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Objective: Childhood bronchial asthma (BA) is a globally significant chronic disease with major health consequences. Recently, focus on the role of the innate immune system has been highlighted. Therefore, this study explores the role of circulating monocytes and natural killer (NK) clusters in childhood asthma. Methods: This case-control study enrolled 50 children with asthma divided equally into severe and mild groups and 26 healthy children. Flow-cytometry analysis was used to identify circulating blood monocytes and natural killers' subsets. In addition, pulmonary function test (spirometry) for children with asthma was performed. Results: This study showed significant negative correlations between frequency of total circulating, classical, intermediate, and nonclassical monocytes with ratio of forced expiratory volume/forced vital capacity (FEV1/FVC) (r = −0.637, P < 0.001; r = −0.575, P < 0.001; r = −0.657, P < 0.001; r = −0.329, P = 0.004, respectively). Also, there was significant negative correlations between frequency of total NKs and CD56dim CD16+ NK with FEV1/FVC (r = −0.584, P < 0.001) and (r = −0.579, P < 0.001). Significant predictors of childhood asthma severity were frequencies of total monocytes, total NKs, intermediate monocytes, and CD56dimCD16+ NK. Conclusion: Finally, we concluded that the FEV1/FVC is linked to aberrations of monocytes' and natural killers' immunophenotypic subsets in children with asthma. The frequencies of total monocytes and NK are significant predictors of severity of childhood asthma. The frequencies of CD14high CD16+ intermediate monocytes and CD56dim CD16+ NK cells are the best independent predictors of severity in children with asthma. [ABSTRACT FROM AUTHOR]

Highlights • The phenotypes of monocyte subsets differ at different stages of atherosclerosis. • UA patients exhibit an increased frequency of chemokine receptors and PRRs. • This increased frequency is seen mainly in intermediate monocytes of UA patients. • HSP60 induces IL-12p70 production in intermediate monocytes from control subjects. Abstract Background and aims Macrophages derived from monocytes play an important role in atherosclerosis progression. Subpopulations of circulating classical, intermediate, and non-classical monocytes possess distinct functions and phenotypes, and participate in the pathogenesis of disease. The aim of this study was to compare the quantity and phenotypes of circulating monocyte subpopulations in patients with established atherosclerosis and healthy control individuals. Additionally, the study aimed to provide insight into the functional activity of monocytes against a heat shock protein (HSP60). Methods Chemokine and pattern recognition receptors in monocyte subsets obtained from peripheral blood of acute and chronic coronary artery disease patients and controls were quantified by flow cytometry. Furthermore, monocytes from healthy controls were stimulated in vitro with HSP60, and the cytokines produced by them were evaluated by flow cytometry. Results Eighteen controls (C), 34 individuals with risk factors for cardiovascular disease (RF), 32 patients with stable angina (SA), and 16 patients with unstable angina (UA) were enrolled in the study. The absolute count of intermediate monocytes was found to be increased in patients of the UA group; high frequencies of the chemokine receptors CCR2, CCR5, and CX3CR1 were also observed in this subpopulation. Moreover, the pattern recognition receptors TLR2 and TLR4 were more frequent in intermediate monocytes from the UA group. Furthermore, the intermediate monocytes from healthy individuals produced IL-12p70 after stimulation with HSP60. Conclusions Our results show that intermediate monocytes of UA patients exhibited an enhanced expression of the receptors involved in the recognition of damage-associated molecular patterns (DAMPs) and enhancement of the migratory function. Hence, they might contribute to the propagation and progression of inflammation observed in atherosclerosis, especially in the acute setting. [ABSTRACT FROM AUTHOR]

Background and aims Monocytes are known to play a key role in the initiation and progression of atherosclerosis and contribute to plaque destabilization through the generation of signals that promote inflammation and neoangiogenesis. In humans, studies investigating the features of circulating monocytes in advanced atherosclerotic lesions are lacking. Methods Patients (mean age 69 years, 56% males) with intermediate asymptomatic carotid stenosis (40–70% in diameter) were evaluated for maximal stenosis in common carotid artery, carotid bulb and internal carotid artery, overall disease burden as estimated with total plaque area (TPA), greyscale and neovascularization in 244 advanced carotid plaques. Absolute counts of circulating CD14+ monocytes, of classical (CD14 high CD16−), intermediate (CD14 high CD16+) and non-classical (CD14 low CD16+) monocytes and HLA-DR+ median fluorescence intensity for each subset were evaluated with flow cytometry. Results No correlation was found between monocytes and overall atherosclerotic burden, nor with high sensitivity C-reactive protein (hsCRP) or interleukin-6 (IL-6). In contrast, plaque signs of neovascularization were associated with significantly lower counts of circulating CD14+ monocytes (297 versus 350 cells/mm 3 , p = 0.039) and of classical monocytes (255 versus 310 cells/mm 3 , p = 0.029). Conclusions Neovascularized atherosclerotic lesions selectively associate with lower blood levels of CD14+ and CD14 high CD16− monocytes independently of systemic inflammatory activity, as indicated by normal hsCRP levels. Whether the reduction of circulating CD14+ and CD14 high CD16− monocytes is due to a potential redistribution of these cell types into active lesions remains to be explored. [ABSTRACT FROM AUTHOR]