When leukocytes degrade phospholipid cell membranes, they also break down a type of phospholipid present called arachidonic acid. Break down of this arachidonic acid leads to the release of leukotrines, of which there are a wide variety. It is not yet known which exact leukotrine(s) play a role in the DMD pathophysiology, hence the use of the term "leukotrine" as a whole.
Reference: Cuzzo B, Lappin SL. Physiology, Leukotrienes. [Updated 2022 Aug 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526114/