Induction of higher expression of IL-beta and TNF-alpha, lower expression of IL-10 and cyclic guanosine monophosphate by pulmonary arterial hypertension following cardiopulmonary bypass.

OBJECTIVE

Pulmonary arterial hypertension [PAH] and cardiopulmonary bypass [CPB] induce systemic inflammatory cytokines that are critical factors related to postoperative mortality of open heart surgery. We studied the expression of proinflammatory cytokines and cyclic guanosine monophosphate [cGMP] in patients suffering from PAH after CPB.

METHODS

Seventy-six patients who underwent valve replacement surgery were recruited and divided into two groups according to their pulmonary arterial pressure [< 50 mmHg for Group A and > or = 50 mmHg for Group B]. Blood samples were taken to measure the concentrations of interleukin-1 beta [IL-1 beta], tumour necrosis factor alpha [TNF-alpha], interleukin-10 [IL-10] and cGMP.

RESULTS

IL-1 beta and TNF-alpha were significantly higher in Group B [28.6 +/- 9.1 mmHg] than in Group A [65.8 +/- 10.2 mmHg] at baseline. After CPB, IL-1 beta of both groups rose significantly, while only TNF-alpha of Group B rose significantly higher. There were significant differences between the two groups after CPB. IL-10 and cGMP in Group B were lower than in Group A at baseline. They all decreased significantly after CPB. Significant differences were seen between the groups after CPB.

CONCLUSION

Patients suffering from PAH had different levels of proinflammatory and anti-inflammatory cytokines compared to normal patients. PAH aggravates the production of IL-1 beta and TNF-alpha, while it decreases the production of IL-10 and cGMP after CPB.