BACKGROUND
Rheumatic Heart Disease is the most common acquired cardiovascular disease among children and young adults, and remains endemic in most low- and middle income countries. Rheumatic Heart Disease follows acute rheumatic fever (ARF), a systemic inflammatory condition triggered by Group A Streptococcus infection. Timely ARF diagnosis is critical to implement antibiotic prophylaxis to prevent relapses due to recurrent Group A Streptococcus infections. However, no defined biomarkers for ARF and diagnosis is based on non-specific clinical criteria first developed 80 years ago.
METHODS
We undertook unbiased multi-omic testing (proteomics, metabolomics, RNAseq, epigenomics, flow cytometry) of peripheral blood samples from two cohorts in Uganda, contrasting acute and convalescent ARF cases and well-defined controls.
RESULTS
We identified a 5-protein signature that discriminates ARF patients from overlapping clinical presentations in a discovery cohort (receiver operating characteristic-area under the curve (ROC-AUC)=1.0, known alternate diagnosis; ROC-AUC=0.97, unknown alternate diagnosis), which retained very good diagnostic value is a geographically distinct validation cohort (ROC-AUC=0.83, unknown alternate diagnosis). Pathway analysis identified several enriched pathways that support existing knowledge of ARF pathogenesis. We further identified multiple components of the epithelial-mesenchymal transition pathway as highly-associated with acute ARF, suggesting that acute tissue damage and repair is central to ARF pathogenesis.
CONCLUSION
Our results identify new molecular pathways associated with ARF pathogenesis, and clinically useful ARF diagnostic biomarkers. A specific diagnostic test would revolutionise ARF diagnosis and treatment, and reduce the global burden of Rheumatic Heart Disease.