A genetic modification of the plasminogen activator inhibitor-1 gene in conjunction with lower respiratory infections during early life was associated with increased risk of asthma, morbidities, and reduced lung function, according to Seong H. Cho, MD, and his associates.
A history of respiratory syncytial virus (RSV) and a history of other lower respiratory infections (LRIs) before the age of 2 were independently associated with asthma in Latino people aged 8-21, with odd ratios of 9.9 and 9.1, respectively, while PAI-1 was not independently associated. In combination, the OR for PAI-1/RSV increased to 17.7, and the OR for PAI-1/other LRIs increased to 11.7.
©SilverV/Thinkstock
Lung function was also adversely affected by the joint effect of PAI-1 and early life infection. In patients with PAI-1/LRI, forced expiratory volume in 1 second (FEV1) percent predicted and FEV1/forced vital capacity (FVC) percent predicted were significantly less than in the control group. Similar but less significant results were seen in the PAI-1/RSV group. Recurring hospitalizations were also significantly more likely in the PAI-1/RSV group, with an OR of 3.1.
“Further prospective studies are needed to replicate our RSV-genotype findings in other non-Latino populations, and determine if PAI-1 variants may serve as a biomarker of risk, which may provide impetus for clinical trials of primary prevention of asthma. In the interim, PAI-1 genotype in combination with significant LRI identifies individuals at increased risk of developing asthma,” the investigators wrote.
Find the full study in PLoS One (doi: 10.1371/journal.pone.0157848).