The rs7041_C allele was also more frequent in the RSV bronchiolitis group compared with controls (OR 1.12, 95% CI 1.02, 1.4, P = 0.03) in the Netherlands, especially in mechanically ventilated patients (P = 0.009).
Genotyping revealed predominance of the 280M-containing genotypes (M/M or T/M) in cases compared with controls (37.8% versus 20.8%, respectively; odds ratio, 2.03; 95% confidence interval, 1.1-3.9; P = 0.025), demonstrating an association between the common CX3CR1-T280M variations and increased risk of severe RSV bronchiolitis.
One of the variants was a highly functional nonsynonymous variant in ADRB2 (rs1800888), which was also nominally associated with asthma (p = 0.027) and active asthma (p = 0.013) among European Americans with severe RSV bronchiolitis without including the ESP.