hemaphagocytic lymphohistiocytosis HLH

  • primary form: genetic or familial
  • secondary form: from mutation either in perforin gene or genes for exocytosis of cytotoxic granules
  • happens with infection, autoimmune disease, AIDS
  • can affect many organs: GI, endocrine, skin, liver
  • features include high ferritin, bilirubin, triglycerides, low fibrinogen
  • elevated IL2 receptor, typically with positive CD25 subunit 1
  • macrophage activation syndrome is a type of hemophagocytic lymphohistiocytosis HLH seen in immunocompromised patients
  • histoplasmosis infection can result in secondary HLH
  • very high ferritin (>15,000) is diagnostic of HLH
  • checking quantitative immunoglobulins may be helpful in determining need for IVIG
  • steroids is primary treatment option, followed by etoposide
  • can present with pancytopenia

Footnotes

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