title: SP-A1, SP-A2 and SP-D gene polymorphisms in severe acute respiratory syncytial infection in Chilean infants.
abstract: Respiratory syncytial virus (RSV) is the principal pathogen that causes acute lower respiratory tract infection (ALRI) in infants. Severe RSV-ALRI has been associated with the host genetic susceptibility. To assess whether severe RSV disease in infants is associated with certain single nucleotide polymorphism (SNP) into the gene of SP-A1, SP-A2 and SP-D, a prospective study was performed among blood donors and RSV-infected infants aged <or=6 months, considering their severity, according to a strict scoring system. Allele and genotype frequencies were compared using χ(2)-test. Association studies and haplotype analysis were tested by using Armitagës trend test and Unphased 3.0 program. A total of 118 RSV-infected infants and 104 blood donors were enrolled into the study; 59 infants had a severe respiratory disease, 34 children developed a moderate illness and 25 had a mild disease. There was no difference in the allelic and genotypic frequencies of SP-A1, but intragenic haplotypes showed significant differences among infected infants and blood donors (p=0.0021). 1A(0) variant of SP-A2 was the most frequent allele in all groups. Thr(11) allele of SP-D is significantly higher in RSV infants (p=0.028), as given by its higher frequency in severe disease (p=0.046). Heterozygous Thr(11)/Met(11) was significantly more common in infected infants (p=0.037), because it has higher frequency in critically ill children (p=0.017). Thr(160) allele was significantly higher in severe infants compared with blood donors (p=0.046) and infants with mild disease (p=0.018). Thr(11)-Thr(160)-Ser(270) haplotype was significantly more common in RSV-infants, due to severe (p=0.00000034) and moderate disease (p=0.000009). Differences were also found among severe and mild disease (p=0.026). Differences found with other authors, indicate the need for local studies to identify genetic biomarkers of severity.
authors: Programa de Virología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Chile.
authors: Sandra
authors: S
authors: Ampuero
authors: Vivian
authors: V
authors: Luchsinger
authors: Lorena
authors: L
authors: Tapia
authors: María Angélica
authors: MA
authors: Palomino
authors: Carmen E
authors: CE
authors: Larrañaga