Leukotriene B4 synthesis and neutrophil chemotaxis in chronic granulocytic leukaemia.

Abstract

A sensitive gas chromatography-mass spectrometric method was used to measure the generation in whole blood of leukotriene B4 (LTB4), a potent stimulator of neutrophil chemotaxis, in eight patients with chronic granulocytic leukaemia (CGL) and 12 healthy controls. LTB4 was detectable in unstimulated samples from all the patients (mean 194 (70 SEM) pg/ml), and the capacity for LTB4 production after stimulation with calcium ionophore (A23187) was similar in patients (32.1 (11) ng/10(6) leucocytes) and controls (38.1 (4) ng/10(6) leucocytes). In response to stimuli which induce neutrophil activation, LTB4 production was significantly greater in the patients than in controls: 35.6 (13) v 13.0 (3) ng/ml, p less than 0.05 (f-met-leu-phe); and 42.4 (16) v 14.7 (4) ng/ml, p less than 0.02 (opsonised zymosan). Anti-IgE stimulated considerably more LTB4 production in patients with CGL than in controls (3.86 (1.6) v 0.83 (0.43) ng/ml; p less than 0.005) and this correlated significantly (p less than 0.05) with the basophil count. Neutrophil chemotaxis to LTB4, however, was significantly impaired in the patients with CGL even at the highest concentration of LTB4 (10(-5) M). Chemotaxis to f-met-leu-phe, phagocytosis, and bacterial killing were normal. Thus although LTB4 synthesis is normal or even enhanced in patients with CGL, specific defects in LTB4-mediated responses may contribute to neutrophil dysfunction in this disease.