Objectives: The G-308A polymorphism of the tumor necrosis factor alpha (TNF-alpha) gene has been suggested to be linked to high TNF promoter activity in in vitro studies. However, there have been some controversies in in vivo studies. This study investigated whether A allele at TNF-308 site is associated with (1) the changes in plasma cytokine levels during and after cardiopulmonary bypass (CPB) and (2) an increased incidence of pulmonary morbidity after CPB.
Design: Prospective and observational investigation.
Setting: A university hospital, single institution.
Participants: Patients scheduled for cardiac surgery with CPB.
Intervention: TNF genotype was determined by the real-time polymerase chain reaction method. IL-6 and TNF-alpha levels were measured by enzyme-linked immunosorbent assay at the following time points: T1, before initiation of CPB; T2, 30 minutes of CPB; T3, 30 minutes after CPB; T4, 2 hours after CPB; and T5, 24 hours after CPB. The oxygen index, serum creatinine level, 24-hour blood loss, intubation time, and length of intensive care unit (ICU) stay were examined.
Measurements and main results: The levels of TNF-alpha in group A (TNF-308GA/AA, n = 25) were higher at T3, T4, and T5 than group G (TNF-308GG, n = 225). The levels of IL-6 showed no statistical difference. The oxygenation index, serum creatinine level, 24-hour blood loss, intubation time, and length of ICU stay showed no statistical difference.
Conclusions: TNF G-308A polymorphism may be associated with excess TNF-alpha secretion in this study and may not be associated with excess IL-6 secretion and postoperative morbidity after CPB.