Woody eyes, be gone!

In this issue of Blood, Shapiro et al describe the first-in-class experience of infusing plasma-derived Glu-plasminogen to 14 patients with congenital deficiency of plasminogen as part of an ongoing, phase 2/3, open-label clinical trial, reporting encouraging results. ¹ Congenital plasminogen deficiency is caused by homozygous or compound-heterozygous mutations in the plasminogen (PLG) gene, located on chromosome 6q26. It is, in the words of the authors, “ultra-rare,” predicted to affect ∼1 to 2 per million people. ² Plasminogen is activated to plasmin and is critical for intravascular and extravascular fibrinolysis. Other functions include wound healing, cell migration, tissue remodeling, angiogenesis, and embryogenesis. Glu-plasminogen has a glutamic acid residue at its N-terminus, as opposed to Lys-plasminogen, which has a lysine. Glu-plasminogen is the predominant form found in circulation and has a half-life of 2 to 2.5 days, whereas the half-life of Lys-plasminogen is 0.8 days. ³