A case series of secondary Hemophagocytic Lymphohistiocytosis in the critical care patients

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory condition associated with fever, cytopenia, hepatomegaly and hemophagocytes caused by activated macrophages. HLH can be primary (familiar) or secondary (acquired), and it is diagnosed when patients meet at least 5 out of 9 diagnostic criteria (fever, splenomegaly, cytopenia, hypertriglyceridemia, low fibrinogen, hemophagocytes, low natural killer cells activity, elevated ferritin and CD25 cells) or Confirmation of an HLH-associated genetic mutation. We present a case series of 3 patients with HLH syndrome likely secondary to infections and rheumatologic conditions, requiring critical care level of care due to their worsening clinical status requiring aggressive management and advanced therapies, representing a diagnostic challenge due to its similarities with multiple other diseases (e.g. macrophage activation syndrome, Still disease, disseminated intravascular coagulation). High clinical suspicion and knowledge about the syndrome are key players when managing these types of patients, because even if we treat the cause (infections, and other conditions as mentioned above), they might require additional medication such as high dose steroids and immunomodulators like anakinra.

Fortunately, success was achieved for all the patients represented in this case series. They were treated for their primary diagnosis likely causing HLH plus the additional therapeutic support, since this is a very rare condition and each case presented within a few months difference, they were able to be diagnosed quickly enough so the proper individualized treatment was applied.