Rhinovirus infection in young children is associated with elevated airway TSLP levels

To the Editor: Rhinovirus wheezing illnesses during early childhood are strongly linked with development of asthma later in life [1]. Indeed, rhinovirus infection in the first 3 years of life is associated with an almost 10-fold increase in risk for asthma at age 6 years [1]. The exact mechanism by which rhinovirus elicits a pro-asthmatic propensity in young children is largely unknown, but is purportedly related to a viral-induced T-helper cell (Th)2 airway inflammatory response [2]. Interestingly, the discovery of interactions between epithelial innate immunity and adaptive allergic responses has unveiled new potential links between rhinovirus and asthma. Of particular interest is the epithelial-derived cytokine thymic stromal lymphopoietin (TSLP), which is considered a “master Th2 cytokine” because it primes the differentiation of naive T0 cells into Th2 lymphocytes via activation of antigen presenting cells [3]. TSLP is induced by rhinovirus infection or by exposure to double stranded (ds)RNA (viral surrogate) in the lungs of allergic mice [4], and in human bronchial epithelial cells (HBEC) [5]. Together, these data suggest that TSLP may be the missing link between innate antiviral epithelial immunity and the Th2 immune response characteristic of asthma. This cross-sectional preliminary study aimed to investigate whether rhinovirus infections that occur naturally during the first 3 years of life are associated with elevated airway TSLP levels and enhanced Th2 responses, which may potentially facilitate the establishment of rhinovirus-induced pro-asthmatic changes during early childhood. We measured nasal airway TSLP, Th2 cytokines and antiviral responses in nasal washes obtained from newborns, infants and toddlers (≤3 years) with PCR-confirmed acute …