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. Mast Cell Activation Syndrome: A Primer for the Gastroenterologist Digestive Diseases and Sciences Springer Nature Link Mast cell activation syndrome, neck pain and the vagus nerve 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. Impact of Mast Cell Activation on Neurodegeneration: A Potential Role for GutBrain Axis and Helicobacter pylori Infection Frontiers Glutathione deficiency in the pathogenesis of SARS CoV 2 infection and its effects upon the host immune response in severe COVID 19 disease