Both doses increased significantly the generation of leukotriene B5 (LTB5) from EPA by polymorphonuclear (PMN) and mononuclear leukocytes, while only the high dose decreased leukocyte arachidonic acid (AA) and the generation of LTB4 and prostaglandin E2 from AA. Only the high dose led to inhibition of PMN leukocyte chemotaxis to multiple stimuli by a mean of 57-70% (P less than 0.01), without altering monocyte chemotaxis, the production of platelet-activating factor by mononuclear leukocytes, or the IgE-dependent release of histamine from basophils. Both doses of EPA increased the responses of T lymphocytes to phytohemagglutinin by a mean of 73% or more (P less than 0.01) without modifying the numbers of helper and suppressor T lymphocytes.

EPA affects the functions of several types of leukocytes critical to inflammation and immunity.