A radioimmunoassay for leukotriene B4 using 125I-labeled tracer and its clinical application

Leukotriene B4 was extracted from porcine blood with the help of HPLC. The antiserum was raised by immunizing rabbits with LTB4 which had been conjugated with bovine serum albumin. The titer of the antibody was 1 : 7000, the affinity coefficient, 2.1 x 109 L/M. Its cross-reaction with LTA4, LTC4, LTD4 and other arachidonate metabolites were 0.4 ∼ 6.4%. The 125I-LTB4 tracer was prepared by using the chloramine T procedure. The minimal detectable limit was 25 pg per tube. The recovery was 84.2 ∼ 113%. The intra- and inter-assay coefficient of variation were 5.2% and 9.7%, respectively. The amount produced by normal human PMNL which were stimulated by ionophore A23187 and arachidonic acid was 695.5 +- 329.7 pg/106 cells. The ability of PMNL in leukemia patients to produce LTB4 was increased to various extent. The LTB4 values in patients with acute cerebral thrombosis or acute myocardial infarction tended to increase, but they were not altered in those with cerebral hemorrhage or non-AMI coronary heart diseases