Generation of leukotriene B4 by hemodialyzer membranes: a novel index of biocompatibility.

Leukotriene B4 (LTB4) plays an important role in acute and chronic inflammatory and hypersensitive reactions. We studied the time course of LTB4 biosynthesis in whole blood in 18 patients with end-stage renal failure maintained on regular hemodialysis with two different membranes, cuprophane and polyacrylonitrile (AN 69). The basal levels of LTB4 from dialysis patients did not differ significantly from a normal control group. Compared to predialytic values, the cuprophane membrane caused a maximal release of LTB4 by a factor of about 4.5 (p less than 0.01) within the first 10 to 20 minutes. Thereafter the level fell and returned to baseline range at the end of the hemodialysis session. With the use of the AN 69 membrane no significant increase of LTB4 could be demonstrated. The changes in LTB4 concentration showed a close temporal correlation to the alterations in white blood cell count. We conclude that (1) LTB4 is a biologically important mediator of neutrophil activation during hemodialysis, and (2) LTB4 may be a sensitive marker of biocompatibility in vivo.