Presentation of hemophagocytic lymphohistiocytosis due to a novel MUNC 13–4 mutation masked by partial therapeutic immunosuppression
1 Division of Allergy and Immunology, The Children’s Hospital of Philadelphia, 3550 Market Street, Philadelphia, PA 19104-4399, USA
2 Divisions of Hematology and Oncology, The Children’s Hospital of Philadelphia, 34th and Civic Center Boulevard, Philadelphia, PA 19104, USA
3 Division of Rheumatology, The Children’s Hospital of Philadelphia, 34th and Civic Center Boulevard, Philadelphia, PA 19104, USA
4 Department of Pathology and Laboratory Medicine, The Children’s Hospital of Philadelphia, 34th and Civic Center Boulevard, University of Pennsylvania School of Medicine, Philadelphia, PA, 19104, USA
Pediatric Rheumatology 2012, 10:13 doi:10.1186/1546-0096-10-13Published: 3 May 2012
Hemophagocytic lymphohistiocytosis is a potentially fatal disease characterized by excessive macrophage and lymphocyte activity. Patients can be affected following immune activation after an oncologic, autoimmune or infectious trigger. An associated gene mutation may be found which impairs cytolytic lymphocyte function. We describe a pediatric case of hemophagocytic lymphohistiocytosis with a novel mutation of MUNC 13–4 whose diagnosis was confounded by concurrent immunosuppression. Clinical reassessment for hemophagocytic lymphohistiocytosis is necessary in persistently febrile patients with laboratory derangements in the setting of immunosuppressive agent exposure.