IL-8 Gene Variants and Expression in Childhood Asthma.

Abstract

PurposeTo examine the IL-8 expression levels and association of genetic variants with the risk of childhood persistent asthma prognosis.MethodsOverall, 170 asthmatic children and 170 healthy controls were included in this case–control study. The human IL-8 serum levels were measured using ELISA. The IL-8 mRNA expression levels were assessed by a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The genotyping was performed by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) methods.ResultsThe IL-8 expression at both protein and mRNA levels was found to be significantly elevated in asthmatic children compared to healthy subjects (P < 0.0001, P = 0.004; respectively). Higher levels of IL-8 mRNA are detected in subjects with moderate to severe asthma. The presence of IL8-251 A/T (rs4073) and + 781C/T (rs2227306) polymorphisms was significantly associated with an increased risk of asthma (P = 0.002, P = 0.036, respectively). In addition, we noted a significant association between these polymorphisms and an elevated risk of atopic asthma (P < 0.05). For rs2227306 SNP, the highest median level of IgE was detected for the presence of TT genotype (865 ± 99.74 IU/mL). Although, the rs4073 polymorphism conferred a higher risk to develop asthma at an advanced stage of severity (P = 0.008). The rs4073 T and rs2227306 C alleles are considered as risk factors for asthma development. The rs4073 T allele is represented also as a risk factor for asthma severity in Tunisian children.ConclusionsBoth IL-8 gene and protein expression may play a key role in asthma pathogenesis.Electronic supplementary materialThe online version of this article (doi:10.1007/s00408-017-0058-6) contains supplementary material, which is available to authorized users.