This study was performed in Microbiology and Immunology Department, Department of Tropical diseases in Kasr El Aini Hospital and Liver Transplant Unit in El Manial Specialist University hospital in the period from June 2011 to June 2012. The study included 150 persons. Case group includes 50 patients suffering of end stage liver disease and are listed for liver transplantation. Another 50 patients include those who performed liver transplantation and are currently on immunosuppressive medications. In 2 patients those with end stage liver disease; TST was not read as they were discharged. Six patients from the transplanted group were excluded as they didn’t return for testing (either TST or QFT-IT).so the sum of actual patients on which the study was made was 92 patients. Control group includes 50 healthy individuals.