Hemophagocytic lymphohistiocytosis

Hemophagocytic syndrome (HPS), also known as hemophagocytic lymphohistiocytosis (HLH), is a hyperinflammatory response syndrome caused by genetic or acquired immune dysregulation. Based on the etiology, HPS can be divided into two main categories: Primary (familial) hemophagocytic syndrome (FHPS): More common in neonates. It is a genetic disorder, and patients often carry HPS-related gene defects, diagnosed by genetic testing. Secondary (reactive) hemophagocytic syndrome (SHPS): More common in adults, but can also occur in children. It is often associated with underlying diseases such as infections, tumors, or rheumatic conditions, which trigger immune system activation, ultimately leading to a series of reactive diseases. If currently known HPS-related genes are not detected, but the primary disease is also unclear, it is also classified as secondary HPS. The main symptoms include persistent fever, hepatosplenomegaly, pancytopenia, and the presence of hemophagocytosis in bone marrow, liver, spleen, and lymph node tissues.