Decreased Mean Platelet Volume Is Associated with Loss of Asthma Control and Exacerbation in Children with Asthma.

Introduction: Platelet activation contributes to airway inflammation. Mean platelet volume (MPV) has been proposed as a marker of systemic inflammation. However, its association with asthma control is unclear. This study aimed to explore the association between asthma control status and MPV in children with asthma and to determine whether MPV and C-reactive protein (CRP) levels are markers of systemic inflammation across varying disease activities, including during exacerbations.

Methods: In this cross-sectional study, 414 children (331 with asthma, 83 controls) were analysed. Asthma diagnosis and control status were determined according to the GINA guidelines. Peripheral blood indices, including MPV, CRP, and spirometric parameters, were compared across the following groups: controlled asthma, uncontrolled asthma, asthma exacerbation, and controls. Children with exacerbation were re-evaluated 3 months after discharge.

Results: The MPV was significantly lower in children with asthma exacerbation and uncontrolled asthma than in those with controlled asthma or healthy controls. MPV exhibited a strong inverse correlation with CRP levels across all asthma subgroups (r = -0.361 to -0.664, p < 0.001). The CRP levels and white blood cell (WBC) counts increased during exacerbations and decreased upon clinical recovery, whereas the MPVs increased post-exacerbation. No significant correlations were observed in the healthy controls.

Conclusion: MPV decreases in children during asthma exacerbations and uncontrolled disease, inversely correlating with CRP levels, and normalizes with clinical improvement. These findings support MPV as a non-invasive biomarker of systemic inflammation and asthma control in paediatric patients. The distinct activation profile of platelets in inflammation may provide novel insights into disease monitoring and therapeutic targeting.