Background: Interleukin (IL)-4 is a pleiotropic cytokine, severed as an important component of the adaptive immune system, and implicated in the pathophysiology of sepsis. Data from other studies show that the -589T/C polymorphism in IL-4 promoter may alter IL-4 expression and susceptibility of inflammatory or autoimmune diseases. Whether this genetic variation is associated with sepsis susceptibility is unknown. The aim of this study was to search for the association of IL-4 -589T/C with the susceptibility to sepsis.
Methods: The polymorphism was genotyped among 308 severe trauma patients using restriction fragment length polymorphism polymerase chain reaction. The IL-4 and interferon-γ levels in the supernatants were determined with enzyme-linked immunosorbent assay.
Results: The IL-4/-589C allele was shown to be significantly associated with higher plasma IL-4 and lower interferon-γ production after lipopolysaccharide stimulation, indicating its effect on regulating T helper T(H)1/T(H)2 balance. Moreover, homozygosity and heterozygosity for the -589C were associated with an increased susceptibility of sepsis (p = 0.009; OR, 1.69; 95% confidence interval, 1.14-2.51). There was no relationship between the IL-4 -589T/C and multiple organ dysfunction scores in severe trauma patients.
Conclusions: These results suggest that the IL-4 -589T/C polymorphism might affect T(H)1/T(H)2 balance and predispose trauma patients to susceptibility sepsis.