Syngeneic blood stem cell transplantation for infectious mononucleosis-related aplastic anaemia.

A 17-year-old girl developed severe aplastic anaemia following an episode of infectious mononucleosis. Her identical twin sister underwent mobilization with filgrastim and subsequent leukapheresis for blood stem cell collection. The cells were freshly infused without prior immunosuppression. The patient became transfusion-independent and achieved a trilineage complete haematological response. Her engraftment lasted 6 months, but subsequently she relapsed with pancytopenia. The patient then received a second infusion of syngeneic blood stem cells, preceded by conditioning with cyclophosphamide and antithymocyte globulin. This led to durable trilineage haematological recovery still ongoing at 16 months after her second transplant.