Perimyocarditis following streptococcal group A infection: From clinical cases to bioinformatics analysis

Background: Streptococcal infection is known to be associated with non-suppurative complications, including rheumatic fever. A less well recognized complication is perimyocarditis. Methods: We report 4 cases of myocarditis in young males associated with acute streptoccal infection. Following this clinical observation we employed bioinformatic techniques to identify common epitopes between Streptococcus group A and human muscle proteins. We used Blast to search all the proteome (1697 proteins) of the Streptococcus pyogenes M1 GAS against the human proteome of 34,180 proteins. Results: 4 patients with streptococcal A related myocarditis were treated and made a complete recovery. One cardiac protein, ATP2A2 (NP-733765.1)), a cardiac Ca2+ ATPase, shared an epitope with Streptococcus group A and a high probability of being presented on a MHC Class II molecule. Conclusion: Streptococcal myocarditis may be a commoner entity than previously appreciated. Bioinformatic techniques have identified a suspected common epitope between the streptococcal proteins and a cardiac Ca2+ ATPase.