2 immunophenotypes were negatively associated with the development of myocarditis: CD33dim HLA DR + CD11b (OR = 0.85, 95% CI = 0.73–0.99, P = 0.044) and CD25 on naive-mature B cells (OR = 0.73, 95% CI = 0.55–0.97, P = 0.031). Here, ITGAM is linked to myocarditis.