Title: Bacille Calmette-Guérin lymphadenitis: a potential complication of immune reconstitution following haematopoietic stem cell transplant Authors: Christo Tsilifis 1,2 , Ina Schim van der Loeff [PhD] 1,2 , Eleri Williams [MD] 1 Stephen Owens [PhD] 1,3 , Steven M Powell 1 , Andrew R Gennery [MD] 1,2 , Mary Slatter [MD] 1,2 1 Great North Children’s Hospital (GNCH), Victoria Wing, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP, United Kingdom 2 Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, 3rd Floor, William Leech Building, Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom 3 Population Health Sciences Institute, Newcastle University Newcastle upon Tyne, NE1 7RU Corresponding author: Christo Tsilifis E-mail: c.tsilifis@nhs.net Word count: 630 words Key words: immunodeficiency, BCG, HIV, mycobacteria, HSCT