Relationship of serum troponin I, NT-proBNP, APE1/Ref-1, virus titers and myocardial inflammation. (A) Serum troponin I was positively correlated with serum NT-proBNP (r = 0.586, p < 0.01); (B) Serum NT-proBNP showed positive association with virus titers (r = 0.764, p < 0.01); (C,D) Both Serum troponin I and APE1/Ref-1 indicated positive correlations with the degree of inflammation, myocarditis score. Especially, serum APE1/Ref-1 demonstrated a stronger association (r = 0.352, p < 0.05 in serum troponin I; r = 0.750, p < 0.01 in serum APE1/Ref-1). (n = 5 in control; n = 10 in day 3; n = 10 in day 7; n = 7 in day 10).