Evaluation of levels of T. cruzi ribosomal P protein homologous antigens and IgG antibodies among patients with Endomyocardial Fibrosis in Mulago Uganda

Abstract

Endomyocardial Fibrosis (EMF) is a chronic inflammatory disease of the heart whose cause is still unknown yet about 10 to 12 million people are affected worldwide. In Uganda EMF prevalence is about 10-20% of all the cardiac cases per year. It has been suggested that antigenic mimicry of human ribosomal P protein by proteins resulting from infections may induce cross-reactive autoimmune responses leading to EMF. The human and eukaryotic ribosomal P proteins, whose c-terminal sequence are homologous to that of the Trypanosoma cruzi ribosomal P protein (TcP0 & TcP2β), are thought to be involved in EMF etiology. We aimed to determine the levels of T. cruzi ribosomal P protein c-terminal sequence homologous antigens and IgG antibodies in serum of healthy controls and EMF patients who were admitted at cardiology clinic Mulago Uganda. Methods Ethical approval was sought from the School of Biomedical Sciences higher degrees research and ethics committee (SBS-HDREC). A cross sectional study was conducted on 30 archived EMF serum samples and 18 archived serum from healthy controls using an in- house enzyme linked Immunosorbent assay. Data was entered into Microsoft excel and analyzed using graph pad prism version 7 and presented as medians. Comparison between the homologous antigens and IgG antibodies among EMF patients and healthy controls was performed using Mann-Whitney U test at a significant level set at P < 0.05 Results Our data shows that there was higher median TcP2β antigen levels in EMF patients than in the healthy controls (P<0.0001) and the median anti- TcP0 antibody levels were significantly higher in the healthy controls as compared to the EMF patients (P =0.0010). Conclusion The postulated hypothesis is more complex than was earlier on stated, the higher TcP0 antibodies levels in healthy controls demonstrates a protective role of these antibodies. The higher TcP2β antigen levels shows that EMF could be genetically pre-programmed, therefore genetic studies should be carried out to address the difference in homologous antigens and antibodies in EMF patients and healthy controls.