A Rare Case of Hemophagocytic Lymphohistiocytosis and Macrophage Activation Syndrome in Settings of Etanercept Use and Epstein-Barr Virus Infection

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome in which widespread activation of the immune system leads to a state of excessive inflammation causing tissue damage. While this condition is mainly established in the pediatric population; due to its rarity, physicians often do not suspect this condition in adults. However, while diagnostic criteria are based on protocols tailored for the pediatric society, recognizing this condition in a timely manner in adults is utterly important to prevent a dismal prognosis. In instances where a concomitant rheumatological disorder is present, the syndrome is referred to as macrophage activation syndrome (MAS). This report describes a case of an adult patient who presented with mucosal bleeding and abdominal pain who was later diagnosed with MAS.

Autoimmune Hemolytic Anemias: Classifications, Pathophysiology, Diagnoses and Management

“…Cold-antibody autoimmune hemolytic anemia, referred to as cold agglutinin syndrome (CAS) or cold agglutinin disease (CAD), is a rare autoimmune condition characterized by the presence of high levels of cold-sensitive autoantibodies in the blood, primarily IgM, as well as autoantibodies that remain active at temperatures below 30 • C (86 • F) [3,12,20,[70][71][72][73][74][75][76]. The antibodies have a particular affinity for red blood cells, often the Ii RBC antigens [3,12,77,78], causing them to aggregate (agglutination), activate the complement system, and undergo intra-and/or extravascular hemolysis [3,12,20,[67][68][69][70][71][72][73][74][75][76][77]. Historically, CAD included both CAD and CAS; however, these two conditions are now recognized as different and have been separated into distinct entities.…”

“…Cold agglutinin syndrome (CAS) is a transient condition that is secondary to a bacterial or viral infection, such as Mycoplasma pneumoniae or Epstein-Barr virus causing mononucleosis [2,3,70,77]. CAS can also occur following certain malignancies and other autoimmune disorders [70,[73][74][75].…”