Massive release of TH2 cytokines induced a cytokine storm during a severe mast cell activation event in a patient with indolent systemic mastocytosis

One of the severe MCA events led to life-threatening symptoms over several days. During this event, the massive release of T2 cytokines induced a hyperinflammatory state, fulfilling published criteria for cytokine release syndrome. Administration of IL-6- and IL-5-inhibiting biologicals might significantly shorten the acute phase of severe MCA events, likely offering significant clinical benefits to mastocytosis patients.