Baseline immune status associates respiratory viral infection in preterm infants: A prospective cohort study

Preterm infants (PI) are particularly vulnerable to respiratory viral infections (RVI), which may affect their lung development and immune responses, increasing the risk of recurrent wheezing (RW) and asthma. This study aimed to evaluate the cytokine immune profile in PI admitted to neonatal intensive care units (NICUs) and to explore its association with RVI and subsequent respiratory outcomes during the first year of life. A prospective cohort of 118 PI (<32 weeks gestational age) was studied in 2 NICUs. Nasopharyngeal aspirates were collected at birth and discharge for virological and immunological analyses. Infants were classified into 4 groups based on RVI and RW presence. Cytokine levels were measured using Luminex and ELISA. Infants with RVI and/or RW showed higher rates of BPD and respiratory readmissions. Distinct cytokine patterns were observed: V-/W+ infants showed elevated baseline TNF-α and reduced IL-13 and TGF-β over time. V+/W- infants had increasing TNF-α levels during hospitalization. Notably, immune profiles at birth differed even in the absence of RVI, suggesting innate predispositions. Correlation analyses revealed significant associations between cytokines and clinical factors like birth weight and oxygen need. Preterm infants without RVI who developed RW appeared to exhibit a distinct pro-inflammatory cytokine profile early in life. This cytokine pattern may be associated with respiratory outcomes later in infancy, although predictive value cannot be inferred from this study and requires confirmation in larger, more representative cohorts.