Evaluation of Ficolin-3 deficiency as a risk factor in the development of rheumatic heart disease.

Objective: Ficolin-3 is a crucial protein for the activation of the complement system. Previous work has indicated this protein may play a role in the pathogenesis of rheumatic heart disease (RHD), and it has been hypothesised that ficolin-3 has potential as a biomarker for early identification of patients with suspected RHD. This study investigated FCN3 gene polymorphisms rs532781899 (c.349del) and rs4494157 (c.658 + 250 C > A) and ficolin-3 serum concentrations in an ethnically diverse cohort of 53 RHD cases and 45 healthy controls from across Africa.

Results: Ficolin-3 was found to be increased by 16% in RHD patients (p = 0.03) compared to controls, but polymorphisms did not associate with the risk of developing RHD nor with ficolin-3 concentrations. Carriers of the c.349del haploinsufficiency locus had normal levels of ficolin-3, while the previously described c.658 + 250 C > A RHD susceptibility locus was found equally in cases and controls. The higher serum ficolin-3 in RHD supports the potential role of this protein in RHD pathogenesis. However, these results suggest that rs532781899 and rs4494157 are not risk factors for the development of RHD in patients from sub-Saharan Africa and would not be reliable as early-stage markers of RHD susceptibility.