The recruitment of leukocytes and their interaction with the vessel wall: the role of interleukin-1 and tumor necrosis factor

Variant Angina is Associated with Myocarditis

Background

Vasospastic angina (VSA) is caused by severe diffuse or segmental coronary artery spasms. Patients with variant angina have poor clinical outcomes, although nitrates and calcium blockers help improve patient symptoms because there is no understanding of the etiology and causal treatment. The present study investigated whether VSA is associated with inflammation of the heart.

Patients and Methods

A total of 109 patients with VSA diagnosed by the presence of recurrent angina pectoris, typical electrocardiography, and coronary angiography were recruited, and 61 normal participants and 61 patients with acute myocardial infarction (AMI) and coronary artery stenosis were recruited as controls. The plasma levels of 24 cytokines were measured using a magnetic Luminex assay, and endothelin-1 and histamine levels tested using enzyme-linked immunosorbent assay and mass-spectrometry, respectively, for all participants. Furthermore, four patients with VSA underwent 18-fluorine fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT).

Results

The plasma levels of interleukin (IL)-12p70, IL-13, PDL-1, IL-10, IL-6, IL-15, macrophage inflammatory protein (MIP)-1α, and MIP-1β in patients with VSA were significantly higher than those in both normal controls and patients with AMI (p<0.001) but did not differ between normal controls and patients with AMI. ¹⁸F-FDG PET/CT showed that the left ventricle, coronary perivascular tissue volume, and coronary perivascular FDG uptake were significantly increased in all four patients.

Conclusion

Our findings demonstrate that VSA patients have significantly elevated plasma cytokine levels and myocardial and pericoronary inflammation, suggesting that VSA is associated with myocarditis. This study provides novel insights into the etiology and treatment of VSA.

Latent Collagenase Production by Cells Derived from Nasal Polyps in Culture

We investigated the interactions between nasal polyp-derived fibroblast-like cells (NPFCs) and nasal secretions to clarify the role of connective tissue metabolism in nasal and paranasal pathology, especially in chronic sinusitis. In response to stimulation by human interleukin 1 (IL-1), NPFCs produced latent collagenase. Collagenase production was also stimulated by nasal secretions from patients with chronic sinusitis in vitro, but not by nasal secretions from nasal allergic patients. A soluble factor was isolated from the nasal secretions of patients with chronic sinusitis by ammonium sulfate precipitation and Sephadex G-75 gel chromatography. High performance liquid chromatography indicated that the molecular weight of the active fraction was approximately 20,000 daltons. This factor affected NPFCs, but did not affect the endothelial cells derived from nasal mucosa in culture. Collagenase production by NPFCs was considerably inhibited by anti-IL-1 antibody. These results indicate that IL-1 is one major factor to prolong the nasal and paranasal inflammatory lesions.

Targeting the leukocyte activation cascade: getting to the site of inflammation using microfabricated assays

This paper describes the use of microfabricated devices to study the leukocyte activation cascade (LAC). The devices consist of microchannels fabricated in polydimethylsiloxane using soft lithography. Microfluidics, used to generate physiologically relevant levels of shear flow, was achieved by the simple attachment of a syringe pump. Microchannel surfaces were modified by self-assembled monolayer (SAM) chemistries. The devices were adapted to standard 96-well tissue culture format with microchannels that could accommodate either a monolayer of endothelial cells or a SAM with immobilized chemokines. Chemotaxis was performed using linear gradients of chemokine set in a 3D matrix. Using this approach, we demonstrated robust chemotaxis of primary human leukocytes (PHLs) in response to a gradient of the chemokine CCL2. Rolling and adhesion assays performed under shear flow demonstrated that leukocyte recruitment to the substrate was highly sensitive to both biological and physical forces. CCL2 and CXCL12 treatment of PHLs dose dependently increased activation and adhesion. These actions could be inhibited by the use of peptide or small molecule antagonists. These devices provide a robust platform to perform LAC assays under in vivo-like conditions.

Chemokines and bone remodeling

Bone remodeling is characterized by spatial and temporal coupling of bone resorption and formation and is necessary for skeletal growth and normal bone structure maintenance. Imbalance of this process is related to metabolic bone disorders such as osteoporosis or rheumatoid arthritis. For this reason, bone remodeling is under the control of several local and systemic factors, including molecules of the immune system. The importance of the interplay of both the skeletal and immune systems is reflected by the emerging interdisciplinary research field, called osteoimmunology, focused on common aspects of osteology and immunology. This review focuses on the role of inflammatory mediators, such as cytokines in bone remodeling and, in particular, a subfamily of chemotactic cytokines or chemokines which are involved not only in several aspects of physiological bone remodeling but also in pathological bone disorders, such as rheumatoid arthritis or osteoporosis. Understanding the role of inflammation and chemokines will provide new insights for the treatment of diseases affecting both skeletal and immune systems, by the development of new therapeutic strategies targeting common inflammatory mediators.

Value of degenerative change in neutrophils as a diagnostic test for Kawasaki syndrome

STUDY OBJECTIVE

To determine whether the presence of vacuoles and toxic granulation in neutrophils can be used as a diagnostic test to help differentiate children with Kawasaki syndrome from those with clinically similar illnesses.

DESIGN

Peripheral blood smears of 23 patients with Kawasaki syndrome, 23 disease control patients, and 23 hematology laboratory control subjects were examined in random order by technicians unaware of either the diagnosis or the previously recorded laboratory results.

SETTING

Tertiary care children's hospital in Ottawa, Canada.

PATIENTS

All 23 consecutive patients with Kawasaki syndrome satisfied established criteria for the diagnosis. Disease control patients were selected from the hospital registry of patients with other illnesses frequently considered as part of the differential diagnosis for Kawasaki syndrome.

MEASUREMENTS AND MAIN RESULTS

Compared with disease control patients, patients with Kawasaki syndrome had a higher percentage of neutrophils with vacuoles (mean +/- SEM, 31% +/- 5% vs 14% +/- 3%; p = 0.006) and toxic granulation (mean +/- SEM, 43% +/- 7% vs 14% +/- 4%; p less than 0.001). If the sum of the number of neutrophils with vacuoles and the number with toxic granulation (per 100 mature neutrophils examined) was at least 70, this "toxic neutrophil" test had a specificity of 0.96 and a likelihood ratio of a positive test result of 12.

CONCLUSIONS

Degenerative change in neutrophils is common in the early stages of Kawasaki syndrome. The toxic neutrophil test is potentially a helpful adjunct to the clinical examination, particularly in the case of infants and other patients with subtle manifestations who might otherwise be at risk for delayed diagnosis.

Spontaneous tumor necrosis factor production in Kawasaki disease

Tumor necrosis factor production by peripheral blood mononuclear cells was measured in 18 patients with Kawasaki disease. In patients studied during the acute febrile phase of their disease, there was increased spontaneous TNF production (mean 26.9 +/- 40.3 U/ml) compared with that of control subjects (1.0 +/- .86 U/ml) (p less than or equal to 0.025). Spontaneous TNF production by patients tested in the subacute or convalescent phase of the illness was significantly lower than that in patients tested during the acute illness (p less than or equal to 0.025). In all patients studied with serial acute and subacute-convalescent samples, TNF production was normal in the follow-up samples. Because TNF is a potent mediator of inflammation and causes damage to vascular endothelial cells, we suggest that TNF may be important in the pathogenesis of both the immune activation and endothelial cell damage characteristic of this illness.