A lipoprotein-associated PHOSPHOLIPASE A2 which modulates the action of platelet activating factor by hydrolyzing the SN-2 ester bond to yield the biologically inactive lyso-platelet-activating factor. It has specificity for phospholipid substrates with short-chain residues at the SN-2 position, but inactive against long-chain phospholipids. Deficiency in this enzyme is associated with many diseases including asthma, and hypercholesterolemia.