Surfactant protein-B polymorphisms and mortality in the acute respiratory distress syndrome.

Objective: To determine whether polymorphisms of the surfactant protein B gene may be associated with increased mortality in patients with the acute respiratory distress syndrome.

Design: A prospective cohort study.

Setting: Four adult intensive care units at a tertiary academic medical center.

Patients: Two hundred fourteen white patients who had met criteria for acute respiratory distress syndrome.

Interventions: None.

Measurements And Main Results: Patients were genotyped for a variable nuclear tandem repeat polymorphism in intron 4 of the surfactant protein B gene and the surfactant protein B gene +1580 polymorphism. For the variable nuclear tandem repeat surfactant protein B gene polymorphism, patients were found to have either a homozygous wild-type genotype or a variant genotype consisting of either a heterozygous insertion or deletion polymorphism. Logistic regression was performed to analyze the relationship of the polymorphisms to mortality in patients with acute respiratory distress syndrome. In multivariate analysis, the presence of variable nuclear tandem repeat surfactant protein B gene polymorphism was associated with a 3.51 greater odds of death at 60 days in patients with acute respiratory distress syndrome as compared to those patients with the wild-type genotype (95% confidence interval 1.39-8.88, p = 0.008). There was no association found between the +1580 variant and outcome (p = 0.15).

Conclusions: In this study, the variable nuclear tandem repeat surfactant protein B gene polymorphism in intron 4 is associated with an increased 60 day mortality in acute respiratory distress syndrome after adjusting for age, severity of illness, and other potential confounders. Additional studies in other populations are needed to confirm this finding.