The clinicopathologic features of fulminant myocarditis

To date, this largest cohort of histochemical analyses of FM, based on endomyocardial biopsy samples, has revealed dominant infiltration of innate immune cells in the early stage, followed by lymphocytes. This finding suggests that the activation of innate immunity is the initial mechanism triggering the cytokine storm in FM. The results also support the beneficial effects of immunomodulatory therapy using glucocorticoids and immunoglobulins rather than immunosuppression by promoting M2 macrophage polarization. This study was registered at https://clinicaltrials.gov/study/NCT03268642.