ARE SUSCEPTIBILITY to INFECTIVE ENDOCARDITIS and EFFECTIVENESS of ANTIBIOTIC PROPHYLAXIS LINKED to FLUCTUATIONS of the IMMUNE SYSTEM? A NOVEL HYPOTHESIS

Introduction: An amendment incorporated into the 2007 AHA and 2009 ESC guidelines on infective endocarditis led to a substantial restriction in indications for the administration of antibiotic prophylaxis. This may have resulted in a subsequent steady increase in the number of cases of infective endocarditis worldwide. Methods: It has been hypothesised that susceptibility to infective endocarditis, together with effectiveness of antibiotic prophylaxis, may be linked to fluctuations of the immune system. Throughout a person’s lifetime, individual susceptibility to infective endocarditis may vary in an identical situation of risk. As a consequence, a personalised targeted approach should be adopted when prescribing antibiotic prophylaxis to prevent onset of endocarditis, taking into account a series of factors including age, comorbidities, cortisol levels, and ethnicity. Children affected by bicuspid aortic valve and injection drug users are amongst the newly-emerging higher risk populations. Conclusion: This up-to-dated narrative review summarizes all the available scientific evidence concerning the variable influence of the immune system on susceptibility to infective endocarditis.