Serum Eosinophilic Cationic Protein Is a Reliable Biomarker for Childhood Asthma

Abstract

<b><i>Background:</i></b> Eosinophilic cationic protein (ECP) is associated with airway inflammation and asthma. However, the clinical value of measuring ECP in childhood asthma is not fully known. We aimed to study the diagnostic performance of serum ECP and other common asthma biomarkers, individually and in combinations. <b><i>Methods:</i></b> In a cross-sectional study, 5–16-year-old children with current asthma (CA) (<i>n</i> = 37), transient asthma (TA) (<i>n</i> = 43), (previous history of wheezing/asthma), and healthy children (HC) (<i>n</i> = 86) were investigated for ECP, blood eosinophil count (B-Eos), fractional exhaled nitric oxide (FeNO), and lung function, i.e., spirometry (forced expiratory volume during the first second [FEV1]/forced vital capacity [FVC] ratio). <b><i>Results:</i></b> Both ECP and B-Eos were higher in CA compared to TA (<i>p</i> < 0.01) and HC (<i>p</i> < 0.0001). ECP and B-Eos were also higher in TA compared to HC (<i>p</i> < 0.05 and <i>p</i> < 0.001, respectively). FeNO was higher in CA (<i>p</i> < 0.0001) and TA (<i>p</i> < 0.01) compared to HC but similar between the asthma groups. The FEV1/FVC ratio was lower in CA compared to TA and HC (both <i>p</i> < 0.01) but similar between TA and HC. The best diagnostic performance regarding CA was found for ECP and B-Eos with receiver operating characteristics area under curve (AUC) of 0.801 and 0.810, respectively. The optimal cutoff for ECP (29 μg/L) yielded a sensitivity and specificity of 70.3% and 81.4%. The corresponding AUCs for FeNO and FEV1/FVC were 0.732 and 0.670, respectively. ECP and B-Eos showed the highest AUCs (0.669 and 0.673) for differentiation between CA and TA. Combining ECP with FeNO and FEV1/FVC increased the odds ratio (OR) for having CA from OR 3.97–10.3 for the single biomarkers to OR 20.2 (95% confidence interval: 5.76–68.6). <b><i>Conclusion:</i></b> Our results show that serum ECP is a reliable biomarker in the diagnosis of childhood asthma, with additional value in combination with FeNO and FEV1/FVC, and that ECP can be an alternative to B-Eos.

Current Insights on the Impact of Proteomics in Respiratory Allergies

“…These results demonstrate that the sampling method is critical in proteomic experiments. In addition, the level of ECP is consistent with it being an important protein in eosinophil-mediated allergic inflammation such as asthma [ 42 , 43 ] and chronic rhinosinusitis [ 44 ].…”

Asthma and Allergy: Unravelling a Tangled Relationship with a Focus on New Biomarkers and Treatment

“…In a population-based study with 259-animal sensitized, most were sensitized to two or more dog allergens, and co-sensitization to Can f 5 [prostate (i.e., male) specific allergen] and Can f 1/2 conferred the greatest risk for asthma [ 124 ]. In line with this, a recent study in children with mild to severe asthma showed that sensitization to a greater number of dog components may identify children whose asthma severity is driven by dog exposure and may benefit from targeted interventions such as exposure mitigation and immunotherapy [ 125 ]. To this end, molecular-based allergy diagnostics such as CRD provides clinicians with opportunities to better characterize children with polysensitization [ 126 ].…”