Increased high sensitivity C-reactive protein in more severe wheeze/asthma phenotypes in child- and adulthood in ALLIANCE
The relevance of high-sensitivity C-reactive protein (hsCRP), a marker of low-grade systemic inflammation, remains unclear with regard to its association with severity and clinical outcomes in wheeze/asthma. We aimed to assess the role of hsCRP across different phenotypes and severity levels. We studied children with preschool wheeze (≥ 2 episodes), and patients with GINA-defined asthma (school-age/adult) compared with healthy controls (HCs) in the well-characterized ALLIANCE (All Age Asthma Cohort) study. HsCRP was measured (AU5800®-CRP-Latex test) in 944 study participants (pediatric: n = 728; adult: n = 216) at baseline. Age-stratified analyses (age groups 0–5, 6–18, ≥ 18 years) of standardized log10-transformed hsCRP concentrations (age, sex, BMI, site) were performed using univariable tests and regression models. The validated ASSESS score and its dimensions (exacerbations, lung function, inhaled corticosteroids, symptom control) were primary outcomes. Adult patients with asthma showed higher hsCRP than HCs (OR 2.22, 95% CI 1.56–3.24). Across all ages, hsCRP increased with clinical severity of wheeze/asthma. The ASSESS score correlated positively with hsCRP in patients aged ≥ 6 years (R = 0.19, p = 0.007). hsCRP was increased in school-age asthmatics with prior exacerbations (OR 1.37, 95% CI 1.01–1.87), and in adult asthmatics with impaired lung function (R = 0.2, p = 0.013). Inhaled corticosteroid use was associated with lower hsCRP in preschool wheezers (OR 0.66, 95% CI 0.50–0.85) but higher levels in adults (OR 1.99, 95% CI 1.02–4.09). HsCRP was increased in adult asthmatics compared to HCs and was associated with several severity-related clinical characteristics. ICS use was associated with higher hsCRP levels in adults, potentially reflecting greater disease severity, whereas ICS use in preschool wheezers was associated with lower hsCRP levels. These age-dependent effects may mirror varying disease courses across the lifespan and progression of asthma. The association of hsCRP with asthma severity in child- and adulthood may indicate its potential relevance for the course of disease and monitoring clinical outcomes. Future longitudinal studies are needed to assess, whether hsCRP may support therapy monitoring. ClinicalTrials.gov; Pediatric arm: NCT02496468, Registration date: 03 July 2015; Adult arm: NCT02419274, Registration date: 14 April 2015.