Eosinophil cationic protein (ECP) in school children living in a mountainous area of Norway: a population-based study of ECP as a tool for diagnosing asthma in children with reference values

Virome in the Lungs: The Role of Anelloviruses in Childhood Respiratory Diseases

More recently, increasing attention has been directed to exploring the function of the global virome in health and disease. Currently, by new molecular techniques, such as metagenomic DNA sequencing, the virome has been better unveiled. By investigating the human lung virome, we could provide novel insights into respiratory diseases. The virome, as a part of the microbiome, is characterized by a constant change in composition related to the type of diet, environment, and our genetic code, and other incalculable factors. The virome plays a substantial role in modulating human immune defenses and contributing to the inflammatory processes. Anelloviruses (AVs) are new components of the virome. AVs are already present during early life and reproduce without apparently causing harm to the host. The role of AVs is still unknown, but several reports have shown that AVs could activate the inflammasomes, intracellular multiprotein oligomers of the innate immune system, which show a crucial role in the host defense to several pathogens. In this narrative revision, we summarize the epidemiological data related to the possible link between microbial alterations and chronic respiratory diseases in children. Briefly, we also describe the characteristics of the most frequent viral family present in the lung virome, Anelloviridae. Furthermore, we discuss how AVs could modulate the immune system in children, affecting the development of chronic respiratory diseases, particularly asthma, the most common chronic inflammatory disease in childhood.

Relationships between cotinine, lower respiratory tract infection, and eosinophil cationic protein in children

INTRODUCTION

The aim of this study was to investigate the effect of passive smoking on urine eosinophil cationic protein (u-ECP) in children with lower respiratory tract infections (LRTI).

METHOD

This was a case-control study. The study cohort consisted of 150 children with LRTI (case group) and 150 healthy children (control), all from a urban setting. The statistical parameters were: a minimum of 139 children for a 95% confidence interval (95% CI), 80% power, and a possible exposure prevalence of 50%. The u-cotinine and u-ECP levels were measured by radioimmunoassay and fluoroimmunoassay methods, respectively. Data were analyzed by the McNemar chi-square test, t-test, and Pearson correlation.

RESULTS

When the generally accepted cut-off level of 30 ng/mg urinary cotinine/creatinine was applied, 87.3% of the children with LRTI and 84.7% of healthy children were passive smokers. Using a cut-off level of 60 ng/mg, passive smoking increased the prevalence of LRTI by 4.7-fold (p=0.000). The mean u-ECP values were significantly higher in the case group than in the healthy control group (p=0.018). A positive association was found between u-cotinine and u-ECP values in children with LRTI (p=0.034).

CONCLUSION

The results of this study indicate that passive smoking may play an important role in the development of respiratory infections and can cause airway inflammation in children with existing LRTI.

T cell and eosinophil activation in mild and moderate atopic and nonatopic children's asthma in remission

BACKGROUND

Inflammation in the pathogenesis of asthma is associated with products of activated T cells and eosinophils. The aim of this study was to determine whether ongoing inflammation persists in children with different phenotypes of asthma despite the disease in remission.

METHODS

Serum samples were collected from 68 children with atopic or nonatopic asthma in remission and from 15 healthy children. Soluble interleukin-2 receptor (sIL-2R), IL-2 and IL-4 were examined by using an enzyme-linked immunosorbent assay. Total and specific immunoglobulin E, and eosinophil cationic protein (ECP) were analysed by fluoroimmunoassay (Pharmacia CAP System).

RESULTS

In patients with moderate persistent atopic asthma, sIL-2R was increased significantly when compared with mild persistent atopic asthma (P < 0.05). No changes of sIL-2R were seen in nonatopic asthmatics compared with atopics and controls. The level of IL-2 was elevated in moderate persistent atopic and nonatopic asthmatic children compared with controls (P < 0.05 and P < 0.05 respectively) and compared with mild persistent atopic asthmatics and mild persistent nonatopic asthmatics (P < 0.05 in both cases). The levels of IL-4 in most patients and controls remained below the sensitivity of the assay. Eosinophil cationic protein levels in moderate persistent atopic and nonatopic asthmatics were significantly higher than in mild persistent asthma severity cases (P < 0.001 and P < 0.01 respectively) and in healthy children (P < 0.01 in both cases).

CONCLUSION

Changes in the concentration of sIL-2R, IL-2 and ECP reflect increased T cell and eosinophil activity in relation to the level of severity of asthma in atopic and nonatopic children, thereby proving the presence of persistent inflammation despite the absence of disease symptoms.

Measurement of airway inflammation in asthma

Chronic airway inflammation is considered responsible for symptoms and disorders of airway function associated with asthma. This process is the target of anti-inflammatory therapy, so a number of standardized, noninvasive techniques have been developed to assess it. More recent approaches include the measurement of exhaled gases and nonvolatile substances in breath condensate. Results from studies using a wide variety of inflammatory markers have shown group differences between patients with asthma and healthy control subjects, but evidence for the diagnostic use of these markers in individual patients is scarce. Similarly, despite many studies demonstrating some correlation between markers of airway inflammation and a measure of disease control, none has yet convincingly shown a place for the use of these markers in an individual with corticosteroid-treated asthma. However, application of these markers continues to further our understanding of the disease process and provides the potential for more appropriate, customized therapy.