1 I Clinica Medica, Department of Internal Medicine and Medical Specialties, "Sapienza" University of Rome, Rome, Italy.
2 Department of Clinical Medicine, "Sapienza" University of Rome, Rome, Italy.
3 I Clinica Medica, Department of Internal Medicine and Medical Specialties, "Sapienza" University of Rome, Rome, Italy. Electronic address: pasquale.pignatelli@uniroma1.it.