 - Hepatitis B virus HBV: patients with positive serology for hepatitis B defined as positivity for hepatitis B surface antigen HBsAg or anti-hepatitis B core antibody HBc; patients who are positive for anti-HBc may be considered for inclusion in the study on a case-by-case basis if they are hepatitis B viral deoxyribonucleic acid DNA negative and are willing to undergo ongoing HBV DNA testing by real-time polymerase chain reaction PCR; patients with positive serology may be referred to a hepatologist or gastroenterologist for appropriate monitoring and management 