Hemophagocytic lymphohistiocytosis
Pronunciation: HEE-mo-fag-oh-SY-tik LIM-fo-his-tee-oh-sy-TOE-sis
Also written as: HLH — Hemophagocytic lymphohistiocytosis
A life-threatening syndrome of excessive immune activation characterized by fever, cytopenias, and organ dysfunction.
Full Definition
Hemophagocytic lymphohistiocytosis is a hyperinflammatory syndrome resulting from uncontrolled activation of lymphocytes and macrophages. It can be primary (genetic) or secondary to infections, malignancies, or autoimmune diseases. The condition is characterized by persistent fever, cytopenias, hepatosplenomegaly, elevated ferritin levels, and evidence of hemophagocytosis in bone marrow or other tissues. HLH associated with hematologic malignancies carries a particularly poor prognosis and requires immediate recognition and treatment with immunosuppressive therapy.
Usage
Usage note: Use full term in initial documentation; HLH acceptable in subsequent references within same document.
In Context
- "The patient met five of eight HLH-2004 criteria, prompting initiation of the HLH-94 protocol." — Diagnostic workup summary
- "Hemophagocytic lymphohistiocytosis was suspected given the constellation of fever, pancytopenia, and markedly elevated ferritin." — Differential diagnosis note