A cytokine assay for interleukin-@ , IL-@ , IL-@ , tumour necrosis factor - ( TNF - ) and polymorphonuclear elastase was performed with peripheral blood at different time-points -LSB- ( t@ ) pre-CPB , ( t@ ) end of CPB , ( t@ ) @ h , ( t@ ) @ h , ( t@ ) @ h postoperatively -RSB- .