolytic properties are attributed to these cells. To explore their global effect, we have studied their involvement in the clot formation with thromboelastometry, which gives global view over the clotting process, in particular on the structure of the clot and on the kinetic of its formation.

METHODS

PMN were isolated from healthy blood donors and resuspended into autologous platelet-free plasma. The ROTEM device was used. Coagulation was triggered only by adding calcium chloride. Thromboelastometric profiles of PMN-rich plasma (PMN-RP) were compared with autologous platelet-rich (PRP) and platelet-poor plasma (PPP). The inhibition of both tissue factor and intrinsic pathways was also studied.

RESULTS AND CONCLUSIONS

The procoagulant activity of resting PMN was demonstrated as the initiation of fibrin formation with PMN-RP was significantly faster compared with both PRP and PPP. The kinetic of plasma clotting was remarkably improved with PMN-RP compared with PPP. However, the clot with PMN-RP had the same poor viscoelastical properties as PPP. Thromboelastometry gives a new point of view in the involvement of PMN in coagulation, in the absence of any PMN pre-activation. Their impact was centred on the kinetic and the facilitation of the clot formation.

The effects of prenatal exposure of mice to cigarette smoke on offspring immune parameters

While direct exposure to cigarette smoke (CS) was shown in numerous human and animal studies to impair host immune responses, effects on the offspring following in utero CS exposure are relatively unknown. Thus, a toxicological study was performed that extended our previous investigations examining the effects of relatively low-dose CS exposure on immune tumor surveillance parameters of the prenatally exposed offspring. In the current study, pregnant B6C3F1 mice were exposed by inhalation to mainstream CS (at a concentration equivalent to smoking approximately 1 pack of cigarettes/d) for 5 d/wk, 4 h/d from gestational day 4 to parturition. Smoke-induced effects on a number of immune parameters were examined in 3- (and/or 5-), 10-, and 20-wk-old male and female offspring, including lymphoid organ weight/cellularity; blood and bronchopulmonary lavage cell numbers/profiles; splenic lymphocyte proliferation; mixed lymphocyte reactions; and, host resistance against transplanted melanoma cells. Exposure in utero to CS significantly increased circulating white blood cell and lymphocyte numbers in both sexes for up to 2.5 mo after birth (compared to their age-/sex-matched, air-exposed counterparts). In addition, 3-wk-old male and female offspring from smoke-exposed mothers had decreased mitogen-stimulated T-lymphocyte proliferation, while 5-wk-old male pups had increased mixed lymphocyte response compared to their sex-matched, air-exposed counterparts. Although effects of prenatal smoke exposure on overall offspring immunity were relatively modest, these findings could suggest that early toxic insult by CS may alter subsequent immune homeostasis in the offspring, leading, possibly, to changes in disease vulnerability.

Impaired ex vivo leukotriene B4 production characterizes the metabolic syndrome and is improved after weight reduction

CONTEXT

Neutrophil (polymorphonuclear neutrophil) production of leukotriene B4 (LTB4) may be associated with alterations in immune and inflammatory function that characterize the metabolic syndrome (MetS).

OBJECTIVE

We investigated whether polymorphonuclear neutrophil production of LTB(4) and its metabolites 20-hydroxy-LTB4 (20-OH-LTB4) and 20-carboxyl-LTB4 were altered in subjects with features of the MetS before and after weight reduction.

DESIGN, SETTING, PATIENTS, AND INTERVENTION

In a case-controlled comparison, men and postmenopausal women with features of the MetS were matched with controls. Subjects with MetS were then matched and randomly assigned to either a 12-wk weight reduction study followed by 4-wk weight stabilization or 16-wk weight maintenance.

MAIN OUTCOME MEASURES

Measurements were performed at baseline and at the end of the 16-wk period. Stimulated neutrophil LTB4 and its metabolites were measured by HPLC.

RESULTS

In the case-controlled study, body mass index, waist circumference, blood pressure, fasting triglycerides, and glucose were all significantly increased in subjects with features of the MetS (P < 0.05). Production of LTB4 and 20-OH-LTB4 was significantly lower compared with controls (P < 0.005). The weight loss intervention resulted in a 4.6-kg reduction in body weight and 6.6-cm decrease in waist circumference relative to controls and a significant increase in LTB4 and 20-OH-LTB4.

CONCLUSIONS

Subjects with features of the MetS have lower stimulated LTB4, which is not due to increased metabolism of LTB4. Weight reduction restored the production of neutrophil LTB4, suggesting that in addition to modifying cardiovascular risk, weight loss may also help with the management of perturbed inflammatory responses in overweight subjects.

Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting

BACKGROUND

An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing surgical revascularization.

METHODS

Baseline clinical details were obtained prospectively in 1938 patients undergoing CABG. The differential leukocyte was measured before surgery, and patients were followed-up 3.6 years later. The primary end point was all-cause mortality.

RESULTS

The preoperative N/L ratio was a powerful univariable predictor of mortality (hazard ratio [HR] 1.13 per unit, P < .001). In a backward conditional model, including all study variables, it remained a strong predictor (HR 1.09 per unit, P = .004). In a further model, including the European system for cardiac operative risk evaluation, the N/L ratio remained an independent predictor (HR 1.08 per unit, P = .008). Likewise, it was an independent predictor of cardiovascular mortality and predicted death in the subgroup of patients with a normal white blood cell count. This excess hazard was concentrated in patients with an N/L ratio in the upper quartile (>3.36).

CONCLUSION

An elevated N/L ratio is associated with a poorer survival after CABG. This prognostic utility is independent of other recognized risk factors.

Simvastatin treatment modifies polymorphonuclear leukocyte function in high-risk individuals: a longitudinal study

BACKGROUND

Although extensive experimental evidence supports a primary role of polymorphonuclear leukocytes (PMNs) in atherosclerosis, few data exist concerning the functional properties of these cells and their pharmacological modulation in high-risk individuals.

OBJECTIVE

The production of the proinflammatory chemokine interleukin-8 (IL-8), migration and chemotaxis, and reactive oxygen species (ROS) generation were investigated in a longitudinal study in PMNs obtained from high-risk individuals during statin treatment. As a secondary endpoint we compared PMN function of high-risk patients with that of controls.

METHODS AND RESULTS

PMNs were isolated from 21 high-risk individuals before treatment and 3 and 30 days after the beginning of simvastatin treatment, and from healthy controls. During treatment a significant reduction was observed both in resting (P = 0.009) and N-formyl-Met-Leu-Phe (fMLP)-stimulated (P = 0.008) IL-8 production, and in the chemotactic index (P = 0.038), whereas ROS generation did not significantly change. In comparison with cells from controls, PMNs obtained from patients before starting simvastatin treatment showed higher resting and fMLP-stimulated IL-8 release (P = 0.007 and P = 0.002, respectively) and ROS generation (resting, P = 0.009; and fMLP-stimulated, P = 0.046), whereas migration and the chemotactic index did not significantly differ.

CONCLUSIONS

An activation of neutrophils is present in high-risk individuals, shown by the enhanced production of IL-8, and increased ROS generation. The 4-week statin treatment is able to reduce the cell capability to produce IL-8, and to decrease chemotaxis, thus affecting the proinflammatory properties of PMNs.