In their article in the September 2009 issue of HEPATOLOGY, Österreicher et al. conclude with a protective role for angiotensin-converting enzyme 2 (ACE2) on liver injury.1 ACE2 acts to counterbalance up-regulation of the renin-angiotensin system (RAS) through degradation of angiotensin II to angiotensin 1-7. Based on previous reports on other disease models of RAS overactivity, we would like to highlight another potential anti-RAS mechanism. In these models, immunoassay studies have identified the presence of circulating antibodies against ACE and angiotensin II considered to exert a neutralizing effect.2, 3 Currently, no studies evaluating the levels of serum/tissue anti-RAS antibodies in chronic liver disease models are reported in the literature. It is possible that standardization of their titers could prove to be of prognostic significance.
To the Editor:
Michael G. Lenos M.D.*, Sofia-Maria Tsaniklidou M.D., * Department of Pathology, General Hospital of Athens ‘HIPPOCRATION’, Athens, Greece, Department of Microbiology, General Hospital of Athens ‘GENNIMATAS’, Athens, Greece.