Prof. Nashan has published extensively in the fields of transplantation, immunosuppression and hepatobiliary surgery (more than 340 manuscripts in e.g. Lancet, New England Journal of Medicine, American Journal of Transplantation, Transplantation etc.) and serves on multiple advisory boards for various organizations, companies and government bodies. He was President of the German Transplantation Society, Chairman of the Foundation Board of the German Organ Donation Foundation, Vice-Chairman of the Permanent Committee of Organ Transplantation of the German Medical Association, Board and Council Member of Eurotransplant and Counselor of the European Society of Organ Transplantation. He is Fomer President and Past-President of the German Transplantation Society and a member of the sections of liver and kidney/pancreas transplantation in the National German Institute for Quality Assessment in Health Care (IQTIG).
In 2018 he organized a cooperation of the Organ Procurement Organization of the First Affiliated Hospital with the KeTLOD Project of the University of Barcelona (DTI), Spain. He received the Chinese Government Friendship Award in September 2019. Since 2023 he is member of the COTDF (Chinese Organ Transplantation Development Foundation) Advisory Board.