English

Abstract

Background: Rheumatic heart disease is an inflammatory disease which predominantly affects the valvular endocardium culminating in crippling valve deformities. Inorder to find out the role of complement proteins in inducing the pathogenesis, serum analysis of complement proteins C3a, C4a, C5a, C3c and C3d and acute phase protein MBL in patients with Rheumatic heart disease were performed. Methods and Results: Blood samples were collected from twenty eight subjects who were diagnosed with Rheumatic heart disease (RHD). Same number of samples was also collected from healthy volunteers as control. The levels of the anaphylatoxins namely C3a, C4a and C5a and the acute phase protein MBL (Mannose Binding Lectin) were assessed quantitatively in the samples using Sandwich ELISA. The breakdown products of the complement protein C3b namely C3c and C3d were assessed qualitatively using western blot assay. Among the three anaphylatoxins, the C5a level and the MBL level were significantly higher in RHD subjects than the control samples. The breakdown products of C3b namely C3c and C3d were observed only in RHD patients and not in control samples. Conclusions: Significant levels of C5a and MBL noticed in blood samples of RHD subjects when compared to the healthy controls indicate that these two proteins might corroborate the chronic inflammatory activity present in these individuals and contribute to valve injury through complement activation. Along with these results, the presence of C3c and C3d only in the RHD samples and not in the controls indicates that these products of C3 complement protein may also contribute for the inflammatory pathogenesis of the disease.