PLG and Pleural effusion: A second limitation of the current study is that PHF was diagnosed indirectly, by measuring FDPs and D-dimer [4,8,9], while fibrinolytic enzymes responsible for PHF such as plasmin, serum tryptase, or non-plasmic polymorphonuclear elastase were not measured [2,8–10], neither in the pleural effusion nor in the plasma.