The study is randomized, double-blind, placebo controlled. All subjects will be randomly assigned to one of three treamtent groups, LTB4 at two different dose levels or corresponding placebo. Treatment duration is 4 weeks and follow-up period is 2 weeks. Subjects will visit the clinic on a daily basis during the treatment period to receive a daily intravenous injection of the study drug. 40 subjects will be enrolled, seven clinics in Canada will participate in the study.