The role of angiotensin II and endothelin receptor antibodies in COVID19 patients with HFpEF

Abstract Background The infection caused by the coronavirus SARS-COV-2, is associated with an unusual pattern of organ damage in comparison to other viral-induced pathologies. A theory of autoimmunity induced by ACE-2/SARS-COV-2 spike protein complex or its degradation products, was proposed as a possible explanation for the versatile and multiorgan damage in COVID-19. Aim The aim of the study is to determine whether antibodies against angiotensin II receptor type 1 (AT1R) or endothelin-1 receptor type A (ETAR) do exist in plasma of COVID -19 patients with heart failure with preserved ejection fraction and whether they correlate to the severity of the disease. Methods A total of 61 patients with COVID-19 and heart failure with preserved ejection fraction and 48 controls (free of COVID19) with heart failure with preserved ejection fraction were included. Patients were divided into two groups: patients with severe disease (admitted at the intensive care (n=30)), patients with milder clinical presentation that remained in the general therapeutical department (n=31). The plasma levels of IL-6 and auto-antibodies against AT1R or ETAR in peripheral blood were measured and compared between COVID19 patients with severe and milder disease and age matched controls. Clinical and standard laboratory parameters were also collected and their association with the research biomarkers was analysed. Results Auto-antibodies against AT1R were significantly increased in severe disease course (median 19.60 U/mL, IQR 4.8-34.75) compared to milder disease (median 10.95 U/mL, IQR 7.69 – 17.67, p=0.017) and the control group (median 6.79 U/mL, IQR 5.10 – 14.05, p< 0.001). ETAR antibody titers were also significantly increased in severe disease (median 14.52, IQR 6.76-32.94), compared to milder disease course (median 8.73 U/mL, IQR 6.59 –13.45, p=0.023) and to the control group (median 6.64, IQR 6.79 – 17.92, p <0.001). The same was the trend regarding IL-6 antibodies. Severe disease (median 12.11 U/mL, IQR 5.59–19.38); milder disease disease (median 8.64U/mL, IQR 1.84 – 14.13, p=0.039); control group (median 4.28U/mL, IQR 0.11–1.43, p<0.001).Both AT1R and ETAR correlated to IL-6 plasma levels. The results did not show association with the concomitant therapy. Conclusion In conclusion, we establishеd the presence of AT1R and ETAR autoantibodies in COVID-19 patients with heart failure with preserved ejection fraction. They correlated to IL-6 plasma levels (systemic inflammation) and are associated with severe form of the disease.