Hepatic Involvement in Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome which results in uncontrolled systemic proliferation of benign macrophages in all reticuloendothelial organs producing worsening peripheral blood cytopenia(s); hypercytokinemia leading to hepatic injury producing hyperferritinemia, hypertriglyceridemia, hypofibrinogenemia; and if not diagnosed and treated early may lead to disseminated intravascular coagulation (DIC), multiorgan dysfunction, and death in nearly all individuals. It is postulated that hepatic injury/dysfunction starts early in the course of the disease which may mimic nonspecific hepatitis like prodrome to fulminant hepatic failure; possibly requiring liver transplant. While HLH as an entity is being increasingly recognized nowadays across wide specialties (both pediatric and adults); hepatic involvement in this setting has been poorly characterized. This chapter is aimed to highlight on the diagnosis and classification of HLH with a special emphasis on the pathophysiology of hepatic dysfunction, histomorphology of liver; and the current concept and controversies on the role of liver transplantation in this clinical setting.