Introduction: Ongoing cardiac damage can be identified by the presence of high levels of autoantibodies to human cardiac myosin (HCM) in acute rheumatic fever and rheumatic heart disease (ARF/RHD). We hypothesize that these antibodies and in particular antibodies to immuno-dominant epitopes of the S2 region of HCM can be used for both sero-diagnosis of ARF/RHD and monitoring of the disease progression. Since India is a major contributor to global burden of ARF/RHD and is associated with different circulating M types of Group A streptococci and HLA types of patients, it is important that we validate the HCM immuno-dominant epitopes as has been determined in some other populations.
Methods: In our pilot study, ELISA was performed with serial samples of sera from patients with ARF/RHD and controls. Using 32, 25mer overlapping peptides from the S2 region of HCM (Mimitopes, Australia), we determined antibody titers.
Results: Our pilot study demonstrates that the mean reactivity of patient group is higher for epitopes S2-21 & S2-22 in contrast to the other studies which suggest S2-1, 2 & 8 as immuno-dominant epitopes.
Discussion: ELISA performed on our patient serum samples (EC/GOVT-07/2012) from India is useful in identifying the immuno-dominant S2 epitopes. This could lead to the identification of a universal serological marker for the diagnosis and assessment of ongoing cardiac damage in patients with ARF/RHD. Our findings from the Indian cohort will be presented and it would add to the discussion for the need for an economically viable, rapid, point-of-care test for ARF/RHD.