Mast Cell Activation Syndrome and Its Impact on the Lymphatics Mast cells are hypersensitive immune cells that release histamine and other inflammatory mediatorsoften in response to oxidative stress, environmental toxins, and immune imbalance. Many patients with MCAS have low levels of glutathione. Lipid orchestrated paracrine circuit coordinates mast cell maturation and anaphylaxis through functional interaction with fibroblasts: Immunity Glutathione IRE1 determines ferroptosis sensitivity through regulation of glutathione synthesis Nature Communications Mast cell Wikipedia