A study to evaluate nasal mucosal IgA development in neonates using a non-invasive sampling method

Current research has provided valuable information on nasal mucosal immunity, but data on neonates is scarce, as sampling of neonatal nasal epithelial lining fluid (NELF) was previously difficult. Information on mucosal immunoglobulin development in neonates is very important for understanding mucosal immunity maturation. Objective: To study the use of a NELF sampling method using “nasal strips” in neonates and to study neonatal nasal mucosal IgA development from 0-4 months. Method: Neonates of different chronological ages in a tertiary centre were recruited. NELF was obtained by inserting 0.5cm x 1.5cm L-shaped filter paper strips (“nasal strips”) made of synthetic adsorptive matrix gently into subjects’ nostrils for 1 minute¹. All NELF samples were analysed for IgA by ELISA method. Results: 35 infants (17 males, 18 females) with post-conceptional age 33-41 weeks were recruited. Age at recruitment ranged from 1-115 days. Sampling with nasal strip was smooth and well tolerated. Total IgA levels at 1, 2 and 3 months were 40-fold, 80-fold and 110-fold higher compared to levels at birth, Spearman Correlation Coefficient 0.567, p < 0.001 (Fig 1) Conclusion: This study shows that nasal strip sampling of NELF is reliable and well tolerated even by preterm babies. Nasal IgA increases rapidly from birth to 3 months. Further studies can be designed to study effects of prematurity on immunoglobulin development in neonates