Retroperitoneal Abscess in Severe Combined Immunodeficiency Probably Due to BCG Vaccine

Severe combined immunodeficiency (SCID) is characterized by the impairment of T cells with or without B and Natural Killer (NK) cells, leading to recurrent bacterial and viral infections. Although hematopoietic stem cell transplantation (HSCT) is the curative treatment of SCID, many complications and especially infections can develop afterwards. Herein, we report a seven-month-old girl who was diagnosed with SCID and underwent HSCT from HLA-full-matched related donor. However, the patient was complicated with retroperitoneal abscess and chest wall granuloma following HSCT, probably due to the Bacillus Calmette Guerin (BCG) vaccine. The symptoms of the patient were controlled with anti-tuberculosis therapy and intravenous antibiotics.