Hemophagocytic lymphohistiocytosis after allogeneic bone marrow transplantation during chronic norovirus infection.

Hemophagocytic lymphohistiocytosis (HLH) is a macrophage activating syndrome that is known to develop in patients with autoimmune disease, malignancies or infection, for example with Epstein-Barr virus, cytomegalovirus or varicella zoster virus. We describe a 24-month old boy with acute myelogenous leukaemia relapse and allogeneic bone marrow transplantation, who developed HLH on day +40 during chronic infection with norovirus. Here, we report for the first time the development of HLH in combination with chronic norovirus infection after allogeneic bone marrow transplantation in a hematopoietic malignancy.