André Tichelli focuses on Internal medicine, Transplantation, Surgery, Aplastic anemia and Immunology. Many of his studies on Internal medicine apply to Oncology as well. His work deals with themes such as Hematopoietic cell, Transplantation Conditioning and Cohort, Pathology, which intersect with Transplantation.

His Surgery research is multidisciplinary, incorporating elements of Incidence and Cumulative incidence. His Aplastic anemia study combines topics from a wide range of disciplines, such as Gastroenterology, Paroxysmal nocturnal hemoglobinuria, Bone marrow failure and Anemia. André Tichelli has researched Immunology in several fields, including Natural killer cell and Stem cell.