A cytokine assay for interleukin-1 , IL-6 , IL-10 , tumour necrosis factor - ( TNF - ) and polymorphonuclear elastase was performed with peripheral blood at different time-points [ ( t1 ) pre-CPB , ( t2 ) end of CPB , ( t3 ) 3 h , ( t4 ) 24 h , ( t5 ) 48 h postoperatively ] .